Accepted Manuscript Title: CHEMOPREVENTIVE AND THERAPEUTIC POTENTIAL OF CHRYSIN IN CANCER: MECHANISTIC PERSPECTIVES Author: Eshvendar Reddy Kasala Lakshmi Narendra Bodduluru Rajaram Mohanrao Madana K.V. Athira Ranadeep Gogoi Chandana C Barua PII: DOI: Reference:

S0378-4274(15)00020-X http://dx.doi.org/doi:10.1016/j.toxlet.2015.01.008 TOXLET 8988

To appear in:

Toxicology Letters

Received date: Revised date: Accepted date:

30-10-2014 8-1-2015 13-1-2015

Please cite this article as: Kasala, Eshvendar Reddy, Bodduluru, Lakshmi Narendra, Madana, Rajaram Mohanrao, Athira, K.V., Gogoi, Ranadeep, Barua, Chandana C, CHEMOPREVENTIVE AND THERAPEUTIC POTENTIAL OF CHRYSIN IN CANCER: MECHANISTIC PERSPECTIVES.Toxicology Letters http://dx.doi.org/10.1016/j.toxlet.2015.01.008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

CHEMOPREVENTIVE AND THERAPEUTIC POTENTIAL OF CHRYSIN IN CANCER: MECHANISTIC PERSPECTIVES Eshvendar Reddy Kasala*a, Lakshmi Narendra Bodduluru a,RajaramMohanraoMadanaa, Athira K.V, Ranadeep Gogoia, Chandana C Baruab, a

Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and

Research (NIPER), Guwahati-781032, Assam, India. b

Department of Pharmacology and Toxicology, College of Veterinary Science, Assam

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Agricultural University, Guwahati-781032, Assam, India.

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* Correspondence author Eshvendar Reddy Kasala,

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PhD Scholar,

Telephone: +91 9700820750

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E-mail address: [email protected]

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NIPER-Guwahati

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Highlights:  Short account on role of chrysinin multistep carcinogenesis process  Chemopreventive and therapeutic studies of chrysin in cell lines and animal models  Succinct description of mechanistic perspectivesof chrysin  A colossal narration of effect of chrysin on signalling pathways and molecular targets

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 Brief note on pharmacokinetics of chrysin

ABSTRACT

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Chrysin, a naturally occurring flavone, abundantly found in numerous plant extracts including propolis and in honey is one of the most widely used herbal medicine in Asian countries.

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Nowadays, chrysin has become the foremost candidate exhibiting health benefits, owing to its

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multiple bioactivities such as antioxidant, anti-inflammatory, anti‑allergic, anti-diabetic, anti-

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estrogenic, antibacterial and antitumor activities. Anticancer activity is most promising among

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the multiple pharmacological effects displayed by chrysin. In vitro and in vivo models have shown that chrysin inhibits cancer growth through induction of apoptosis, alteration of cell cycle

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and inhibition of angiogenesis, invasion and metastasis without causing any toxicity and

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undesirable side effects to normal cells. Chrysin displays these effects through selective modulation of multiple cell signaling pathways which are linked to inflammation, survival,

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growth, angiogenesis, invasion and metastasis of cancer cells. This broad spectrum of antitumor activity in conjunction with low toxicity underscores the translational value of chrysin in cancer

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therapy. The present review highlights the chemopreventive and therapeutic effects, molecular targets and antineoplastic mechanisms that contribute to the observed anticancer activity of

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chrysin.

Keywords: Cancer, Chrysin, Flavone, Chemoprevention, Apoptosis.

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1. INTRODUCTION

Cancer, a major public health concern worldwide,is a group of diseases characterized by uncontrolled growth and multiplication of abnormal cells that invade and metastases to other parts of the body. It is a leading cause of mortality and morbidity in the western countries and the second leading cause of death in third world countries, thus imparting a significant societal burden [1]. Despite the efforts of innumerable researchers worldwide to ameliorate the miserable

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outcomes of cancer, it stills continues to be a huge burden on mankind. This is largely because of steady increase in life expectancy and growing urbanization as well as cumulative adoption of

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cancer-associated lifestyle choices like smoking, daily life habits and westernized diet. Evidently, as per the estimates given by Globocan 2012 [2], it accounts for 14.1 million new

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cases and 8.2 million deaths in 2012, and is projected for a continuous rise, with an estimated

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22.2 million new cancer cases and about 13.2 million deaths worldwide per year by 2030 [3].

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Carcinogenesis is a multistep process that initiates with cellular transformation of normal cells

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into cancer cells, progresses to hyperproliferation and culminates in the acquisition of angiogenic

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properties, invasive potential, and establishment of metastatic lesions [4]. Over the past fifty years, there has been tremendous progress in our understanding of the molecular biology of

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cancer and in the development of anticancer therapies. Nonetheless, we have not conquered this dreadful disease yet and it still remains as a formidable challenge for public health. The main

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cause for this fiasco is that the physiological and mechanistic dysregulations responsible for cancer initiation and promotion implicate often hundreds of genes or signaling cascades so that it

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appears evident that multi-target drugs or combination of drugs that can act on multiple targets

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are necessary to overcome such a multifaceted disease. However, most currently available treatments are based on the modulation of a specific single target with agents referred to as mono-targeted therapies [5]. Besides ineffective targeting, the mono-targeted drugs induce

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toxicity and side effects which sometimes are bigger complications than the disease itself [6]. Additionally, the increasing resistance and cost of the treatment are the other limitations associated with targeted therapies. However, multi-target drugs could overcome the limitations of monotherapies by attacking the disease system on multiple fronts [7]. Extensive research over the years has made it clear that most chronic illnesses like cancer can only be cured by multi 3|Page

targeted, as opposed to mono-targeted therapy. Hence, promiscuous targeting of a cancer cell’s multiple bypass mechanisms is a therapeutic virtue. Consequently, agents that can modulate multiple cellular targets are now attractive objects of research. Literature evidence suggests that natural compounds from the plant sources interact with multiple targets and influence numerous biochemical and molecular cascades in cancer cells and could represent a more realistic approach to the actuality of carcinogenesis [5, 8]. The safety, efficacy, ease of availability and affordability of these compounds provides additional window of opportunities, including their potential to overcome resistance to chemotherapy in association with other traditional anticancer drugs [8].Chrysin is one such agent with a potential to target multiple signaling targets in cancer cells

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without showing toxicity to normal cells.

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Flavonoids are naturally occurring polyphenolic phytochemicals that are ubiquitous in plants and comprise of several classes, including flavanols, flavans and flavones. They have been to

possess

anti-cancer

and

chemopreventive

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demonstrated

properties

in

numerous

epidemiological studies. Chrysin (5, 7-dihydroxyflavone) (Fig. 1) is a natural flavone found in

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many plant extracts, including blue passion flower (Passiflora caerulea), honey and propolis,

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which have high economic value and medicinal importance. Literature reports have

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demonstrated that chrysin possess multiple biological activities such as antioxidant [9], anti-

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inflammatory [10], antibacterial [11], antihypertensive [12], anti-allergic [13], vasodilator [14], anti-diabetic [15], anxiolytic [16], antiviral [17], anti-estrogenic [18], hepatoprotective [19], anti-

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aging [20],anticonvulsant [21] and anticancer [22] effects. Amongst this, the anticancer potential is well illustrated from studies in a wide variety of cancer cell lines and animal tumor models,

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making it chrysin’s most promising property.Thus, understanding of the biological mechanisms triggered by chrysin in tumor cells might provide new therapeutic strategies with reduced side

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effects in cancer. This review focuses on the anticancer biology of chrysin with main emphasis

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on the in vitro and in vivo studies and on the underlying molecular mechanisms.

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Cancer chemoprevention- A Promising Approach Carcinogenesis is a multistage process involving a series of events comprising of genetic and epigenetic changes at the molecular level that consist of apparently three distinguishable but closely connected stages: initiation, promotion and progression, and it takes many years to turn into complete malignancy. Thus, there are plentiful opportunities to intervene in the development 4|Page

of cancer before the onset of malignancy [23]. Chemoprevention, which is referred to as the use of nontoxic naturalor synthetic chemicals to intervene in multistage carcinogenesis, has emerged asa most promising and pragmatic approach to reduce the risk of cancer. The term “chemoprevention”was coined by Michael Sporn way back in 1976, defining it as the use of either natural or synthetic substances or their combination to inhibit, reverse or delay the process of carcinogenesis [24]. Chemoprevention has successfully been achieved in numerous in vitro as well as in vivo studies over the years, and has been validated in several human intervention trials

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[7].

2. ANTICANCER ACTIVITY OF CHRYSIN:

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2.1 Chemopreventive Effects of Chrysin:

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Chemoprevention is an emerging, appealing, and an innovative strategy in experimental oncology, for cancer prevention by a variety of mechanisms directed at major stages of

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carcinogenesis such as initiation, promotion and progression [25].The mechanisms by which

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chrysin acts in this process are illustrated in Fig. 2. The possible methods of intervening

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carcinogenesis include modulation of carcinogen biotransformation, scavenging free radicals and altering the expression of genes involved in cell signaling pathways, particularly those regulating

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apoptosis, cell proliferation and differentiation [26]. Induction of phase II detoxification

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enzymes, such as glutathione S-transferase (GST) or NAD(P)H:quinone oxidoreductase (QR) is

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one of the major mechanism of protection against initiation of carcinogenesis [27]. Chrysin has a preventive effect on cancer induced chemically as well as on xenograft

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tumor models by inducing the activity of antioxidant and detoxification enzymes, reducing the activities of cytochrome P450 (CytP450)-dependent monooxygenases, inhibiting cellular 7,12-

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proliferation and inducing apoptosis. Chrysin inhibited the development of

dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinomas by

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influencing multiple mechanisms including prevention of procarcinogen activation, upregulation of antioxidant and carcinogen detoxification enzymes (glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), GST and QR), induction of apoptosis, inhibition of tumour cellular proliferation, invasion, angiogenesis and metastasis [28]. Protective effects of chrysin against DMBA induced breast and two stage skin carcinomas were due to its ability to 5|Page

modulate phase I and phase II enzymes [29, 30]. Additionally, chrysin has shown to induce breast cancer resistance protein (BCRP) in Caco-2 cells via aryl hydrocarbon receptor (AhR) induction and enhance the transport of benzo(a)pyrene-3-sulfate, a toxic phase II metabolite of lung carcinogen benzo(a)pyrene [46]. Chrysin and other flavonoids such as fisetin, galangin, myricetin, kaempferol, and apigenin, were reported as a potent inhibitors of P-form phenolsulfotransferase mediated sulfation induced carcinogenesis in human hepatoma cell line Hep G2 [47]. Thus, the chemopreventive activity of chrysin was described in several preclinical studies and the details of which are presented in table 1.

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2.2 In vitroAnticancer Activity of Chrysin: The antitumor cytotoxicity of chrysin has been extensively studied over the years in a large

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variety of cancer cell lines. Chrysin is able to kill cancer cells of several histotypes, including hematological, colon, lung, breast, nasopharyngeal, cervical, liver, prostate, glioblastoma,

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thyroid and pancreatic cancer [20, 32]. Moreover, it is interesting to note that chrysin has been reported to exert preferential cytotoxicity against cancer over non-cancer cell lines. Non

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transformed cells of different origin, e.g. fibroblasts and epithelial cells have been reported to be

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much more resistant to the cytotoxic effect of chrysin than cancer cells [48, 49]. In addition,

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chrysin elicited cell death in several models of primary or acquired drug resistance. For example, chrysin can suppress interleukin-6 (IL-6)-induced dihydrodiol dehydrogenases (AKR1C1/1C2:

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aldo-keto reductive superfamily C1/C2) expression in non-small cell lung cancer (NSCLC) cells

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and overcome drug resistances to cisplatin and adriamycin [50]. Chrysin also enhances sensitivity of doxorubicin resistant BEL-7402 cells (BEL-7402/ADM) to doxorubicin by

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inhibiting the expression of nrf2 and its downstream genes hemo oxygenase-1, AKR1B10, and multidrug resistance-associated protein 5 (MRP5) by suppressing phosphatidylinositol-3 kinase-

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Akt (PI3K-Akt) and extracellular-signal-regulated kinase (ERK) pathway [51]. Shuzhong et al suggested that chrysin could be used alone or in combination to reverse BCRP-mediated multi

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drug resistance (MDR) as it can effectively and potentially inhibit BCRP-mediated efflux to increase the cellular accumulation of BCRP substrates and restore the sensitivity of MDR cells

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[48]. Exhaustive list of in vitro studies in various cancer cell lines along with their origin and IC 50 values are summarized in table 2.

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2.3 Anticancer Activity of Chrysin in Combination Protocols Besides its anticancer properties as single agent, chrysin has also been incorporated in combination protocols. Importantly, combining chrysin with different cytotoxic drugs resulted in additive or synergistic tumor cell killing. For example, chrysin was found to cooperate with various chemotherapeutic drugs including doxorubicin, cisplatin and ciglitazone to induce apoptosis and to inhibit survival of tumor cells [70-72]. Generally for reducing the mechanisms of resistance in clinical cancer chemotherapy, anticancer drugs are often used in combination.

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Interestingly, chrysin increased the cytotoxicity of doxorubicin (DOX) in several cell lines, as observed by the lower IC50 value and increase in the maximum response achieved. For example,

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combined treatment of chrysin with DOX synergistically potentiates DOX-induced cytotoxicity in NSCLC cell lines. DOX when used in combination with 30µM of chrysin, the IC50 value

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diminished from 0.365, 0.589, 0.067 and 0.066 to 0.238, 0.351, 0.015 and 0.035 µM in H157, A549, H460 and H1975 cells respectively [70]. In a similar work, Hong et al investigated the

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combinatorial treatment of chrysin with ciglitazone. When chrysin and ciglitazone were used in

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combination, ciglitazone was needed in a lower dose, and minimal cytotoxicity was observed on

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normal breast cells [72]. Chrysin was found to enhance the antimetastatic activity of death receptor 5 monoclonal antibody (DR5 mAb) targeting tumor necrosis factor related apoptosis

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inducing ligand (TRAIL) receptor in Balb/c mice implanted with 4T1 cells [33]. Furthermore,

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chrysin cooperated with TRAIL to induce apoptosis in tumor cells. Moreover, chrysin has the potential to overcome TRAIL induced resistance in cancer cells as chrysin pretreatment could

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sensitize various human cancer cells to tumor necrosis factor-alpha (TNF-α)-induced apoptosis and inhibition of TNF α -mediated nuclear transcription factor-kappaB (NF-κB) activation [73,

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74]. These studies suggest that chrysin not only has a cytotoxic potential, but can also increase the antitumor activity of chemotherapeutic drugs and overcome the resistance by sensitizing

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them toapoptosis.

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2.4 In vivoAnticancer Activity of Chrysin: In addition to its antitumor activity in a variety of cancer cell lines, chrysin also suppressed tumor growth in vivo in a number of animal studies. In an animal model of Nnitrosodiethylamine (DEN) induced and ferric nitrilotriacetate promoted renal carcinogenesis, 7|Page

chrysin (20 and 40mg/kg) was shown to exhibit chemopreventive activity by ameliorating oxidative stress and inflammation via NF-κB pathway [40]. Chrysin suppressed the growth of 1,2-dimethylhydrazine induced colorectal cancer in female Wistar rats by recovering antioxidant mineral levels in the intestinal mucosa, reducing nitrosative stress and cell proliferation [35]. Khan et al reported that chrysin (250mg/kg) can abrogate N-nitrosodiethylamine (DEN) induced early hepatocarcinogenesis and induce apoptosis in preneoplastic nodules in male Wistar rats [36]. Same authors in another study showed that chrysin derivative, dimethyl chrysin can also attenuate the canonical Wnt and NF-κB signaling pathway and up regulates apoptotic gene expression in early hepatocarcinogenesis induced by DEN in male Wistar rats [37]. Chrysin is

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also reported to show chemopreventive activity in azoxymethane induced colon carcinogenesis in both mice and rat models through modulation of cryptal cell proliferation activity and

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apoptosis [31, 38].

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In xenograft models, the antitumor effect of chrysin was tested and found effective against HTh7 cells (human anaplastic thyroid carcinoma), 4T1 cells (murine breast carcinoma),

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Ehrlich ascites carcinoma cells and MDA-MB-231 cells (human breast carcinoma) through inhibition of angiogenesis and induction of apoptosis [32, 33, 39, 44]. In addition, in the mouse

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xenograft model of leukemia induced by implanting WEHI-3 cells in BALB/c mice, chrysin was

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shown to inhibit tumor growth by enhancing populations of T-cells and B-cells, and promoting

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macrophage phagocytosis and natural killer cell cytotoxicity [34]. Based on these evidences, it can be concluded that apoptosis inducing, antiproliferative, anti-invasive, anti-metastatic, and

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anti-angiogenic properties of chrysin adds up to its in vivo anticancer potential.

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3. MECHANISM OF ACTION STUDIES

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Understanding the molecular mechanism of action is essential to predict the potential therapeutic and side effects of drugs. For this purpose, the molecular and cellular mechanism by which

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chrysin induces cytotoxicity has been summarized in below sections.

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3.1 Apoptosis:

Apoptosis plays a major role in establishing a natural balance between cell death and cell

renewal in mature animals by destroying excess, damaged, or abnormal cells. Apoptosis plays a crucial role in eliminating the mutated and hyperproliferative neoplastic cells from the organism and is therefore considered as a protective mechanism against the development of cancer. Cancer 8|Page

development is associated with increased proliferation and decreased apoptosis [5]. Induction of apoptosis in cancer cells is the key molecular mechanism responsible for the anti-cancer activities of most of the currently studied potential anti-cancer agents, including chrysin. Samarghandian et al reported that chrysin inhibits the growth of human lung adenocarcinoma epithelial cell line (A549) by inducing apoptosis via increase in the Bcl-2-associated X protein/ B cell lymphoma 2 (Bax/Bcl-2) ratio and activation of caspase-3 and -9 [59]. In another study, chrysin suppressed tumor growth by inducing apoptosis in neuroblastoma cells (NGP and SK-NAS), by increasing cleaved Poly ADP-ribose polymerase (PARP) and caspase-3 and concurrently decreasing pro-survival proteins survivin and XIAP (X-linked inhibitor of apoptosis protein)

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[75]. Chrysin also inhibits proliferation of PC-3 cells in a dose dependent manner through the induction of apoptosis, as evidenced by annexin V-FITC assay [64].

It was reported that

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flavonoids, including chrysin, significantly reduce cellular viability and induce oligonucleosomal DNA fragmentation and apoptosis through a mechanism that require the activation of caspases-3

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&8, indicating that chrysin-induced apoptosis could act via a ligand receptor mediated cell death mechanism in human U937 leukemia cells [63]. On the other hand, Woo et alhave shown that

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chrysin induced apoptosis in the U937 cells was likely to be caspases and mitochondria

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dependent, and possibly occurs via deregulation of PI3K/Akt, with involvement of XIAP [76].

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Chrysin has also been reported to have the ability to abolish the stem cell factor (SCF)/c-Kit

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signaling in human myeloid leukemia cells by preventing the PI3K pathway [77]. Moreover, chrysin as a histone deacetylase inhibitor (HDACi )induce apoptosis in human melanoma A375

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cells by decreasing the levels of NF-κB targeted and HDACi related genes such as Bcl extralarge (Bcl-xL), survivin and increasing the level of caspase-3 proteins [57]. Furthermore, 5, 7-

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dihydroxy-8-nitrochrysin, a derivative of chrysin inducedapoptosis in MDA-MB-453 human breast cancer cells via caspase activation and modulation of the Akt/FOXO3a pathway [78].

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Intracellular reactive oxygen species (ROS) intervene various cellular responses,

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including cell differentiation, cell cycle progression, apoptotic and necrotic cell death. It has been described in many studies that chrysin is a powerful inducer of ROS and depletion of intracellular GSH plays a significant role in apoptosis induction by chrysin [71, 79].This is likely

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caused by the reversible interaction between chrysin and GSH. Brechbuhl et al reported that chrysin sustains a significant depletion of intracellular GSH concentrations in human NSCLC cells and sensitizes these cells to DOX, otherwise considered an ineffective chemotherapeutic drug in the cure of NSCLC [70]. In another study, Yang et al found that the chrysin derivative, 8bromo-7-methoxychrysin (BrMC) promoted accumulation of ROS products in HepG2 cells in a 9|Page

concentration dependent manner. N-acetyl cysteine (NAC) pretreatment not only slashed ROS generation but also attenuated BrMC induced apoptosis in HepG2 cells [80]. Kachadourian et al showed that chrysin potentiates cisplatin toxicity, in part, via synergizing pro-oxidant effects of cisplatin by inducing mitochondrial dysfunction, and by depleting cellular GSH, an important antioxidant defense [71]. Same authors, in another study reported that chrysin is an effective inducer of GSH depletion and could potentiate the toxicity of known prooxidants such as rotenone, 2-methoxyestradiol, and curcumin through mitochondrial dysfunction in HL-60 and PC-3 cells [79]. This prooxidant behaviour of chrysin is similar to that exhibited by several antioxidant phytochemicals such as curcumin, resveratrol and nimbolide in cancer cell lines and

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can be attributed to the redox status, free radical source, partial pressure of oxygen and ability to participate in a fenton type chemical reaction [81-84]. Taken together the aforementioned studies

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shows that chrysin is a potent pro-apoptotic agent in several cell lines, and its activity is mediated through different mechanisms namely permeabilization of outer mitochondrial

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membrane, generation of ROS, and modulation of Bcl-2 family proteins.

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3.2 Cell proliferation:

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In multicellular organisms, cellular homeostasis is maintained through a balance in cell

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proliferation and apoptosis. The cell cycle is strictly regulated in normal cells by checkpoints,

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and sequential activation and inactivation of cyclin-dependent kinases (cdks) that drive cell cycle progression through phosphorylation and dephosphorylation of several regulatory proteins.

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Defects in cell cycle regulation and mutations in genes controlling the cell cycle are common phenomena in cancer, and agents that suppress proliferation of tumor cells have therapeutic

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value. Several cancer chemopreventive agents like curcumin, resveratrol and nimbolide have been described to suppress the proliferation of tumor cells. Zhang et al reported that chrysin and

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other flavonoids induce cytotoxic effects in human esophageal squamous cell carcinoma KYSE-

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510cell line. DNA fragmentation and flow cytometric analyses of KYSE-510 cells have shown that its cytotoxicity is mediated through G (2)/M cell cycle arrest by up-regulation of p21(waf1) and down-regulation of cyclin B1 at both the mRNA and protein levels and by induction of

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apoptosis through an up-regulation of p53-inducible gene 3 (PIG3) and cleavage of caspases 9 and 3 [62]. Likewise, chrysin induced cytotoxic effects on SW480 cells by arresting cell cycle at G2/M phase in a dose-dependent manner. In the same study authors reported that combining chrysin with apigenin doubled the proportion of SW480 cells in G2/M phase [85]. Weng et al reported that chrysin exhibits a dose-dependent and time-dependent ability to block cell cycle 10 | P a g e

progression of rat C6 glioma cell line at the G1 phase accompanied by significant increase in the expression of cyclin-dependent kinase inhibitor, p21(Waf1/Cip1) followed by reduction of both CDK2/ cyclin E and CDK4/ cyclin D kinase activities. This chrysin-induced cell growth arrest appears due to the activation of P38 mitogen-activated protein kinase (p38-MAPK) and inhibition of proteasome activity resulting in stabilization of p21 [66]. Chrysin has also been reported to possess potent in vitro anti-cancer activity in human melanoma A375 cells by suppressing cell proliferation, inducing G1 cell cycle arrest with the upregulation of p21 independent of p53 status and decrease in cyclin D1, cdk2 protein levels. Chrysin caused inhibition of HDAC-8 activity through histone modifications such as acetylation and methylation

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at p21 promoter particularly at STAT(Signal transducer and activator of transcription) binding site (−692/−684) and resulted in increased p21 promoter activity [57]. A study by Zhang et al

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demonstrated that chrysin and its phosphate derivatives exhibited potential anti-cancer effects on human cervical carcinoma cells by down-regulating the proliferating cell nuclear antigen

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(PCNA), a cofactor for DNA polymerase-δ that plays a central role in the cell cycle besides blocking apoptosis [56]. Treatment of OE33 cells with chrysin caused G2/M arrest through

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upregulation of growth arrest and DNA-damage-inducible β (GADD45β) and 14-3-3sigma and

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down-regulation of cyclin B1 at the mRNA and protein levels, and induces p53-independent

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mitochondrial-mediated apoptosis through upregulation of PIG3 and cleavage of caspase-9 and

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caspase-3 [58]. CDK9, the principal component of the positive transcription elongation factor b, phosphorylates Ser2 residues in the carboxy-terminal domain (CTD) of RNA polymerase II

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(RNAPII), which is required for transcript elongation. Polier et al showed that inhibition of CDK9 activity by chrysin prevents phosphorylation of RNAPII and thereby inhibits transcription

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which leads to the downregulation of the short-lived anti-apoptotic protein myeloid cell leukemia 1(Mcl-1) and, consequently, to the induction of apoptosis in leukemic CEM cells [86]. Overall,

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these results indicate that chrysin inhibits tumor cell proliferation and exerts its growth inhibitory

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effects through alterations of cyclins, cdks, PCNA and p53 levels. 3.3 Angiogenesis: Angiogenesis is an obligatory process for tumor progression and has emerged as a valid

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therapeutic target for solid tumors. Effective inhibition of tumor angiogenesis could offer crucial suppression of not only tumor growth but also metastasis. Many solid tumors induce vascular proliferation by production of angiogenic factors, prominently vascular endothelial growth factor (VEGF). Chrysin has shown to inhibit the release of VEGF from human breast cancer (MDA cells) and glioma (U-343 and U-118 cells) in vitro at the concentration of 100µ/L [87]. Chrysin 11 | P a g e

also reported to suppress insulin induced HIF-1α expression and resultant VEGF release in human prostate cancer DU145 cells through Akt signaling pathway in vitro and inhibits DU145 prostate xenograft-induced angiogenesis in nude mice in vivo [43]. In another study, oral administration of chrysin has significantly suppressed growth of lung metastatic colonies and angiogenesis by abrogating hypoxia-induced STAT3 phosphorylation and VEGF gene expression in Balb/c mice implanted with 4T1 cells [33]. Overall, these results indicate that chrysin inhibits angiogenesis through inhibition of STAT3 and VEGF release mediated by hypoxia through Akt signaling pathway.

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3.4 Metastasis: Metastasis is one of the tumor hallmarks described by Hanahan and Weinberg [4, 5]. Matrix

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metalloproteinases (MMPs) are a group of enzymes which play an important role in tumor invasion during metastasis. These are secreted as inactive zymogens and require activation to

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exert efficient degradation of extra cellular matrix (ECM). Chrysin inhibits metastatic potential of human triple-negative breast cancer cells by modulating matrix metalloproteinase-10,

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epithelial to mesenchymal transition and PI3K/Akt signaling pathway [88]. Emerging evidence

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shows that metastasis needs interplay between cancer cells and micro-environmental biofactors.

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Indoleamine 3, 5-dioxygenase-1 (IDO-1) produced by cancer, local lymph nodes, and satellite

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cells have been established as one of the biofactors. Abnormal IDO-1 activity has partly contributed to immunosuppressive environment by repressing T lymphocyte and natural killer

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cell activities, and activating regulatory T cells (Treg, CD4+CD25+). Chrysin exhibited potent enzyme inhibitory activity on IDO-1 in human neuronal stem cells (hNSC), which in turn

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ameliorate cancer immunosuppressive environment and attenuate metastatic potential [89]. In addition chrysin and its homoleptic copper (II) complex derivative were reported to attenuate

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rapidly proliferating and metastasizing 518A2 melanoma cells [90].All together, the above

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reports indicate that modulation of MMP-10 and attenuation of immune suppression via inhibition of IDO-1enzyme activity are the important anti-metastasis mechanisms of chrysin in cancer therapy.

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3.5 NF-κB pathway: The NF-κB pathway is one of the most important cellular signal transduction pathways involved in immunity, inflammation, proliferation and defense against apoptosis. NF-κB is generally considered to be a survival factor that increases the expression of various anti-apoptotic genes, e.g. Bcl-2, Bcl-xL, Mcl-1 and c-FLIP (Cellular FLICE (FADD-like IL-1β-converting enzyme)12 | P a g e

inhibitory protein) that block apoptosis. Cancer cells evade apoptosis through constitutive activation of NF-κB in response to a number of carcinogens and inflammatory stimuli, including cytokines (TNF-α), interleukin-1, growth factors, cigarette smoke, environmental pollutants, ionizing radiation and oxidative stress [91]. Chrysin was found to significantly sensitize the TNF-α induced apoptosis in human nasopharyngeal carcinoma cell line CNE-1, human colorectal cancer cell line HCT-116, and the human liver cancer cell line HepG2, in which such sensitization is closely associated with inhibitory effect on NF-κB activation resulting in the down-regulation of c-FLIP-L, one of the key anti-apoptotic genes capable of blocking TNF caspases activity [73]. Furthermore, this finding is in agreement with recent reports showing that suppresses

the

NF-κB

induction

mediated

by

TNF-α,

interleukin-1β

or

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chrysin

lipopolysaccharide (LPS) in respiratory epithelial A549 cells and Caco-2 human colorectal

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cancer cells [73, 92]. On the contrary, Lirdprapamongkol et al [74] reported that, the TRAIL sensitization effect of chrysin on A549 and HeLa human cancer cell lines is neither mediated by

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the inhibition of TRAIL-induced NF-κB activation nor by glutathione depletion but through Mcl1 downregulation by inhibiting STAT3 phosphorylation. The reported action of chrysin in

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TRAIL sensitization by inhibiting STAT3 and downregulating Mcl-1 was supported by using

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cucurbitacin- I, a STAT3-specific inhibitor, which reduced Mcl-1 levels and increased TRAIL-

3.6 Wnt signaling pathway:

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induced cell death, similar to that observed with chrysin treatment.

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NF-κB has been recognized to enhance its carcinogenic potential by coordinately activating the canonical Wnt/ β-catenin signaling pathway. It was reported that there exists a

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functional cross-talk between NF-κB and Wnt/ β-catenin signaling pathway and the activation of NF-κB is recognized to synergistically induce activation of canonical Wnt/ β-catenin in various

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tumors [93]. The functional cross-talk between NF-κB and Wnt/ β-catenin signaling pathway is

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mediated through glycogen synthase kinase 3β (GSK-3β), a key component of the Wnt signaling. Activation of GSK-3β leads to accumulation of free β-catenin in the cytosol that eventually translocate to the nucleus trans-activating various target genes implicated in tumorigenesis. Khan

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et al reported that chrysin up regulates the expression of GSK3β and downregulation of casein kinase-2, thereby phosphorylating β-catenin at Ser33/37 leading to its degradation in the cytoplasm and attenuation of the Wnt signaling pathway in the early hepatocarcinogenesis rat model induced by DEN [37]. 3.7 Miscellaneous: 13 | P a g e

Chrysin was also reported to have an effect on additional signaling pathways other than those discussed in the preceding sections. EGFR: Receptor protein tyrosine kinases play a key role in signal transduction pathways that regulate cell division and differentiation. Among the growth factor receptor kinases that has been identified as being important in cancer is epidermal growth factor receptor (EGFR) kinase. The role of EGFR has been thoroughly studied in breast, ovarian, lung and in hormone-refractory prostate cancers. Lv et al prepared series of long chain derivatives of chrysin and found that few of them exhibit potent EGFR inhibitory activity that can be potential anticancer agents [94]. PPARγ: Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-dependent

PT

transcription factor belongs to member of the nuclear hormone receptor superfamily that plays a key role in lipid and glucose metabolism. In recent years, over-expression of PPARγ has been

RI

established in a variety of tumor cells and PPARγ agonists can induce apoptosis [95, 96]. It has been reported that BrMC, a chrysin derivative induce apoptosis of human gastric and hepatic cells

by

activating

PPARγ

[80].

In

another

SC

cancer

study,

5-Allyl-

7-gen-

difluoromethylenechrysin (ADFMChR), a chrysin derivative induced apoptosis in COC1 cells by

U

activation of PPARγ, accompanied by reduction of protein levels of NF-κB and Bcl-2, and

N

increase of Bax expression [97]. Chrysin and its derivatives also activate PPARγ to inhibit

A

cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) activity through various

M

pathways distinguished from thiazolidones [98].

Ubiquitin-proteasome pathway: The ubiquitin-proteasome pathway plays a significant role in

D

regulating apoptosis and the cell cycle. The function of proteasomes is mediated by three main catalytic activities: (1) trypsin-like (T-L), (2) chymotrypsin-like (CTL) and (3) peptidylglutamyl

TE

peptide hydrolyzing (PGPH). Chrysin is reported to inhibit chymotrypsin-like and trypsin-like proteasomes in a dose-dependent manner in various tumor cell lines [99, 100].

EP

Nrf2: Nrf2 is a chief cytoprotective transcription factor that plays a vital role in antioxidant and

CC

detoxification processes. Recent studies have reported that constitutive activation of the Nrf2mediated signaling pathway is associated with development of chemoresistance in many of cancer cell types. Gao et al reported that chrysin is an effective adjuvant sensitizer to reduce

A

doxorubicin resistance in Nrf2 activation associated resistance in BEL-7402/ADM cells through down-regulation of Nrf2 signaling pathway by reducing downstream genes such as HO-1, AKR1B10, and MRP5. Chrysin treatment significantly reduced nrf2 expression in cells at both the mRNA and protein levels through down-regulation of PI3K-Akt and ERK pathways [51]. The overview of all the molecular targets modulated by chrysin is shown in Fig.3. 14 | P a g e

4. PHARMACOKINETIC STUDIES Pharmacokinetic data are very important to better understand the in vivo pharmacological and toxicological effects of new compounds. However, despite its therapeutic potential, bioavailability of chrysin and probably other flavonoids in humans is very low, primarily due to poor absorption, rapid metabolism, and rapid systemic elimination. One study demonstrated that in normal humans after a single oral dose of 400 mg chrysin mean plasma concentration remains below 0.1 μM owing to extensive presystemic intestinal as well as hepatic glucuronidation and

PT

sulphation and efflux of metabolites back into the intestine for hydrolysis and faecal elimination. [101]. Very similar findings were obtained in a study conducted in rat in vivo. After a single dose

RI

of chrysin (5 mg/kg, orally), small amounts of chrysin glucuronide were found in urine and only unchanged chrysin in faeces. After i.v and i.padministration of chrysin at doses ranging 1-5

SC

mg/kg, no unchanged chrysin but high concentrations of chrysin metabolites were present in the bile with chrysin glucuronide being excreted 10-fold higher in amount than chrysin

U

sulphate[101]. In other studies volunteers have received oral doses of chrysin ranging from 300

N

to 625 mg without any reported toxicity, indicating the safety and efficacy of chrysin [102, 103].

A

Furthermore, there is anecdotal evidence of bodybuilders taking 2–3 g of chrysin/day without

M

any associated side effects. Chrysin is also used as a sport supplement widely, with athletes taking doses of up to 2–3 g per day [104].

D

As most of these studies indicate, chrysin has poor bioavailability, and several attempts to increase the bioavailability of chrysin have been made, including the use of liposomal chrysin

TE

[105], nanoparticles of chrysin [106] and synthetic analogues of chrysin [68]. For example, methylated flavone i.e., 5,7-dimethoxyflavone (5,7-DMF) possesses increased metabolic stability

EP

as well as intestinal transport in in vitro cells and showed high oral absorption as well as

CC

bioavailability in the rat in vivo [68]. It should be noted that high oral bioavailability may not always be important for a flavonoid to exert a desirable effect. This is exemplified by a recent study of a combination of the UDP

A

glucuronosyl transferase 1A1 (UGT1A1) inducing flavone chrysin and the anticancer drug irinotecan in the treatment of metastatic colorectal cancer in humans [104]. The idea here is that chrysin easily enters the colorectal epithelial cells after oral administration to induce UGT1A1 without being absorbed into the systemic circulation. This increases the conjugation of irinotecan, preventing its side effect, severe diarrhea, from occurring. 15 | P a g e

5. CONCLUSION: Cancer is not one disease but a combination of many; to effectively halt tumor progression, a drug that can target multiple dysregulated proteins would be ideal. Targeted therapies have their limitations, the most prominent being that cancer cells develop resistance to them. Combinations of targeted therapies with either other targeted therapies or more traditional therapies may be the solution to this problem. Chrysin, a natural polyphenol, appears to possess a blend of

PT

anticarcinogenic, proapoptotic, antiangiogenic, antimetastatic, immunomodulatory, antioxidant and antimutagenic activities. (Fig.4) The molecular mechanisms underlying the pleotropic

RI

activities of chrysin are diverse and involve combinations of cell signaling pathways at multiple levels of tumorigenesis. With the ongoing problems of drug resistance, toxicity, and high

SC

treatment cost associated with the current FDA-approved anticancer drugs, it would be most advantageous to look into chrysin as an anticancer agent, to be administered alone or in

U

combination with available anticancer drugs; such explorations may demonstrate that chrysin

A

N

offers not only efficacy but also affordability.

M

6. CONFLICT OF INTEREST

D

Authors declare no conflict of interest.

7. ACKNOWLEDGEMENTS

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We would like to thank the Dr. K.C Saikia, Director, National Institute of Pharmaceutical Education and Research (NIPER)-Guwahati for his support and encouragement. We would also to

thank

Rajesh

EP

like

Thipparaboina

(Research

scholar,

National

Institute

of

CC

PharmaceuticalEducation and Research (NIPER)-Hyderabad) and M Jalandhar Reddy (MS Pharmacology &Toxicology, NIPER-Guwahati) for their critical review of the manuscript. .

A

8. REFERENCES: 1.

Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D. Global cancer statistics. CA Cancer J Clin 2011; 61:69-90.

16 | P a g e

2.

Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, et al. GLOBOCAN 2012 v1. 0, Cancer Incidence and Mortality Worldwide: IARC Cancer Base No. 11 [Internet]. Lyon, France: International Agency for Research on Cancer. c2013 [cited 2013 Oct 17]. globocan. iarc. fr 2013.

3.

Bray F, Jemal A, Grey N, Ferlay J, Forman D. Global cancer transitions according to the HumanDevelopment Index (2008-2030): a population-based study. Lancet Oncol 201213, 790-801.

4.

Singh SR. Cancer Stem Cells: Recent Developments and Future Prospects. Cancer Lett 2013; 338:1-2 Teiten MH1, Eifes S, Dicato M, Diederich M. Curcumin-the paradigm of a multi-target

PT

5.

natural compound with applications in cancer prevention and treatment. Toxins 2010;

6.

RI

128-62.

Hasima N, Aggarwal BB. Cancer-linked targets modulated by curcumin. Int J

7.

SC

BiochemMolBiol 2012; 3:328-51.

Zimmermann GR1, Lehár J, Keith CT. Multi-target therapeutics: when the whole is

Russo M1, Spagnuolo C, Tedesco I, Russo GL. Phytochemicals in Cancer Prevention and

N

8.

U

greater than the sum of the parts. Drug Discov Today 2007; 12:34-42.

Chen YH, Yang ZS, Wen CC, Chang YS, Wang BC, Hsiao CA, et al. Evaluation of the

M

9.

A

Therapy: Truth or Dare? Toxins 2010; 2:517-51.

structure-activity relationship of flavonoids as antioxidants and toxicants of zebrafish

10.

D

larvae. Food Chem 2012; 134:717-24. Gresa-Arribas N, Serratosa J, Saura J, Solã C. Inhibition of CCAAT/enhancer binding

TE

protein δ expression by chrysin in microglial cells results in anti-inflammatory and neuroprotective effects. J Neurochem. 2010; 115:526-36. Wang J, Qiu J, Dong J, Li H, Luo M, Dai X, et al. Chrysin protects mice from

EP

11.

CC

Staphylococcus aureus pneumonia. J ApplMicrobiol 2011; 111:1551-8. 12.

Villar IC, Jiménez, Galisteo M, Garcia-Saura MF, Zarzuelo A, Duarte J. Effects of

A

chronic chrysin treatment in spontaneously hypertensive rats. Planta Med 2002; 68:847-

13.

50.

Du Q, Gu X, Cai J, Huang M, Su M. Chrysin attenuates allergic airway inflammation by modulating the transcription factors T-bet and GATA-3 in mice. Mol Med Rep 2012; 6:100-4.

17 | P a g e

14.

Duarte J, Jiménez R, Villar IC, Pérez-Vizcaíno F, Jiménez J, Tamargo J. Vasorelaxant effects of the bioflavonoid chrysin in isolated rat aorta. Planta Med 2001; 67:567-569.

15.

Torres-Piedra M, Ortiz-Andrade R, Villalobos-Molina R, Singh N, Medina-Franco JL, Webster SP, et al. A comparative study of flavonoid analogues on streptozotocinnicotinamide induced diabetic rats: quercetin as a potential antidiabetic agent acting via 11beta-hydroxysteroid dehydrogenase type 1 inhibition. Eur J Med Chem 2010; 45:260612.

16.

Brown E, Hurd NS, McCall S, Ceremuga TE. Evaluation of the anxiolytic effects of chrysin, a Passiflora incarnata extract, in the laboratory rat. AANA J 2007; 75:333-7. Critchfield JW, Butera ST, Folks TM. Inhibition of HIV activation in latently infected

PT

17.

cells by flavonoid compounds. AIDS Res Hum Retroviruses 1996; 12:39-46.

Machala M1, Kubínová R, Horavová P, Suchý V. Chemoprotective potentials of

RI

18.

homoisoflavonoids and chalcones of Dracaena cinnabari: modulations of drug

19.

SC

metabolizing enzymes and antioxidant activity. Phytother Res 2001; 15:114-8. Pushpavalli G, Veeramani C, Pugalendi KV. Influence of chrysin on hepatic marker

U

enzymes and lipid profile against D-galactosamine-induced hepatotoxicity rats. Food

Anand KV1, Mohamed Jaabir MS, Thomas PA, Geraldine P. Protective role of chrysin

A

20.

N

ChemToxicol 2010; 48:1654-1659.

M

against oxidative stress in d-galactose-induced aging in an experimental rat model. GeriatrGerontolInt 2012; 12:741-50. Medina JH, Paladini AC, Wolfman C, de Stein ML, Calvo D, Diaz LE, et al. Chrysin (5,

D

21.

7-di-OH-flavone), a naturally-occurring ligand for benzodiazepine receptors, with

22.

TE

anticonvulsant properties. BiochemPharmacol. 1990; 40:2227-2231. Khoo BY, Chua SL, Balaram P. Apoptotic effects of chrysin in human cancer cell lines.

He S1, Sun C, Pan Y. Red Wine Polyphenols for Cancer Prevention. Int J Mol Sci. 2008;

CC

23.

EP

Int J MolSci 2010; 11:2188-2199.

9:842–853.

A

24.

25.

Sporn MB. Chemoprevention of cancer.Lancet 1993; 342:1211-3.

Surh YJ. Cancer chemoprevention with dietary phytochemicals. Nat Rev Cancer 2003; 3:768-80..

18 | P a g e

26.

Hursting SD, Slaga TJ, Fischer SM, DiGiovanni J, Phang JM. Mechanism-based cancer prevention approaches: targets, examples, and the use of transgenic mice. J Natl Cancer Inst 1999; 91:215-225.

27.

Talalay P. Chemoprotection against cancer by induction of phase 2 enzymes. Biofactors 2000; 12:5-11.

28.

Karthikeyan S, Srinivasan R, Wani SA, Manoharan S. Chemopreventive potential of chrysin in 7, 12-dimethylbenz (a) anthracene-induced hamster buccal pouch carcinogenesis. Int J Nutr, Pharmacol, Neurol Dis 2013; 3:46-53.

29.

Prabhakar MM, Manoharan S, Baskaran N, Srinivasan R, Karthikeyan S, Wani SA.

PT

Chemopreventive potential of chrysin in 7, 12-dimethylbenz (a) anthracene in-duced skin carcinogenesis in Swiss albino mice. Int J PhramSci 2012; 3:89-96

Srinivasan R, Manoharan S. Chemopreventic potential of chrysin in 7, 12-

RI

30.

dimethylbenz(a) anthracene induced mammary carcinogenesis in Sprague-Dawley rats. J

31.

SC

Cell and Tissue Res 2011; 11:2909-18.

Miyamoto S, Yasui Y, Ohigashi H, Tanaka T, Murakami A. Dietary flavonoids suppress

U

azoxymethane-induced colonic preneoplastic lesions in male C57BL/KsJ-db/db mice.

Yu XM, Phan T, Patel PN, Jaskula-Sztul R, Chen H. Chrysin activates Notch1 signaling

A

32.

N

ChemBiol interact 2010; 183:276-283.

M

and suppresses tumor growth of anaplastic thyroid carcinoma in vitro and in vivo. Cancer 2013; 119:774-81.

Lirdprapamongkol K, Sakurai H, Abdelhamed S, Yokoyama S, Maruyama T,

D

33.

Athikomkulchai S, et al. A flavonoid chrysin suppresses hypoxic survival and metastatic

34.

TE

growth of mouse breast cancer cells. Oncol Rep 2013; 30:2357-64. Lin CC, Yu CS, Yang J-S, Lu CC, Chiang JH, Lin JP, et al. Chrysin, a natural and

EP

biologically active flavonoid, influences a murine leukemia model in vivo through

CC

enhancing populations of T-and B-cells, and promoting macrophage phagocytosis and

35.

Sequetto PL, Oliveira TT, Soares IA, Maldonado IR, Mello VJ, Pizziolo VR, et al. The

A

NK cell cytotoxicity. In Vivo 2012; 26:665-70.

flavonoid chrysin attenuates colorectal pathological remodeling reducing the number and severity of pre-neoplastic lesions in rats exposed to the carcinogen 1, 2dimethylhydrazine. Cell tissue Res 2013; 352:327-39.

19 | P a g e

36.

Khan MS, Devaraj H, Devaraj N. Chrysin abrogates early hepatocarcinogenesis and induces apoptosis in N-nitrosodiethylamine-induced preneoplastic nodules in rats. ToxicolApplPharmacol 2011; 251:85-94.

37.

Khan MS, Halagowder D, Devaraj SN. Methylated chrysin induces co-ordinated attenuation of the canonical Wnt and NF-kB signaling pathway and upregulates apoptotic gene expression in the early hepatocarcinogenesis rat model. Chembiol interact 2011; 193:12-21.

38.

Miyamoto S, Kohno H, Suzuki R, Sugie S, Murakami A, Ohigashi H, et al. Preventive effects of chrysin on the development of azoxymethane-induced colonic aberrant crypt

39.

PT

foci in rats. Oncol Rep 2006; 15:1169-74. Sun LP, Chen AL, Hung HC, Chien YH, Huang JS, Huang CY, et al. Chrysin: a histone

RI

deacetylase 8 inhibitor with anticancer activity and a suitable candidate for the standardization of Chinese propolis. J Agric Food Chem 2012; 60:11748-58. Rehman MU, Tahir M, Ali F, Quaiyoom Khan A, Khan R, Lateef A, et al. Chrysin

SC

40.

Suppresses Renal Carcinogenesis Via Amelioration of Hyperproliferation, Oxidative

Quan MF, Xiao LH, Liu ZH, Guo H, Ren KQ, Liu F, et al. 8-bromo-7-methoxychrysin

N

41.

U

Stress and Inflammation: Plausible Role of NF-? B. ToxicolLett 2013; 146:58.

42.

M

Gastroenterol 2013; 19:7680-95.

A

inhibits properties of liver cancer stem cells via downregulation of β-catenin. World J

Liu H, Hwang J, Li W, Choi TW, Liu K, Huang Z, et al. A derivative of chrysin

D

suppresses two-stage skin carcinogenesis by inhibiting mitogen-and stress-activated kinase 1. Cancer Prev Res 2014; 7:74-85. Fu B, Xue J, Li Z, Shi X, Jiang B-H, Fang J. Chrysin inhibits expression of hypoxia-

TE

43.

inducible factor-1alpha through reducing hypoxia-inducible factor-1alpha stability and

Orsolić N, Kosalec I, Basić I. Synergystic antitumor effect of polyphenolic components

CC

44.

EP

inhibiting its protein synthesis. Mol Cancer Ther 2007; 6:220-226.

of water soluble derivative of propolis against Ehrlich ascites tumour. Biol Pharm Bull 2005; 28:694-700.

A

45.

Liu H, Liu K, Huang Z, Huang Z, Thimmegowda NR, Hwang J, et al. A chrysin derivative suppresses skin cancer growth by inhibiting cyclin-dependent kinases. J BiolChem 2013 ;288 :25924-37.

20 | P a g e

46.

Ebert B, Seidel A, Lampen A. Phytochemicals induce breast cancer resistance protein in Caco-2 cells and enhance the transport of benzo [a] pyrene-3-sulfate. ToxicolSci 2007; 96:227-36.

47.

Eaton EA, Walle UK, Lewis AJ, Hudson T, Wilson AA, Walle T. Flavonoids, potent inhibitors of the human P-form phenolsulfotransferase. Potential role in drug metabolism and chemoprevention. Drug MetabDispos 1996; 24:232-7.

48.

Zhang S, Yang X, Morris ME. Flavonoids are inhibitors of breast cancer resistance protein (ABCG2)-mediated transport. MolPharmacol 2004; 65:1208-16.

49.

Cárdenas M, Marder M, Blank VC, Roguin LP. Antitumor activity of some natural

PT

flavonoids and synthetic derivatives on various human and murine cancer cell lines. Bioorg Med Chem 2006; 14:2966-71.

Wang HW, Lin CP, Chiu JH, Chow KC, Kuo KT, Lin CS, et al. Reversal of

RI

50.

inflammation†associated dihydrodiol dehydrogenases (AKR1C1 and AKR1C2)

SC

overexpression and drug resistance in non-small cell lung cancer cells by wogonin and chrysin. Int J Cancer 2007; 120:2019-27.

Gao AM, Ke ZP, Shi F, Sun GC, Chen H. Chrysin enhances sensitivity of BEL-

U

51.

Phan T, Yu XM, Kunnimalaiyaan M, Chen H. Antiproliferative effect of chrysin on

M

52.

A

ChemBiol Interact 2013; 206:100-8.

N

7402/ADM cells to doxorubicin by suppressing PI3K/Akt/Nrf2 and ERK/Nrf2 pathway.

anaplastic thyroid cancer. JofSurg Res 2011; 170:84-8. Li F, Awale S, Tezuka Y, Esumi H, Kadota S. Study on the constituents of Mexican

D

53.

propolis and their cytotoxic activity against PANC-1 human pancreatic cancer cells. J

54.

TE

Nat prod 2010; 73:623-7.

Zhu ZY, Wang WX, Wang ZQ, Chen LJ, Zhang JY, Liu XC, et al. Synthesis and

Zheng X, Meng WD, Xu YY, Cao JG, Qing FL. Synthesis and anticancer effect of

CC

55.

EP

antitumor activity evaluation of chrysin derivatives. Eur J Med Chem 2014; 75:297-300.

56.

Zhang T, Chen X, Qu L, Wu J, Cui R, Zhao Y. Chrysin and its phosphate ester inhibit

A

chrysin derivatives. Bioorg Med ChemLett 2003; 13:881-4.

cell proliferation and induce apoptosis in Hela cells. Bioorg Medicinal Chem 2004;

57.

Pal-Bhadra M, Ramaiah MJ, Reddy TL, Krishnan A, Pushpavalli S, Babu KS, et al. Plant

12:6097-105.

HDAC inhibitor chrysin arrest cell growth and induce p21WAF1 by altering chromatin of STAT response element in A375 cells. BMC cancer 2012; 12:180. 21 | P a g e

58.

Zhang Q, Zhao XH, Wang ZJ. Flavones and flavonols exert cytotoxic effects on a human oesophageal adenocarcinoma cell line (OE33) by causing G2/M arrest and inducing apoptosis. Food ChemToxicol 2008; 46:2042-53.

59.

Samarghandian S, Nezhad MA, Mohammadi G. Role of Caspases, Bax and Bcl-2 in Chrysin-Induced Apoptosis in the A549 Human Lung Adenocarcinoma Epithelial Cells. Anticancer Agents Med Chem 2014; 15:901-9

60.

Ronnekleiv-Kelly SM, Geiger PG, Kennedy GD. Chrysin Activates the Aryl Hydrocarbon Receptor and Reduces Colon Cancer Cell Viability. J Surg Res 2012; 172:305. Parajuli P, Joshee N, Rimando AM, Mittal S, Yadav AK. In vitro antitumor mechanisms

PT

61.

of various Scutellaria extracts and constituent flavonoids. Planta Med 2009; 75:41-48. Zhang Q, Zhao XH, Wang ZJ. Cytotoxicity of flavones and flavonols to a human

RI

62.

esophageal squamous cell carcinoma cell line (KYSE-510) by induction of G2/M arrest

63.

SC

and apoptosis. Toxicol In Vitro 2009; 23:797-807.

Monasterio A, Urdaci MC, Pinchuk IV, Lopez-Moratalla N, Martinez-Irujo JJ.

U

Flavonoids induce apoptosis in human leukemia U937 cells through caspase-and caspase-

Samarghandian S, Afshari JT, Davoodi S. Chrysin reduces proliferation and induces

A

64.

N

calpain-dependent pathways. Nutr Cancer 2004; 50:90-100.

65.

M

apoptosis in the human prostate cancer cell line pc-3. Clinics 2011; 66:1073-9. Pilátová M, Stupáková V, Varinská L, Sarisský M, Mirossay L, Mirossay A, et al. Effect

D

of selected flavones on cancer and endothelial cells. Gen PhysiolBiophys 2010; 29:13443.

Weng MS, Ho YS, Lin JK. Chrysin induces G1 phase cell cycle arrest in C6 glioma cells

TE

66.

through inducing p21Waf1/Cip1 expression: involvement of p38 mitogen-activated

Izuta H, Shimazawa M, Tazawa S, Araki Y, Mishima S, Hara H. Protective effects of

CC

67.

EP

protein kinase. BiochemlPharmacol 2005; 69:1815-1827.

Chinese propolis and its component, chrysin, against neuronal cell death via inhibition of

A

mitochondrial apoptosis pathway in SH-SY5Y cells. J Agric Food Chem 2008; 56:8944-

68.

53.

Walle T, Ta N, Kawamori T, Wen X, Tsuji PA, Walle UK. Cancer chemopreventive properties of orally bioavailable flavonoids: methylated versus unmethylated flavones. BiochemPharmacol 2007; 73:1288-96.

22 | P a g e

69.

Hu K, Wang W, Cheng H, Pan S, Ren J. Synthesis and cytotoxicity of novel chrysin derivatives. MedlChem Res 2011; 20:838-46.

70.

Brechbuhl HM, Kachadourian R, Min E, Chan D, Day BJ. Chrysin enhances doxorubicin-induced cytotoxicity in human lung epithelial cancer cell lines: the role of glutathione. ToxicolApplPharmacol 2012; 258:1-9.

71.

Kachadourian R, Leitner VM, Day BJ. Selected flavonoids potentiate the toxicity of cisplatin in human lung adenocarcinoma cells: a role for glutathione depletion. Int J Oncol 2007; 31:161.

72.

Hong TB, Rahumatullah A, Yogarajah T, Ahmad M, Yin KB. Potential effects of chrysin

73.

PT

on MDA-MB-231 cells. Int J MolSci 2010; 11:1057-69. Li X, Huang Q, Ong CN, Yang XF, Shen HM. Chrysin sensitizes tumor necrosis factor-

RI

a-induced apoptosis in human tumor cells via suppression of nuclear factor-kappaB. Cancer Lett 2010; 293:109-16.

Lirdprapamongkol K, Sakurai H, Abdelhamed S, Yokoyama S, Athikomkulchai S,

SC

74.

Viriyaroj A, et al. Chrysin overcomes TRAIL resistance of cancer cells through Mcl-1

Burke JF, Schlosser L, Chen H, Kunnimalaiyaan M. Chrysin induces growth suppression

N

75.

U

downregulation by inhibiting STAT3 phosphorylation. Int J Oncol 2013; 43:329-337.

Woo KJ, Jeong YJ, Park JW, Kwon TK. Chrysin-induced apoptosis is mediated through

M

76.

A

through apoptosis in neuroblastoma cells. J Am Col Surg 2012; 215:S70.

caspase activation and Akt inactivation in U937 leukemia cells. Biochemlbiophys Res

77.

D

Commun 2004; 325:1215-22.

Lee SJ, Yoon JH, Song KS. Chrysin inhibited stem cell factor (SCF)/c-Kit complex-

TE

induced cell proliferation in human myeloid leukemia cells. Biochem Pharmacol2007; 74:215-225.

Zhao XC, Cao XC, Liu F, Quan MF, Ren KQ, Cao JG. Regulation of the FOXO3a/Bim

EP

78.

CC

signaling pathway by 5, 7-dihydroxy-8-nitrochrysin in MDA-MB-453 breast cancer cells. Oncol lett 2013; 5:929-34.

A

79.

80.

Kachadourian R, Day BJ. Flavonoid-induced glutathione depletion: potential implications for cancer treatment. Free RadicBiol Med 2006; 41:65-76. Yang XH, Zheng X, Cao JG, Xiang HL, Liu F, Lv Y. 8-Bromo-7-methoxychrysininduced apoptosis of hepatocellular carcinoma cells involves ROS and JNK. World J gastroenterol 2010; 16:3385-93.

23 | P a g e

81.

Thayyullathil F, Chathoth S, Hago A, Patel M, Galadari S. Rapid reactive oxygen species (ROS) generation induced by curcumin leads to caspase-dependent and-independent apoptosis in L929 cells. Free RadicBiol Med 2008; 45:1403-12.

82.

Madan E, Prasad S, Roy P, George J, Shukla Y. Regulation of apoptosis by resveratrol through JAK/STAT and mitochondria mediated pathway in human epidermoid carcinoma A431 cells. Biochemical Biophys Res Commun 2008; 377:1232-7.

83.

Mohan KVP, Gunasekaran P, Varalakshmi E, Hara Y, Nagini S. In vitro evaluation of the anticancer effect of lactoferrin and tea polyphenol combination on oral carcinoma cells. Cell BiolInt 2007; 31:599-608. Bodduluru LN, Kasala ER, Thota N, Barua CC, Sistla R. Chemopreventive and

PT

84.

therapeutic effects of nimbolide in cancer: The underlying mechanisms. Toxicol In Vitro

85.

RI

2014; 28:1026-35.

Wang W, VanAlstyne PC, Irons KA, Chen S, Stewart JW, Birt DF. Individual and

SC

interactive effects of apigenin analogs on G2/M cell-cycle arrest in human colon carcinoma cell lines. Nutr Cancer 2004; 48:106-14.

Polier G, Ding J, Konkimalla BV, Eick D, Ribeiro N, Köhler R, et al. Wogonin and

U

86.

N

related natural flavones are inhibitors of CDK9 that induce apoptosis in cancer cells by

Schindler R, Mentlein R. Flavonoids and vitamin E reduce the release of the angiogenic

M

87.

A

transcriptional suppression of Mcl-1. Cell Death Dis 2011; 2:e182.

peptide vascular endothelial growth factor from human tumor cells. The J Nutr 2006;

88.

D

136:1477-82.

Yang B, Huang J, Xiang T, Yin X, Luo X, Huang J, et al. Chrysin inhibits metastatic

TE

potential of human triple negative breast cancer cells by modulating matrix metalloproteinase-10, epithelial to mesenchymal transition, and PI3K/Akt signaling

Chen SS, Corteling R, Stevanato L, Sinden J. Polyphenols inhibit indoleamine 3,5-

CC

89.

EP

pathway. J ApplToxicol 2014; 34:105-12.

dioxygenase-1 enzymatic activity--a role of immunomodulation in chemoprevention. Discov Med 2012; 14:327 33.

A

90.

Spoerlein C, Mahal K, Schmidt H, Schobert R. Effects of chrysin, apigenin, genistein and their homoleptic copper (II) complexes on the growth and metastatic potential of cancer cells. J InorgBiochem 2013; 127:107-15.

91.

Dreesen O, Brivanlou AH. Signaling pathways in cancer and embryonic stem cells. Stem Cell Rev 2007; 3:7-17.

24 | P a g e

92.

Chen CC, Chow MP, Huang WC, Lin YC, Chang YJ. Flavonoids inhibit tumor necrosis factor- α induced up-regulation of intercellular adhesion molecule-1 (ICAM-1) in respiratory epithelial cells through activator protein-1 and nuclear factor-ĸB: structureactivity relationships. MolPharmacol 2004; 66:683-93.

93.

Du Q, Geller DA. Cross-regulation between Wnt and NF-ĸB signaling pathways. For Immunopathol Dis Therap 2010; 1:155-81.

94.

Lv PC, Wang KR, Li QS, Chen J, Sun J, Zhu HL. Design, synthesis and biological evaluation of chrysin long-chain derivatives as potential anticancer agents. Bioorg Med Chem 2010; 18:1117-23. Li M, Lee TW, Mok TSK, Warner TD, Yim APC, Chen GG. Activation of peroxisome

PT

95.

proliferator-activated receptor-gamma by troglitazone (TGZ) inhibits human lung cell

96.

RI

growth. J Cell Biochem 2005; 96:760-74.

Leung WK, Bai AHC, Chan VYW, Yu J, Chan MWY, To KF, et al. Effect of

SC

peroxisome proliferator activated receptor gamma ligands on growth and gene expression profiles of gastric cancer cells. Gut 2004; 53:331-338.

Li HZ, Cao JG, Deng YA, Xu JH, Xie WY. [Induction of apoptosis of human ovarian

U

97.

N

cancer CoC1 cells by 5-allyl-7-gen-difluoromethylenechrysin through activation of

A

peroxisome-proliferator activated receptor-gamma]. Zhonghua Yi XueZaZhi 2007;

98.

M

87:2914-8.

Liang YC, Tsai SH, Tsai DC, Lin-Shiau SY, Lin J-K. Suppression of inducible

D

cyclooxygenase and nitric oxide synthase through activation of peroxisome proliferatoractivated receptor-gamma by flavonoids in mouse macrophages. FEBS lett 2001; 496:12-

99.

TE

8.

Wu YX, Fang X. Apigenin, chrysin, and luteolin selectively inhibit chymotrypsin-like

CC

32.

EP

and trypsin-like proteasome catalytic activities in tumor cells. Planta Med 2010; 76:128-

100.

Shen M, Chan TH, Dou QP. Targeting tumor ubiquitin-proteasome pathway with polyphenols for chemosensitization. Anticancer Agents Med Chem 2006; 12:891-901.

A

101.

102.

Walle T, Otake Y, Brubaker JA, Walle UK, Halushka PV. Disposition and metabolism of the flavonoid chrysin in normal volunteers. Br J ClinPharmacol 2001; 51:143-6. Brown GA, Vukovich MD, Martini ER, Kohut ML, Franke WD, Jackson DA, et al. Effects of androstenedione-herbal supplementation on serum sex hormone concentrations in 30-to 59-year-old men. Int J for VitamNutr Res 2001; 71:293-301.

25 | P a g e

103.

Brown GA, Vukovich MD, Martini ER, Kohut ML, Franke WD, Jackson DA, et al. Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men. J Am Col Nutr 2001; 20:520-28.

104. Tobin PJ, Beale P, Noney L, Liddell S, Rivory LP, Clarke S. A pilot study on the safety of combining chrysin, a non-absorbable inducer of UGT1A1, and irinotecan (CPT-11) to treat metastatic colorectal cancer. Cancer chemotherPharmacol 2006; 57:309-16. 105.

Yatvin M. Liposome drug delivery of polycyclic, aromatic, antioxidant or antiinflammatory compounds: Google Patents, 2004.

106.

Zheng H, Li S, Pu Y, Lai Y, He B, Gu Z. Nanoparticles generated by PEG-Chrysin

A

CC

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TE

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M

A

N

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conjugates for efficient anticancer drug delivery. Eur J Pharm Biopharm 2014; 7:454-60

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Fig.1 Structure of chrysin (5, 7-Dihydroxy-2-phenyl-4H-chromen-4-one). (CAS Number: 48040-0; Molecular Formula: C15H10O4; Molecular Weight: 254.24 g mol−1)

Fig.2 Schematic representation of multistep process of carcinogenesis and its intervention by chrysin. Carcinogenesis is initiated with the transformation of the normal cell into a cancer cell (initiation). These cancer cells undergo tumour promotion into preneoplastic cells, which progress to neoplastic cells. Chrysin prevents carcinogenesis by inhibiting metabolic activation of the procarcinogen and/or alternatively stimulate the detoxification of carcinogens, suppresses the promotion and progression by inducing growth arrest and apoptosis, inhibition of

PT

inflammation-promoted cell proliferation, angiogenesis, invasion and metastasis. Fig.3 Molecular targets of chrysin. Dark and light colored rectangular boxes denote the targets

SC

RI

inhibited and promoted by chrysin respectively.

Fig.4 Schematic representation of chrysin mediated intracellular signaling transduction pathways

U

on carcinogenesis processes. Chrysin is known to exert anticancer effects by inducing apoptosis through activation both extrinsic and intrinsic pathways. It also induces cell cycle arrest through

N

altering the levels of cyclin and CDKs. In addition Chrysin inhibits cell proliferation,

A

angiogenesis, invasion and metastasis by modulating Ras-Raf-MAPKs, PI3K-Akt, STAT, NF-

A

CC

EP

TE

D

M

κB and Wnt-βcatenin and Notch signaling pathways.

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SC

RI

PT

Fig 1:

A

CC

EP

TE

D

M

A

N

U

Fig 2:

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M

A

N

U

SC

RI

PT

Fig 3:

A

CC

EP

TE

D

Abbreviations: Akt/PKB, Protein kinase-B; AP-1, Activated protein -1; Apaf-1, Apoptotic protease activating factor 1; AKR1B10, Aldo–keto reductase 1B10; AKR1C1 &C2, Aldo–keto reductase C1&C2; Bax, Bcl-2associated X protein; Bcl-2, B cell lymphoma-2; Bcl-xL, B-cell lymphoma-extra-large, CAT, Catalase; CDKs, Cyclin dependent kinases; Ck2, Casein kinase-2; COX-2, Cyclooxygenase-2; Cyt P450, Cytochrome P450; Cyt b5, Cytochrome b5; CD, Cluster of differentiation; Cyt-c, Cytochrome-C; Dvl2, dishevelled homolog-2; EGFR, Epidermal growth factor receptor; EMT, Epithelial-mesenchymal transition; ERK, Extracellular-signal-regulated kinase; FADD, Fas-associated death domain; FasL, Fatty acid synthase ligand; c-FLIP, Cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein; GADD45β, Growth arrest and DNA-damage-inducible β; GPx, Glutathione peroxidase; GR, Glutathione reductase ; GST, Glutathione-S-transferase; GSK-3β, Glycogen synthase kinase 3β; GST-P, Glutathione S-Transferase pi; HDAC, Histone deacetylase; Hes-1, Hairy and enhancer of split-1; HIF-1α, Hypoxia-inducible factor-1α; HDAC, Histone deacetylases; HO-1, Heme oxygenase -1; ICAM-1, Intercellular Adhesion Molecule 1; IGF-2, Insulin-like growth factor 2; IKK β, IκB kinase β; IL-6, Interleukin -6; JNK, C-jun N-terminal kinase; Msk-1, Mitogen- and Stress-Activated Kinase-1; MCL-1, Myeloid cell leukemia 1; MMP-10, Matrix metalloproteinase-10; NF-κB, Nuclear factor kappa B; Nrf-2, Nuclear factor (erythroid-derived 2)like 2; NK, Natural killer cells; iNOS, inducible Nitric Oxide Synthase; PCNA, Proliferating cell nuclear antigen; PGE2, Prostaglandin E2; PIG3, p53-inducible gene 3; PI3K, Phosphatidylinositol-3 kinase; PLC-c1, Phospholipase C (PLC)c1; P38MAPK, P38 Mitogen-activated protein kinase; QR, NADPH:quinone oxidoreductase; Rb, Retinoblastoma; SCF/c-Kit, Stem cell factor/c-Kit; SOD, Superoxide dismutase; STAT, Signal transducer and activator of transcription;PPARγ, Peroxisome proliferator-activated receptor γ; TRAIL, Tumor necrosis factor apoptosis inducing ligand; VEGF, Vascular endothelial growth factor; xIAP, X-linked inhibitor of apoptosis protein; ZO-1, Zona occludens-1.

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M

A

N

U

SC

RI

PT

Fig 4:

D

Abbreviations: Akt/PKB, Protein kinase-B; Apaf-1, Apoptotic protease activating factor 1; Bad, Bcl2 -associated

TE

death promoter; Bax, Bcl2 -associated X protein; Bcl2, B cell lymphoma 2; Bcl-xL, B-cell lymphoma-extra-large; Bid, BH3 interacting-domain death agonist; c-FLIP, Cellular FLICE (FADD-like IL-1β-converting enzyme)inhibitory protein; ChR, Chrysin;

CDKs,

Cyclin dependent kinases; Ck2, Casein kinase-2; COX-2,

EP

Cyclooxygenase-2; Dvl2, dishevelled homolog2; EGFR, Epidermal growth factor receptor; ERK, Extracellularsignal-regulated kinase; GSK-3, Glycogen synthase kinase 3; GST-Pi, Glutathione S-transferase pi; Hes-1, Hairy

CC

and enhancer of split-1; HIF-1α, Hypoxia-inducible factor-1α; HDAC, Histone deacetylases; IGF-2, Insulin like growth factor-2; IκB, Inhibitor of kappa B; IKK, Inhibitory kappa kinase; JNK, c-jun N-terminal kinase; MAPKs, Mitogen-activated protein kinases; Mcl-1, Myeloid cell leukemia 1; MMP-10, Matrix metalloproteinase-10; NF-κB,

A

Nuclear factor kappa B; NICD, Notch1 intracellular domain; PDK-1, Pyruvate dehydrogenase kinase-1; Ras, rat sarcoma; Raf, Rapidly accelerated fibrosarcoma; PARP, Poly (ADP-ribose) polymerase; PI3K, Phosphoinositide 3kinase; ROS, Reactive oxygen species; TNF-α, Tumor necrosis factor alpha; STAT-3, Signal transducer and activator of transcription-3; TRAIL, Tumor necrosis factor apoptosis inducing ligand; VEGF, Vascular endothelial growth factor; xIAP, X-linked inhibitor of apoptosis protein.

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Table 1 Chemopreventive and chemotherapeutic effects of chrysin and its derivatives in animal models.

CARCINOGEN/ CELL

DOSE, ROUTE AND

ANIMAL

LINE DMBA (0.5 percent

Male Syrian

DMBA in liquid paraffin

golden

thrice a week, for 14 weeks.)

hamsters

Oral

DMBA 2

Skin

(25μg in 0.1 ml acetone/mouse)

3

4

5

Breast

Colon

REF

decreasing phase-I enzymes (Cyt 450& Cyt

16 weeks through oral gavage

b5) and increasing phase-II enzymes (GST,

Male Swiss

250mg/kg, weekly thrice for

albino mice

25 weeks through oral gavage

250mg/kg, for 16 weeks

Sprague-

(25mg/kg, S.C)

250mg/kg, weekly thrice for

Dawley rats

through oral gavage

Male

Azoxymethane

Modulation of Phase I (↓Cyt P450& Cyt b5) and Phase II (↑GSH, GST, DTD and GR)

[30]

enzymes in the liver of tumor bearing mice. Alters the activity of carcinogen biotransformation enzymes by modulating

[31]

Phase I and Phase II enzymes. Inhibits of proliferation activity by

C57BL/KsJ-

(15mg/kg, I.P)

[29]

GSH, DTD and GR).

Female

DMBA

Modulates carcinogen metabolism by

100ppm in diet for 8weeks

db/db mice

decreasing PCNA and growth factors

[32]

like leptin and IGF-1.

Anaplastic

HTh7 cells

Male nude

75 mg/kg, daily for 21 days

Thyroid

(3 x 106 cells), S.C

mice

4T1 cells

Female Balb/c

(1×105), I.P

mice

through oral gavage

Apoptosis through activation of Notch1 signaling associated cleavage of PARP.

SC

1

MECHANISM OF ACTION

DURATION

PT

CANCER

RI

S.NO

[33]

Inhibits angiogenesis diminished VEGF

10

12

Female Wistar

Liver

Liver

Colon

Breast

50 mg/kg/day for three weeks through oral route.

A

(20mg/kg, S.C)

N-nitrosodiethylamine

Suppresses metastatic growth by decreasing

U

1,2 Dimethylhydrazine

expression.

through oral gavage

N

mice

M

Colorectal

A

11

(1×105), I.P

rats

D

9

Male BALB/c

TE

8

WEHI-3 cells

Leukemia

(200 mg/kg, I.P )

EP

7

Breast

Renal

[35]

NK Cell Cytotoxicity. Inhibits cell proliferation. Recovers antioxidant mineral levels.

[36]

Reduces nitrosative stress. Reduces inflammation by decreasing expression of COX-2 and NF-κB p65 levels.

11 weeks through oral gavage

Induces apoptosis by decreasing the levels

[37]

of p53, Bax, caspase 3, β-arrestin and BclxL.

rats

Azoxymethane

Male F344

(20mg/kg, S.C )

rats. Female BALB/c nude

100 mg/kg of 5,7 DMF,

Attenuation of the canonical Wnt and NF-

weekly thrice for 11 weeks

κB signaling pathways.

through oral gavage

Up regulation of apoptotic gene expression.

0.001-0.001% in food for 4

Modulates cryptal cell proliferation activity

weeks

Inhibits apoptosis.

90mg/kg, daily for 42 weeks through oral gavage

Inhibits of HDAC8 enzymatic activity.

[38]

[39]

[40]

mice N-nitrosodiethylamine

13

Promotes Macrophage phagocytosis and

rats

(200 mg/kg, I.P)

(5× 106), S.C

14 weeks through oral gavage

Enhances Populations of T-and B cells.

250mg/kg, weekly thrice for

Male Wistar

MDA-MB-231 cells

200mg/kg, weekly thrice for

[34]

hypoxic survival and STAT3 activation.

Male Wistar

N-nitrosodiethylamine

CC

6

250mg/kg, daily for 31 days

Amelioration of hyperproliferation,

(200 mg/kg, I.P) and

Male Wistar

20&40mg/kg, daily for 16

ferricnitrilotriacetate

rats

weeks through oral gavage

oxidative stress and inflammation via NF-

[41]

κB pathway.

(9 mg/kg, I.P) 14

Liver

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LCSCs from MHCC97 Cells (5 × 104), S.C

Balb/c-nu mice

12.5, 25 or 50 mg/kg BrMC for 20days through gastric

Down regulates the β-catenin expression.

[42]

lavage DMBA (200 nmol)+TPA 15

Skin

(17 nmol) in acetone applied on the skin

16

17

18

Compound 69407, 200nmol FVB/N male mice

BALB/c male

(3 x 106) cells, S.C

nude mice

Ehrlich

EAT

Male albino

ascites

(2 x 106) cells, I.P

mice

A431

BALB/c nude

(5×105) cells S.C

mouse

Skin

Attenuates the MSK1/histone H3 signaling

[43]

through topical application

DU145

Prostate

twice weekly for 18 weeks

Inhibits HIF-1α expression through Akt 30 Mmol/L along with cells

signaling and abrogation of VEGF

[44]

expression 50 mg/kg, daily for 7 days

Enhances functional activity of

through oral route

macrophages

Compound 69407, 50mg/kg,

Inhibits neoplastic transformation and

thrice weekly for 21 days

tumor growth and by targeting Cdk2 and

through IP

Cdk4 in an ATP-noncompetitive manner.

[45]

[46]

PT

Abbreviations: Akt/PKB, Protein kinase-B; Bax, Bcl-2-associated X protein; Bcl-xL, B-cell lymphoma-extra-large; BrMC, 8-bromo-7-methoxychrysin; CDKs, Cyclin dependent kinases; COX-2, Cyclooxygenase-2; Cyt b5, Cytochrome

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b5; Cyt P450, Cytochrome P450; DMBA, 7,12-Dimethylbenz(a)anthracene; DTD, DT-diaphorase; DMF, Dimethoxy flavone; EAT, Ehrlich ascites tumor; GR, Glutathione reductase; GSH, Glutathione; GST, Glutathione-S-transferase;

SC

HDAC8, Histone deacetylase-8; HIF-1α, Hypoxia-inducible factor-1α; LCSCs, liver cancer stem cells; Msk-1, Mitogenand Stress-Activated Kinase-1; NF-κB, Nuclear factor kappa B; NK cells, Natural Killer cells; PARP, Poly (ADP-ribose)

U

polymerase; PCNA, Proliferating cell nuclear antigen; QR, NADPH:quinone oxidoreductase; TPA, 12-OTetradecanoylphorbol-13-acetate; STAT-3, Signal transducer and activator of transcription-3; VEGF, Vascular

A

CC

EP

TE

D

M

A

N

endothelial growth factor.

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Table 2 In vitro cytotoxic effects of Chrysin against various tumor cell lines. Type of Cancer

Cell line

Origin

IC50

Reference

1

Oropharyngeal

KB

Human

13 ± 2 μM

[50]

2

Mammary

LM3

Murine

17 ± 6 μM

[50]

3

Melanoma

B16-F0

Murine

22 ± 2 μM

[50]

4

Anaplastic Thyroid

KAT18

Human

50 μM

[53]

5

Anaplastic Thyroid

HTh7

Human

50 μM

[53]

6

Pancreatic

PANC-1

Human

88.7 μM

[54]

7

Liver

H22

Human

1671 μM

[55]

8

Gastric

SGC-7901

Human

5.8 μM

[56]

PT

S.no

Colon

HT-29

Human

3.1 μM

[56]

Cervical

HeLa

Human

14.2 μM

[57]

11

Melanoma

A375

Human

40 μM

[58]

12

Oesophageal

OE33

Human

13

Lung

A549

Human

14

Colon

DLD-1

Human

50 μM

[61]

15

Rectal

SW837

Human

100 μM

[61]

Human

100 μM

[62]

Human

100 μM

[62]

RI

9 10

[59] [60]

SC

107 μM

38.7 ± 0.8 μM

MDA-MB-

Breast

17

Glioma

U87-MG

18

Esophageal squamous

KYSE-510

Human

63 μM

[63]

19

Leukemia

U937

16 μM

[64]

20

Prostate

PC-3

Human

8.5± 0.01 μM

[65]

Human

21

Hepatocellular

HepG2

Human

88.5 μmol/l

[66]

22

Acute TCL (Bcl-2 overexpressed)

Jurkat

Human

78.7 μmol/l

[66]

23

Acute T-lymphoblastic leukemia

CEM

Human

79.8 μmol/l

[66]

24

Glioma

C6

Rat

10-50μM

[67]

25

Neuroblastoma

SH-SY5Y

Human

20 μM

[68]

TE

D

M

A

N

231

U

16

Squamous cell carcinoma

FaDu

Human

10 μM

[69]

27

Breast

MCF-7

Human

18 μM

[69]

Oral

SCC-9

Human

80 μM

[69]

29

Prostate

DU-145

Human

9.81 μM

[70]

30

Leukemia

K562

Human

>100 μM

[70]

EP

26

A

CC

28

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