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Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20
Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells a
b
b
Wuen Yew Teoh , Hooi Poay Tan , Sui Kiong Ling , Norhanom Abdul c
Wahab & Kae Shin Sim
a
a
Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia b
Click for updates
Phytochemistry Program, Natural Products Division, Forest Research Institute Malaysia, 52109, Kepong, Selangor, Malaysia c
Biology Division, Centre for Foundation Studies in Science, University of Malaya, 50603 Kuala Lumpur, Malaysia Published online: 04 Mar 2015.
To cite this article: Wuen Yew Teoh, Hooi Poay Tan, Sui Kiong Ling, Norhanom Abdul Wahab & Kae Shin Sim (2015): Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells, Natural Product Research: Formerly Natural Product Letters, DOI: 10.1080/14786419.2015.1017726 To link to this article: http://dx.doi.org/10.1080/14786419.2015.1017726
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content.
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This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
Natural Product Research, 2015 http://dx.doi.org/10.1080/14786419.2015.1017726
SHORT COMMUNICATION Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells Wuen Yew Teoha, Hooi Poay Tanb, Sui Kiong Lingb, Norhanom Abdul Wahabc and Kae Shin Sima*
Downloaded by [University of Connecticut] at 13:30 12 April 2015
a
Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia; bPhytochemistry Program, Natural Products Division, Forest Research Institute Malaysia, 52109, Kepong, Selangor, Malaysia; cBiology Division, Centre for Foundation Studies in Science, University of Malaya, 50603 Kuala Lumpur, Malaysia (Received 2 January 2015; final version received 5 February 2015)
Gynura bicolor (Compositae) is a popular vegetable in Asia and believed to confer a wide range of benefits including anti-cancer. Our previous findings showed that the ethyl acetate extract of G. bicolor possessed cytotoxicity and induced apoptotic and necrotic cell death in human colon carcinoma cells (HCT 116). A combination of column chromatography had been used to purify chemical constituents from the ethyl acetate and water extract of G. bicolor leaves. Eight chemical constituents 5-p-transcoumaroylquinic acid (I), 4-hydroxybenzoic acid (II), rutin (III), kampferol-3-Orutinoside (IV), 3,5-dicaffeoylquinic acid (V), kampferol-3-O-glucoside (VI), guanosine (VII) and chlorogenic acid (VIII) were isolated from G. bicolor grown in Malaysia. To our best knowledge, all chemical constituents were isolated for the first time from G. bicolor leaves except rutin (III). 3,5-dicaffeoylquinic acid (V), guanosine (VII) and chlorogenic acid (VIII) demonstrated selective cytotoxicity (selective index . 3) against HCT 116 cancer cells compared to CCD-18Co human normal colon cells. Keywords: Gynura bicolor; 3,5-dicaffeoylquinic acid; chlorogenic acid; guanosine; cytotoxicity; HCT 116 cells
1. Introduction Gynura bicolor (Compositae), which is a popular vegetable in Asia especially in Taiwan and Japan, is locally known as ‘Hong Feng Cai’ (Chinese) and ‘Sambung Nyawa Ungu’ (Malay). The leaves of G. bicolor show reddish purple colour on the abaxial side and green colour on the adaxial side. The aerial parts are often consumed and believed to confer a wide range of benefits such as anti-cancer, anti-hyperglycaemic, antioxidant and anti-inflammatory effects (Hayashi et al. 2002; Li et al. 2009; Lu et al. 2012; Wu et al. 2013). Traditionally, it had been used for
*Corresponding author. Email: [email protected] q 2015 Taylor & Francis
2
W.Y. Teoh et al.
post-labour recovery, blood circulation improvement, treatment of dysmenorrhea and haemoptysis (Li 2006). Previous phytochemical analysis of G. bicolor leaves revealed the presence of sesquiterpenes, anthocyanins, flavonols and megastigmane-type norisoprenoids (Shimizu et al. 2009, 2010; Lu et al. 2010; Chen et al. 2012). Some people had used G. bicolor to treat colon cancer, and based on our previous findings (Teoh et al. 2013), the leaves of G. bicolor possessed cytotoxicity and induced apoptotic and necrotic cell death in human colon carcinoma cells (HCT 116). Hence, in this study, effort was put into phytochemical investigation on the leaves to explore potential chemical constituents that have cytotoxicity against HCT 116 cells.
Downloaded by [University of Connecticut] at 13:30 12 April 2015
2. Results and discussion 2.1. Identification of chemical constituents H and 13C NMR assignments of all isolated constituents are provided in Supplementary material, available online. Chemical structures of all isolated constituents are shown in Figure 1. By comparison with NMR spectral data in the literature, we isolated 5-p-trans-coumaroylquinic acid (I) (Lu et al. 2000), 4-hydroxybenzoic acid (II) (Youn et al. 2010), rutin (III) (Kanada et al. 2012), kaempferol-3-O-rutinoside (IV) (Feng et al. 2007), 3,5-dicaffeoylquinic acid (V) (Lee et al. 2010), kaempferol-3-O-glucoside (VI) (Feng et al. 2007), guanosine (VII) (Kim et al.
1
R1
O
O
O
O
OH
OH OH
HO OH
OR
I R=R1=H V R=caffeoy1, R1=OH
OH II
R1
VIII R=H, R1=OH
OH O
HO
O III R=Rha, R1=OH O OH
IV R=Rha, R1=H
N
HN
VI R=R1=H
O
H2N
RO
N
N
HO O
O
OH OH OH
OH OH VII
Figure 1. Structures of chemical constituents (I – VIII) isolated from the leaves of G. bicolor.
Natural Product Research
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Table 1. Cytotoxic effect of isolated chemical constituents against HCT 116 and CCD-18Co cells. IC50a (mg/mL) (SIb) Chemical constituents
Downloaded by [University of Connecticut] at 13:30 12 April 2015
5-p-trans-coumaroylquinic acid (I) 4-Hydroxybenzoic acid (II) Rutin (III) Kampferol-3-O-rutinoside (IV) 3,5-Dicaffeoylquinic acid (V) Kampferol-3-O-glucoside (VI) Guanosine (VII) Chlorogenic acid (VIII) Cis-platinc a b c
HCT 116
CCD-18Co
.100 .100 .100 .100 79.7 ^ 4.5 (4.4) .100 81.0 ^ 6.6 (. 6.2) 79.3 ^ 3.1 (5.1) 2.9 ^ 0.1 (. 4.3)
ND ND ND ND 350 ^ 1.7 ND . 500 403.3 ^ 9.5 .12.5
Data are presented as mean ^ standard deviation from three independent experiments triplicate for each. Selectivity index (SI). Positive reference standard; ND, not determined.
2003) and chlorogenic acid (VIII) (Lee et al. 2010) from G. bicolor leaves. The identities of all isolated constituents were confirmed by negative ionisation ESI-MS. To our best knowledge, all constituents were isolated for the first time from G. bicolor leaves except constituent III, rutin. 2.2. Cytotoxic effect of the isolated chemical constituents As shown in Table 1, all isolated constituents did not show cytotoxic effect (with IC50 values . 100 mg/mL) against HCT 116 cells at 72 h incubation except 3,5-dicaffeoylquinic acid (V, IC50 value of 79.7 mg/mL), guanosine (VII, IC50 value of 81.0 mg/mL) and chlorogenic acid (VIII, IC50 value of 79.3 mg/mL). Constituent with selectivity index (SI) more than 3 indicates high selectivity against cancerous cells compared to normal cells (Be´zivin et al. 2003). The cytotoxic effect of constituents V, VII and VIII against CCD18Co normal colon cells was comparatively low with IC50 values of 350 ^ 1.7, . 500 and 403.3 ^ 9.5 mg/ml, respectively. Constituent VII appeared to be highly selective against HCT 116 cells with SI value of 6.2, followed by VIII with SI value of 5.1 and V with SI value of 4.4. To our knowledge, the SI of constituents V, VII and VIII on HCT 116 and CCD-18Co cells had not been reported. From SI point of view, constituents V, VII and VIII had showed cytotoxicity against colon cancer cells while exerting minimal cytotoxicity against normal colon cells. The selective property of these three chemical constituents of G. bicolor could be usefull against colon cancer. 3. Conclusion In this work, seven chemical constituents were isolated from G. bicolor leaves for the first time. 3,5-Dicaffeoylquinic acid (V), guanosine (VII) and chlorogenic acid (VIII) from G. bicolor leaves showed selective cytotoxic effect on HCT 116 cells by in vitro MTT assay. By consuming G. bicolor, these chemical constituents may help in treatment of colon cancer. Further studies on the cell death mechanism of these constituents are under way in order to provide more convincing evidence. Supplementary material Experimental details relating to this article are available online together with Figure S1.
4
W.Y. Teoh et al.
Acknowledgement The authors are grateful to Dr Yong Kien Thai from the Institute of Biological Sciences, Faculty of Science, University of Malaya, Malaysia for plant identification.
Funding The authors wish to thank the Ministry of Higher Education of Malaysia (MOHE) and the University of Malaya for financial assistance [grant number FRGS FP013/2012A], [grant number PPP PV042/2012A].
Downloaded by [University of Connecticut] at 13:30 12 April 2015
References Be´zivin C, Tomasi S, Lohe´zic-Le De´ve´hat F, Boustie J. 2003. Cytotoxic activity of some lichen extracts on murine and human cancer cell lines. Phytomedicine. 10:499– 503. Chen J, Mangelinckx S, Adams A, Li WL, Wang ZT, De Kimpe N. 2012. Chemical constituents from the aerial parts of Gynura bicolor. Nat Prod Commun. 7:1563– 1564. Feng WS, Hao ZY, Zheng XK, Kuang HX. 2007. Chemical constituents from leaves of Celastrus gemmatus Loes. Yao Xue Xue Bao. 42:625–630. Hayashi M, Iwashita K, Katsube N, Yamaki K, Kobori M. 2002. Kinjiso (Gynura bicolor DC.) colored extract induce apoptosis in HL60 leukemia cells. Nippon Shokuhin Kagaku Kogaku Kaishi. 49:519–526. doi:10.3136/nskkk.49. 519. Kanada RM, Simionato JI, Arruda RF, Santin SMO, Souza MC, Silva CC. 2012. N-trans-feruloyltyramine and flavonol glycosides from the leaves of Solanum sordidum. Braz J Pharmacogn. 22:502–506. doi:10.1590/S0102695X2012005000029. Kim J, Lee SH, Sun N, Choung DH, Kim WK, Lee S, Song KB. 2003. Isolation of an angiotensin converting enzyme inhibitory substance from Chrysanthemum boreale Makino. J Food Sci. 68:816–819. doi:10.1111/j.1365-2621. 2003.tb08248.x. Lee EJ, Kim JS, Kim HP, Lee JH, Kang SS. 2010. Phenolic constituents from the flower buds of Lonicera japonica and their 5-lipoxygenase inhibitory activities. Food Chem. 120:134–139. doi:10.1016/j.foodchem.2009.09.088. Li TSC. 2006. Taiwanese native medicinal plants: phytopharmacology and therapeutic values. Boca Raton (FL): CRC Press/Taylor and Francis Group. Li WL, Ren BR, Min-Zhuo, Hu Y, Lu CG, Wu JL, Chen J, Sun S. 2009. The anti-hyperglycemic effect of plants in genus Gynura cass. Am J Chin Med. 37:961–966. doi:10.1142/S0192415X09007430. Lu CH, Yang HC, Chang WL, Chang YP, Wu CC, Hsieh SL. 2012. Development of beverage product from Gynura bicolor and evaluation of its antioxidant activity. Genomic Med Biomarkers Health Sci. 4:131–135. doi:10.1016/ j.gmbhs.2013.04.001. Lu H, Pei Y, Li W. 2010. Studies on flavonoids from Gynura bicolor DC. Zhongguo Xian Dai Ying Yong Yao Xue. 27:613–614. Lu Y, Sun Y, Foo LY, McNabb WC, Molan AL. 2000. Phenolic glycosides of forage legume Onobrychis viciifolia. Phytochemistry. 55:67–75. doi:10.1016/S0031-9422(00)00143-6. Shimizu Y, Imada T, Zhang H, Tanaka R, Ohno T, Shimomura K. 2010. Identification of novel poly-acylated anthocyanins from Gynura bicolor leaves and their antioxidative activity. Food Sci Technol Res. 16:479–486. doi:10.3136/fstr.16.479. Shimizu Y, Imayoshi Y, Kato M, Maeda K, Iwabuchi H, Shimomura K. 2009. Volatiles from leaves of field-grown plants and shoot cultures of Gynura bicolor DC. Flavour Frag J. 24:251–258. doi:10.1002/ffj.1938. Teoh WY, Sim KS, Richardson JSM, Wahab NA, Hoe SZ. 2013. Antioxidant capacity, cytotoxicity and acute oral toxicity of Gynura bicolor. Evid Based Complement Altern Med. article ID 958407, 10 pages. Wu CC, Lii CK, Liu KL, Chen PY, Hsieh SL. 2013. Antiinflammatory activity of Gynura bicolor (紅鳳菜 Ho´ng Fe`ng Ca`i) ether extract through inhibits nuclear factor kappa B activation. J Tradit Complement Med. 3:48–52. doi:10. 4103/2225-4110.106547. Youn UJ, Lee YJ, Jeon HR, Shin HJ, Son YM, Nam JW, Han AR, Seo EK. 2010. A pyridyl alkaloid and benzoic acid derivatives from the rhizomes of Anemarrhena asphodeloides. Nat Prod Sci. 16:203–206.
Natural Product Research: Formerly Natural Product Letters Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gnpl20
Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells a
b
b
Wuen Yew Teoh , Hooi Poay Tan , Sui Kiong Ling , Norhanom Abdul c
Wahab & Kae Shin Sim
a
a
Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia b
Click for updates
Phytochemistry Program, Natural Products Division, Forest Research Institute Malaysia, 52109, Kepong, Selangor, Malaysia c
Biology Division, Centre for Foundation Studies in Science, University of Malaya, 50603 Kuala Lumpur, Malaysia Published online: 04 Mar 2015.
To cite this article: Wuen Yew Teoh, Hooi Poay Tan, Sui Kiong Ling, Norhanom Abdul Wahab & Kae Shin Sim (2015): Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells, Natural Product Research: Formerly Natural Product Letters, DOI: 10.1080/14786419.2015.1017726 To link to this article: http://dx.doi.org/10.1080/14786419.2015.1017726
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content.
Downloaded by [University of Connecticut] at 13:30 12 April 2015
This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
Natural Product Research, 2015 http://dx.doi.org/10.1080/14786419.2015.1017726
SHORT COMMUNICATION Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells Wuen Yew Teoha, Hooi Poay Tanb, Sui Kiong Lingb, Norhanom Abdul Wahabc and Kae Shin Sima*
Downloaded by [University of Connecticut] at 13:30 12 April 2015
a
Faculty of Science, Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia; bPhytochemistry Program, Natural Products Division, Forest Research Institute Malaysia, 52109, Kepong, Selangor, Malaysia; cBiology Division, Centre for Foundation Studies in Science, University of Malaya, 50603 Kuala Lumpur, Malaysia (Received 2 January 2015; final version received 5 February 2015)
Gynura bicolor (Compositae) is a popular vegetable in Asia and believed to confer a wide range of benefits including anti-cancer. Our previous findings showed that the ethyl acetate extract of G. bicolor possessed cytotoxicity and induced apoptotic and necrotic cell death in human colon carcinoma cells (HCT 116). A combination of column chromatography had been used to purify chemical constituents from the ethyl acetate and water extract of G. bicolor leaves. Eight chemical constituents 5-p-transcoumaroylquinic acid (I), 4-hydroxybenzoic acid (II), rutin (III), kampferol-3-Orutinoside (IV), 3,5-dicaffeoylquinic acid (V), kampferol-3-O-glucoside (VI), guanosine (VII) and chlorogenic acid (VIII) were isolated from G. bicolor grown in Malaysia. To our best knowledge, all chemical constituents were isolated for the first time from G. bicolor leaves except rutin (III). 3,5-dicaffeoylquinic acid (V), guanosine (VII) and chlorogenic acid (VIII) demonstrated selective cytotoxicity (selective index . 3) against HCT 116 cancer cells compared to CCD-18Co human normal colon cells. Keywords: Gynura bicolor; 3,5-dicaffeoylquinic acid; chlorogenic acid; guanosine; cytotoxicity; HCT 116 cells
1. Introduction Gynura bicolor (Compositae), which is a popular vegetable in Asia especially in Taiwan and Japan, is locally known as ‘Hong Feng Cai’ (Chinese) and ‘Sambung Nyawa Ungu’ (Malay). The leaves of G. bicolor show reddish purple colour on the abaxial side and green colour on the adaxial side. The aerial parts are often consumed and believed to confer a wide range of benefits such as anti-cancer, anti-hyperglycaemic, antioxidant and anti-inflammatory effects (Hayashi et al. 2002; Li et al. 2009; Lu et al. 2012; Wu et al. 2013). Traditionally, it had been used for
*Corresponding author. Email: [email protected] q 2015 Taylor & Francis
2
W.Y. Teoh et al.
post-labour recovery, blood circulation improvement, treatment of dysmenorrhea and haemoptysis (Li 2006). Previous phytochemical analysis of G. bicolor leaves revealed the presence of sesquiterpenes, anthocyanins, flavonols and megastigmane-type norisoprenoids (Shimizu et al. 2009, 2010; Lu et al. 2010; Chen et al. 2012). Some people had used G. bicolor to treat colon cancer, and based on our previous findings (Teoh et al. 2013), the leaves of G. bicolor possessed cytotoxicity and induced apoptotic and necrotic cell death in human colon carcinoma cells (HCT 116). Hence, in this study, effort was put into phytochemical investigation on the leaves to explore potential chemical constituents that have cytotoxicity against HCT 116 cells.
Downloaded by [University of Connecticut] at 13:30 12 April 2015
2. Results and discussion 2.1. Identification of chemical constituents H and 13C NMR assignments of all isolated constituents are provided in Supplementary material, available online. Chemical structures of all isolated constituents are shown in Figure 1. By comparison with NMR spectral data in the literature, we isolated 5-p-trans-coumaroylquinic acid (I) (Lu et al. 2000), 4-hydroxybenzoic acid (II) (Youn et al. 2010), rutin (III) (Kanada et al. 2012), kaempferol-3-O-rutinoside (IV) (Feng et al. 2007), 3,5-dicaffeoylquinic acid (V) (Lee et al. 2010), kaempferol-3-O-glucoside (VI) (Feng et al. 2007), guanosine (VII) (Kim et al.
1
R1
O
O
O
O
OH
OH OH
HO OH
OR
I R=R1=H V R=caffeoy1, R1=OH
OH II
R1
VIII R=H, R1=OH
OH O
HO
O III R=Rha, R1=OH O OH
IV R=Rha, R1=H
N
HN
VI R=R1=H
O
H2N
RO
N
N
HO O
O
OH OH OH
OH OH VII
Figure 1. Structures of chemical constituents (I – VIII) isolated from the leaves of G. bicolor.
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Table 1. Cytotoxic effect of isolated chemical constituents against HCT 116 and CCD-18Co cells. IC50a (mg/mL) (SIb) Chemical constituents
Downloaded by [University of Connecticut] at 13:30 12 April 2015
5-p-trans-coumaroylquinic acid (I) 4-Hydroxybenzoic acid (II) Rutin (III) Kampferol-3-O-rutinoside (IV) 3,5-Dicaffeoylquinic acid (V) Kampferol-3-O-glucoside (VI) Guanosine (VII) Chlorogenic acid (VIII) Cis-platinc a b c
HCT 116
CCD-18Co
.100 .100 .100 .100 79.7 ^ 4.5 (4.4) .100 81.0 ^ 6.6 (. 6.2) 79.3 ^ 3.1 (5.1) 2.9 ^ 0.1 (. 4.3)
ND ND ND ND 350 ^ 1.7 ND . 500 403.3 ^ 9.5 .12.5
Data are presented as mean ^ standard deviation from three independent experiments triplicate for each. Selectivity index (SI). Positive reference standard; ND, not determined.
2003) and chlorogenic acid (VIII) (Lee et al. 2010) from G. bicolor leaves. The identities of all isolated constituents were confirmed by negative ionisation ESI-MS. To our best knowledge, all constituents were isolated for the first time from G. bicolor leaves except constituent III, rutin. 2.2. Cytotoxic effect of the isolated chemical constituents As shown in Table 1, all isolated constituents did not show cytotoxic effect (with IC50 values . 100 mg/mL) against HCT 116 cells at 72 h incubation except 3,5-dicaffeoylquinic acid (V, IC50 value of 79.7 mg/mL), guanosine (VII, IC50 value of 81.0 mg/mL) and chlorogenic acid (VIII, IC50 value of 79.3 mg/mL). Constituent with selectivity index (SI) more than 3 indicates high selectivity against cancerous cells compared to normal cells (Be´zivin et al. 2003). The cytotoxic effect of constituents V, VII and VIII against CCD18Co normal colon cells was comparatively low with IC50 values of 350 ^ 1.7, . 500 and 403.3 ^ 9.5 mg/ml, respectively. Constituent VII appeared to be highly selective against HCT 116 cells with SI value of 6.2, followed by VIII with SI value of 5.1 and V with SI value of 4.4. To our knowledge, the SI of constituents V, VII and VIII on HCT 116 and CCD-18Co cells had not been reported. From SI point of view, constituents V, VII and VIII had showed cytotoxicity against colon cancer cells while exerting minimal cytotoxicity against normal colon cells. The selective property of these three chemical constituents of G. bicolor could be usefull against colon cancer. 3. Conclusion In this work, seven chemical constituents were isolated from G. bicolor leaves for the first time. 3,5-Dicaffeoylquinic acid (V), guanosine (VII) and chlorogenic acid (VIII) from G. bicolor leaves showed selective cytotoxic effect on HCT 116 cells by in vitro MTT assay. By consuming G. bicolor, these chemical constituents may help in treatment of colon cancer. Further studies on the cell death mechanism of these constituents are under way in order to provide more convincing evidence. Supplementary material Experimental details relating to this article are available online together with Figure S1.
4
W.Y. Teoh et al.
Acknowledgement The authors are grateful to Dr Yong Kien Thai from the Institute of Biological Sciences, Faculty of Science, University of Malaya, Malaysia for plant identification.
Funding The authors wish to thank the Ministry of Higher Education of Malaysia (MOHE) and the University of Malaya for financial assistance [grant number FRGS FP013/2012A], [grant number PPP PV042/2012A].
Downloaded by [University of Connecticut] at 13:30 12 April 2015
References Be´zivin C, Tomasi S, Lohe´zic-Le De´ve´hat F, Boustie J. 2003. Cytotoxic activity of some lichen extracts on murine and human cancer cell lines. Phytomedicine. 10:499– 503. Chen J, Mangelinckx S, Adams A, Li WL, Wang ZT, De Kimpe N. 2012. Chemical constituents from the aerial parts of Gynura bicolor. Nat Prod Commun. 7:1563– 1564. Feng WS, Hao ZY, Zheng XK, Kuang HX. 2007. Chemical constituents from leaves of Celastrus gemmatus Loes. Yao Xue Xue Bao. 42:625–630. Hayashi M, Iwashita K, Katsube N, Yamaki K, Kobori M. 2002. Kinjiso (Gynura bicolor DC.) colored extract induce apoptosis in HL60 leukemia cells. Nippon Shokuhin Kagaku Kogaku Kaishi. 49:519–526. doi:10.3136/nskkk.49. 519. Kanada RM, Simionato JI, Arruda RF, Santin SMO, Souza MC, Silva CC. 2012. N-trans-feruloyltyramine and flavonol glycosides from the leaves of Solanum sordidum. Braz J Pharmacogn. 22:502–506. doi:10.1590/S0102695X2012005000029. Kim J, Lee SH, Sun N, Choung DH, Kim WK, Lee S, Song KB. 2003. Isolation of an angiotensin converting enzyme inhibitory substance from Chrysanthemum boreale Makino. J Food Sci. 68:816–819. doi:10.1111/j.1365-2621. 2003.tb08248.x. Lee EJ, Kim JS, Kim HP, Lee JH, Kang SS. 2010. Phenolic constituents from the flower buds of Lonicera japonica and their 5-lipoxygenase inhibitory activities. Food Chem. 120:134–139. doi:10.1016/j.foodchem.2009.09.088. Li TSC. 2006. Taiwanese native medicinal plants: phytopharmacology and therapeutic values. Boca Raton (FL): CRC Press/Taylor and Francis Group. Li WL, Ren BR, Min-Zhuo, Hu Y, Lu CG, Wu JL, Chen J, Sun S. 2009. The anti-hyperglycemic effect of plants in genus Gynura cass. Am J Chin Med. 37:961–966. doi:10.1142/S0192415X09007430. Lu CH, Yang HC, Chang WL, Chang YP, Wu CC, Hsieh SL. 2012. Development of beverage product from Gynura bicolor and evaluation of its antioxidant activity. Genomic Med Biomarkers Health Sci. 4:131–135. doi:10.1016/ j.gmbhs.2013.04.001. Lu H, Pei Y, Li W. 2010. Studies on flavonoids from Gynura bicolor DC. Zhongguo Xian Dai Ying Yong Yao Xue. 27:613–614. Lu Y, Sun Y, Foo LY, McNabb WC, Molan AL. 2000. Phenolic glycosides of forage legume Onobrychis viciifolia. Phytochemistry. 55:67–75. doi:10.1016/S0031-9422(00)00143-6. Shimizu Y, Imada T, Zhang H, Tanaka R, Ohno T, Shimomura K. 2010. Identification of novel poly-acylated anthocyanins from Gynura bicolor leaves and their antioxidative activity. Food Sci Technol Res. 16:479–486. doi:10.3136/fstr.16.479. Shimizu Y, Imayoshi Y, Kato M, Maeda K, Iwabuchi H, Shimomura K. 2009. Volatiles from leaves of field-grown plants and shoot cultures of Gynura bicolor DC. Flavour Frag J. 24:251–258. doi:10.1002/ffj.1938. Teoh WY, Sim KS, Richardson JSM, Wahab NA, Hoe SZ. 2013. Antioxidant capacity, cytotoxicity and acute oral toxicity of Gynura bicolor. Evid Based Complement Altern Med. article ID 958407, 10 pages. Wu CC, Lii CK, Liu KL, Chen PY, Hsieh SL. 2013. Antiinflammatory activity of Gynura bicolor (紅鳳菜 Ho´ng Fe`ng Ca`i) ether extract through inhibits nuclear factor kappa B activation. J Tradit Complement Med. 3:48–52. doi:10. 4103/2225-4110.106547. Youn UJ, Lee YJ, Jeon HR, Shin HJ, Son YM, Nam JW, Han AR, Seo EK. 2010. A pyridyl alkaloid and benzoic acid derivatives from the rhizomes of Anemarrhena asphodeloides. Nat Prod Sci. 16:203–206.
