Journal of Ethnopharmacology 153 (2014) 635–640
Contents lists available at ScienceDirect
Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jep
Research paper
Effect of Cydonia oblonga Mill. leaf extracts or captopril on blood pressure and related biomarkers in renal hypertensive rats Wen-ting Zhou a,1, Adil Abdurahman a,1, Elzira Abdusalam a, Wuliya Yiming a, Parida Abliz b, Qimangul Aji a, Mehray Issak a, Guldiyar Iskandar a, Nicholas Moore a,c,n, Anwar Umar a,c,nn a
Department of Pharmacology, Xinjiang Medical University, Urumqi 830011, PR China Department of Pharmacognosy, Xinjiang Medical University, 830011 Urumqi, PR China c Department of Pharmacology, Universite de Bordeaux Segalen, F-33076 Bordeaux, France b
art ic l e i nf o
a b s t r a c t
Article history: Received 24 December 2013 Received in revised form 2 March 2014 Accepted 6 March 2014 Available online 21 March 2014
Ethnopharmacological relevance: Cydonia oblonga Mill. (COM) is used in traditional Uyghur medicine to treat or prevent cardiovascular disease. In a previous study COM leaf extracts were found to be active in renal hypertensive rats (RHR). The present study tests the dose-dependence of the effect of ethanol leaf extracts on hypertension and on biomarkers associated with blood pressure control, such as angiotensinII (AII), plasma renin activity (PRA), apelin-12 (A), endothelin (ET) and nitric oxide (NO), compared to captopril. Methods: Two-kidney one-clip (2K1C) Goldblatt model rats were divided randomly into six groups: sham, model, captopril 25 mg/kg, COM leaf extract 80, 160 and 320 mg/kg (n ¼ 10 each). Drugs were administered orally daily for eight weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured before treatment and every 2 weeks. Blood and kidney samples were collected after the last treatment to measure AII, PRA, A, ET and NO. Results: RHR had increased blood pressure, AII, A, PRA, ET and decreased NO. Treatment with captopril reduced blood pressure, AII, A, PRA, and ET, though not quite to normal values. COM leaf extracts significantly and dose-dependently reduced blood pressure, AII, A, RA and ET, whereas NO was increased. The highest dose of COM had the same effects as captopril. Conclusion: The effects of COM extracts on blood pressure and biomarkers were dose-dependent and at the highest dose similar to those of captopril. This suggests an action of COM on the renin–angiotensin system, which could explain its antihypertensive effect. & 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Cydonia oblonga Mill. Renal hypertensive rats Angiotensin-II Endothelin
1. Introduction The south-western part of Xinjiang around Hotan and Kashgar is renowned for its large number of centenarians, and it has been found that Uyghur men from the region of Hotan have lower blood pressure that other central Asians (Kawamura et al., 2000, 2003; Wufuer et al., 2004). In traditional Uyghur medicine, the fruit and leaves of Quince (Cydonia oblonga Mill.) are used to treat or prevent hypertension and other cardiovascular diseases (Sadik, 1993), among other (Aibaidula et
Abbreviations: ACE, angiotensin converting enzyme; ET, endothelin; RHR, renal hypertensive rats (2K1C); 2K1C, Goldblatt 2 kidney 1 clip RHR; A-12, Apelin-12; COM, Cydonia Oblonga Mill. extracts; NO, nitric oxide n Corresponding author at: Department of Pharmacology, University of Bordeaux Segalen, 33076 Bordeaux, France. Tel.: þ 335 575 715 60; fax: þ 335 575 746 71. nn Corresponding author at: Departement of Pharmacology, Xinjiang Medical University, 830011 Urumqi, Xinjiang, PR China. Tel./fax: þ 869 914 362 421. E-mail addresses: [email protected] (N. Moore), [email protected] (A. Umar). 1 Both are equal contributors to this work. http://dx.doi.org/10.1016/j.jep.2014.03.014 0378-8741/& 2014 Elsevier Ireland Ltd. All rights reserved.
al., 2009; Aslan et al., 2010; Yan et al., 2009), as they are in traditional Turkish medicine which has the same cultural roots (Kultur, 2007). Quince fruit and leaves contain many ingredients, with known antioxidant activity (Silva et al., 2002, 2004a, 2004b, 2005; Wojdylo et al., 2013; Xakir and Aikebaier, 2006). In a systematic exploration of its cardiovascular and metabolic effects, we have shown that Cydonia oblonga Mill. (COM) extracts could oppose hyperlipidaemia in hyperlipidaemic rats (Abliz et al., 2014), and that extracts of leaves and fruit of COM had an antihypertensive effect of a magnitude not very different from that of captopril, a reference antihypertensive drug acting on the renin–angiotensin system (RAS) (Zhou et al., 2014). The ethanol extracts of COM leaves appeared to be the more effective. Because of the similarity of effects with captopril, we sought to explore the effects of these COM leaf extracts on markers of the RAS and other vasoactive systems. We therefore tested the dose-dependence of the effects of these extracts in the same standard experimental model of renal hypertension, the 2 kidney-1 clip Goldblatt rat model (2K1C)
636
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
(Barger, 1979; Goldblatt, 1958, 1964; Pinto et al., 1998; Reinhold et al., 2009; Umar et al., 2010; Xian and Huang, 2007), compared to the effects of captopril on blood pressure and on the usual biomarkers associated with blood pressure and the renin–angiotensin system: angiotensin II, renin activity, apelin-12, endothelin and nitric oxide.
2. Materials and methods 2.1. Test products Cydonia Oblonga Mill. (COM) leaf extract, as provided by the department of pharmacology, Xinjiang Medical University. In brief, Cydonia Oblonga Mill. (COM) leaves were collected in October 2010 from the Kashgar area in Kargilik County, Xinjiang, dried and crushed. Voucher specimens were left in the herbarium of the Traditional Chinese Medicine Ethnical Herbs Specimen Museum of Xinjiang Medical University under number NO.TCMEHSM2013_100; the appropriate amount of the leaf powder was weighed, and immerged into 20 times its volume of 65% alcohol for one hour followed by 3 reflux extractions. Filtrates were combined, concentrated under reduced pressure and recovered. The resulting extract was directly freeze-dried over 24 h, to provide COM leaf alcohol extracts. Captopril (25 mg, lot number 100803) was purchased from Shanxi Huixing Pharmaceutical Co., Ltd. 2.2. Reagents and instruments Medical alcohol (75%, Weiye Experimental Material Company, lot number: 11030801); penicillin sodium for injection (800,000 units/ piece, Zhongguo Pharmaceutical co. ltd, lot number: 101003017); pentobarbital sodium (Solar Bio, lot number: 6900183); Rat Angiotensin II, renin activity, apelin-12, endothlin-1, Nitrous oxide (NO) kits (R&D, lot number: CK-E30668); BP-6 non-invasive blood pressure measuring device for animals (Chengdu Taimeng Technology Co. Ltd), U-shaped silver clip (inside diameter: 0.20 mm); LXJ-IIB-type lowspeed large-capacity multi-tube centrifuge (Shanghai Anting Scientific Instrument Factory); TDL-5M desktop large-capacity refrigerated centrifuge (Changsha Xiangyi centrifuge instrument Co. Ltd); FSH-2A adjustable high-speed homogenizer; radiation immunity γ-arithmometer, Coda KM-00025-00 automatic enzyme immunoassay instrument (Bio-Rad). 2.3. Animals Sixty male Wistar rats weighing 200 720 g were provided by the Experimental Animal Center of Xinjiang Medical University, license number: SCXK (Xin): 2003-000, fed on a daily basis with free access to regular pellet fodder and clean tap water. The animals were kept under constant temperature (20 71.1 1C) and illumination (12–12 h light/dark cycle) until the day of experiment. 2.4. Methods 2.4.1. Establishment of 2K1C renal hypertensive rat model (Chelko et al., 2012; Soltani Hekmat et al., 2011; Umar et al., 2010) To induce hypertension according to the Goldblatt 2K1C model, (Barger, 1979; Goldblatt, 1958, 1964; Pinto et al., 1998; Reinhold et al., 2009; Umar et al., 2010; Xian and Huang, 2007) 200 720 g male wistar rats were anesthetized with sodium pentobarbital (50 mg kg 1 intraperitoneally). The left renal artery was exposed by retroperitoneal flank incision and dissected free of the renal vein and connective tissue. A silver clip with a lumen of 0.22 mm
was placed around the artery for partial occlusion; in shamoperated control rats, the artery was not clipped. The right kidney was left untouched. After 6 weeks the systolic blood pressure (SBP) was measured using the tail-cuff method in conscious rats. Only hypertensive rats (SBP above 150 mm Hg) were used in the experiments.
2.4.2. Grouping and administration Fifty renal hypertensive and ten non hypertensive (sham) rats were randomly divided into 5 groups: A sham control group, a renal hypertensive model control group, and renal hypertensive rats treated with captopril 25 mg/kg, COM 80 mg/kg (low-dose), 160 mg/kg (medium-dose) or 320 mg/kg (high-dose), diluted in 0.9‰ (physiological) saline. Rats were treated daily by gastric gavage of the appropriate study drug or of the same volume of physiological saline. The rats were weighed weekly, and drug doses adjusted accordingly.
2.4.3. Measurement of blood pressure Before and 2, 4, 6 and 8 weeks after administration, the 6 groups of rats were placed in a quiet, dry and well-ventilated environment to measure their systolic blood pressure (SBP) and diastolic blood pressure (DBP) with BP-6 non-invasive blood pressure measuring device for rats. Blood pressures were recorded 1 h after drug or saline administration. All measures were repeated 3 times and averaged.
2.4.4. Sample collection and determination of biomarkers (1) Blood serum and plasma samples Blood pressure was measured 1 h after last administration. Rats were then anesthetized with 30 mg/kg of 1% pentobarbital sodium, and blood was collected in the abdominal aorta. Sample for serum was collected without added anticoagulant. After centrifugation for 10 min at 3000 rpm at 4 1C, the serum was preserved at 80 1C. Apelin-12 and NO in serum were determined according to the manufacturer's instructions on the kit. Sample for blood plasma was promptly poured into anticoagulated tubes with pre-added enzyme inhibitor (10%, 30 μl disodium EDTA and 40 μl aprotinin), shaken and centrifuged 10 minutes at 3000 rpm/4 1C. Plasma was then preserved at 80 1C. Plasma concentrations of angiotensin-II (AII), endothelin-1 (ET) and renin activity (RA) were determined according to the manufacturer's instruction on the kit. (2) Renal tissue sample A 0.5 g sample of each rat's right kidney was taken, wrapped in aluminum foil and preserved at 80 1C. For analysis, 4.5 ml physiological saline solution were added to produce a 10% tissue homogenate, which was then centrifuged for 15 min at 3000 rpm. The supernatant fluid was used to measure the content of AII and apelin-12 in the kidney tissue. 2.5. Data processing Data were processed with SPSS 17.0 statistics software and results are given as mean 7standard deviation. Multiple means were compared with One-Way ANOVA. After homogeneity of variance test, heterogeneous differences were tested with Dunnett's t method and the homogeneous one with the LSD-t method. Test standard was α ¼0.05. Main comparisons were of COM low and high doses and captopril vs model animals.
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
637
extracts resulted in a dose-dependent decrease in blood pressure, that started later than with captopril, but was similar to that of captopril after 8 weeks for the highest dose (Table 2, Fig. 1). Similar results were found for diastolic blood pressure (Table 3).
3. Results 3.1. Weight During the experiment, the rats' weight increased regularly. Model rats however put on less weight than the sham controls. Captopril treated rats put on more weight than model controls. The higher dose of COM was also associated with significantly higher weights, without quite reaching the weights of sham controls. (Table 1) 3.2. Systolic and diastolic blood pressures Blood pressure remained stable throughout the study period in the sham rats, and increased regularly in the model group. Treatment with captopril resulted in a reduction in blood pressure that was apparent from the second week of treatment, though it never reached the sham control values. Treatment with COM leaf
3.3. Angiotensin-II, apelin-12, plasma renin activity, endothelin, nitroxide In renal hypertensive rats, angiotensin II, apelin-12, PRA and ET were significantly increased compared to sham rats. NO on the opposite was reduced by 14%. Captopril opposed these changes for all parameters, again without return to basal values, except for NO, which was higher than in the sham control rats. COM dose-dependently reduced these increased parameters, and also increased NO to higher values that sham, in a dose-dependent manner, with the highest dose resulting in numbers that were very close to those of captopril (Table 4, Fig. 2).
Table 1 Changes in rat weights over time in sham, model, captopril- and Cydonia oblonga-treated renal hypertensive rats. (N ¼ 10 per group). Group
N
2 Weeks
4 Weeks
6 Weeks
8 Weeks
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
252.8 7 26.1 224.57 23.8 253.17 25.0 236.3 7 28.8 224.87 33.6 243.37 29.7#
272.2 7 20.0 224.67 23.8 264.07 38.6 232.8 7 38.6 226.6 7 37.5 241.3 7 33.7#
274.4 7 20.4 231.3 7 23.4 273.6 7 24.1 244.57 32.7 243.37 43.5 255.0 7 28.4#
282.3 7 20.5 252.2 7 31.7 278.7 7 26.1 247.8 7 39.5 246.7 7 37.4 263.0 7 28.3#
#
Po 0.05 vs model.
Table 2 Systolic blood pressure in sham, model, captopril- and Cydonia oblonga-treated renal hypertensive rats. (N ¼ 10 per group). Group
Dose (mg/kg)
Before treatment
2 Weeks
4 Weeks
6 Weeks
8 Weeks
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
127.17 6.5 182.5 7 7.4n 180.4 7 8.7n 184.4 7 6.7n 182.4 7 7.3n 181.9 7 8.5n
126.7 7 3.5 182.9 7 6.6n 166.27 7.8n# 177.8 7 5.7n 174.0 7 7.9n# 172.9 7 8.6n#
128.17 8.2 189.5 7 5.4n 160.4 7 9.1n# 174.4 7 5.7n# 172.4 7 6.6n# 169.9 7 7.5n#
127.1 78.5 190.5 76.4n 159.4 79.7n# 170.4 710.7n# 168.4 76.3n# 164.9 79.5n#
126.7 7 4.5 191.9 7 5.6n 157.2 7 5.8n# 166.8 7 7.4n# 162.0 7 5.1n# 159.9 7 10.6n#
n
#
Po 0.05 vs sham. Po 0.05 vs model.
Fig. 1. Evolution of Systolic Blood Pressure in sham, model renal hypertensive rats (RHR), and in RHR treated with captopril 25 mg/kg or increasing doses of Cydonia oblonga Mill. leaf extracts (COM) (See Table 2 for SD and statistical analysis).
638
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
Table 3 Diastolic blood pressure in sham, model, captopril- and Cydonia oblonga Mill. (COM) - treated renal hypertensive rats. (N ¼ 10 per group). Group
Dose (mg/kg)
Before treatment
2 Weeks
4 Weeks
6 Weeks
8 Weeks
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
90.1 76.5 137.5 77.4n 136.4 78.7n 134.4 76.7n 135.477.3n 136.9 78.5n
89.7 7 3.5 138.9 7 6.6n 126.2 7 7.8n# 137.8 7 5.7n 135.07 7.9n 132.9 7 8.6n#
89.17 8.2 139.5 7 5.4n 125.4 7 9.1n# 135.47 5.7n 132.4 7 6.6n# 130.9 7 7.5n#
91.17 8.5 139.8 7 6.4n 122.4 7 9.7n# 132.4 7 10.7n# 129.4 7 6.3n# 127.9 7 9.5n#
90.7 74.5 140.3 75.6n 120.2 75.8n# 128.8 77.4n# 124.0 75.1n# 121.9 710.6n#
n
#
Po 0.05 vs sham. Po 0.05 vs model.
Table 4 Plasma angiotensin-II (AII), serum apelin-12, plasma renin activity (PRA), endothelin (ET-1) and nitroxide (NO) in sham, model, captopril- and Cydonia oblonga-treated renal hypertensive rats. (N ¼ 10 per group). Group
Dose (mg/kg)
AII (pg/ml)
Apelin-12 (pg/ml)
PRA (ng/ml)
ET-1 (pg/m)
NO (μmol/ml)
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
317.2 713.6 380.8 715.3n 348.9 714.1n# 363.1 716.2n# 356.1 717.0n# 349.3 711.9n#
172.8 7 10.6 224.67 11.2n 193.0 7 10.4n# 210.8 7 9.3n# 205.7 7 7.1n# 190.5 7 13.5n#
1.0770.18 3.02 70.21n 1.63 70.11n# 1.84 70.34n# 1.81 70.20n# 1.76 70.17n#
92.17 12.7 152.2 7 8.5n 115.4 7 16.3n# 143.9 7 18.0n 137.7 7 16.2n# 121.3 7 22.7n#
57.3 74.72 50.3 73.92n 66.7 75.38n# 65.1 77.26n# 68.5 78.27n# 68.4 74.89n#
n
#
Po 0.05 vs sham. Po 0.05 vs model.
Fig. 2. Posttreatment values for biomarkers in renal hypertensive rats. (see Table 4 for statistical analyses).
3.4. Renal angiotensin-II and apelin-12 Goldblatt 2K1C renal hypertensive rats had greatly elevated renal angiotensin II and apelin-12, which were reduced almost to normal by captopril, and to the same extent by the highest dose of COM, the other doses having a dose-related effect (Table 5).
4. Discussion Renal hypertension is a common cause of secondary hypertension in man, usually following renal artery stenosis or hyperplasia. The reduction of renal blood flow results in abnormally activated RAS, leading to sodium and water retention, and high blood pressure (Adamczak and Wiecek, 2011; Chaudhary et al., 2011; Reinhold et al., 2009; Tracy, 2011; Yerram et al., 2012). The Goldblatt 2 kidney 1 clip rat model is a standard model for hypertension, alongside the genetic models (Tracy, 2011), and is
Table 5 Effects of Cydonia Oblonga Mill. extracts on renal angiotensin II (AII), and apelin-12 contents in renal hypertensive rats. Group
N
Dose (mg/kg)
AII (pg/mg)
Apelin-12 (pg/mg)
Sham Model Captopril COM low COM medium COM high
10 10 10 10 10 10
— — 25 80 160 320
11.2 7 2.6 20.8 7 3.3n 14.9 7 3.1n# 18.17 2.4n 16.5 7 2.7n# 14.3 7 2.9n#
4.23 7 0.64 7.61 7 0.23n 5.05 7 0.47n# 6.85 7 0.33n# 6.29 7 0.71n# 5.58 7 0.59n#
n
#
P o0.05 vs sham. Po 0.05 vs model.
commonly used to screen antihypertensive drugs. Its pathophysiological process has many similarities with human renal hypertension, including the abnormal activation of the renin– angiotensin system. RAS can adjust water-sodium balance and
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
vasoconstriction, which play a crucial role on the development of renal hypertension. Undoubtedly, the key factor in RAS is angiotensin II (AII). The angiotensin converting enzyme (ACE) hydrolyzes angiotensin I to active angiotensin II and also degrades apelin. Apelin is a small peptide, which can express in the blood vessels, heart and brain and can regulate vascular and myocardial contractility. Apelin usually follows AII concentrations, modulating the pressor effect of AII (Berry et al., 2004; Kasai et al., 2004; Najafipour et al., 2012; O’Shea et al., 2003; Soltani Hekmat et al., 2011Zeng et al., 2007). Endothelin (ET) and AII are mutually promotive (Li and Schiffrin, 1995; Reinhold et al., 2009; Tran et al., 2009; Willette et al., 1998; Wang et al., 2007; Yoshida et al., 1991). ET is able to greatly contract the coronary and renal arteries, and elevate systemic blood pressure, which makes it the strongest vasopressive substance known so far; NO is one of the major endothelial-derived vasorelaxant substances. These are manifest in our hypertensive rats, where simultaneously the PRA increases with AII and ET, as NO decreases, all changes that are opposed but not fully reversed by the angiotensin converting enzyme inhibitor captopril. The ethanol extracts of Cydonia oblonga Mill. leaves had dose-dependent effects on blood pressure and on the biomarkers that mimic those of captopril on all the markers studied. Like captopril they reduce AII and ET, despite the very strong PRA drive inherent in the model, and increase NO. Other antihypertensive drugs such as labetalol do not change the PRA in this model, and propranolol very inconsistently (Gulati and Liard, 1979; Gulati and Gulati, 1980), compared to ACE inhibitors of course, or angiotensin inhibitors. (Guillaume et al., 2009) The dose-dependent effects of COM extracts on the renin– angiotensin system markers in these RHR, similar to those of captopril, lead us to believe that these extracts possess ACEinhibitor-like properties that merit further exploration. Especially it would be useful to attempt to determine which of the many constituents found in COM are involved in these effects. Our results also bring further arguments for a possible involvement of the traditional use of Cydonia oblonga Mill. for cardiovascular diseases in the longevity observed in South-west Xinjiang.
Acknowledgment This research work was supported by National Natural Science Foundation of China (No. 81060268). References Abliz, A., Aji, Q., Abdusalam, E., Sun, X., Abdurahman, A., Zhou, W., Moore, N., Umar, A., 2014. Effect of Cydonia oblonga Mill. leaf extract on serum lipids and liver function in a rat model of hyperlipidaemia. Journal of Ethnopharmacology 151, 970–974. Adamczak, M., Wiecek, A., 2011. The management of atherosclerotic renovascular disease. Kidney and Blood Pressure Research 34, 277–283. Aibaidula, G., Maimaiti, G., Simayi, A., Abbas, A., 2009. Antibacterial effect of flavone extract from Xinjiang Cydonia oblonga Mill. Food Science 30, 134–136. Aslan, M., Orhan, N., Orhan, D.D., Ergun, F., 2010. Hypoglycemic activity and antioxidant potential of some medicinal plants traditionally used in Turkey for diabetes. Journal of Ethnopharmacology 128, 384–389. Barger, A.C., 1979. The Goldblatt memorial lecture. Part I: Experimental renovascular hyptertension. Hypertension 1, 447–455. Berry, M.F., Pirolli, T.J., Jayasankar, V., Burdick, J., Morine, K.J., Gardner, T.J., Woo, Y.J., 2004. Apelin has in vivo inotropic effects on normal and failing hearts. Circulation 110, II187–193. Chaudhary, K., Botdorf, J., Whaley-Connell, A., 2011. Atherosclerotic renovascular hypertension: current trends in diagnosis and management. Missouri Medicine 108, 37–41. Chelko, S.P., Schmiedt, C.W., Lewis, T.H., Lewis, S.J., Robertson, T.P., 2012. A novel vascular clip design for the reliable induction of 2-kidney, 1-clip hypertension in the rat. Journal of Applied Physiology 112, 362–366. Goldblatt, H., 1958. Experimental renal hypertension; mechanism of production and maintenance. Circulation 17, 642–647. Goldblatt, H., 1964. Hypertension of renal origin. Historical and experimental background. American Journal of Surgery 107, 21–25.
639
Guillaume, P., Provost, D., Legrand, P., Godes, M., Lacroix, P., 2009. Models of cardiovascular disease: measurement of antihypertensive activity in the conscious rat (SHR, DOCA-salt, and Goldblatt hypertension models). Current Protocals in Pharmacology, 53 (Chapter 5, Unit 5). Gulati, O.P., Gulati, N., 1980. Effects of labetalol in chronic two-kidney Goldblatt hypertension (2-KGH) in rats. Archives Internationales de Pharmacodynamie et de Therapie 243, 255–260. Gulati, O.P., Liard, J.F., 1979. Effects of propranolol in chronic two-kidney Goldblatt hypertension in rats. Archives Internationales de Pharmacodynamie et de Therapie 240, 285–293. Kasai, A., Shintani, N., Oda, M., Kakuda, M., Hashimoto, H., Matsuda, T., Hinuma, S., Baba, A., 2004. Apelin is a novel angiogenic factor in retinal endothelial cells. Biochemical and Biophysical Research Communications 325, 395–400. Kawamura, H., Jumabay, M., Mitsubayashi, H., Izumi, Y., Soma, M., Ozawa, Y., Rehemudula, D., Mahmut, M., Mu, Y., Aisa, M., Cheng, Z.H., Wang, S.Z., 2000. 24hour blood pressure in Uygur, Kazakh and Han elderly subjects in China. Hypertension Research: Official Journal of the Japanese Society of Hypertension 23, 177–185. Kawamura, H., Ozawa, Y., Jumabay, M., Mitsubayashi, H., Izumi, Y., Mahmut, M., Ming, M.Y., Aisa, M., Cheng, Z.H., Wang, S.Z., 2003. Time-series analysis of systolic blood pressure variation in thirty-three Uygur centenarians in China. Hypertension Research: Official Journal of the Japanese Society of Hypertension 26, 597–601. Kultur, S., 2007. Medicinal plants used in Kirklareli Province (Turkey). Journal of Ethnopharmacology 111, 341–364. Li, J.S., Schiffrin, E.L., 1995. Effect of chronic treatment of adult spontaneously hypertensive rats with an endothelin receptor antagonist. Hypertension 25, 495–500. Najafipour, H., Soltani Hekmat, A., Nekooian, A.A., Esmaeili-Mahani, S., 2012. Apelin receptor expression in ischemic and non- ischemic kidneys and cardiovascular responses to apelin in chronic two-kidney-one-clip hypertension in rats. Regulatory Peptides 178, 43–50. O’Shea, M., Hansen, M.J., Tatemoto, K., Morris, M.J., 2003. Inhibitory effect of apelin12 on nocturnal food intake in the rat. Nutritional Neuroscience 6, 163–167. Pinto, Y.M., Paul, M., Ganten, D., 1998. Lessons from rat models of hypertension: from Goldblatt to genetic engineering. Cardiovascular Research 39, 77–88. Reinhold, S.W., Uihlein, D.C., Boger, C.A., Kloiber, S., Frolich, K., Bergler, T., Banas, B., Schweda, F., Kramer, B.K., 2009. Renin, endothelial NO synthase and endothelin gene expression in the 2kidney-1clip Goldblatt model of long-term renovascular hypertension. European Journal of Medical Research 14, 520–525. Sadik, R., 1993. Uyghur Studies Commonly used Herbs. Xinjiang Science and Technology Publishing House, Urumqi Silva, B.M., Andrade, P.B., Martins, R.C., Valentao, P., Ferreres, F., Seabra, R.M., Ferreira, M.A., 2005. Quince (Cydonia oblonga Miller) fruit characterization using principal component analysis. Journal of Agricultural and Food Chemistry 53, 111–122. Silva, B.M., Andrade, P.B., Mendes, G.C., Seabra, R.M., Ferreira, M.A., 2002. Study of the organic acids composition of quince (Cydonia oblonga Miller) fruit and jam. Journal of Agricultural and Food Chemistry 50, 2313–2317. Silva, B.M., Andrade, P.B., Valentao, P., Ferreres, F., Seabra, R.M., Ferreira, M.A., 2004a. Quince (Cydonia oblonga Miller) fruit (pulp, peel, and seed) and Jam: antioxidant activity. Journal of Agricultural and Food Chemistry 52, 4705–4712. Silva, B.M., Casal, S., Andrade, P.B., Seabra, R.M., Oliveira, M.B., Ferreira, M.A., 2004b. Free amino acid composition of quince (Cydonia oblonga Miller) fruit (pulp and peel) and jam. Journal of Agricultural and Food Chemistry 52, 1201–1206. Soltani Hekmat, A., Najafipour, H., Nekooian, A.A., Esmaeli-Mahani, S., Javanmardi, K., 2011. Cardiovascular responses to apelin in two-kidney-one-clip hypertensive rats and its receptor expression in ischemic and non-ischemic kidneys. Regulatory Peptides 172, 62–68. Tracy, R.E., 2011. Renal vasculature in essential hypertension: a review of some contrarian evidence. Contributions to Nephrology 169, 327–336. Tran, L.T., MacLeod, K.M., McNeill, J.H., 2009. Endothelin-1 modulates angiotensin II in the development of hypertension in fructose-fed rats. Molecular and Cellular Biochemistry 325, 89–97. Umar, A., Imam, G., Yimin, W., Kerim, P., Tohti, I., Berke, B., Moore, N., 2010. Antihypertensive effects of Ocimum basilicum L. (OBL) on blood pressure in renovascular hypertensive rats. Hypertension Research : Official Journal of the Japanese Society of Hypertension 33, 727–730. Wang, M.H., Fok, A., Huang, M.H., Wong, N.L., 2007. Interaction between endothelin and angiotensin II in the up-regulation of vasopressin messenger RNA in the inner medullary collecting duct of the rat. Metabolism: Clinical and Experimental 56, 1372–1376. Willette, R.N., Minehart, H., Ellison, J., Simons, T., Short, B., Pullen, M., Ohlstein, E.H., Nambi, P., 1998. Effects of endothelin receptor antagonism and angiotensinconverting enzyme inhibition on cardiac and renal remodeling in the rat. Journal of Cardiovascular Pharmacology 31 (1), S277–283. Wojdylo, A., Oszmianski, J., Bielicki, P., 2013. Polyphenolic composition, antioxidant activity, and polyphenol oxidase (PPO) activity of quince (Cydonia oblonga Miller) varieties. Journal of Agricultural and Food Chemistry Wufuer, M., Fang, M.W., Cheng, Z.H., Qiu, C.C., 2004. Polymorphism of angiotensin converting enzyme gene and natural longevity in the Xinjiang Uygur people: an association study. Zhonghua yi xue za zhi 84, 1603–1606. Xakir, X., Aikebaier, M., 2006. Biological activities of tannins in Quince (Cydonia oblonga Miller) in Xinjiang. Letters in Biotechnology 17, 840. Xian, H.M., Huang, K.Z., 2007. Development of hypertension animal model research. Internal Medicine 2, 121–123.
640
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
Yan, W., Rozi, H., Mahmut, P., 2009. Antimicrobial activity of crude alkaloid extract from Cydonia Oblonga Mill fruit. Food Science 30, 147–149. Yerram, P., Karuparthi, P.R., Chaudhary, K., 2012. Pathogenesis and management of renovascular hypertension and ischemic nephropathy. Minerva Urologica e nefrologica ¼ The Italian Journal of Urology and Nephrology 64, 63–72. Yoshida, K., Yasujima, M., Kohzuki, M., Tsunoda, K., Kudo, K., Kanazawa, M., Yabe, T., Abe, K., Yoshinaga, K., 1991. Chronic synergistic effect of endothelin-1 and angiotensin II on blood pressure in conscious rats. Journal of Cardiovascular Pharmacology 17 (7), S514–516.
Zeng, X.X., Wilm, T.P., Sepich, D.S., Solnica-Krezel, L., 2007. Apelin and its receptor control heart field formation during zebrafish gastrulation. Developmental Cell 12, 391–402. Zhou, W., Abdusalam, E., Abliz, P., Reyim, N., Tian, S., Aji, Q., Issak, M., Iskandar, G., Moore, N., Umar, A., 2014. Effect of Cydonia oblonga Mill. fruit and leaf extracts on blood pressure and blood rheology in renal hypertensive rats. Journal of Ethnopharmacology.
Contents lists available at ScienceDirect
Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jep
Research paper
Effect of Cydonia oblonga Mill. leaf extracts or captopril on blood pressure and related biomarkers in renal hypertensive rats Wen-ting Zhou a,1, Adil Abdurahman a,1, Elzira Abdusalam a, Wuliya Yiming a, Parida Abliz b, Qimangul Aji a, Mehray Issak a, Guldiyar Iskandar a, Nicholas Moore a,c,n, Anwar Umar a,c,nn a
Department of Pharmacology, Xinjiang Medical University, Urumqi 830011, PR China Department of Pharmacognosy, Xinjiang Medical University, 830011 Urumqi, PR China c Department of Pharmacology, Universite de Bordeaux Segalen, F-33076 Bordeaux, France b
art ic l e i nf o
a b s t r a c t
Article history: Received 24 December 2013 Received in revised form 2 March 2014 Accepted 6 March 2014 Available online 21 March 2014
Ethnopharmacological relevance: Cydonia oblonga Mill. (COM) is used in traditional Uyghur medicine to treat or prevent cardiovascular disease. In a previous study COM leaf extracts were found to be active in renal hypertensive rats (RHR). The present study tests the dose-dependence of the effect of ethanol leaf extracts on hypertension and on biomarkers associated with blood pressure control, such as angiotensinII (AII), plasma renin activity (PRA), apelin-12 (A), endothelin (ET) and nitric oxide (NO), compared to captopril. Methods: Two-kidney one-clip (2K1C) Goldblatt model rats were divided randomly into six groups: sham, model, captopril 25 mg/kg, COM leaf extract 80, 160 and 320 mg/kg (n ¼ 10 each). Drugs were administered orally daily for eight weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured before treatment and every 2 weeks. Blood and kidney samples were collected after the last treatment to measure AII, PRA, A, ET and NO. Results: RHR had increased blood pressure, AII, A, PRA, ET and decreased NO. Treatment with captopril reduced blood pressure, AII, A, PRA, and ET, though not quite to normal values. COM leaf extracts significantly and dose-dependently reduced blood pressure, AII, A, RA and ET, whereas NO was increased. The highest dose of COM had the same effects as captopril. Conclusion: The effects of COM extracts on blood pressure and biomarkers were dose-dependent and at the highest dose similar to those of captopril. This suggests an action of COM on the renin–angiotensin system, which could explain its antihypertensive effect. & 2014 Elsevier Ireland Ltd. All rights reserved.
Keywords: Cydonia oblonga Mill. Renal hypertensive rats Angiotensin-II Endothelin
1. Introduction The south-western part of Xinjiang around Hotan and Kashgar is renowned for its large number of centenarians, and it has been found that Uyghur men from the region of Hotan have lower blood pressure that other central Asians (Kawamura et al., 2000, 2003; Wufuer et al., 2004). In traditional Uyghur medicine, the fruit and leaves of Quince (Cydonia oblonga Mill.) are used to treat or prevent hypertension and other cardiovascular diseases (Sadik, 1993), among other (Aibaidula et
Abbreviations: ACE, angiotensin converting enzyme; ET, endothelin; RHR, renal hypertensive rats (2K1C); 2K1C, Goldblatt 2 kidney 1 clip RHR; A-12, Apelin-12; COM, Cydonia Oblonga Mill. extracts; NO, nitric oxide n Corresponding author at: Department of Pharmacology, University of Bordeaux Segalen, 33076 Bordeaux, France. Tel.: þ 335 575 715 60; fax: þ 335 575 746 71. nn Corresponding author at: Departement of Pharmacology, Xinjiang Medical University, 830011 Urumqi, Xinjiang, PR China. Tel./fax: þ 869 914 362 421. E-mail addresses: [email protected] (N. Moore), [email protected] (A. Umar). 1 Both are equal contributors to this work. http://dx.doi.org/10.1016/j.jep.2014.03.014 0378-8741/& 2014 Elsevier Ireland Ltd. All rights reserved.
al., 2009; Aslan et al., 2010; Yan et al., 2009), as they are in traditional Turkish medicine which has the same cultural roots (Kultur, 2007). Quince fruit and leaves contain many ingredients, with known antioxidant activity (Silva et al., 2002, 2004a, 2004b, 2005; Wojdylo et al., 2013; Xakir and Aikebaier, 2006). In a systematic exploration of its cardiovascular and metabolic effects, we have shown that Cydonia oblonga Mill. (COM) extracts could oppose hyperlipidaemia in hyperlipidaemic rats (Abliz et al., 2014), and that extracts of leaves and fruit of COM had an antihypertensive effect of a magnitude not very different from that of captopril, a reference antihypertensive drug acting on the renin–angiotensin system (RAS) (Zhou et al., 2014). The ethanol extracts of COM leaves appeared to be the more effective. Because of the similarity of effects with captopril, we sought to explore the effects of these COM leaf extracts on markers of the RAS and other vasoactive systems. We therefore tested the dose-dependence of the effects of these extracts in the same standard experimental model of renal hypertension, the 2 kidney-1 clip Goldblatt rat model (2K1C)
636
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
(Barger, 1979; Goldblatt, 1958, 1964; Pinto et al., 1998; Reinhold et al., 2009; Umar et al., 2010; Xian and Huang, 2007), compared to the effects of captopril on blood pressure and on the usual biomarkers associated with blood pressure and the renin–angiotensin system: angiotensin II, renin activity, apelin-12, endothelin and nitric oxide.
2. Materials and methods 2.1. Test products Cydonia Oblonga Mill. (COM) leaf extract, as provided by the department of pharmacology, Xinjiang Medical University. In brief, Cydonia Oblonga Mill. (COM) leaves were collected in October 2010 from the Kashgar area in Kargilik County, Xinjiang, dried and crushed. Voucher specimens were left in the herbarium of the Traditional Chinese Medicine Ethnical Herbs Specimen Museum of Xinjiang Medical University under number NO.TCMEHSM2013_100; the appropriate amount of the leaf powder was weighed, and immerged into 20 times its volume of 65% alcohol for one hour followed by 3 reflux extractions. Filtrates were combined, concentrated under reduced pressure and recovered. The resulting extract was directly freeze-dried over 24 h, to provide COM leaf alcohol extracts. Captopril (25 mg, lot number 100803) was purchased from Shanxi Huixing Pharmaceutical Co., Ltd. 2.2. Reagents and instruments Medical alcohol (75%, Weiye Experimental Material Company, lot number: 11030801); penicillin sodium for injection (800,000 units/ piece, Zhongguo Pharmaceutical co. ltd, lot number: 101003017); pentobarbital sodium (Solar Bio, lot number: 6900183); Rat Angiotensin II, renin activity, apelin-12, endothlin-1, Nitrous oxide (NO) kits (R&D, lot number: CK-E30668); BP-6 non-invasive blood pressure measuring device for animals (Chengdu Taimeng Technology Co. Ltd), U-shaped silver clip (inside diameter: 0.20 mm); LXJ-IIB-type lowspeed large-capacity multi-tube centrifuge (Shanghai Anting Scientific Instrument Factory); TDL-5M desktop large-capacity refrigerated centrifuge (Changsha Xiangyi centrifuge instrument Co. Ltd); FSH-2A adjustable high-speed homogenizer; radiation immunity γ-arithmometer, Coda KM-00025-00 automatic enzyme immunoassay instrument (Bio-Rad). 2.3. Animals Sixty male Wistar rats weighing 200 720 g were provided by the Experimental Animal Center of Xinjiang Medical University, license number: SCXK (Xin): 2003-000, fed on a daily basis with free access to regular pellet fodder and clean tap water. The animals were kept under constant temperature (20 71.1 1C) and illumination (12–12 h light/dark cycle) until the day of experiment. 2.4. Methods 2.4.1. Establishment of 2K1C renal hypertensive rat model (Chelko et al., 2012; Soltani Hekmat et al., 2011; Umar et al., 2010) To induce hypertension according to the Goldblatt 2K1C model, (Barger, 1979; Goldblatt, 1958, 1964; Pinto et al., 1998; Reinhold et al., 2009; Umar et al., 2010; Xian and Huang, 2007) 200 720 g male wistar rats were anesthetized with sodium pentobarbital (50 mg kg 1 intraperitoneally). The left renal artery was exposed by retroperitoneal flank incision and dissected free of the renal vein and connective tissue. A silver clip with a lumen of 0.22 mm
was placed around the artery for partial occlusion; in shamoperated control rats, the artery was not clipped. The right kidney was left untouched. After 6 weeks the systolic blood pressure (SBP) was measured using the tail-cuff method in conscious rats. Only hypertensive rats (SBP above 150 mm Hg) were used in the experiments.
2.4.2. Grouping and administration Fifty renal hypertensive and ten non hypertensive (sham) rats were randomly divided into 5 groups: A sham control group, a renal hypertensive model control group, and renal hypertensive rats treated with captopril 25 mg/kg, COM 80 mg/kg (low-dose), 160 mg/kg (medium-dose) or 320 mg/kg (high-dose), diluted in 0.9‰ (physiological) saline. Rats were treated daily by gastric gavage of the appropriate study drug or of the same volume of physiological saline. The rats were weighed weekly, and drug doses adjusted accordingly.
2.4.3. Measurement of blood pressure Before and 2, 4, 6 and 8 weeks after administration, the 6 groups of rats were placed in a quiet, dry and well-ventilated environment to measure their systolic blood pressure (SBP) and diastolic blood pressure (DBP) with BP-6 non-invasive blood pressure measuring device for rats. Blood pressures were recorded 1 h after drug or saline administration. All measures were repeated 3 times and averaged.
2.4.4. Sample collection and determination of biomarkers (1) Blood serum and plasma samples Blood pressure was measured 1 h after last administration. Rats were then anesthetized with 30 mg/kg of 1% pentobarbital sodium, and blood was collected in the abdominal aorta. Sample for serum was collected without added anticoagulant. After centrifugation for 10 min at 3000 rpm at 4 1C, the serum was preserved at 80 1C. Apelin-12 and NO in serum were determined according to the manufacturer's instructions on the kit. Sample for blood plasma was promptly poured into anticoagulated tubes with pre-added enzyme inhibitor (10%, 30 μl disodium EDTA and 40 μl aprotinin), shaken and centrifuged 10 minutes at 3000 rpm/4 1C. Plasma was then preserved at 80 1C. Plasma concentrations of angiotensin-II (AII), endothelin-1 (ET) and renin activity (RA) were determined according to the manufacturer's instruction on the kit. (2) Renal tissue sample A 0.5 g sample of each rat's right kidney was taken, wrapped in aluminum foil and preserved at 80 1C. For analysis, 4.5 ml physiological saline solution were added to produce a 10% tissue homogenate, which was then centrifuged for 15 min at 3000 rpm. The supernatant fluid was used to measure the content of AII and apelin-12 in the kidney tissue. 2.5. Data processing Data were processed with SPSS 17.0 statistics software and results are given as mean 7standard deviation. Multiple means were compared with One-Way ANOVA. After homogeneity of variance test, heterogeneous differences were tested with Dunnett's t method and the homogeneous one with the LSD-t method. Test standard was α ¼0.05. Main comparisons were of COM low and high doses and captopril vs model animals.
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
637
extracts resulted in a dose-dependent decrease in blood pressure, that started later than with captopril, but was similar to that of captopril after 8 weeks for the highest dose (Table 2, Fig. 1). Similar results were found for diastolic blood pressure (Table 3).
3. Results 3.1. Weight During the experiment, the rats' weight increased regularly. Model rats however put on less weight than the sham controls. Captopril treated rats put on more weight than model controls. The higher dose of COM was also associated with significantly higher weights, without quite reaching the weights of sham controls. (Table 1) 3.2. Systolic and diastolic blood pressures Blood pressure remained stable throughout the study period in the sham rats, and increased regularly in the model group. Treatment with captopril resulted in a reduction in blood pressure that was apparent from the second week of treatment, though it never reached the sham control values. Treatment with COM leaf
3.3. Angiotensin-II, apelin-12, plasma renin activity, endothelin, nitroxide In renal hypertensive rats, angiotensin II, apelin-12, PRA and ET were significantly increased compared to sham rats. NO on the opposite was reduced by 14%. Captopril opposed these changes for all parameters, again without return to basal values, except for NO, which was higher than in the sham control rats. COM dose-dependently reduced these increased parameters, and also increased NO to higher values that sham, in a dose-dependent manner, with the highest dose resulting in numbers that were very close to those of captopril (Table 4, Fig. 2).
Table 1 Changes in rat weights over time in sham, model, captopril- and Cydonia oblonga-treated renal hypertensive rats. (N ¼ 10 per group). Group
N
2 Weeks
4 Weeks
6 Weeks
8 Weeks
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
252.8 7 26.1 224.57 23.8 253.17 25.0 236.3 7 28.8 224.87 33.6 243.37 29.7#
272.2 7 20.0 224.67 23.8 264.07 38.6 232.8 7 38.6 226.6 7 37.5 241.3 7 33.7#
274.4 7 20.4 231.3 7 23.4 273.6 7 24.1 244.57 32.7 243.37 43.5 255.0 7 28.4#
282.3 7 20.5 252.2 7 31.7 278.7 7 26.1 247.8 7 39.5 246.7 7 37.4 263.0 7 28.3#
#
Po 0.05 vs model.
Table 2 Systolic blood pressure in sham, model, captopril- and Cydonia oblonga-treated renal hypertensive rats. (N ¼ 10 per group). Group
Dose (mg/kg)
Before treatment
2 Weeks
4 Weeks
6 Weeks
8 Weeks
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
127.17 6.5 182.5 7 7.4n 180.4 7 8.7n 184.4 7 6.7n 182.4 7 7.3n 181.9 7 8.5n
126.7 7 3.5 182.9 7 6.6n 166.27 7.8n# 177.8 7 5.7n 174.0 7 7.9n# 172.9 7 8.6n#
128.17 8.2 189.5 7 5.4n 160.4 7 9.1n# 174.4 7 5.7n# 172.4 7 6.6n# 169.9 7 7.5n#
127.1 78.5 190.5 76.4n 159.4 79.7n# 170.4 710.7n# 168.4 76.3n# 164.9 79.5n#
126.7 7 4.5 191.9 7 5.6n 157.2 7 5.8n# 166.8 7 7.4n# 162.0 7 5.1n# 159.9 7 10.6n#
n
#
Po 0.05 vs sham. Po 0.05 vs model.
Fig. 1. Evolution of Systolic Blood Pressure in sham, model renal hypertensive rats (RHR), and in RHR treated with captopril 25 mg/kg or increasing doses of Cydonia oblonga Mill. leaf extracts (COM) (See Table 2 for SD and statistical analysis).
638
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
Table 3 Diastolic blood pressure in sham, model, captopril- and Cydonia oblonga Mill. (COM) - treated renal hypertensive rats. (N ¼ 10 per group). Group
Dose (mg/kg)
Before treatment
2 Weeks
4 Weeks
6 Weeks
8 Weeks
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
90.1 76.5 137.5 77.4n 136.4 78.7n 134.4 76.7n 135.477.3n 136.9 78.5n
89.7 7 3.5 138.9 7 6.6n 126.2 7 7.8n# 137.8 7 5.7n 135.07 7.9n 132.9 7 8.6n#
89.17 8.2 139.5 7 5.4n 125.4 7 9.1n# 135.47 5.7n 132.4 7 6.6n# 130.9 7 7.5n#
91.17 8.5 139.8 7 6.4n 122.4 7 9.7n# 132.4 7 10.7n# 129.4 7 6.3n# 127.9 7 9.5n#
90.7 74.5 140.3 75.6n 120.2 75.8n# 128.8 77.4n# 124.0 75.1n# 121.9 710.6n#
n
#
Po 0.05 vs sham. Po 0.05 vs model.
Table 4 Plasma angiotensin-II (AII), serum apelin-12, plasma renin activity (PRA), endothelin (ET-1) and nitroxide (NO) in sham, model, captopril- and Cydonia oblonga-treated renal hypertensive rats. (N ¼ 10 per group). Group
Dose (mg/kg)
AII (pg/ml)
Apelin-12 (pg/ml)
PRA (ng/ml)
ET-1 (pg/m)
NO (μmol/ml)
Sham Model Captopril COM low COM medium COM high
— — 25 80 160 320
317.2 713.6 380.8 715.3n 348.9 714.1n# 363.1 716.2n# 356.1 717.0n# 349.3 711.9n#
172.8 7 10.6 224.67 11.2n 193.0 7 10.4n# 210.8 7 9.3n# 205.7 7 7.1n# 190.5 7 13.5n#
1.0770.18 3.02 70.21n 1.63 70.11n# 1.84 70.34n# 1.81 70.20n# 1.76 70.17n#
92.17 12.7 152.2 7 8.5n 115.4 7 16.3n# 143.9 7 18.0n 137.7 7 16.2n# 121.3 7 22.7n#
57.3 74.72 50.3 73.92n 66.7 75.38n# 65.1 77.26n# 68.5 78.27n# 68.4 74.89n#
n
#
Po 0.05 vs sham. Po 0.05 vs model.
Fig. 2. Posttreatment values for biomarkers in renal hypertensive rats. (see Table 4 for statistical analyses).
3.4. Renal angiotensin-II and apelin-12 Goldblatt 2K1C renal hypertensive rats had greatly elevated renal angiotensin II and apelin-12, which were reduced almost to normal by captopril, and to the same extent by the highest dose of COM, the other doses having a dose-related effect (Table 5).
4. Discussion Renal hypertension is a common cause of secondary hypertension in man, usually following renal artery stenosis or hyperplasia. The reduction of renal blood flow results in abnormally activated RAS, leading to sodium and water retention, and high blood pressure (Adamczak and Wiecek, 2011; Chaudhary et al., 2011; Reinhold et al., 2009; Tracy, 2011; Yerram et al., 2012). The Goldblatt 2 kidney 1 clip rat model is a standard model for hypertension, alongside the genetic models (Tracy, 2011), and is
Table 5 Effects of Cydonia Oblonga Mill. extracts on renal angiotensin II (AII), and apelin-12 contents in renal hypertensive rats. Group
N
Dose (mg/kg)
AII (pg/mg)
Apelin-12 (pg/mg)
Sham Model Captopril COM low COM medium COM high
10 10 10 10 10 10
— — 25 80 160 320
11.2 7 2.6 20.8 7 3.3n 14.9 7 3.1n# 18.17 2.4n 16.5 7 2.7n# 14.3 7 2.9n#
4.23 7 0.64 7.61 7 0.23n 5.05 7 0.47n# 6.85 7 0.33n# 6.29 7 0.71n# 5.58 7 0.59n#
n
#
P o0.05 vs sham. Po 0.05 vs model.
commonly used to screen antihypertensive drugs. Its pathophysiological process has many similarities with human renal hypertension, including the abnormal activation of the renin– angiotensin system. RAS can adjust water-sodium balance and
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
vasoconstriction, which play a crucial role on the development of renal hypertension. Undoubtedly, the key factor in RAS is angiotensin II (AII). The angiotensin converting enzyme (ACE) hydrolyzes angiotensin I to active angiotensin II and also degrades apelin. Apelin is a small peptide, which can express in the blood vessels, heart and brain and can regulate vascular and myocardial contractility. Apelin usually follows AII concentrations, modulating the pressor effect of AII (Berry et al., 2004; Kasai et al., 2004; Najafipour et al., 2012; O’Shea et al., 2003; Soltani Hekmat et al., 2011Zeng et al., 2007). Endothelin (ET) and AII are mutually promotive (Li and Schiffrin, 1995; Reinhold et al., 2009; Tran et al., 2009; Willette et al., 1998; Wang et al., 2007; Yoshida et al., 1991). ET is able to greatly contract the coronary and renal arteries, and elevate systemic blood pressure, which makes it the strongest vasopressive substance known so far; NO is one of the major endothelial-derived vasorelaxant substances. These are manifest in our hypertensive rats, where simultaneously the PRA increases with AII and ET, as NO decreases, all changes that are opposed but not fully reversed by the angiotensin converting enzyme inhibitor captopril. The ethanol extracts of Cydonia oblonga Mill. leaves had dose-dependent effects on blood pressure and on the biomarkers that mimic those of captopril on all the markers studied. Like captopril they reduce AII and ET, despite the very strong PRA drive inherent in the model, and increase NO. Other antihypertensive drugs such as labetalol do not change the PRA in this model, and propranolol very inconsistently (Gulati and Liard, 1979; Gulati and Gulati, 1980), compared to ACE inhibitors of course, or angiotensin inhibitors. (Guillaume et al., 2009) The dose-dependent effects of COM extracts on the renin– angiotensin system markers in these RHR, similar to those of captopril, lead us to believe that these extracts possess ACEinhibitor-like properties that merit further exploration. Especially it would be useful to attempt to determine which of the many constituents found in COM are involved in these effects. Our results also bring further arguments for a possible involvement of the traditional use of Cydonia oblonga Mill. for cardiovascular diseases in the longevity observed in South-west Xinjiang.
Acknowledgment This research work was supported by National Natural Science Foundation of China (No. 81060268). References Abliz, A., Aji, Q., Abdusalam, E., Sun, X., Abdurahman, A., Zhou, W., Moore, N., Umar, A., 2014. Effect of Cydonia oblonga Mill. leaf extract on serum lipids and liver function in a rat model of hyperlipidaemia. Journal of Ethnopharmacology 151, 970–974. Adamczak, M., Wiecek, A., 2011. The management of atherosclerotic renovascular disease. Kidney and Blood Pressure Research 34, 277–283. Aibaidula, G., Maimaiti, G., Simayi, A., Abbas, A., 2009. Antibacterial effect of flavone extract from Xinjiang Cydonia oblonga Mill. Food Science 30, 134–136. Aslan, M., Orhan, N., Orhan, D.D., Ergun, F., 2010. Hypoglycemic activity and antioxidant potential of some medicinal plants traditionally used in Turkey for diabetes. Journal of Ethnopharmacology 128, 384–389. Barger, A.C., 1979. The Goldblatt memorial lecture. Part I: Experimental renovascular hyptertension. Hypertension 1, 447–455. Berry, M.F., Pirolli, T.J., Jayasankar, V., Burdick, J., Morine, K.J., Gardner, T.J., Woo, Y.J., 2004. Apelin has in vivo inotropic effects on normal and failing hearts. Circulation 110, II187–193. Chaudhary, K., Botdorf, J., Whaley-Connell, A., 2011. Atherosclerotic renovascular hypertension: current trends in diagnosis and management. Missouri Medicine 108, 37–41. Chelko, S.P., Schmiedt, C.W., Lewis, T.H., Lewis, S.J., Robertson, T.P., 2012. A novel vascular clip design for the reliable induction of 2-kidney, 1-clip hypertension in the rat. Journal of Applied Physiology 112, 362–366. Goldblatt, H., 1958. Experimental renal hypertension; mechanism of production and maintenance. Circulation 17, 642–647. Goldblatt, H., 1964. Hypertension of renal origin. Historical and experimental background. American Journal of Surgery 107, 21–25.
639
Guillaume, P., Provost, D., Legrand, P., Godes, M., Lacroix, P., 2009. Models of cardiovascular disease: measurement of antihypertensive activity in the conscious rat (SHR, DOCA-salt, and Goldblatt hypertension models). Current Protocals in Pharmacology, 53 (Chapter 5, Unit 5). Gulati, O.P., Gulati, N., 1980. Effects of labetalol in chronic two-kidney Goldblatt hypertension (2-KGH) in rats. Archives Internationales de Pharmacodynamie et de Therapie 243, 255–260. Gulati, O.P., Liard, J.F., 1979. Effects of propranolol in chronic two-kidney Goldblatt hypertension in rats. Archives Internationales de Pharmacodynamie et de Therapie 240, 285–293. Kasai, A., Shintani, N., Oda, M., Kakuda, M., Hashimoto, H., Matsuda, T., Hinuma, S., Baba, A., 2004. Apelin is a novel angiogenic factor in retinal endothelial cells. Biochemical and Biophysical Research Communications 325, 395–400. Kawamura, H., Jumabay, M., Mitsubayashi, H., Izumi, Y., Soma, M., Ozawa, Y., Rehemudula, D., Mahmut, M., Mu, Y., Aisa, M., Cheng, Z.H., Wang, S.Z., 2000. 24hour blood pressure in Uygur, Kazakh and Han elderly subjects in China. Hypertension Research: Official Journal of the Japanese Society of Hypertension 23, 177–185. Kawamura, H., Ozawa, Y., Jumabay, M., Mitsubayashi, H., Izumi, Y., Mahmut, M., Ming, M.Y., Aisa, M., Cheng, Z.H., Wang, S.Z., 2003. Time-series analysis of systolic blood pressure variation in thirty-three Uygur centenarians in China. Hypertension Research: Official Journal of the Japanese Society of Hypertension 26, 597–601. Kultur, S., 2007. Medicinal plants used in Kirklareli Province (Turkey). Journal of Ethnopharmacology 111, 341–364. Li, J.S., Schiffrin, E.L., 1995. Effect of chronic treatment of adult spontaneously hypertensive rats with an endothelin receptor antagonist. Hypertension 25, 495–500. Najafipour, H., Soltani Hekmat, A., Nekooian, A.A., Esmaeili-Mahani, S., 2012. Apelin receptor expression in ischemic and non- ischemic kidneys and cardiovascular responses to apelin in chronic two-kidney-one-clip hypertension in rats. Regulatory Peptides 178, 43–50. O’Shea, M., Hansen, M.J., Tatemoto, K., Morris, M.J., 2003. Inhibitory effect of apelin12 on nocturnal food intake in the rat. Nutritional Neuroscience 6, 163–167. Pinto, Y.M., Paul, M., Ganten, D., 1998. Lessons from rat models of hypertension: from Goldblatt to genetic engineering. Cardiovascular Research 39, 77–88. Reinhold, S.W., Uihlein, D.C., Boger, C.A., Kloiber, S., Frolich, K., Bergler, T., Banas, B., Schweda, F., Kramer, B.K., 2009. Renin, endothelial NO synthase and endothelin gene expression in the 2kidney-1clip Goldblatt model of long-term renovascular hypertension. European Journal of Medical Research 14, 520–525. Sadik, R., 1993. Uyghur Studies Commonly used Herbs. Xinjiang Science and Technology Publishing House, Urumqi Silva, B.M., Andrade, P.B., Martins, R.C., Valentao, P., Ferreres, F., Seabra, R.M., Ferreira, M.A., 2005. Quince (Cydonia oblonga Miller) fruit characterization using principal component analysis. Journal of Agricultural and Food Chemistry 53, 111–122. Silva, B.M., Andrade, P.B., Mendes, G.C., Seabra, R.M., Ferreira, M.A., 2002. Study of the organic acids composition of quince (Cydonia oblonga Miller) fruit and jam. Journal of Agricultural and Food Chemistry 50, 2313–2317. Silva, B.M., Andrade, P.B., Valentao, P., Ferreres, F., Seabra, R.M., Ferreira, M.A., 2004a. Quince (Cydonia oblonga Miller) fruit (pulp, peel, and seed) and Jam: antioxidant activity. Journal of Agricultural and Food Chemistry 52, 4705–4712. Silva, B.M., Casal, S., Andrade, P.B., Seabra, R.M., Oliveira, M.B., Ferreira, M.A., 2004b. Free amino acid composition of quince (Cydonia oblonga Miller) fruit (pulp and peel) and jam. Journal of Agricultural and Food Chemistry 52, 1201–1206. Soltani Hekmat, A., Najafipour, H., Nekooian, A.A., Esmaeli-Mahani, S., Javanmardi, K., 2011. Cardiovascular responses to apelin in two-kidney-one-clip hypertensive rats and its receptor expression in ischemic and non-ischemic kidneys. Regulatory Peptides 172, 62–68. Tracy, R.E., 2011. Renal vasculature in essential hypertension: a review of some contrarian evidence. Contributions to Nephrology 169, 327–336. Tran, L.T., MacLeod, K.M., McNeill, J.H., 2009. Endothelin-1 modulates angiotensin II in the development of hypertension in fructose-fed rats. Molecular and Cellular Biochemistry 325, 89–97. Umar, A., Imam, G., Yimin, W., Kerim, P., Tohti, I., Berke, B., Moore, N., 2010. Antihypertensive effects of Ocimum basilicum L. (OBL) on blood pressure in renovascular hypertensive rats. Hypertension Research : Official Journal of the Japanese Society of Hypertension 33, 727–730. Wang, M.H., Fok, A., Huang, M.H., Wong, N.L., 2007. Interaction between endothelin and angiotensin II in the up-regulation of vasopressin messenger RNA in the inner medullary collecting duct of the rat. Metabolism: Clinical and Experimental 56, 1372–1376. Willette, R.N., Minehart, H., Ellison, J., Simons, T., Short, B., Pullen, M., Ohlstein, E.H., Nambi, P., 1998. Effects of endothelin receptor antagonism and angiotensinconverting enzyme inhibition on cardiac and renal remodeling in the rat. Journal of Cardiovascular Pharmacology 31 (1), S277–283. Wojdylo, A., Oszmianski, J., Bielicki, P., 2013. Polyphenolic composition, antioxidant activity, and polyphenol oxidase (PPO) activity of quince (Cydonia oblonga Miller) varieties. Journal of Agricultural and Food Chemistry Wufuer, M., Fang, M.W., Cheng, Z.H., Qiu, C.C., 2004. Polymorphism of angiotensin converting enzyme gene and natural longevity in the Xinjiang Uygur people: an association study. Zhonghua yi xue za zhi 84, 1603–1606. Xakir, X., Aikebaier, M., 2006. Biological activities of tannins in Quince (Cydonia oblonga Miller) in Xinjiang. Letters in Biotechnology 17, 840. Xian, H.M., Huang, K.Z., 2007. Development of hypertension animal model research. Internal Medicine 2, 121–123.
640
W.-t. Zhou et al. / Journal of Ethnopharmacology 153 (2014) 635–640
Yan, W., Rozi, H., Mahmut, P., 2009. Antimicrobial activity of crude alkaloid extract from Cydonia Oblonga Mill fruit. Food Science 30, 147–149. Yerram, P., Karuparthi, P.R., Chaudhary, K., 2012. Pathogenesis and management of renovascular hypertension and ischemic nephropathy. Minerva Urologica e nefrologica ¼ The Italian Journal of Urology and Nephrology 64, 63–72. Yoshida, K., Yasujima, M., Kohzuki, M., Tsunoda, K., Kudo, K., Kanazawa, M., Yabe, T., Abe, K., Yoshinaga, K., 1991. Chronic synergistic effect of endothelin-1 and angiotensin II on blood pressure in conscious rats. Journal of Cardiovascular Pharmacology 17 (7), S514–516.
Zeng, X.X., Wilm, T.P., Sepich, D.S., Solnica-Krezel, L., 2007. Apelin and its receptor control heart field formation during zebrafish gastrulation. Developmental Cell 12, 391–402. Zhou, W., Abdusalam, E., Abliz, P., Reyim, N., Tian, S., Aji, Q., Issak, M., Iskandar, G., Moore, N., Umar, A., 2014. Effect of Cydonia oblonga Mill. fruit and leaf extracts on blood pressure and blood rheology in renal hypertensive rats. Journal of Ethnopharmacology.
