S-44-2: ANTIHYPERTENSIVE EFFECT OF GALANGIN IN RENAL ARTERY STENOSIS-INDUCED HYPERTENSIVE RATS

Abstract

Background: Galangin is a natural flavonoid found in honey and Alpinia officinarum. Several reports have suggested the anti-mutagenic, antioxidant, anti-proliferative, and apoptotic effects. However, the antihypertensive effect of galangin in renovascular hypertension has not been investigated. Aims: This study aims to investigate the effect of galangin on blood pressure and cardiac changes in renovascular hypertension. Methods: Male Sprague Dawley rats (180–220 g) were induced hypertension by clipping the left renal artery, 2-kidney-1-clip (2K-1C). After 3 weeks of the induction period, galangin (30 and 60 mg/kg) and losartan (10 mg/kg) were given to the rats for 4 weeks (n = 8/group). Blood pressure and cardiac function were evaluated at the end of the experimental day. The level of angiotensin-converting enzyme (ACE) activity, angiotensin II, and oxidative stress markers were assessed in the plasma and cardiac tissue of rats. The protein expression of angiotensin II receptor type 1 (AT1R), transforming growth factor-beta 1 (TGF- β 1) and collagen type I (Col I) were determined in cardiac tissue. Statistical analysis was carried out by one-way ANOVA followed by Tukey post hoc test. A p value less than 0.05 was considered statistically significant. Results: Hypertension and cardiac dysfunction and hypertrophy were observed in 2K-1C rats compared to the sham-operated rats (p < 0.05). Treatment with galangin (30 and 60 mg/kg) decreased high blood pressure and improved cardiac function as well as alleviated left ventricular hypertrophy in 2K-1C hypertensive rats (p < 0.05). This result was related with the reduction of systemic ACE activity and angiotensin II levels in 2K-1C hypertensive rats that were treated with galangin (p < 0.05). Moreover, the expression of AT1R, TGF- β 1 and Col I in cardiac tissue was modulated by treatment with galangin (p < 0.05). Additionally, galangin showed anti-oxidative effects as it reduced the production of superoxide and malondialdehyde levels in cardiac tissue of rats (p < 0.05). Conclusion: Galangin exhibited an antihypertensive effect and alleviated cardiac alteration in renovascular hypertensive rats. The underlying mechanism might be related to its inhibitory effects on renin-angiotensin system and anti-oxidative properties renal artery stenosis-induced hypertensive rats. Furthermore, the beneficial effect of galangin on heart might mediate the suppression of AT1R, TGF- β 1 and Col I pathway.