Ficus deltoidea is used in Malay traditional medicine for the treatment of a number of disorders, including hypertension. There is, however, no scientific evidence on its anti-hypertensive effects. This study, therefore, investigated the effects of a standardized ethanolic-water extract of Ficus deltoidea Angustifolia (FD-A) on blood pressure (BP) in spontaneously hypertensive rats (SHR). Male SHR with systolic BP of >150 were divided into 4 groups (n = 8) and given either FD-A (800 or 1000 mg kg-1 day-1) or losartan (10 mg kg-1 day-1) or 0.5 ml of distilled water (control) daily for 28 days. BP, body weight, food and water intake, serum and urinary electrolytes, endothelin-1 (ET-1), total antioxidant capacity (TAC) and components of the renin-angiotensin-aldosterone system were measured. Data were analyzed using ANOVA with statistical significance set at p < 0.05. Following treatment, BP, heart rate, and heart weight in FD-A and losartan-treated rats were significantly lower than those in the controls. Serum TAC and urinary calcium excretion were significantly higher, whereas serum ET-1 concentration was significantly lower in FD-A treated rats when compared to those in controls. No significant differences were found in the components of the renin-angiotensin-aldosterone system between controls and FD-A treated rats. In conclusion, FD-A when given daily at doses of either 800 or 1000 mg kg-1 day-1 body weight reduces BP in SHR. This effect does not seem to involve the renin-angiotensin-aldosterone-system but might involve some other mechanisms. Abbreviations: FD-A: Ficus deltoidea Angustifolia; ACE: Angiotensin-converting enzyme; SHR: Spontaneously hypertensive rats; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; AUC: Area under curve; RAAS: Renin Angiotensin Aldosterone System.
Keywords: angiotensin; blood pressure; renin.