Antioxidant Associated Antihypertensive Performance of Purified Gambir (Uncaria gambir Roxb.) on Prednisone Salt-Induced Hypertensive Rats

Abstract

AIM: Purified gambir (Uncaria gambir Roxb.) is potential for treating hypertension based on the antioxidant activity of its catechin compound. In this study, we investigated the antihypertensive performances of purified gambir on hypertensive rats and the correlation with its antioxidant activity. METHODS: Rats (2–3-months-old and the body weight [BW] of 200–250 g) were divided into five groups. Groups 1, 2, and 3 were treated orally with water suspension of purified gambir at doses of 2.5; 5; and 10 mg/kg BW once a day for 14 days, group 4 and 5 were captopril treated groups (positive control) and Carboxymethyl Cellulose Sodium suspension treated (negative control) respectively. The systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, blood flow, and blood volume were recorded once a day before and on 1, 3, 7, and 14 days after commencement. The blood was taken before and at the end of recording the Plasma Nitric Oxide (NO) concentrations. Two-way ANOVA was used to analyze the changes of those parameters, except for plasma NO concentrations analyzed by one-way ANOVA, followed by Duncan multirange test (95% confidence interval). RESULTS: The study showed significant antihypertensive effects (p < 0.05), influenced by doses and gambir administration duration. The plasma NO concentrations of animals were increased after administration of purified gambir (p < 0.05), although there was no significant difference in plasma NO concentrations in gambir doses. CONCLUSION: These indicated that purified gambir proceeded antioxidant-associated antihypertensive effects at doses of 2.5–10 mg/kg BW when administered for 14 days on the salt-prednisone induced hypertensive rats. Based on the cardiovascular parameters, the smallest dose (2.5 mg/kg BW) exhibited the best reduction in blood pressure compared to other groups. Regarding NO plasma concentrations, it showed the medium-dose group, 5 mg/kg BW, caused the highest increase of NO plasma concentration.