Efficacy of Khār-i-khasak (Tribulus terrestris Linn.) in prehypertension: a randomized, double-blind, placebo-controlled trial

Abstract

Abstract Background Prehypertension is a state of above-normal blood pressure that does not meet the criteria for the diagnosis of hypertension and its prevalence estimated in population-based samples ranges from 22 to 52%. It conveys potentially many deleterious consequences such as high risk of progression to hypertension and cardiovascular disease later in life. Objectives The present study was conducted to evaluate the blood pressure-lowering effect of Khār-i-khasak (Tribulus terrestris Linn.) in prehypertensive individuals. Methods This randomized, double-blind, placebo-controlled, clinical trial was conducted at the National Institute of Unani Medicine, Hospital, Bengaluru, after approval by the Institutional Ethics Committee. Prehypertensive individuals over 18 years of age were enrolled after obtaining their written informed consent and were randomly allocated to the test or placebo group. The test and placebo groups were administered powdered dried fruits of Khār-i-khasak (6g) and matched placebo (6g) in three divided doses for two months respectively. The efficacy assessment was determined by changes in systolic and diastolic blood pressures. Results Both systolic and diastolic blood pressure showed a significant decline in the test group (p<0.001) as compared to the placebo group. The average decline in systolic/diastolic blood pressure was −7.7/5.5 mmHg in the test group and −1.9/0.2 mmHg in the placebo group. During the post-therapy follow-up period, no prehypertensive developed full-blown hypertension in either group. Safety parameters were found to be within normal limits. Conclusions The test drug Khār-i-khasak (T. terrestris Linn.) was found to be effective and safe in lowering blood pressure compared to placebo in prehypertensive individuals.