Preclinical investigation of the cardiovascular actions induced by aqueous extract of Pimpinella anisum L. seeds in rats

Abstract

Ethnopharmacology relevance Pimpinella anisum is used in traditional medicine because of its pharmacological properties which include cardiovascular action. However, no scientific information supports this use. This study investigated the effects of Pimpinella on arterial blood pressure (BP) and its pharmacological mechanism of action. Pimpinella seeds were extracted with water, concentrated and freeze-dried yielding the aqueous extract (AE). A non-invasive BP assessment method was used (via the caudal artery) on Wistar, Wistar Kyoto, SHRs and rats that were submitted to high intake of dietary salt. Direct BP and heart rate were evaluated in Wistar rats in the absence or presence of atropine, L-NAME and angiotensin II. Spontaneous diuresis and the effect of AE on depolarized portal vein of Wistar rats was also examined. The data revealed that AE reduced BP in all groups evaluated and its effects were not due to diuretic, sympatholytic or parasympathomimetic actions. Additionally, it was shown that AE does not act as an angiotensin receptor blocker and does not induce hypotension by reducing vascular resistance induced by oxide nitric. In the depolarized portal vein, AE inhibited calcium influx, which indicates that AE acts as calcium channel blocker. This study validates the cardiovascular actions of Pimpinella and characterizes the hypotensive effects of Pimpinella that are related to the blockade of calcium channels.