# Vasorelaxant and Blood Pressure-Lowering Effects of Cnidium monnieri Fruit Ethanol Extract in Sprague Dawley and Spontaneously Hypertensive Rats

## TL;DR

This study shows that an extract from Cnidium monnieri fruit can relax blood vessels and lower blood pressure in rats, suggesting potential as a treatment for hypertension.

## Contribution

The study demonstrates the vasorelaxant and blood pressure-lowering effects of Cnidium monnieri extract in rat models of hypertension.

## Key findings

- CME induced concentration-dependent vasorelaxation in aortic rings via an endothelium-independent mechanism.
- Imperatorin and osthole, active compounds in CME, showed significant vasorelaxant effects with low half-maximal effective concentrations.
- Oral administration of CME significantly reduced blood pressure in spontaneously hypertensive rats.

## Abstract

Cnidium monnieri (L.) Cusson, a member of the Apiaceae family, is rich in coumarins, such as imperatorin and osthole. Cnidium monnieri fruit (CM) has a broad range of therapeutic potential that can be used in anti-bacterial, anti-cancer, and sexual dysfunction treatments. However, its efficacy in lowering blood pressure through vasodilation remains unknown. This study aimed to assess the potential therapeutic effect of CM 50% ethanol extract (CME) on hypertension and the mechanism of its vasorelaxant effect. CME (1–30 µg/mL) showed a concentration-dependent vasorelaxation on constricted aortic rings in Sprague Dawley rats induced by phenylephrine via an endothelium-independent mechanism. The vasorelaxant effect of CME was inhibited by blockers of voltage-dependent and Ca2+-activated K+ channels. Additionally, CME inhibited the vascular contraction induced by angiotensin II and CaCl2. The main active compounds of CM, i.e., imperatorin (3–300 µM) and osthole (1–100 µM), showed a concentration-dependent vasorelaxation effect, with half-maximal effective concentration values of 9.14 ± 0.06 and 5.98 ± 0.06 µM, respectively. Orally administered CME significantly reduced the blood pressure of spontaneously hypertensive rats. Our research shows that CME is a promising treatment option for hypertension. However, further studies are required to fully elucidate its therapeutic potential.