# Effect of Torilis japonica Fruit Extract for Endothelium-Independent Vasorelaxation and Blood Pressure Lowering in Rats

## TL;DR

This study shows that Torilis japonica fruit extract can relax blood vessels and lower blood pressure in rats, suggesting potential for treating hypertension.

## Contribution

The study identifies the vasorelaxant and blood pressure-lowering effects of Torilis japonica extract in rats, highlighting its potential for hypertension treatment.

## Key findings

- TJE induced endothelium-independent vasodilation in rat aortic rings in a concentration-dependent manner.
- Oral TJE administration significantly reduced blood pressure in spontaneously hypertensive rats.
- TJE's effects were mediated through voltage-dependent and receptor-operated Ca2+ channels.

## Abstract

Torilis japonica (TJ) fruit, is a herb that is traditionally used for erectile dysfunction (ED). Given the shared mechanisms of ED and hypertension through vascular smooth muscle, we hypothesized that TJ would be effective in vasodilation and blood pressure reduction. This study confirmed the authenticity of TJ samples via DNA barcoding and quantified the main active compound, torilin, using HPLC. TJ was extracted with distilled water (TJW) and 50% ethanol (TJE), yielding torilin contents of 0.35 ± 0.01% and 2.84 ± 0.02%, respectively. Ex vivo tests on thoracic aortic rings from Sprague–Dawley rats showed that TJE (3–300 µg/mL) induced endothelium-independent, concentration-dependent vasodilation, unlike TJW. Torilin caused concentration-dependent relaxation with an EC50 of 210 ± 1.07 µM. TJE’s effects were blocked by a voltage-dependent K+ channel blocker and alleviated contractions induced by CaCl2 and angiotensin II. TJE inhibited vascular contraction induced by phenylephrine or KCl via extracellular CaCl2 and enhanced inhibition with nifedipine, indicating involvement of voltage-dependent and receptor-operated Ca2+ channels. Oral administration of TJE (1000 mg/kg) significantly reduced blood pressure in spontaneously hypertensive rats. These findings suggest TJ extract’s potential for hypertension treatment through vasorelaxant mechanisms, though further research is needed to confirm its efficacy and safety.