# Vascular and Glycemic Modulation by Prosthechea livida, an Orchid Used as Traditional Medicine

## TL;DR

This study explores the potential of an orchid used in traditional Mexican medicine to lower blood sugar and relax blood vessels, with promising safety results.

## Contribution

The study provides first-time scientific evidence of Prosthechea livida's antidiabetic and vasodilatory effects and evaluates its pharmacological safety.

## Key findings

- The extract significantly reduced blood glucose levels in mice at multiple time points.
- The extract induced vasorelaxation in rat aortic rings but had no antihypertensive effect in hypertensive rats.
- Toxicity tests showed minimal liver damage with active regeneration observed histopathologically.

## Abstract

Background: Mexico, one of the world’s most biodiverse countries, holds a rich tradition of using medicinal plants to manage chronic diseases such as type 2 diabetes and hypertension. Despite their historical significance, the scientific validation of these plants’ mechanisms and safety remains limited. Natural products have shown potential in improving insulin sensitivity, reducing insulin resistance, and promoting vasodilation. Prostachea livida (Lindl.) W.E.Higgins, a native orchid, is believed to possess therapeutic properties, yet its pharmacological effects are unexplored. Objective: The current investigation is aimed to bridge traditional knowledge and scientific evidence by investigating the antidiabetic, vasodilatory and antihypertensive activities of a 1:1 dichloromethane and methanol extract from Prosthechea livida bulbs, alongside an evaluation of its pharmacological safety. Methods: Antidiabetic effects of the extract were evaluated in a non-insulin-dependent mouse model using a 100 mg/kg dose. Vasodilatory activity was assessed ex vivo using rat aortic rings, exploring its mechanism through calcium channel blockade. Antihypertensive effects were evaluated in spontaneously hypertensive rats, while acute and subacute toxicity tests were conducted in a murine model. Results: The extract significantly reduced glycemia between 1, 3, 5, and 7 h compared to the positive control (* p = 0.04, *** p < 0.001) and induced vasorelaxation but showed no antihypertensive effects in vivo. Toxicity tests indicated no severe damage, though elevated transaminase activity and increased liver weight were observed. Histopathological analysis revealed minimal hepatocellular lesions with active regeneration. Conclusions: Prosthechea livida demonstrates potential in the discovery of active metabolites to treat diabetes, with significant hypoglycemic and vasorelaxant effects and promising pharmacological safety. Further research is needed to fully understand its therapeutic applications and ensure its safe integration.