The Antihypertensive Effects of Hydroalcoholic Extract of Allium Eriophyllum Leaves on Rats with Simultaneous Type 2 Diabetes and Renal Hypertension

Background: Some species of Allium family are known to have antihypertensive, anti-diabetic, and lipid lowering effects.

Objectives: This study aimed to examine the possible mechanisms of antihypertensive, anti-diabetic, and anti-lipid activities of Allium eriophyllum which grows in Fars province, Iran in a rat model of simultaneous type 2 diabetes and renal hypertension.

Materials and Methods: This study was conducted on six groups of male Spargue-Dawley rats each containing 8 - 10 animals, including a sham-control, a diabetic, a renal hypertensive, and three simultaneously hypertensive–diabetic groups receiving vehicle or 30 or 100 mg/kg/day hydroalcoholic extract of Allium eriophyllum. Four weeks after induction of diabetes, renal hypertension was induced and the animals started receiving the vehicle or extract for the subsequent four weeks. Afterwards, blood pressure, fasting blood sugar, serum cholesterol, triglyceride, and markers of oxidative stress were measured, and isolated studies were performed on aortic rings.

Results: Systolic blood pressure, heart rate, fasting blood sugar, maximal response, and effective concentrations 50 (EC₅₀) of phenylephrine and acetylcholine of the hypertensive-diabetic group receiving vehicle were significantly higher compared to those of the sham-control group, and treatment with the extract led to a significant reduction in these variables. Moreover, serum superoxide dismutase and glutathione reductase and maximal response of acetylcholine were significantly lower in the hypertensive-diabetic group receiving vehicle in comparison to the sham-control group, and treatment with the extract significantly reduced these variables.

Conclusions: The present study findings indicated that antihypertensive, anti-diabetic, and anti-lipid effects of the extract might be partly due to its antioxidant mechanism. It was also revealed that its antihypertensive effects may be additionally mediated by improving the release of nitric oxide as well as by sympatholytic activities.