Querecetin, a flavonoid antioxidant, strongly protect against hypercholesterolemia in rats

الملخص EN

The aim of the present study was the evaluation of possible protective effects of quercetin (QE), a flavonoid antioxidant, against experimentally-induced atherosclerosis in rats.

Experimental atherosclerosis was produced by feeding rats a diet enriched in coconut oil (15 % by weight) and cholesterol (2% by weight) for 30 days.

QE (15 mg kg−1 day, intraperitoneal (i.p.) injection) was injected for 3 days prior to cholesterol administration; these injections were continued to the end of the study (for 4 weeks).

It has been believed that oxidative stress plays a role in pathogenesis of atherosclerosis.

Lipid profile parameters such as plasma total cholesterol, HDL-C, LDL-C, VLDL-C, LDL : HDL ratio and triglycerides were elevated in hypercholesterolemic rats.

Plasma and liver glutathione-S-transferase enzyme levels were unaffected in all studied groups.

In order to determine the changes of cellular antioxidant defense system, antioxidant enzymes such as glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities, were measured in rat liver homogenate.

Moreover, lipid peroxides expressed as thiobarbituric acid substance (TBARS) level in both serum and liver homogenate, were measured.

Hypercholesterolemia induced significant increase in lipid profile and lipid peroxidation and decreased the antioxidant enzyme activity.

TBARS level in serum and liver were significantly increased (P < 0.05) and also the antioxidant levels significantly decreased (P < 0.05) in hypercholesterolemic group.

QE treatment significantly decreased the elevated TBARS (P < 0.05), lipid profiles (p < 0.05) and also increased the antioxidant enzyme activities (P < 0.05).

QE treatment has shown protective effect possibly through decreasing lipid peroxidation and increasing antioxidant enzyme activity.

These findings point out that QE treatment has protective effect in atherosclerosis by decreasing oxidative stress associated with atherosclerosis.