Comparative study of the effects of melatonin and vitamin E on serum insulin level and lipid profile in normal and diabetic rats

الملخص EN

Diabetes mellitus markedly raises the risk of micro vascular and macro vascular diseases.

There is a clearly documented link between diabetic complications and lipid peroxidation.

The present study aimed at studying the antioxidant effects of both melatonin and vitamin E on serum insulin level and lipid profile in normal and diabetic rats.

This study was carried out on 60 albino rats divided into 2 main groups control and diabetics each of them is further subdivided into 3 subgroups.

(n=10).

The results of this study revealed that both vitamin E and melatonin in normal rats produced significant increase in insulin and tissue glutathione peroxidase levels and significant decrease in malondialdehyde (MDA) level, but both produced insignificant effects on lipid profile.

In diabetic rats melatonin produced significant decrease in cholesterol, triglycerides, LDL cholesterol and free fatty acid (F.F.A) levels in addition; there was significant increase in HDL cholesterol.

Vitamin E had the same melatonin effect, but to a lesser extent. Similarly, the antioxidant effect of melatonin in diabetic rats resulted in more suppression of tissue MDA level compared to effect of vitamin E.

Also, tissue glutathione peroxidase activity was significantly higher in melatonin treated diabetic rats compared to vitamin E treated diabetic rats.

From this study we can conclude that the antioxidant effect of melatonin is more potent than that of vitamin E, so, it can be used in preventing diabetic complications and correcting dyslipidemia.