Antidiabetic and antioxidant effects of S-methyl cysteine sulfoxide isolated from onions (Allium cepa Linn) as compared to standard drugs in alloxan diabetic rats.

Antidiabetic and antoxidant effects of S-methyl cysteine sulfoxide (SMCS) isolated from A. cepa and two standard drugs, glibenclamide and insulin were studied and compared in alloxan diabetic rats after using each of them for treatment for two months. These drugs ameliorated the diabetic condition significantly, viz. maintenance of body weight and control of blood sugar in rats. Further they lowered the levels of malondialdehyde, hydroperoxide and conjugated dienes in tissues exhibiting antioxidant effect on lipid peroxidation in experimental diabetes. This is achieved by their stimulating effects on glucose utilization and the antioxidant enzymes, viz. superoxide dismutase and catalase. The probable mechanism of action of SMCS and glibenclamide may be partly dependent on the stimulation of insulin secretions and partly due to their individual actions. In the amelioration of diabetes the standard drugs showed a better action, but as an antioxidant SMCS proved to be a better one.