Oxidative stress in streptozocin-diabetic rats: Amelioration by mulberry (Morus Indica L.) leaves.

Abstract

OBJECTIVE: To investigate amelioration of oxidative stress by mulberry (Morus indica L.) leaves in streptozocin (STZ)-diabetic rats, as the leaves of mulberry (Morus indica L.) of Moraceae, are reported to be rich in a number of bioactive principles, i.e. antioxidant vitamins, flavonoids and moracins that can fight against oxidative stress in diabetes. METHOD: Normal wistar albino rats and STZ-diabetic rats were treated with dried mulberry leaf powder at 25% in the diet for a period of 8 weeks. The antioxidant role of mulberry was assessed by determining the effect of the leaves on hepatic lipid peroxidation, a marker of oxidative stress and the activity of hepatic antioxidant enzymes and serum antioxidant vitamins in comparison with untreated normal and diabetic rats. RESULTS: Increased oxidative stress as shown by increased lipid peroxidation and increased activity of catalase (CAT) in hepatic tissue, decreased serum ascorbic acid (vitamin C) and tocopherol (vitamin E) in diabetic rats were countered by mulberry leaves. In addition, decreased activities of hepatic antioxidant enzymes, i.e. glucose-6-phosphate dehydrogenase (G6PDH), glutathione peroxidase (GPx), glutathinone-S-tranferase (GST) and superoxide dismutase (SOD) were significantly increased by 34%, 61%, 19% and 53% respectively in mulberry leaves-treated diabetic rats as compared with diabetic control rats. CONCLUSION: Treatment with mulberry leaves protected STZ-diabetic rats from lipid peroxidation and elevated the activities of defense enzymes. This study reveals ameliorating effect of mulberry leaves on oxidative stress in diabetic rats by the synergistic action of a number of bioactive compounds present in mulberry leaves.