Antihyperglycemic, Antioxidant and Antiglycation Activities of Mulberry Leaf Extract in Streptozotocin-Induced Chronic Diabetic Rats

摘要

In Thailand, beverages containing mulberry leaf (Morus alba L.) are believed to promote good health, especially in people with diabetes. We examined the effects of long-term administration of an ethanolic extract of mulberry leaf (MA) on blood glucose, oxidative damage, and glycation in streptozotocin-induced diabetic rats. Daily administration of 1 g/kg MA for six weeks decreased blood glucose by 22%, which was comparable to the effect of 4 U/kg insulin. Lipid peroxidation, measured as malondialdehyde and lipid hydroperoxide concentrations (3.50 pl 0.33 and 3.76 pl 0.18 oM, respectively) decreased significantly (P < 0.05) compared to nontreated control diabetic rats (8.19 pl 0.45 and 7.50 pl 0.46 oM, respectively). Hemoglobin AC, a biomarker for chronic exposure to high concentration of glucose, was also significantly decreased in the MA-treated group (6.78 pl 0.30%) in comparison to untreated group (9.02 pl 0.30%). The IC of in vitro antiglycation and free radical scavenging activities of MA were 16.4 pl 5.6 og/ml and 61.7 pl 2.1 og/ml, respectively. These findings support that long-term administration of MA has antihyperglycemic, antioxidant and antiglycation effects in chronic diabetic rats, which may be beneficial as food supplement for diabetics.