Effect of Resveratrol From Iraqi Black Grape Skin on Blood Glucose Levels in Experimental Animals

Resveratrol is a phytoalexin naturally produced by several plants in response to injury or pathogenic attack, such as bacterial or fungal infections. In this study, approximately 0.5 kg of fresh black grape skin cultivated in Iraq was macerated in 80% ethanol for three days. Hydrolysis was performed using 10% HCl at 60 °C, followed by filtration. The filtrate was then extracted with chloroform. The organic layer was evaporated to dryness, and the residue was subjected to further purification using silica gel G60 in an open column with a mobile phase consisting of benzene:methanol:acetic acid (20:4:1). Final purification was carried out using preparative layer chromatography (PLC). The resulting pure resveratrol (Res) was dried and stored in a cool, dark place for further analysis using UV absorption, TLC, HPLC, and FTIR spectroscopy. Five groups of albino mice (n = 5 per group) were used in the study. Four groups were rendered hyperglycemic by administration of alloxan. The animals were then treated intraperitoneally for two weeks as follows: Group 2 received Res at a dose of 5 mg/day; Group 3 received Res at 0.25 mg/day; Group 4 received glibenclamide at 600 µg/kg/day; Group 1 consisted of normal non-diabetic animals, and Group 5 represented untreated diabetic controls. The effects of resveratrol on liver function were evaluated by measuring blood glucose levels, serum malondialdehyde (MDA), and superoxide dismutase (SOD) as indicators of antioxidant activity. Additionally, in vitro kinetic assays were conducted to determine serum levels of aspartate aminotransferase (AST/SGOT) and alanine aminotransferase (ALT/SGPT).