Antioxidant Activity and Glucose Diffusion Relationship of Traditional Medicinal Antihyperglycemic Plant Extracts

Plants with hypoglycemic properties are important in the treatment of diabetes. One of the mechanisms in reducing blood glucose is preventing the digestive absorption of glucose. The aim of this study was to evaluate the antioxidant properties of some traditional medicinal plants collected from different regions of Iran and their effects on glucose diffusion decrease. The amounts of phenolic compounds, total flavonoids, total polysaccharides, antioxidant activity and lipid peroxidation were determined respectively by folin ciocalteu, querceting, sulfuric acid, FRAP and thiobarbituric acid - reactive substanses (TBARS) in eleven confirmed traditional antihyperglycemic medicinal plants prepared at 50g/l concentrations using the boiling method. Phenolic compounds of Eucalyptus globules (100.8± 0.01 mg /g), total flavonoids content of Juglans regia (16.9± 0.01 mg /g) and total polysaccharide amount of Allium satirum (0.28± 0.05) were the highest. Significant relationship was observed between the polyphenols and flavonoids (p < 0.05). The grape seed extract showed the highest antioxidant activity (133± 0.02 mg/g) together with decreased glucose diffusion as well as increased polyphenols (p < 0.05), but the increase in antioxidant activity was not related to glucose diffusion. Antihyperglycemic plant extracts containing higher polyphenols showed more efficiently in vitro glucose diffusion decrease, but no significant relationship was observed between antioxidant activity increase and glucose diffusion.