Antihyperglycemic and Anti-Oxidant Potential of Ethanol Extract of Vitex Thyrsiflora Leaves on Diabetic Rats

Abstract

The antihyperglycemic effect of an ethanol extract of Vitex thyrsiflora leaves was investigated in normal male rats and streptozotocin-induced diabetic male rats and its antioxidant potential was evaluated. After preparation of the extract, it was subjected to a phytochemistry screening, and tested on male rats made hyperglycemic in the Oral Glucose Tolerance Test (OGTT) and in streptozotocin diabetic rats. Glibenclamide (10 mg/kg) was served as a positive control in both experiments. During both experiments, the extract was tested at 200 and 300 mg/kg. The evaluation of the antioxidant potential was done through the determination of the total polyphenols and total flavonoid contents, and by using the ferric reducing antioxidant power assay and the free radical scavenging activity on DPPH method. The results show that the extract contains alkaloids, flavonoids, steroids, saponins and phenolic compounds. The test on hyperglycemic rats in OGTT showed that, the extract was effective (at a dose of 200 mg/kg) to significantly decreased glucose-induced hyperglycemia (**p ˂ 0.01). The extract was ineffective on streptozotocin-induced diabetic rats. The study of the antioxidant potential showed that, polyphenols and flavonoids increase with the concentration of the extracts. IC 50 value was found to be 65.97, based on the log (inhibitor) vs. normalized response-Variable slope. FRAP appears to be significantly highly correlated with total polyphenols content and total flavonoids content. This shows that the ethanol extract of V. thyrsiflora leaves could be served to prevent acute hyperglycema, but not a chronic hyperglycemic state.