EVALUATION OF ANTIDIABETIC POTENTIAL OF ROOTS AND STEMS OF G. ARBOREA

Objectives: Roots and stems of Gmelina arborea Roxb. (Verbenaceae) are used in many Ayurvedic (Dashmula) and herbal formulations (Diabecon) and reported to possess hypoglycemic activities which formed the basis of the present investigation. Methanolic extracts of stems and roots of Gmelina arborea were evaluated for antidiabetic activity in diabetic rats. Methods: Total phenolics and flavonoids were estimated in methanolic, aqueous and ethyl acetate extracts of roots and stems of G. arborea . Antidiabetic activity of methanolic extracts of stems and roots of G. arborea was investigated in streptozotocin induced diabetic rats for 21 days at two dose levels (250 and 500 mg/kg) with glibenclamide (0.25 mg/kg) used as a standard drug. Results: Methanolic extracts of stems and roots showed considerable amount of phenolics and flavonoids compared to aqueous and ethyl acetate extracts. It also showed significant (p<0.001) reduction in fasting blood glucose level in both normal and diabetic rats. Methanolic extract of stems and roots at 500 mg/kg showed significant decrease (54.69% and 45.31% respectively) in blood glucose levels when compared to the standard. In addition, change in body weight, serum lipid profile and GHb (whole blood) levels were also compared amongst various groups treated with different extracts and significant antidiabetic activity observed might be attributed to appreciable amount of phenolics and flavonoids in methanolic extract of roots and stems. The results clearly indicate potential antidiabetic effects of roots and stems of this plant. Conclusion: These findings support the use of G. arborea in herbal formulations for diabetes and will be helpful to explore isolation and identification of bioactives from this drug to manage diabetes and related complications.