EVALUATION OF IN-VITRO AND IN-VIVO ANTI-DIABETIC EFFECT OF 80% METHANOL EXTRACT AND SOLVENT FRACTIONS OF THE LEAVES OF ETHULIA GRACILIS (ASTERACEAE) IN STREPTOZOTOCIN-INDUCED DIABETIC MICE

Abstract

Background: Diabetic Mellitus is one of the most common chronic diseases and its burden continues to increase in the world. Current treatment strategies for diabetic mellitus have been circumscribed due to limitations like high costs, accessibility issues, and probable side effects. Medicinal plants may offer safe, affordable, and accessible alternatives. Therefore, it is vital to assess medicinal plants for their pharmacological effects to support the use of current diabetes medications. Method: The Ethulia gracilis leaves were macerated with 80% methanol. Then, 80% methanol extract was further fractionated using n-hexane, chloroform, and distilled water. The blood glucose-lowering activity of 80% methanol extract and its solvent fractions were evaluated at 250, 500, and 1000mg/kg dose ranges in normoglycemic, glucose-loaded, and streptozotocin-induced diabetic mice models. Animals were assigned to different study groups by a completely random distribution. The in vitro α–amylase inhibitory activity of the crude extract and its solvent fractions were evaluated by using 3,5-dinitrosalicylic acid (DNSA) assay model. The results were analyzed using one-way ANOVA, followed by Tukey's post-hoc multiple comparison test. Result: Acute and subacute toxicity study of 80% methanol extract of the leaves of Ethulia gracilis did not show any sign of toxicity and mortality in the mice during the observation period. The 80% methanol extract showed a significant blood glucose-lowering effect on normoglycemic and oral glucose-loaded mice at the dose of 1000mg/kg (47.98%, p<0.001 and 28.98%, p<0.001), respectively, as compared to negative control. After 14 days of treatment, in a streptozotocin-induced diabetic mice model, at 1000mg/kg dose the 80% methanol extract and chloroform fraction significantly(p<0.05) reduced the fasting blood glucose levels with a percentage reduction of 49.65% and 48.89%, respectively. In α– amylase enzyme inhibition activity, among the plant extracts, the highest activity was shown by 80% methanol extract (54.23% at 800 μg/mL) as compared to the standard acarbose which resulted in 85% inhibition at 800 μg/mL. Conclusion: Acute and subacute toxicity study of 80% methanol extract did not produce any sign of toxicity and mortality during the study periods. The present study also revealed that the higher doses of 80% methanol extract and chloroform fraction effectively lowered blood glucose levels in diabetic and normoglycemic mice, and inhibiting α–amylase enzyme activity. This provides scientific support for the local use of plant leaves in the treatment of diabete