Antidiabetic Effects of the Ethanolic Root Extract of<i>Uvaria chamae</i>P. Beauv (Annonaceae) in Alloxan-Induced Diabetic Rats: A Potential Alternative Treatment for Diabetes Mellitus

Abstract

Diabetes mellitus has been a menace to mankind from time immemorial. However, a natural product such as <i>U. chamae</i> P. Beauv (Annonaceae) offers alternative treatment for diabetes mellitus. The study aimed at evaluating antidiabetic activity of the ethanolic root extract of <i>U. chamae</i> in alloxan-induced diabetic rats. Diabetes was induced in Sprague Dawley rats after overnight fast with 150 mg/kg alloxan intraperitoneally. After 72 h, those with plasma glucose levels >200 mg/dl were classified as diabetic. Five diabetic rats in each group were treated daily for 14 days orally with 100, 250, and 400 mg/kg of the extract, glibenclamide (71 <i>µ</i>g/kg) and pioglitazone (429 <i>µ</i>g/kg), respectively, while another group was untreated. Control received 0.5 ml of <i>Acacia senegal</i>. Effects of extract on glucose, other biochemical, and hematological parameters were evaluated. <i>α</i>-amylase and <i>α</i>-glucosidase inhibitory activities of extract and its fractions were also evaluated. Percentage inhibition and IC₅₀ values were determined. Diabetic control was achieved on the 7th day of the study with 100, 250, and 400 mg/kg of the extract showing glucose reduction of 72.14%, 78.75%, and 87.71%, respectively. The HDL-cholesterol levels of diabetic rats treated with extracts were significantly increased. Extract and its fractions caused <i>α</i>-amylase and <i>α</i>-glucosidase inhibition. Histologically, pancreas of diabetic rats treated with extract showed regenerated islet cells which were not seen in rats treated with glibenclamide and pioglitazone. This study showed that <i>U. chamae</i> has antidiabetic activity which may be through <i>α</i>-amylase and <i>α</i>-glucosidase inhibition and regeneration of pancreatic beta cells. Also, it may reduce the risk of cardiovascular disease by increasing HDL-cholesterol levels.