Gmelina arboreaRoxb. (Family: Verbenaceae) Extract Upregulates theβ-Cell Regeneration in STZ Induced Diabetic Rats

Abstract

Gmelina arboreaRoxb. (common name: Et-demata, Family: Verbenaceae) has been used traditionally in Sri Lanka as a remedy against diabetes mellitus. The objective of the present study was to evaluate antidiabetic mechanisms of the aqueous bark extract ofG. arboreain streptozotocin induced (STZ) diabetic male Wistar rats. Aqueous bark extract ofG. arborea(1.00 g/kg) and glibenclamide as the standard drug (0.50 mg/kg) were administered orally using a gavage to STZ diabetic rats (65 mg/kg, ip) for 30 days. The antidiabetic mechanisms of aqueous extract ofG. arborea(1.00 g/kg) were determined at the end of the experiment. The fasting blood glucose concentration was significantly lowered and the serum insulin and C-peptide concentrations were increased by 57% and 39% in plant extract treated rats on day 30, respectively (p<0.05). The histopathology and immunohistochemistry results of the plant extract treated group showed a regenerative effect onβ-cells of the pancreas in diabetic rats. In addition, serum lipid parameters were improved inG. arboreaextract treated diabetic rats. The results revealed that the aqueous stem bark extract ofG. arborea(1.00 g/kg) showed beneficial effects against diabetes mellitus through upregulating theβ-cell regeneration and biosynthesis of insulin in diabetic rats.