Antioxidant and antidiabetic effects of aqueous extract of Senna alata on alloxan-induced diabetic rats

Abstract

This study aimed to evaluate the antioxidant effect and the state of the liver following injury by alloxan monohydrate and treatment with an aqueous extract of Senna alata (SA) leaf. A total of 24 male Albino Wistar rats assigned into 4 groups (A-D) of 6 rats per group were used in this study. Forty-eight hours following administration of alloxan monohydrate and confirmation of diabetes mellitus in groups B-D rats, group C were treated with SA while group D rats were treated with glibenclamide. Rats in groups A and B received distilled water. The treatments were through oral administration, once daily for 21 consecutive days. On day 21 post-treatment, serum samples were collected for in vivo antioxidants and liver enzyme assays. The liver tissues were also collected for macroscopic examination and histomorphology. The in vitro antioxidant activity of SA was also determined using DPPH photometric model. The SA-treated rats recorded significantly reduced activities of ALT, ALP and total bilirubin values when compared to rats in the diabetic untreated group. There was also a significant increase in the activities of catalase, superoxide dismutase and glutathione in SA-treated rats compared to those of the untreated diabetic group. The study also recorded 67.33% in vitro antioxidant activity of SA at 400 μg/ml. Liver photomicrographs of rats treated with the extract were comparable to those of the normal control while diabetic untreated rats showed congestion of the central vein, degeneration and necrosis of hepatocytes. SA has both in vitro and in vivo antioxidant activity and protected the liver against damage by alloxan monohydrate.