Improvement of microvascular complications in STZ-diabetic rats treated with Pterocarpus erinaceus Poir. extract

Pterocarpus erinaceus Poir. from Fabaceae family is a medicinal plant traditionally used in decoction or infusion to treat diabetes mellitus. Although this plant is used in treating diabetes, studies on the effectiveness of its stem bark on the complications induced by chronic hyperglycemia have not been thoroughly addressed. Thus, this study was conducted to prove the efficacy of hydroethanolic extract of stem bark of P. erinaceus on type 2 diabetes and its complications, such as renal fibrosis and retinopathy in rats. STZ diabetics. The dry extract of P. erinaceus stem bark was obtained following the hydroethanolic extraction (v/v). Diabetes was induced with streptozocin in SD rats pretreated with fructose-lard for 20 days. Then, the serum and urinary biochemical parameters were evaluated at the start and the end of the treatment. Rats with blood glucose ≥350 mg/dL and significant proteinuria were selected and treated with P. erinaceus stem bark extract and glibenclamide for 3 weeks. A complete blood count and a histopathological examination of the retina and kidneys were performed at the end of the 41st day of treatment. The results showed that P. erinaceus extract at a dose of 500 mg/kg bw and glibenclamide at a dose of 0.6 mg/kg bw caused a significant decrease (p < 0.0001) in basal blood glucose in STZ diabetic rats during treatment and improved oral glucose intolerance. At the end of the experiment, the treated rats showed a normalization in body weight, food and water consumption. Evaluating of biochemical parameters showed a significant (p < 0.001) decrease in total cholesterol, LDL-C, triglycerides, TG/HDL-C ratio, CPK and oxidative stress in treated rats. No retinal and kidney abnormalities were observed on histological sections in rats treated with plant extract and glibenclamide. In contrast, macular edema and renal fibrosis were observed in the diabetic control group. The findings showed that extract at a dose of 500 mg/kg bw improves oral glucose intolerance, and inhibits lipid deposition and retinal and renal fibrosis. Therefore, the plant extract could be exploited in the production of herbal medicines to manage diabetes and its complications.