Hypoglycemic, hypolipidemic, and hepatoprotective effects of Polyscias fulva (Hiern) Harms ethanolic bark extract in streptozotocin-induced diabetic Wistar rats

Background Polyscias fulva (Hiern) Harms stem bark is used in traditional folk medicine in Kenya for diabetes mellitus and obesity management. This study sought to examine the antidiabetic effects of ethanolic stem bark extract of P. fulva in streptozotocin (STZ)-induced diabetic Wistar albino rats. Methods Diabetes in rats was induced by intraperitoneal injection of STZ (50 mg/kg bwt) in experimental groups. Rats were divided into five groups (n = 5 per group): group 1, control; group 2, diabetic untreated rats; groups 3 and 4, diabetic rats on 200 and 400 mg/kg bwt/day of extract, respectively; and group 5, diabetic rats on metformin (100 mg/kg bwt/day). The rats received oral treatments daily for 21 days, and fasting blood glucose levels and body weights were determined weekly. Liver histopathological analysis and malondialdehyde (MDA) assay as well as serum analysis of lipid profile, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total proteins (TP), albumin (ALB), and globulins were performed at the end of the treatment period. Results Extract had significant hypoglycemic and hypolipidemic effects in the diabetic rats compared with diabetic untreated rats (p < 0.05). Serum levels of ALP, ALT, and AST were significantly lowered, while TP and ALB were elevated in the extract-treated diabetic rats compared with diabetic untreated rats. The levels of liver MDA of extract-treated rats were significantly lowered compared with those of the diabetic untreated group. Extract treatment reversed liver pathological changes observed in the diabetic untreated group. Conclusion This study has provided insights into the potential of the stem bark of P. fulva as an alternative medicine for diabetes mellitus.