Glycemic and Biochemical Effects of Polyphenol-Rich Fraction of <i>Parkia biglobosa</i> Leaves in Wistar rats Experimentally Induced with Diabetes

Abstract

This study evaluated the effect of polyphenol-rich fraction of Parkia biglobosa leaves (PBF) in rats experimentally  induced with diabetes. Thirty albino rats divided into five groups (n=6) were used for this study. Except for group one,  the rats were first maintained on high high-calorie diet for eight weeks followed by streptozotocin injection (40 mg/kg).  Groups 1 and 2 (normal and diabetic controls respectively) received 1 ml of distilled water throughout the experiment.  Group 3 received 50 mg/kg of glibenclamide while groups 4 and 5 received 200 and 400 mg/kg of PBF respectively. After  4 weeks of treatment, after an overnight fast, blood was collected from the rats for haematological and biochemical  analyses. Body weight and fasting blood glucose measurements were taken weekly. The in vitro antioxidant analysis  revealed good ferric reducing power, and DPPH radical-quenching activity (IC₅₀ = 0.47mg/ml). The PBF groups had  markedly (p<0.05) reduced blood glucose and showed better glucose tolerance compared to the untreated group. The  PBF groups also had marked (p<0.05) diminution of liver enzymes’ activities (ALP, ALT, AST) as well as markedly reduced  bilirubin levels relative to the diabetic control. Urea, creatinine, and K+ levels were markedly (p<0.05) reduced in the PBF  groups relative to the untreated, while the PBF groups had markedly high Na+ levels in comparison to the diabetic control. This result justifies the use of the leaves locally for disease management and could serve as a cheaper and low- toxicity alternative in the management of diabetes and associated complications.