Investigation of the Modulatory Effect of Aqueous Extract of Dialium guineense Stem Bark on Oxidative Status of Diabetic Rat Kidneys

Streptozotocin (STZ) is a chemical compound known to damage pancreatic β-cells and cause hyperglycemia. Hyperglycemia plays a key role in glomerular, mesangial cell, and tubular damage in kidneys. Metabolic dysregulation, including hyperglycemia, initiates cellular damage in the kidneys. The present study investigated the modulatory effect of aqueous extract of Dialium guineense (AEDG) stem bark on oxidative status of diabetic rat kidneys. Male rats (Wistar strain, n = 20, mean weight = 165 ± 15 g) were randomly allocated to four groups (5 rats/group): control, diabetic, metformin, and extract groups. Diabetes mellitus (DM) was induced in the rats via intraperitoneal injection of STZ (50 mg/kg body weight, bwt). The diabetic rats were subsequently treated for 21 days with either 50 mg/kg bwt metformin or 1000 mg/kg bwt AEDG. Body weight and blood glucose data were collected on weekly basis. Markers of oxidative stress were measured in rat renal tissue using standard methods. The results showed that STZ-induced DM significantly increased plasma blood glucose concentration, while reducing antioxidant status of the rats. However, treatment of the diabetic rats with 1000 mg/kg bwt aqueous extract of D. guineense stem bark significantly reduced their fasting blood glucose, malondialdehyde (MDA) and nitric oxide (NO) concentrations, but it significantly increased activities of the antioxidant enzymes, and concentrations of total protein, reduced glutathione (GSH), and redox status (GSH/GSSG), in renal tissue (p < 0.05). These results indicate that AEDG stem bark can mitigate against STZ-induced oxidative stress in rat kidneys.