Antioxidant Activity of Methanol Leaf Extract of Vernonia amygdalina in Kidney of Alloxan‐Induced Diabetic Rats
Authors: Adeoye Adegbolagun Tope , Adedapo Adeolu Alex , Omobowale Temidayo Olutayo , Oyagbemi Ademola Adetokunbo 
Published: November 2023

Vernonia amygdalina is a medicinal plant found in tropical Africa. Extracts of the plant are used as tonic, in the control and treatment of cough, feverish conditions, constipation, diabetes and hypertension. Diabetes mellitus is a metabolic disorder resulting from a defect in insulin secretion, insulin action, or both which then leads to chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism. Diabetic nephropathy is a leading cause of end‐stage renal failure worldwide. Oxidative stress (more accurately described as increased levels of reactive oxygen species; ROS) is of great importance in the pathophysiologic mechanisms that have been identified in the development and progression of diabetic nephropathy. The increase in ROS is due to both increased production and to decreased and/or inadequate antioxidant function. Natural products with anti‐oxidant property may sound a promising therapeutic approach to ameliorate renal damage from diabetic nephropathy. The aim of this study is to investigate the antioxidant activities of the methanol leaf extract of Vernonia amygdalina (MLVA) in alloxan‐induced diabetic nephrotoxicity. Diabetes was induced in male Wistar rats by the administration of alloxan monohydrate at 100mg/kg body weight. After 48 hours, rats with fasting blood glucose levels of 200mg/dl and above were considered diabetic and used for the study. The experimental animals were grouped into five groups (A–E) of nine animals each. Group A were non diabetic non treated control rats and received 5% Tween 80 in normal saline. Group B were the diabetic control rats that received no treatment following induction of diabetes. Group C were diabetic rats treated with glibenclamide, Group D were diabetic animals that received 200mg/kg dose of methanol leaf extract of Vernonia amygdalina and Group E were diabetic animals that received 400mg/kg dose of the extract. Biochemical assays was done to measure some biochemical parameters in serum. The kidney was collected and kidney homogenate prepared for the antioxidant studies. Results showed that oral administration of MLVA for 28 days produced significant (p<0.05) decrease in blood glucose. Treatment with MLVA resulted in a significant (p<0.05) improvement in body weight of diabetic rats. Triglycerides and cholesterol levels were significantly (p<0.05) reduced in extract treated rats when compared with the diabetic control. Serum creatinine and urea levels were also significantly lowered following treatment with the extract. Results also showed a significant (p<0.05) decrease in markers of oxidative stress such as Hydrogen Peroxide (H2O2) and Malonaldehyde (MDA) in kidney homogenates of treated groups compared to diabetic control. Glutathione (GSH) and Protein thiol (PT) showed significant increases in kidney homogenates of treated rats and antioxidant enzymes such as Superoxide dismutase (SOD), Glutathione Peroxidase (GPx) and Glutathione‐S‐Transferase (GST) showed significant (p<0.05) increases in kidney homogenates of treated rats.

We conclude from this study that Vernonia amygdalina has antihyperglycaemic, in vivo antioxidant and nephroprotective effects in alloxan‐induced diabetes.