TITLE:
Evaluation of Anti-Diabetic and Antioxidant Potential of Vernonia auriculifera Bark Extract in Streptozotocin-Induced Diabetic Wistar Rats
AUTHORS:
Lucky A. Mahmoud, Naomi Bisem, Geoffrey Kiptoo, Stephen Barasa, Julius Koech
KEYWORDS:
Antidiabetic Activity, Antioxidant, Phytochemicals, Streptozotocin, Vernonia auriculifera, Wistar Rats, Oxidative Stress, Dyslipidaemia
JOURNAL NAME:
Open Access Library Journal,
Vol.13 No.7,
July
6,
2026
ABSTRACT: Background: Diabetes mellitus is a condition characterised by elevated blood glucose levels and oxidative stress, leading to various complications. Medicinal plants represent an important but under utilised source of antidiabetic and antioxidant phytochemical compounds. Objective: This study evaluated the phytochemical composition, in vitro antioxidant activities, and in vivo antidiabetic potential of Vernonia auriculifera Hiern bark extract in streptozotocin-induced diabetic Wistar rats. Methods: The methanolic, ethanolic, and aqueous extracts of the bark were subjected to phytochemical screening. Antioxidant properties were evaluated in vitro by measuring the ferric reducing power (FRAP) and scavenging effect against hydrogen peroxide (H2O2). Twenty-five male albino Wistar rats were randomly assigned to five groups: normal control, diabetic control, diabetic treated with 200 mg/kg extract, diabetic treated with 400 mg/kg extract, and diabetic treated with 100 mg/kg metformin. Extracts and metformin were orally administered for 21 days. Results: Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, glycosides, terpenoids, saponins, and anthraquinones in the methanol extract. The methanol extract showed maximum antioxidant potential, with H2O2 scavenging activity at 60 μg/mL (85%), comparable to ascorbic acid. In vivo, the 400 mg/kg dose significantly reduced blood glucose in diabetic animals from 280 to 97 mg/dL (P Conclusion: Vernonia auriculifera bark extract, particularly at 400 mg/kg, demonstrates significant antidiabetic and antioxidant activities in streptozotocin-induced diabetic Wistar rats.