Volume 20, Issue 45, January - June, 2026

Sub-Chronic Toxicity and Anti- Ulcer Activity of Hydroethanolic Extract of Vernonia amygdalina in Rodent Models

Mega Obukohwo Oyovwi^1,2♦, Eseroghene Cecillia Adegor³, Ejayeta Jeroh¹, Rotu Arientare Rume²

¹Department of Human Physiology, Faculty of Basic Medical Sciences, Delta State University of Science and Technology, Ozoro, Delta State, Nigeria
²Department of Science Laboratory Technology, Delta Central College of Management and Sciences, Ughelli, Delta State, Nigeria
³Department of Pharmacology, National Open University, Abuja, Nigeria

^♦Corresponding Author
Mega Obukohwo Oyovwi (PhD), Department of Human Physiology, Faculty of Basic Medical Sciences, Delta State University of Science and Technology, Ozoro, Delta State, Nigeria

ABSTRACT

This research assessed the sub-chronic toxicity (90-day) and anti-ulcer efficacy of the hydroethanolic leaf extract of Vernonia amygdalina in rodent models. For toxicity testing, Wistar rats were given daily doses of 0, 250, 500, or 1000 mg/kg for 90 days. There were no deaths at any dose. The No Observed Adverse Effect Level (NOAEL) was set at 500 mg/kg. At 1000 mg/kg, there were small increases in serum liver enzymes (ALT, AST, ALP), creatinine, and blood urea nitrogen. Histopathology showed mild hepatocellular necrosis and renal tubular degeneration. For the assessment of anti-ulcer efficacy, Swiss albino mice were administered the extract (100–400 mg/kg) or omeprazole (20 mg/kg) for seven days prior to ulcer induction via ethanol, indomethacin, or pylorus ligation models. The extract at 400 mg/kg showed strong gastroprotection, with 86.3% protection against ulcers caused by ethanol (p < 0.001), 74.2% protection against ulcers caused by indomethacin (p < 0.01), and antisecretory effects that included a 58.4% reduction in gastric juice volume and an increase in gastric pH from 2.1 to 4.2 in the pylorus ligation model. These effects were similar to those of omeprazole. Phytochemical analysis showed that the contents of phenolic (124.5 mg/g) and flavonoid (67.8 mg/g) were very high. The results confirm the historical application of Vernonia amygdalina for gastric ailments and demonstrate a positive safety profile after multiple doses. The extract demonstrates multi-mechanistic anti-ulcer activity through antioxidant, cytoprotective, and antisecretory mechanisms. Additional mechanistic investigations and clinical trials are necessary.

Keywords: Vernonia amygdalina; anti-ulcer efficacy; sub-chronic toxicity; gastric ulcer; rodent models; phytomedicine; NOAEL

Drug Discovery, 2026, 20(45), e12dd3077

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Published: 30 April 2026