OHANADO IKECHUKWU KINDNESS

Peptic Ulcer Disease (PUD) management faces rising challenges from antibiotic resistance and side effects of synthetic drugs. The plant Sida acuta Burm. f. is traditionally used in African Traditional medicine for gastrointestinal ailments. Preliminary studies confirmed its anti-ulcerogenic and antioxidant potential. This study aims to evaluate the in vivo curative anti-ulcer activity of the fractions of the crude methanol extract of S. acuta leaves and to identify the most potent fraction and its possible mechanism of action. The study involved methanol extraction and subsequent fractionation of the extract using solvents of increasing polarity: n-Hexane, Dichloromethane, Ethyl acetate and Aqueous methanol. Phytochemical screening and antioxidant efficacy tests (DPPH, FRAP) were carried out to confirm the extract's components. The in vivo anti-ulcer activity was assessed in Wistar rats using the ethanol-induced ulcer model over five days. Groups received 100 or 200 mg/kg of each fraction, or 40 mg/kg Omeprazole (standard). Ulcer severity was determined via the Mean Ulcer Index (MUI) and percentage ulcer inhibition. Qualitative analysis confirmed Alkaloids, Carbohydrate, Saponins, Terpenoids, Phenols, and Flavonoids. The crude methanol extract, containing significant levels of Total Phenol (38.61 mg GAE/g) and Total Flavonoid (20.70 mg QE/g), exhibited potent antioxidant activity, confirmed by the DPPH (IC50 of 32.26μg/ml) and FRAP (0.21 mM FeSO4 equivalent/g) assays. The in vivo anti-ulcer study, using the ethanolinduced ulcer model in Wistar rats, showed the standard treatment group achieved 73.95% ulcer inhibition. Among the fractions, the n-Hexane fraction exhibited the superior anti-ulcer potential, achieving 61.5% inhibition at 100 mg/kg. The DCM, EtOAC, and Aqueous- Methanol fractions showed moderate to low inhibition (39.70% to 57.07%). The dominant activity concentrated in the non-polar n-Hexane fraction suggests that the primary anti-ulcer mechanism of S. acuta is rooted in cytoprotection (mucosal stabilization) rather than the polar antioxidant effects. This finding successfully validates the traditional use of the plant in treatment of gastrointestinal ailments and identifies the n-Hexane fraction as the primary candidate for future bioassay-guided isolation of novel anti-ulcer compounds.