Indexing

Abstract: Background: Chionanthus africanus (Knobl.) Stearn (Oleaceae) is a medicinal tree used in African traditional healthcare for infectious and inflammatory conditions, yet no in vitro antimicrobial or toxicological data exist for this species. This study evaluated the antibacterial and antifungal activities of the crude ethanol extract and solvent fractions of the leaf, and assessed the acute and sub-acute toxicological safety profile of the crude extract in Wistar rats.

Methods: The crude ethanol extract and n-hexane, ethyl acetate, butanol, and aqueous fractions were screened against ten microbial isolates — comprising Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella spp., Shigella spp.), and fungi (Candida albicans, dermatophyte isolates D1 and D2) — using the agar well diffusion method, with minimum inhibitory (MIC) and minimum bactericidal/fungicidal (MBC/MFC) concentrations determined by the agar dilution method. Acute toxicity was evaluated up to 5000 mg/kg (OECD 425), and sub-acute toxicity was assessed over 28 days at 100, 250, and 500 mg/kg (OECD 407) with haematological and serum biochemical endpoints measured.

Results: The n-hexane fraction was inactive against all organisms. The crude extract, ethyl acetate, butanol, and aqueous fractions exhibited concentration-dependent, selective antimicrobial activity, predominantly against Gram-negative bacteria and fungi. MIC values ranged from 0.63 to >5 mg/mL, with the ethyl acetate fraction showing the lowest MIC (0.63 mg/mL) against dermatophyte D1 and Candida albicans. MBC/MFC values mirrored MIC trends, with the ethyl acetate fraction demonstrating fungicidal activity against D1 at 0.63 mg/mL. Acute toxicity testing yielded an LD₅₀>5000 mg/kg. Sub-acute administration produced no significant alterations (p>0.05) in haematological parameters (RBC, Hb, PCV, WBC, platelets) or serum biochemical markers (ALT, AST, ALP, total protein, urea, creatinine) relative to controls.

Conclusion: C. africanus leaf extract and fractions exhibit selective weak-to-moderate antimicrobial activity, with the ethyl acetate fraction showing the broadest spectrum and lowest MIC/MBC values, particularly against fungal isolates. The extract is orally safe at doses up to 5000 mg/kg acutely and up to 500 mg/kg in sub-acute exposure, with no hepatotoxic or nephrotoxic effects. These findings provide the first antimicrobial and toxicological evidence base for this medicinally relevant species.

Keywords: Chionanthus africanus; antibacterial activity; antifungal activity; MIC; acute toxicity; sub-acute toxicity.

Title: In Vitro Antibacterial and Antifungal Activities of Ethanolic Leaf Extract and Solvent Fractions of Chionanthus africanus with Acute and Sub-Acute Toxicological Safety Profile

Author: Chinelo Eucharia Enedo, Chinenye Henrietta Nedum, Chidinma Ruth Chukwunwejim, Ugochukwu Moses Okezie, Chibueze Jeremiah Ike, Amaka Roseline Onwunyili

International Journal of Recent Research in Life Sciences (IJRRLS)

ISSN 2349-7823

Vol. 13, Issue 3, July 2026 - September 2026

Page No: 1-10

Paper Publications

Website: www.paperpublications.org

Published Date: 28-July-2026