Antimicrobial activity of crude methanolic extract fractions from balanites aegyptiaca (L.) delile

Abstract

Microbial infections remain a major global health concern, with mortality rates continuing to rise each decade. Projections estimate that by 2050, antimicrobial resistance could account for up to 10 million deaths annually. This study investigated the antimicrobial potential of phytochemical groups present in crude extracts of B.aegyptiacaas a possible alternative for managing microbial infections. Plant materials (leaves, stem bark, and root bark) were collected from two local varieties of B. aegyptica which are tentatively referred to as the “sweet” and “sour” varieties growing in Ajeluk village, Katakwi District, North-Eastern Uganda. The dried and pulverized samples (100 g each) were subjected to successive extraction with n-hexane, dichloromethane, and methanol. The resulting crude extracts were concentrated using a rotary evaporator, followed by fractionation through silica gel column chromatography. Fractions were further purified using preparative thin-layer chromatography, with separated bands visualized under Ultra Violet(UV)light, eluted, and tested for antimicrobial activity. Test organisms included multidrug-resistant AmericanType Culture Collection (ATCC) Escherichia coli ATCC 25922, Candida albicans ATCC 10231, and Aspergillus flavus ATCC 6275. The methanolic fractions demonstrated notable antimicrobial activity, with inhibition zones greater than 8 mm. Among the phytochemical groups, phenolics exhibited the strongest activity(23.67 ± 1.15 mm), while coumarin-containing fractions displayed the lowest activity (7.00 ± 0.00 mm). Statistical analysis revealed significant differences between inhibition zones of the phytochemical groups and the positive control (p < 0.05). Phytochemical screening confirmed the presence of phenolics, flavonoids, alkaloids, cardiac glycosides,and coumarins in the extracts. Overall, the findings suggest that B. aegypticacontains diverse bioactive compounds with antimicrobial potential, particularly against fungal pathogens. C. albicansand A. flavuswere more susceptible to these extracts than E. coli, highlighting the plant’s promise as a source of antifungal agents.