Elucidation of the antibacterial and antioxidant properties of aqueous and hydroethanolic extracts of Anthocleista schweinfurthii Gilg (Loganiaceae) against three enterobacteria responsible for gastroenteritis

This study aimed to evaluate the antibacterial and antioxidant properties of aqueous and hydroethanolic extracts of Anthocleista schweinfurthii on three enterobacteria responsible for gastroenteritis. Aqueous and hydroethanolic extracts were prepared from the leaves, stem bark, and roots by maceration.The well diffusion and microdilution methods were used to assess the antibacterial activity of the extracts against three reference strains responsible for gastroenteritis, namely Escherichia coli (ATCC 25922), Shigella sonnei (CMCC51630), and Salmonella enterica serovar Typhi (200836550). The antioxidant activity of the extracts was evaluated using DPPH, ABTS, and FRAP methods. Total polyphenols, primary and secondary antioxidants were assessed using the Folin-Ciocalteu assay. The aqueous and hydroethanolic root extracts demonstrated antibacterial activity against Shigella sonnei. (CMCC51630) and Salmonella typhi (200836550), respectively, with inhibition diameters ranging from 17 ± 1.41 to 21 ± 1.41 mm. The MICs of the extracts ranged from 64 to 512 µg/mL. The aqueous root extracts were the most potent, with the lowest MIC of 64 µg/mL. All extracts were bactericidal against Salmonella enterica serovar Typhi (200836550), while the aqueous root extract was bacteriostatic against Shigella sonnei. (CMCC51630). The aqueous root extract showed the strongest free radical scavenging activity (3.638 ± 0.001), the highest reducing power (427.57 mg EAA/g extract), and the greatest secondary antioxidant content (213.8 mg EAA/g extract). The hydroethanolic root extract was rich in total polyphenols, with a content of 441.49 mg EAA/g DW. Anthocleista schweinfurthii extracts exhibit antibacterial and antioxidant properties, which are essential for treating gastroenteritis and oxidative stress.