Antibacterial activities and antioxidant potential of Adansonia digitata leaves

Abstract

Resistance to synthetic antibiotics remains a significant global health challenge, prompting interest in natural alternatives such as phytochemicals. This study evaluated the antimicrobial potential of methanol and aqueous extracts from Adansonia digitata leaves against various pathogenic bacteria. Quantitative analysis revealed higher concentrations of alkaloids (5.60% in methanol extract), flavonoids, tannins, terpenoids (3.2% in methanol extract), and phenols in the methanol extract compared to the aqueous extract. The methanol extract demonstrated notable antibacterial activity, particularly against Serratia marcescens and Staphylococcus aureus, with a maximum zone of inhibition of 24.00 mm. In contrast, the aqueous extract showed no significant antibacterial effect. However, several bacteria, including Escherichia coli, Klebsiella pneumoniae, and Citrobacter freundii, exhibited resistance to both extracts, despite exposure to concentrations below the Minimum Inhibitory Concentration (MIC). MIC values ranged from 62.50 mg/mL to 500 mg/mL for different bacterial strains, indicating varying susceptibility levels. This resistance highlights the complex way bacteria respond to phytochemicals and indicates that more research is necessary to identify the precise bioactive substances causing antimicrobial action as well as potential resistance pathways.