Phytochemical Screening and Antibacterial Activity of Methanolic Leaf Extract of Guiera senegalensis

Abstract

The increasing resistance of microorganisms to conventional antibiotics, together with the high cost and adverse effects of some synthetic drugs, has encouraged the search for alternative therapeutic agents from medicinal plants. Guiera senegalensis is widely used in West African traditional medicine for conditions such as dysentery, malaria and skin infections, and its therapeutic relevance has been associated with its phytochemical constituents. This study evaluated the phytochemical composition, antioxidant potential and antibacterial activity of the methanolic leaf extract of Guiera senegalensis. Qualitative phytochemical screening was conducted to identify major secondary metabolites, while antioxidant activity was assessed using DPPH, FRAP and TBARS assays. Antibacterial activity was evaluated against selected Gram-positive and Gram-negative bacteria, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined to assess antimicrobial potential. Phytochemical screening indicated the presence of phenols, flavonols, saponins, alkaloids, steroids, tannins and cardiac glycosides. The antioxidant assays showed concentration-dependent activity, although the extract was generally less effective than ascorbic acid. The antibacterial tests demonstrated inhibitory effects against selected bacterial isolates, with bactericidal effects requiring relatively higher concentrations. Overall, the methanolic leaf extract of Guiera senegalensis exhibited antioxidant and antibacterial activities, suggesting that it contains bioactive constituents that may support further investigation as potential natural therapeutic agents.