Phytochemical screening and in vitro antimicrobial properties of Annona muricata extracts against certain human pathogens

All over the world, the use of medicinal plants is gaining more acceptability due to the possibility of discovering novel drugs from them and solving the problem of antimicrobial resistance associated with conventional antibiotics. The phytochemical composition and antimicrobial properties of crude extracts of the leaves, stems, and bark of Annona muricata were evaluated on Escherichia coli, Staphylococcus aureus, and Salmonella typimurium, while the antifungal properties were evaluated against Candida albicans and Candida tropicalis. The Agar well method was used for the study. At concentrations of 150 mg/ml and 300 mg/ml, inhibitory effects were observed on E. coli and S. aureus, with a visible zone of inhibition ranging from 15 mm to 21 mm respectively, and with respect to N- hexane, an antimicrobial activity range of 5 mm to 20 mm, for the leaf extract, which shows effective antimicrobial action against E. coli and S. aureus. Hot water extracts were observed to possess more bioactive compounds compared to organic solvent extracts, and exhibit higher ranges of activity against the tested bacterial species. All extracts exhibited low anti-fungal activity in the range of 8 mm to 15 mm. The phytochemical screening of the extracts of different parts of A. muricata revealed the presence of secondary metabolites such as tannins, alkaloids, saponins, flavonoids, steroids, and cardiac glycosides. The antimicrobial activity of the extracts was compared with a standard antibiotic, ketoconazole, and with ampicillin, which served as the controls). The results showed that A. muricata can be used as an anti-bacterial substance, since it shows broad spectrum activity against a range of bacteria responsible for the most common bacterial illnesses. Further research will be necessary to ascertain its full spectrum of efficacy.