Antibacterial studies on fruit-skin and leaf extracts of Annona muricata in Ota, Nigeria

摘要

The current study examined the phytochemical constituents and antibacterial activity of leaf and fruit-skin extracts of Annona muricata Linn. The extracts were screened qualitatively for their phytochemical constituents following established protocols; disc diffusion method was employed for the antibacterial study on Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa, after which their minimum inhibitory concentrations were determined via double dilution method. Furthermore, selected extracts were screened against 50 multidrug-resistant clinical isolates from immunocompomised patients who are already down with secondary acute respiratory infections. The phytochemical screening of the extracts collectively revealed the presence of tannins, saponins, terpenoids, steroids, phenols, flavonoids, coumarin, alkaloids, antocyanins and betacyanins. Only aqueous leaf (ALA) and fruit-skin ethanol (ESA) extracts showed remarkable activity with 15 - 17 mm inhibition diameter (DIH) against the test organisms. The minimum inhibitory concentrations (MIC) for the ALA and ESA were 25 and 6.25 mgmL~(-1) respectively. The two extracts further showed activity (6-18 mm DIH) against 80% of the multidrug resistant isolates tested. It can therefore be inferred from this study that Annona muricata possibly contains potent bioactive antibacterials that can be developed into nature-friendly drugs to counter the effects of pathogenic bacteria, thereby preserving lives as well as sustaining a viable environment.