Phytochemical Composition, Extraction Yield, and In Vitro Antibacterial Activity of Aqueous and Ethanolic Extracts of Mango (Mangifera indica L.) Leaves and Peels

Background: Antimicrobial resistance has intensified interest in natural products as sources of antibacterial compounds. Mango (Mangifera indica L.) leaves are used in traditional medicine, while the peel is a commonly discarded fruit-processing by-product that may contain potentially useful phytochemicals. Objective: This study compared extraction yield, qualitative phytochemical composition, and in vitro antibacterial activity of aqueous and ethanolic extracts of mango leaves and peels against five clinical bacterial isolates.Methods: Leaves and fruits of the local “Dan Kamaru” mango variety were collected in Kano State, Nigeria. The reported voucher numbers were BUKHAN 262 for leaves and BUKHAN 348 for fruit material. Samples were oven-dried at 40 °C and extracted by maceration using distilled water for 48 h or absolute ethanol for 72 h. Qualitative phytochemical screening followed Brain and Turner (1975). Antibacterial activity was assessed by agar-well diffusion against Staphylococcus aureus, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa at 250, 125, 62.5, and 31.25 mg/mL. Minimum inhibitory concentration (MIC) was reported for S. aureus and P. mirabilis. Results: Extraction yields were 28% for aqueous leaf extract, 24% for aqueous peel extract, 22% for ethanolic leaf extract, and 20% for ethanolic peel extract. All four extracts tested positive for tannins, alkaloids, flavonoids, and triterpenes; phlobatannins and resins were not detected. The largest recorded inhibition zone was 29 mm for aqueous leaf extract against S. aureus at 250 mg/mL. E. coli showed no detectable inhibition with ethanolic leaf extract or either peel extract at the tested concentrations but was inhibited by aqueous leaf extract. Reported MIC values against S. aureus and P. mirabilis were 31.25 mg/mL for both leaf extracts and 62.5 mg/mL for both peel extracts.Conclusion: The tested extracts shared the same qualitative phytochemical classes, while leaf extracts showed lower reported MICs than peel extracts against the two organisms assessed by MIC. These findings provide preliminary comparative in vitro evidence, not proof of clinical efficacy or chemical equivalence. Further work should quantify individual compounds, standardize susceptibility testing, include appropriate controls and replication, and verify the raw data.