Antimicrobial Activity of Mangifera zeylanica Leaf Extract and Development of a Topical Formulation

Background The development of antimicrobial resistance has become a global health concern, leading to significant challenges to the effective management of infectious diseases caused by pathogenic microorganisms. Mangifera zeylanica is an endemic plant in Sri Lanka, traditionally used in ayurveda for its antimicrobial benefits, holds promise as an alternative therapeutic agent. This study investigates the antimicrobial activity of M. zeylanica leaf extract and its potential incorporation into a topical cream formulation. Methodology The antimicrobial activity of ethyl acetate and ethanol leaf extracts of M. zeylanica were investigated against five test microorganisms: Staphylococcus aureus , Escherichia coli , Candida albicans, Pseudomonas aeruginosa, and Staphylococcus epidermidis using agar well diffusion assay. A topical cream formulation incorporating ethanol leaf extract at a concentration of the 25 mg/mL was developed and assessed for its physiochemical properties. Results Both leaf extracts exhibited antimicrobial activity with ethanolic leaf extract showing a higher ZOI against all test microorganisms than ethyl acetate leaf extract. For the ethanolic leaf extract, S. aureus had a significantly lower ZOI at each concentration, compared to the positive control, ampicillin (37.7 ± 0.3 mm at 0.01 mg/mL), while C. albicans showed a significantly higher ZOI at each concentration than its positive control, gentamycin (16.1 ± 0.3 mm at 0.01 mg/mL). The ethanolic leaf extract had MIC and MBC of 12.5 mg/mL. GC-MS and FTIR analysis of the ethanolic leaf extract identified 1,2,3-benzenetriol (86.75%) as the major bio-active compound contributing to the antimicrobial activity. The formulated cream showed ideal spreadability (10.17 g.cm/s), smooth texture and stability, with no phase separation observed during the storage for 14 days and 90 days. Conclusion The ethanolic leaf extract of M. zeylanica demonstrated promising antimicrobial activity against tested bacterial strains and fungal strains, indicating its potential as a therapeutic agent for topical applications.