With the rise of antimicrobial resistance, there’s an urgent need for alternative therapeutic agents. Natural compounds from medicinal plants, particularly those used in traditional medicine, have garnered interest for their potential to combat resistant pathogens. Mangifera zeylanica, a Sri Lankan wild mango species used in Ayurveda, remains underexplored despite traditional use for treating bacterial and fungal skin infections. This study aimed to investigate the antimicrobial properties of its leaf extracts and develop a stable topical cream for potential dermatological application.
Methods
Leaves of M. zeylanica were extracted using ethyl acetate and ethanol via reflux. Antimicrobial activity was tested against Staphylococcus aureus, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Staphylococcus epidermidis using agar well diffusion. MIC and MBC were determined using a resazurin microdilution method. GC-MS and FTIR analyses identified bioactive compounds. A topical cream containing the ethanolic extract was formulated and assessed for physicochemical properties and in vitro antimicrobial activity.
Key Findings
- Broad-spectrum activity: Both ethyl acetate and ethanolic extracts showed antimicrobial effects against all five tested microbes.
- Stronger ethanol extract: The ethanolic extract had higher Zones of Inhibition (ZOI) across all organisms.
- Concentration-dependent effect: Antimicrobial activity increased with extract concentration (25–200 mg/mL).
- Superior to controls:
- C. albicans showed greater ZOI than gentamycin.
- E. coli and P. aeruginosa had higher ZOI than gentamycin at 200 mg/mL.
- S. aureus and S. epidermidis showed lower ZOI than their respective controls.
- MIC & MBC: Both were determined to be 12.5 mg/mL for the ethanolic extract.
- Chemical composition: GC-MS revealed 1,2,3-benzenetriol (pyrogallol) as the main compound (86.75%), with several minor compounds also identified. FTIR confirmed functional groups typical of phenolic and aromatic compounds.
- Cream formulation:
- Contained 25 mg/mL ethanolic extract.
- Had stable properties: pH 5.81, smooth texture, optimal spreadability (10.17 g.cm/s), and viscosity (675800 cP).
- Remained stable under centrifugation, thermal stress, and 90-day storage.
- Antimicrobial cream efficacy: The cream inhibited all test microbes but had smaller ZOIs than direct extract applications. It was particularly effective against C. albicans (more than positive control), but less effective against S. aureus and S. epidermidis.
This study is among the first to establish the antimicrobial potential of M. zeylanica leaf extract and demonstrate its successful incorporation into a stable topical cream. The ethanolic extract, rich in 1,2,3-benzenetriol, showed promising efficacy against bacterial and fungal pathogens, especially C. albicans. The cream formulation offers a practical delivery method for localized treatment of skin infections such as cellulitis, folliculitis, and candidiasis. These findings highlight M. zeylanica as a valuable candidate for plant-based antimicrobial drug development. Future directions include toxicity testing, activity against multidrug-resistant strains, formulation optimization, and in vivo validation.
Link to the study: https://journals.sagepub.com/doi/epub/10.1177/1934578X251342432
