The antimicrobial activity of citrus fruit extracts: An in-vitro assay

ABSTRACT

BACKGROUND: The scarcity of local research on extracts of citrus fruits precludes their use as an alternative medication, particularly in the field of Dermatology.OBJECTIVES: This study aims to determine the antimicrobial activity of citrus fruit extracts and to contribute to existing data supporting the use oi these extracts against superficial bacterial and fungal diseases of the skin.METHODS: Crude ethanolic pulp and/or seed extracts and essential oils of Citrus paradisi(grapefruit), Citrus grandis(pomelo), and Citrofortunella microcarpa(calamansi) were screened for antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans the disc diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of C. microcarpapulp extract against S. aureus was then determined using standard dilution susceptibility testing. Thin layer chromatography was used to identify the presence of flavonoids, using naringin as a standard.RESULTS: The widest zones of inhibition against the test organisms were seen with calamansi pulp extract. Susceptibility testing showed that calamansi pulp extract was bacteriostatic for S. aureusup to 12.5 percent dilution. However, no bactericidal effect was observed. Naringin was identified only in the pulp extract of grapefruit.CONCLUSION: In vitro, calamansi pulp extract was shown to be an effective antimicrobial against S. aureus, P. aeruginosa, and C. albicans. Whether or not this has any dermatologic significance awaits further /w-vj'votesting.