Evaluation of the Antimicrobial Potential of Malaysian Kelulut Honeydew Honey Against Acne Pathogens

Acne is the eighth most prevalent chronic skin disease globally. The increased emergence of antibiotic resistance and chemical-induced side effects make acne treatments challenging. Hence, a natural remedy, Malaysian Kelulut honeydew honey, was proposed in this research due to its beneficial properties and the absence of antibiotic resistance. An in vitro efficacy of honey was evaluated against acne-associated microbes (Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and Candida albicans) via broth microdilution assay. The honey exhibited inhibitory and bactericidal effects against Cutibacterium acnes at 20% and 40%, respectively, while only inhibitory effects were observed against other microbes. Cutibacterium acnes, the most susceptible bacteria in this study, was subjected to time-kill assays to assess the time- and concentration-dependent effects of honey. The honey’s inhibitory (20% honey) and killing (40% honey) kinetics started at the 12th and 4th hour, respectively. Morphological alterations in Cutibacterium acnes following treatments were observed via field emission scanning electron microscopy (FESEM), revealing the deformation of the rod-shaped Cutibacterium acnes and filamentation occurrence. Through liquid chromatography mass spectrometry (LCMS), the potential phytochemicals responsible for honey’s antimicrobial activity were identified to be purine, pteridine, theobromine, nebularine, and nigerose (sakebiose). To conclude, Malaysian Kelulut honeydew honey is a promising anti-acne agent by targeting Cutibacterium acnes. To date, the antimicrobial activities of Malaysian Kelulut honeydew honey have been underexplored, especially against Cutibacterium acnes. Notably, this is the first report of honey inducing filamentation in any Cutibacterium acnes strain, suggesting a possible mechanism of action of honey.