Antifungal activity of Malaysian honey against microsporum gypseum and epidermophyton floccosum / Nur Ashikin Hasan

The emergence of antifungal resistance fungus has lowered the success rates of antifungal therapy thus becoming a major concern worldwide. This has resulted in the re-evaluation of the therapeutic use of ancient remedies including honey. The antibacterial activity of honey has been associated with its osmolarity, acidity, hydrogen peroxide, and non-hydrogen peroxide components. The aim of our study was to investigate the efficacy of Malaysian honeys namely Tualang, Acacia, Nenas and Kelulut as antifungal agent against Microsporum gypseum and Epidermophyton floccosum. The antifungal activity was examined by determining the MIC using the broth dilution assay on microtiter plates. The MFC was determined by re-inoculation into agar plates from a well with each concentration of honey where bacterial growth was inhibited (from the broth of MIC assay). The honey samples were tested at 70%, 60%, 50%, 25%, 12.5%, 6.25%, 3.1 %, 1.6%, 0.8%, 0.4%, 0.2%, and 0.1 % (v/v) dilution. The efficacy of Malaysian honey as antifungal agent was compared with Manuka honey which has been known to exhibit antifungal properties. Artificial honey was used as a control group. The result showed that three types of honey which are Tualang, Nenas and Acacia including Artificial honey had substantial antifungal activity against M. gypseum and E. floccosum. MIC values of Manuka honey are equivalent to other tested honeys and Artificial honey, which are 50% (v/v) for M. gypseum and 49% (v/v) for E. floccosum. However, only Manuka honey demonstrated fungicidal activity towards M gypseum and E.floccosum. Among local honeys, Tualang honey had the lowest MIC value (50% v/v), and thus the best activity, against M gypseum. Meanwhile, Acacia and Nenas honeys had higher MIC values against M gypseum which is 55% (v/v) and 62% (v/v) respectively. When tested against E. floccosum, Tualang, Acacia and N enas honeys suppress the growth of these fungi at concentration of 54% (v/v), 60% (v/v) and 63% (v/v) respectively. Unfortunately, Kelulut honey did not produce any substantial antifungal activity against M gypseum and E. floccosum. Malaysian honeys exhibited variable activities against the two types of fungi. The differences in floral source of honey may contribute to the variation in the potency of the antibacterial activity. Further research should be done to assess the antifungal activity of Malaysian honeys to reveal its true potential.