Background: Malassezia (M.) species are members of the normal part of the skin flora, but they might
induce or be involved with various cutaneous diseases. Although the role of Malassezia in the
pathogenesis of cutaneous diseases is not fully understood, recent studies have shown that decreased
density of Malassezia led to improvement of these diseases.
Objective: To identify the antifungal effect of light emitting diode (LED) against Malassezia, its antifungal
mechanisms and the impact on the keratinocytes.
Methods: LED with various wavelengths (370–630 nm) on Malassezia furfur, Malassezia sympodialis and
Malassezia globosa was irradiated according to dose and then the antifungal effects were thereafter
assessed. After irradiating LED with 392.5 1 nm of wavelength according to dose on Malassezia species,
reactive oxygen species (ROS) and lipid hydroperoxide production assay were measured. In addition, cell
viability and inflammatory cytokines (IL-1a, IL-1b, TNF-a, TGF-b, TLR-2 and COX-2) expressions in normal
human epidermal keratinocytes (NHEKs) by LED irradiation were evaluated.
Results: The growth of Malassezia species was dose-dependently suppressed by both LED with 380 2
and 392.5 1 nm wavelengths. The increases of intracellular and extracellular ROS by LED irradiation with
392.5 1 nm wavelengths were significantly observed compared to control group. The cell viability and
cytokines in NHEKs were not significantly affected by LED irradiation under 5 J/cm2 in vitro.
Conclusion: LED irradiation with 380 2 and 392.5 1 nm wavelengths proved to have antifungal effect
against Malassezia species and no impact on NHEKs under 5 J/cm2
. The findings suggest that LED might be an
adjunctive therapeutic light tool against Malassezia yeasts related cutaneous diseases.
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