title: The antifungal effect of light emitting diode on Malassezia yeasts.
abstract: 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 (370-630nm) 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±1nm 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-1α, IL-1β, TNF-α, TGF-β, 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±1nm wavelengths. The increases of intracellular and extracellular ROS by LED irradiation with 392.5±1nm wavelengths were significantly observed compared to control group. The cell viability and cytokines in NHEKs were not significantly affected by LED irradiation under 5J/cm(2)in vitro.
  
  
  CONCLUSIONS
  LED irradiation with 380±2 and 392.5±1nm wavelengths proved to have antifungal effect against Malassezia species and no impact on NHEKs under 5J/cm(2). The findings suggest that LED might be an adjunctive therapeutic light tool against Malassezia yeasts related cutaneous diseases.
authors.affiliation: Department of Dermatology, Chonnam National University Medical School, 671 Jebongro, Donggu, Gwangju, Republic of Korea.
authors.forename: Hyun Seung
authors.initials: HS
authors.lastname: Wi
authors.forename: Eui Young
authors.initials: EY
authors.lastname: Na
authors.forename: Sook Jung
authors.initials: SJ
authors.lastname: Yun
authors.forename: Jee-Bum
authors.initials: JB
authors.lastname: Lee
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D003881:Dermatomycoses / Q000382:microbiology / Q000628:therapy*; D004307:Dose-Response Relationship, Radiation; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D015603:Keratinocytes / Q000378:metabolism / Q000528:radiation effects; D008027:Light / Q000009:adverse effects; D015227:Lipid Peroxidation / Q000528:radiation effects; D008054:Lipid Peroxides / Q000378:metabolism; D008290:Malassezia / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D051379:Mice; D008812:Mice, Hairless; D010789:Phototherapy / Q000009:adverse effects / Q000379:methods*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D008054:Lipid Peroxides; D017382:Reactive Oxygen Species