title: [Intervention of nicotinamide on skin melanin genesis after UVA exposed].
abstract: OBJECTIVE
  To investigate the interference effect of nicotinamide on UVA-induced melanin genesis and melanin transport in human skin melanocyte.
  
  
  METHODS
  The optimum UVA dose expected to cause cell proliferation: 0.2 J/cm(2), nicotinamide was added immediately after the 0.2 J/cm(2) UVA exposure and the melanin content, cell cycles, cell apoptosis and mRNA express level were measured respectively.
  
  
  RESULTS
  Melanin content in melanocytes was increased significantly after exposed to 0.2 J/cm(2) UVA. Melanin content in melanocytes was decreased after treatment with 10.0 mmol/ml nicotinamide following UVA exposure, but the cell cycles and the cell apoptosis rate were not significantly altered. mRNA express levels of TYR, TRP-1 were modulated by nicotinamide.
  
  
  CONCLUSIONS
  Nicotinamide has more effect on decreasing melanin genesis after UVA exposure, nicotinamide also plays a role in modulating the mRNA express of TYR, TRP-1 gene. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.
authors.affiliation: School of Public Health, Xinjiang Medical University, Urumqi 830054, China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Patam
authors.forename: Xi-peng
authors.initials: XP
authors.lastname: Jin
authors.forename: Yu-bin
authors.initials: YB
authors.lastname: Zhang
authors.forename: Jian-ying
authors.initials: JY
authors.lastname: Pan
authors.forename: Guang-zu
authors.initials: GZ
authors.lastname: Shen
mesh_terms: D002478:Cells, Cultured; D006801:Humans; D008543:Melanins / Q000096:biosynthesis*; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D009536:Niacinamide / Q000494:pharmacology*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D008543:Melanins; D009536:Niacinamide