[Intervention of nicotinamide on skin melanin genesis after UVA exposed].
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.
Patam
Muhammad
M
School of Public Health, Xinjiang Medical University, Urumqi 830054, China.
Jin
Xi-peng
XP
Zhang
Yu-bin
YB
Pan
Jian-ying
JY
Shen
Guang-zu
GZ
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*
D008543:Melanins; D009536:Niacinamide