Green tea polyphenol epigallocatechin-3-gallate inhibits the expression of nitric oxide synthase and generation of nitric oxide induced by ultraviolet B in HaCaT cells / 中华医学杂志(英文版)
Chinese Medical Journal
;
(24): 282-287, 2006.
Article
in English
| WPRIM
| ID: wpr-267138
ABSTRACT
<p><b>BACKGROUND</b>Nitic oxide (NO) has been implicated in the pathogenesis of various inflammatory diseases, including sunburn and pigmentation induced by ultraviolet irradiation. Epigallocatechin-3-gallate (EGCG) is the major effective component in green tea and can protect skin from ultraviolet-induced damage. The purpose of this study was to investigate the protective mechanisms of EGCG on inducible nitric oxide synthase (iNOS) expression and NO generation by ultraviolet B (UVB) irradiation in HaCaT cells.</p><p><b>METHODS</b>HaCaT cells were irradiated with UVB 30 mJ/cm 2 and pretreated with EGCG at varying concentrations. The iNOS mRNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and NO production was quantified by spectrophotometric method. The expression of NF-kappaB P65 was measured by immunofluorescence cytochemistry staining.</p><p><b>RESULTS</b>The expression of iNOS mRNA and generation of NO in HaCaT cells were increased by UVB irradiation. EGCG down regulated the UVB-induced iNOS mRNA synthesis and NO generation in a dose dependent manner. The UVB-induced ctivation and translocation of NF-kappaB were also down regulated by EGCG treatment in HaCaT cells (P < 0.01).</p><p><b>CONCLUSIONS</b>Green tea derived-EGCG can inhibit and down regulate the UVB-induced activation and translocation of NF-kappaB, expression of iNOS mRNA and generation of NO respectively, indicating EGCG may play a protective role from UVB-induced skin damage.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
Radiation Effects
/
Tea
/
Ultraviolet Rays
/
RNA, Messenger
/
Catechin
/
Gene Expression Regulation, Enzymologic
/
Keratinocytes
/
Cells, Cultured
/
Protein Transport
Limits:
Humans
Language:
English
Journal:
Chinese Medical Journal
Year:
2006
Type:
Article
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