Protective effect of green tea polyphenols against ultraviolet B-induced damage to HaCaT cells.

Many deleterious effects on the skin have been associated with the ultraviolet B (UVB) portion of the solar spectrum. The role of green tea polyphenols (GTP) in protecting HaCaT cells against the UVB-induced damages was examined. The promotion effect of low level GTP on cell viability was revealed in a dose-dependent manner. High level GTP had a cytotoxic effect. UVB induced destruction of HaCaT cells, including shedding of cell membrane microvilli, degeneration of nucleus and nucleols and changes of mitochondrial size and internal cristae. GTP alleviated the UVB-induced destructive morphological changes in HaCat cells. It is considered that GTP affords protection against the UVB-induced stress via both interacting with UVB-induced reactive oxygen species and attenuating mitochondrion-mediated apoptosis.