Intervention Study Of EGCG On UV Photodamage And Model Medicine In Different Pharmaceutical Preparations On Permeability In Human Skin

BackgroundUltraviolet irradiation of sunlight including UVA and UVB is the most powerful wavelength which causes sunburn, photoaging and skin tumors. Ultraviolet A radiation, which primarily acts by oxidative stress, and ultraviolet B radiation, which initially acts by absorption in DNA and direct damage to DNA, both produced genomically unstable cell clones. Genomic instability is characteristic of many types of human cancer. Fibroblasts of the skin are the important target cells of UV irradiation.Cells activity after irradiation can be detected by MTT.The HPRT-mutagenesis assay was used asdescribed previously to detect and to characterize UV-induced hprt mutations.The apoptotic rate of cells after irradiation can be detected by flow cytometric analysis.There are many marks to reflect the cell senescence, among them senescence-associated β-galactosidase (SA-β-Gal) is the most representative, and easiest to detect. Four recent studies now indicate that premature senescence accompanied by cell cycle arrest occurs in tumors...