Experimental Study Of Photo-protection Of Selenium On Human Keratinocyte Damaged From Ultraviolet-B Irradiation

ObjectiveTo investigate the damage effects of UVB on eternal human keratinocyteHaCaT cells; and to evaluate photo-protective efficiency of selenium on the cell damaged from UVB irradiation and its mechanisms.Methods1. Cell culture: HaCaT cells were cultured in MEM media with 10% fetal bovine serum; The cells were plated in 96 and 6 wells with anequal number.2. Ultraviolet irradiation: HaCaT cells were shammed or irradiated with different dosages of UVB irradiation (0,30, 60 and 90 mJ/cm~2)and treated with selenium.3. Cell viability assay: The dose- and time- dependent photodamage was observed by light microscopy; MTT assay was used to record cellular activity.4. DNA flow cytometric analysis: HaCaT cells were harvested by trypsin-ethylene diamine tetraaeetic acid (EDTA) release and fixed in 70% ethanol. The apoptotic rate were determined with a DNA flow cytometer.5. antioxidases and MDA assay: To detect the activation of SOD,GSH-Px and the levels of MDA.6. ELISA analysis: The conditioned medium from HaCaT cultures was collected; the secretion levels of IL-10 was detected with Human Cytokine Sandwich ELISA Kits.Results1. The irradiation damage of HaCaT cells was dependent on the irradiated dosages (0, 30, 60, 90mJ/cm~2). The intervention of the tested drugs could protect the cellular activity partly.2. Selenomethionine and sodium selenite showed protective effect on UVB-induced apoptosis.3. Selenomethionine can increase the activation of GSH-Px and SOD meanwhile can decrease the levels of MDA.4. As to cytokine secretion, selenomethionine could decline the secretion amount of IL-10 induced by UVB apparently.ConclusionsThe injury effect of UVB irradiation on cultured human skin cells is dose-dependent and the selenium have photo-protective potency on HaCaT cells damaged from UVB irradiation. Inhibitions of the cytokine secretion of IL-10, increasing the activation of GSH-Px and SOD and decreasing the levels of MDA may be part of mechanisms related to reducing the photo-damage effects of UVB irradiation.