Objective To investigate damage effects of ultraviolet irradiation on human keratinocyte original -HaCaT cells and to evaluate
photo - protective efficiency of
hydroxychloroqine and traditional Chinese medicines (EGCG, Huang Qin, Chuan Xiong) on HaCaT cells damaged from UVB irradiation. Methods Subconfluent HaCaT cells were shammed or irradiated with different dosages of UVB irradiation and treated with above TCM agents. The damage of HaCaT cells was observed by light microscopy. Cell growth was recorded by cell count and cellular activity was detected by MTT method. The secretion amount of IL -6 and TNF -α was measured by ELISA. Results The damage degree of irradiated HaCaT cells was independent with the irradiated dosages and cellular activity was reduced by39% -80%, with the maximum decrease over 90% by the 72h. The intervention of the above drugs may recover the cellular activity by 10% -72%. Compared among the tested agents, the photo -protective efficiency was more apparent in EGCG with OD reading from1. 19 ±0. 07 to 1.28±0. 06(P<0. 01) and in hydroxychloroqine from 0.43 ±0.04 to 0. 96 ±0.04 (P <0. 05), and in blank control group with OD reading from 0. 26 ±0. 04 to 0. 79 ±0. 02. As to cytokine secretion, EGCG could reduce the secretion of IL -6 and TNF -α apparently. Hydroxychloroqine and Huang Qin could only reduce the secretion of IL -6, and the secretion of neither IL-6 nor TNF -a could be suppressed by Chuan Xiong . Conclusion The injury effect of UVB irradiation on cultured
keratinocytes is dose -dependent and the tested drugs have photo -protective potency. Inhibition of cytokine secretion may be one of mechanisms related to reducing the damage effect of UVB irradiation.