Photoprotective Effects of Hydroxychloroqine and TCMs on Human Keratinocytes Damaged from Ultraviolet Irradiation

Objective: To investigate damage effects of ultraviolet irradiation on eternal keratinocyte-HaCaT cells and to evaluate photo-protective efficiency of hydroxychloroqine and Traditional Chinese Medicines(epigallocatechingallate[EGCG], baikal skullcap root and szechwan lovge rhizome) on HaCaT cells damaged by middle wave ultraviolet(UVB) irradiation. Methods: Subconfluent HaCaT cells were sham or UVB irradiated and treated with above TCM agents. The damage degree of HaCaT cells was observed by a light microscop. 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 irradiation damage of HaCaT cells was depended on the irradiated dosages and cellular activity was reduced by 36%-80%, with a maximum decrease over 90% after 72 h. The intervention of the above drugs may increase the cellular activity by 10%-72%. The photo-protective efficiency was more apparent in EGCG (from 1.19±0.07 to 1.28±0.06, P0.01) than that in hydroxychloroqine (from 0.43±0.04 to 0.96±0.04, P0.05). The other two tested drugs also showed photo-protective effect(from 0.44±0.07 to 1.21±0.02, P0.05). As to cytokine secretion, EGCG could decline the secretion amount of IL-6 and TNF-α apparently. Hydroxychloroqine and baikal skullcap root baikal skullcap root could only reduce the secretion of IL-6. The secretion of IL-6 and TNF-α could not be inhibited by szechwan lovge rhizome. 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 the mechanisms related to reducing the damage effect of UVB irradiation.