中文摘要：

目的：研究紫外辐射对皮肤角质形成细胞（HacaT细胞）DNA断裂损伤的影响和白藜芦醇的保护作用。方法：采用彗星电泳研究照射剂量为0～90mJ／cm。时，紫外辐射对DNA的损伤效应以及不同浓度（0．1、1．0、10．0μmol／L）白藜芦醇预处理的保护作用。结果：在0～90mJ／cm2照射剂量范围内，未检测到UVA对DNA的损伤效应。UVB和UVC组，彗星电泳图和5个检测指标（TailDNA％、TailLength、CometLength、TailMoment、OliveTailMoment）均显示随照射剂量增加对DNA损伤加重的量效关系，且相同剂量UVC造成的损伤〉UVB。0．1μmol／L白藜芦醇预处理可明显减轻紫外辐射引起的DNA损伤。结论：在0～90mJ／cm2剂量范围内，紫外辐射可引起DNA断裂并存在量效关系。白藜芦醇可保护DNA免于紫外辐射所造成的DNA断裂损伤。

英文摘要：

Objective To explore the effects of ultraviolet on DNA damage in keratinocytes and to observe the protective role of resveratrol for the cells. Methods Comet assay was employed to evaluate the damage after radiation with different doses of UV rays （UVA, UVB and UVC） of O, 10, 30, 50, 70 and 90 mJ/cm2, and the effects after pretreatment with various concentrations of resveratrol under irradiation with 30 mJ/cm2. Results UVA irradiation （0 - 90 mJ/cm2） had no significant effects on HaCaT ceils. However, TailDNA%, TailLength, CometLength, TailMoment and OliveTailMoment showed both UVB and UVC induced DNA damage in a dose-depentent manner. UVC was more harmful than UVB at the same dose. Conclusions The DNA breakage induced by UVB and UVC is dose-dependent. As compared with UVB, UVC is more harmful to HaCaT cells. Resveratrol exerts a protective effect in HaCaT cells irradiated by UVB or UVC.