黄芩甙对中波紫外线照射HaCaT细胞后光产物的影响

目的 探讨黄芩甙对UVB照射后HaCaT细胞光产物环丁烷嘧啶二聚体(CPD)的产生和清除的影响.方法 以一定剂量UVB照射HaCaT细胞,在照光后不同时间点采用免疫组织化学法检测CPD的产生和清除;以黄芩甙预先孵育HaCaT细胞,再观察黄芩甙对CPD的影响.结果 HaCaT细胞损伤程度随UVB照射剂量增大而加重.30mJ/cm²UVB照射后HaCaT光产物CPD的产生在0.5h左右达到高峰,同时细胞开始清除CPD,照射后4h内清除速率较快,至24h时基本清除CPD.黄芩甙预处理组UVB照射后细胞的CPD产生少于非加药组(U=2.324,P<0.05).结论 UVB照射对HaCaT细胞光损伤程度呈剂量递增性,HaCaT细胞对CPD的清除存在快速清除期及慢速清除期;黄芩甙可减少光产物生成.

The effect of baicalin on the production and removal of cyclobutane pyrimidine dimers by HaCaT cells after UVB irradiation

Objective To investigate the production and removal of cyclobutane pyrimidine dimer (CPD) by HaCaT cells after UVB irradiation, and the effect of baicalin in this process. Methods HaCaT cells were cultured and irradiated with given dosages of UVB, and the production and removal of CPD by HaCaT cells at given time points after UVB irradiation were assessed by immunohistochemical method. In parallel studies, HaCaT cells were preincubated with baicalin, and the effect on CPD was evaluated. Results The damage to HaCaT cells was dependent on the dosage of UVB radiation. After irradiation with 30 mJ/cm2 of UVB, CPD formation peaked at 0.5 h. CPD was removed rapidly from HaCaT cells during the first 4 h; the rate of removal decreased thereafter, and the removal was almost complete by 24 h after the irradiation. The amount of CPD decreased significantly in HaCaT cells that were preincubated with baicalin solution before UVB irradiation than that in those without the preincubation (U = 2.324, P < 0.05). Conclusions UVB radiation results in a dose dependent damage to HaCaT cells. There are two phases in the removal of CPD after UVB irradiation: a rapid phase and a slow phase. Pretreatment of HaCat cells with baicalin before UVB irradiation can decrease the production of CPD.