姜黄素对H2O2诱导A549细胞氧化损伤的保护作用及机制研究

目的 探究姜黄素对H2O2诱导A549细胞氧化损伤的保护作用及其作用机制。方法 使用不同浓度的H2O2对A549细胞进行不同时长的刺激，使用CCK-8法筛选A549细胞存活率约为50%时的H2O2浓度及刺激时间作为建模条件；通过Hoechst 33258染色及Western blot对模型进行验证；实验分为模型组（Model）、VC组（VC）和姜黄素组（CCM）；采用流式细胞术对细胞凋亡情况进行检测，采用Western blot法对凋亡及氧化应激信号通路相关蛋白进行检测。结果 CCK-8实验结果显示，采用600μmol/L的H2O2对A549细胞进行24h刺激，其存活率为56.45±5.33%，Hoechst 33258染色及Western blot结果证实了模型的可靠性。流式细胞术结果显示，VC组和CCM组细胞的凋亡率与Model组相比均降低（P＜0.05，P＜0.01），且CCM组降低更加明显（P＜0.01）。Western blot结果显示，与Model组相比，VC组和CCM组Bax、Caspase-3和Keap1表达降低，Bcl-2和Nrf2表达升高，且CCM组较VC组改变更加明显，差异均有统计学意义（P＜0.01）。结论 姜黄素对H2O2诱导的A549细胞急性损伤具有保护作用，可能与其激活Keap1-Nrf2/ARE信号通路，抑制细胞凋亡有关。

Protective effect and mechanism of curcumin on oxidative damage induced by H2O2 in A549 cells

Objective To explore the protective effect and its mechanism of curcumin on the oxidative damage induced by H2O2 in A549 cells. Methods Cell viability of A549 were treated with different doses of H2O2 for different durations, and detected by a Cell Counting kit-8 assay, and the suitable dose and time points corresponding with 50% cell viability were remained. Cell apoptosis induced by H2O2 was further detected by a Hoechst-33258 staining and western blotting. A549 cells were randomized into three groups for Model group, VC group and CCM group. A549 cell apoptosis was detected by flow cytometry. Proteins associated with Apoptosis and proteins related to oxidative stress signal pathway were detected by western blotting. Results CCK-8 experiment showed cell viability induced by 600μmol/L H2O2 for 24 h was 56.45±5.33%, Hoechst-33258 staining and western blotting results indicated A549 cell apoptosis. Flow cytometry showed cell death was significantly attenuated in VC and CCM groups (P<0.05, P<0.01), and CCM group attenuated more remarkably than VC group (P<0.01). WB results showed the level of B-cell lymphoma 2 (Bcl-2) and nuclear factor erythroid 2-related factor 2 (Nrf2) increased, while Bcl-2 associated X protein (Bax), Caspase-3 and Kelch-like ECH-associated protein1 (Keap1) decreased significantly in VC and CCM groups, and all the differences had statistical significance (P<0.01). Conclusion CCM has a protective effect against H2O2-induced apoptosis in A549 cells, which may be related to the activation of Keap1-Nrf2/ARE cell signaling pathway and the inhibition of apoptosis.