查尔酮类似物清除DPPH自由基和保护H2O2诱导的PC12细胞损伤的抗氧化活性

目的：探究合成的查尔酮类似物清除DPPH自由基和保护H2O2 诱导PC12 细胞损伤的抗氧化活性。方法：将PC12 细胞分为对照组（DMSO组）、损伤组（H2O2组）、查尔酮类似物+H2O2组和阳性对照组（槲皮素+H2O2组）。设计合成16个查尔酮类似物，通过DPPH自由基清除实验检测自由基清除活性；MTT法检测细胞活性；MDA试剂盒检测脂质过氧化；Hoechst染色检测细胞凋亡；Western blot法检测cleaved-caspase-3、Bcl-2 和Bax蛋白表达。结果：筛选得到活性佳、毒性小的抗氧化剂13。与DMSO组比较，H2O2组的细胞存活率、Bcl-2蛋白表达显著下降，而cleaved-caspase-3和Bax蛋白表达、MDA含量显著增加（P ＜0.05）；与H2O2组比较，化合物13组呈剂量依赖性提高细胞存活率，增加Bcl-2蛋白的表达，减少cleaved-caspase-3和Bax蛋白的表达，降低MDA水平（P ＜0.05）。结论：新型查尔酮类似物13抑制H2O2诱导PC12的细胞凋亡，具有良好的抗氧化活性。

The antioxidant activity of chalcones analogues in scavenging DPPH free radical and protecting against H2O2-induced PC12 cell injury

Objective: To investigate the antioxidant activity of the synthesized chalcone analogues in scavenging DPPH free radical and protecting against H2O2-induced PC12 cell injury. Methods: PC12 cells were divided as control group (DMSO group), injury group (H2O2 group), chalcone analogue+H2O2 group and positive control group (quercetin+H2O2 group). Sixteen chalcone analogues were designed and synthesized. DPPH assay was used to detect free radical scavenging activity; MTT assay was used to detect cell activity; MDA kit was used to detect lipid peroxidation; Hoechst staining was used to detect cell apoptosis; Western blot was used to detect cleaved-caspase-3, Bcl-2 and Bax protein expression. Results: Antioxidant 13 with excellent activity and low toxicity was obtained. Compared with DMSO group, the cell survival rate and Bcl-2 protein expression were decreased significantly, but cleaved-caspase-3 and Bax protein expression, MDA content were increased significantly in H2O2 group (all P<0.05); Compared with H2O2 group, cell survival rate was increased, Bcl-2 protein expression was up-regulated, cleaved-caspase-3 and Bax expression was down-regulated, MDA level were decreased in a dose-dependent manner by group 13 treatment (all P<0.05). Conclusion: The novel chalcone analogue 13 can inhibit H2O2-induced PC12 cells apoptosis, which has good antioxidant activity.