氧化型低密度脂蛋白致PC12细胞的毒性作用及抗氧化剂的细胞保护作用

目的探讨氧化型低密度脂蛋白(oxLDL)致PC12细胞的毒性作用及白藜芦醇等抗氧化剂的细胞保护作用。方法 通过噻唑蓝(MTT)实验、乳酸脱氢酶(LDH)释放实验、DNA断端原位末端标记法(TUNEL)实验及caspase-3测定来观察oxLDL对PC12细胞存活率、细胞膜通透性、细胞核及caspase-3活性的影响。抗氧化剂白藜芦醇、丙丁酚及维生素E预处理细胞,再加入不同浓度oxLDL,观察抗氧化剂的细胞保护作用。结果 PC12细胞存活率随着ox-LDL浓度及作用时间增加而下降;LDH释放率、TUNEL阳性细胞数及caspase-3活性随着浓度增高而增高;低密度脂蛋白(LDL)对上述各项指标无影响。白藜芦醇、丙丁酚及维生素E均能减缓oxLDL所致的细胞存活率下降、LDH释放率的升高、TUNEL阳性细胞数的增加,其中白藜芦醇作用最强;白藜芦醇、丙丁酚减缓oxLDL所致的caspase-3活性增高,而维生素E对caspase-3活性无影响。结论oxLDL导致PC12细胞死亡,其浓度与PC12细胞存活率呈剂效关系,其作用时间与PC12细胞成活率呈时效关系。

Cytotoxic effect of oxidized low density lipoprotein on PC12 cells and the neuroprotective effect of antioxidants

Objective To investigate the cytotoxic effect of oxidized low density lipoprotein on PC12 cells and the neuroprotective effect of antioxidants. Methods PC12 cells were applied as a neuron model and exposed to oxLDL. Cell injury was evaluated by cell viability (MTT assay), cell lysis (LDH assay), DNA fragmentation (TUNEL assay) and caspase-3 activity(caspase assay) after treatment.To evaluate potential neuroprotective effects of antioxidants,pretreatment of PC12 cells with various antioxidants, such as resveratrol, probucol and vitamin E, was carried out for 1 h prior to the addition of oxLDL. Results oxLDL induced significant decrease in viability, increase in LDH release, DNA fragmentation and caspase-3 activity. However, no significant alteration was seen in untreated control cultures and LDL control. Resveratrol, probucol and vitamin E had the protective effects against oxLDL. Resveratrol was more effective than probucol and vitamin E. Conclusions oxLDL, but not native LDL, caused a dose-and time-dependent neuron death. Caspases-3 participated in oxLDL-mediated toxicity. Antioxidants, such as resveratrol, probucol and vitamin E attenuated oxLDL-induced toxici- ty.