Protective effect of folic acid on oxidative stress injury and apoptosis of SH-SY5Y cells induced by arsenic / 中华地方病学杂志

ABSTRACT

Objective To investigate the effects of arsenic trioxide (As2O3) on oxidative stress and apoptosis of neuroblastoma cells (SH-SY5Y) and the protective effect of folic acid (FA).Methods SH-SY5Y cells were cultured in vitro,and were divided into six groupscontrol group,low arsenic group (2.5 μmol/L As2O3),medium arsenic group (5.0 μmol/L As2O3),high arsenic group (10.0 μmol/L As2O3),FA intervention group (10.0 μmol/L As2O3,0.3 mmol/L FA),and FA control group (0.3 mmol/L FA).Each group of cells was cultured for 24 h or 5 h.Cell chromatin agglutination was observed by fluorescence staining.The ultrastructure of cells was observed by transmission electron microscope.The changes of oxidative stress related indicators of glutathione (GSH),malondialdehyde (MDA),superoxide dismutase (SOD),and reactive oxygen species (ROS) were detected;caspase 3 activity was also detected.Results Under fluorescence microscope,as the dose of arsenic increased,the nucleus became increasingly highlighted and a small number of cells in the medium and high arsenic groups showed chromatin agglutination,and FA intervention reduced chromatin agglutination.Under transmission electron microscope,the mitochondria of low and medium arsenic groups were slightly swollen and the endoplasmic reticulum was expanded;while the mitochondria of high arsenic group were significantly swollen and the nuclear membrane was ruptured,and the apoptotic bodies were observed.Mitochondria were slightly swollen after FA intervention.There were statistically significant differences in GSH content,SOD activity,ROS level and caspase 3 activity between groups (F =14.905,6.120,12.714,36.657,P ＜ 0.05).GSH content and SOD activity in high arsenic group [0.104 ± 0.074,(12.673 ± 5.106) U/mg prot] were lower than those in control group [1.000 ± 0.000,(34.699 ±3.998) U/mg prot,P ＜ 0.05].GSH content in FA intervention group (0.411 ± 0.344) was higher than that in high arsenic group (P ＜ 0.05).The ROS level and caspase 3 activity in high arsenic group were higher than those in control group (P ＜ 0.05),and the ROS level and caspase 3 activity in FA intervention group were lower than those in high arsenic group (P ＜ 0.05).There was no significant difference in MDA content between groups (F =8.207,P ＜ 0.05).Conclusions Arsenic exposure can inhibit the activity of antioxidants,cause oxidative stress injury,and increase the activity of caspase 3,leading to cell apoptosis.FA plays an antagonistic role in arsenicinduced oxidative damage and apoptosis of nerve cells.