Objective To explore the mechanism of acupuncture′s effect on hippocampal neuron apoptosis in a post-traumatic stress disorder (PTSD) rat model via the reactive oxygen species (ROS)/c-Jun N-terminal kinase (JNK)/p53 pathway.

Methods Thirty rats were randomly divided into normal control group (NC group), PTSD rat model group (PTSD group) and electroacupuncture intervention group (EA group), with 10 rats in each group. The results of behavioral test (open field experiment and elevated cross maze experiment) were compared. The terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining method was used to detect hippocampal neuron apoptosis in each group. DHE fluorescence staining was employed to measure ROS levels in the brain tissue of each group. The content of Ros indexmalondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH)in brain tissue of each group was detected. Western blot analysis was performed to determine the protein expression levels of JNK, p-JNK, p53 and PUMA in hippocampal tissue.

Results The total movement distance of rats in the PTSD group was significantly shorter, and the total number of uprightand central cell entry times were significantly shorter than those in the NC group (P < 0.05). The total distance moved by rats in the EA group was significantly longer, and the total number of upright and central lattice entry times were significantly higher than those in the PTSD group (P < 0.05). The percentage of times and time of entering the open arm in the PTSD group was significantly lower, and the anxiety index was significantly higher than that in the NC group (P < 0.05). The percentage of times and time of entering the open arm in the EA group was significantly higher, and the anxiety index was significantly lower than that in the PTSD group (P < 0.05). The neuronal apoptosis rate of the PTSD group was significantly higher than that of the NC group (P < 0.05); the neuronal apoptosis rate in the EA group was significantly lower than that in the PTSD group (P < 0.05). The mean fluorescence intensity of ROS in brain tissue of the PTSD group was significantly higher than that of the NC group (P < 0.05); the mean fluorescence intensity of ROS in the EA group was significantly lower than that in the PTSD group (P < 0.05). The MDA content in brain tissue of the PTSD group was significantly higher, and SOD activity and GSH content were significantly lower than those of the NC group (P < 0.05); the MDA content in the brain tissue of the EA group was significantly lower, and the SOD activity and GSH content were significantly higher than those of the PTSD group (P < 0.05). The p-JNK/JNK and the expression levels of p53 and PUMA in brain tissue of the PTSD group were significantly higher than those of the NC group (P < 0.05); the p-JNK/JNK and the expression levels of p53 and PUMA in the brain tissue of the EA group were significantly lower than those of the PTSD group (P < 0.05).

Conclusion Acupuncture can inhibit hippocampal neuron apoptosis and relieve fear symptoms in PTSD rats, possibly through the activation of the ROS/JNK/p53 pathway.