Acupuncture improved depressive behavior by regulating expression of hippocampal apoptosis-related factors in psychological stress-induced depression rats

Abstract

To investigate the effect of acupuncture on behavior changes and the expression of reactive oxygen species (ROS), cytochrome C, cysteine-containing aspartate-specific proteases-3 (caspase-3), apoptosis inducing factor (AIF) in the hippocampus of rats exposed to chronic restraint stress (CRS), so as to provide experimental evidence for the prevention and treatment of depression. Thirty two male SD rats were equally randomized into control, model, acupuncture and medication (Fluoxetine) groups according to the random number table. The depression model was established by chronic psychological stress stimulation (fasting, water deprivation, chronic restraint combined with solitary raising for 28 days). Manual acupuncture stimulation (2 circles/s) was applied to "Baihui" (GV20), "Yintang" (GV29) and bilateral "Sanyinjiao" (SP6) for 2 min, followed by retaining the needles for 20 min. Rats in the medication group were treated by gavage of Fluoxetine (0.18 mg/mL, 1 mL/100 g body weight). The treatment was conducted once daily for 28 days. The depression-like behavior was evaluated by using open-field test, sucrose preference test, and body weight. The content of ROS of the right hippocampus tissue was detected by using dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay, and the expression levels of cytochrome C, caspase-3 and AIF proteins of hippocampus were determined by using Western blot. After 28 days' stress procedure, the depression rats in the model group showed a significant decrease in the numbers of crossing and rearing of open-field test, sucrose preference index and the body weight compared to the control group (P<0.01). The content of ROS and expression levels of cytochrome C, caspase-3 and AIF in the hippocampus of the model group were significantly increased relevant to the control group (all P<0.01). After the intervention and compared with the model group, the decreased levels of the numbers of crossing and rearing, body weight and sucrose preference index, and the up-regulated levels of content of ROS and expression of cytochrome C, caspase-3 and AIF proteins were all reversed in both acupuncture and medication groups (P<0.01，P<0.05), displaying an anti-depressant effect. The effect of acupuncture was significantly superior to that of medication in up-regulating the numbers of crossing and rearing (P<0.01, P<0.05), and in down-regulating the expression of caspase-3 (P<0.01). No significant differences were found between the medication and acupuncture groups in increasing the body weight and sucrose preference index, and in down-regulating the expression of cytochrome C and AIF proteins (P>0.05). Acupuncture intervention can significantly reduce ROS content and expression level of cytochrome C, caspase-3 and AIF proteins in the hippocampus possibly by inhibiting the chronic psychological stress-hippocampal oxidative stress-mitochondrial apoptotic pathway in psychological stress-induced depression rats, which may contribute to its effect in relieving depression.