Effects of Electroacupuncture on Cyt-C and Caspase-9 Expression in Hippocampal Tissue of Rats with Chronic Pain and Depression Comorbidity / 中国中医药信息杂志

ABSTRACT

Objective To observe the effects of electroacupuncture(EA)at"Hegu"and"Taichong"on the expressions of cytochrome C(Cyt-C)and Caspase-9 in the hippocampus of rats with chronic pain and depression comorbidity(CPDC);To explore its potential mechanism for the treatment of CPDC.Methods A total of 60 SD rats were randomly divided into sham-operation group,model group,medication group and EA group,with 15 rats in each group.The CPDC model was induced by twice injection of complete Freund's adjuvant into the plantar of the left hind paw.EA group was applied to bilateral"Hegu"and"Taichong"for 20 min,the medication group were treated with duloxetine suspension 10 mg/kg by gavage for 14 days.The mechanical paw withdrawal threshold and thermal withdrawal latency were measured on day 7,14,21 and 28 after the first injection,tail suspension test and sucrose preference test were performed on day 14 and 28,Nissl staining was used to observe hippocampal neurons and the number of Nissl body,the protein expressions of Cyt-C and Caspase-9 in hippocampal tissue were detected by Western blot and immunohistochemistry.Results Compared with the sham-operation group,the mechanical paw withdrawal threshold and thermal withdrawal latency of the model group significantly decreased(P<0.01),the tail suspension immobility time increased(P<0.01),the percentage of sucrose preference decreased(P<0.01),the neurons were thinly arranged,the neurons were damaged and lost,and the number of Nissl body were less(P<0.01),the apoptotic rate of hippocampal neurons increased(P<0.01),the expression of Cyt-C,Caspase-9 and cleaved-Caspase-9/Caspase-9 ratio in hippocampal tissue increased(P<0.01).Compared with the model group,the mechanical paw withdrawal threshold and thermal withdrawal latency of the EA group and medication group significantly increased(P<0.01),the tail suspension immobility time decreased(P<0.01),the percentage of sucrose preference increased(P<0.01),the loss of neurons in hippocampus was reduced,the cells were arranged neatly,and the nucleoli were clear,the number of Nissl body increased(P<0.01),the apoptotic rate of hippocampal neurons decreased(P<0.01),and the expression of Cyt-C,Caspase-9 and cleaved-Caspase-9/Caspase-9 ratio in hippocampal tissue decreased(P<0.01).Conclusion EA at"Hegu"and"Taichong"can alleviate pain and depression in CPDC rats,which may be related to inhibiting the expressions of Cyt-C and Caspase-9 in hippocampal tissue and inhibiting the apoptosis of hippocampal neurons,thus playing a neuroprotective effect.