[Effects of mild moxibustion on Beclin-1/Bcl-2 expression in spinal cord of rats with cervical spondylotic radiculopathy].

Objective: To observe the effects of mild moxibustion on the expression of autophagy and apoptosis factors Beclin-1, Bcl-2 mRNA and protein in spinal cord (including nerve root tissues) of cervical spondylotic radiculopathy (CSR) rats, so as to explore the analgesic mechanism of mild moxibustion at "Dazhui" (GV14) on CSR.

Methods: SD rats were randomly divided into blank group, model group, mild moxibustion group and mild moxibustion+3-methyladenine(3-MA) group, with 10 rats in each group. CSR model was established by inserting the wire into the cervical nerve root. The rats in the blank group were only fed normally without any intervention.The rats in the mild moxibustion group and mild moxibustion+3-MA group were given mild moxibustion at GV14 for 10 min each time,and intraperitoneal injection of 1 mL 0.9% normal saline and 1 mL 3-MA(15 mg/kg)separately. Rats in the model group were given 0.9% normal saline every day. All the three interventions were started from the 3rd day after modeling for 7 days. The rat's behavioral reaction of gait was scored and the pain threshold of rat was measured with a pain analyzer; the expressions of Beclin-1 and Bcl-2 mRNA and protein in the spinal cord (including nerve root) were detected by fluorescence quantitative PCR and immunohistochemistry, separately. The autophagosome and ultrastructure of the spinal nerve root tissue were observed by transmission electron microscope.

Results: After modeling, the gait score was significantly increased (<0.01) and the pain threshold significantly decreased (<0.01) in the model group in comparison with the blank group. There was no statistical difference in Beclin-1 and Bcl-2 mRNA and protein expression between the blank and the model groups. After intervention, compared with the model group, the gait scores were significantly reduced (<0.01), the pain threshold and the expressions of Beclin-1 and Bcl-2 mRNA and protein were significantly increased (<0.01，<0.05) in the mild moxibustion and mild moxibustion+3-MA groups. The improvement of the above indicators as more significant in the mild moxibustion group than that in the mild moxibustion+3-MA group (<0.05). After modeling, the organelles in the spinal nerve root tissue cells of the model group were damaged and there were a small amount of autophagosomes. Compared with the model group, the ultrastructure of the spinal nerve root tissue cells in the mild moxibustion group were relatively complete, and the number of autophagosomes increased.

Conclusion: Mild moxibustion at GV14 has a good analgesic effect on CSR rats, which may be related to its effects in up-regulation of Beclin-1 and Bcl-2 expressions and activation of autophagy and inhibition of apoptosis.