Objective To observe the effect of mild moxibustion(Moxi) at “Dazhui”(GV14) on neuropathic pain

expression of autophagy and apoptosis factor LC3 and Bax proteins and mRNAs in the spinal cord tissue in rats with cervical spondylotic radiculopathy(CSR)

so as to explore its underlying mechanism underlying relief of CSR-induced pain. Methods Forty rats(half male half female) were randomly divided into blank control

model

Moxi

Moxi+autophagy inhibitor 3-methyladenine(3-MA

Moxi+3-MA) groups

with 10 rats in each group. The CSR model was established by loose ligature of the local cervical nerve roots. Three days after modeling

mild Moxi was applied to GV14 for 10 min

once daily for 7 days. Rats of the Moxi+3-MA group received intraperitoneal injection of 3-MA(1 mL

15 mg/kg+ saline) before Moxi

once daily for 7 consecutive days. Rats of the model and Moxi groups were also given normal saline(i.p.

1 mL)

once daily for 7 days. The gait behavior score(1-3 points) was scaled according to the rats' pain reaction and foot paw contracture produced walking disorder and the mechanical pain threshold(MPT) was detected before and after the treatment. The expression of spinal cord LC3 and Bax proteins and mRNAs were detected by immunohistochemistry and quantitative RT-PCR

respectively. Results Compared with the blank control group

the gait disorder score

and percentage of Bax positive cells and expression of Bax mRNA were significantly increased(P<0.01

P<0.05)

and MPT was markedly decreased in the model group(P<0.01). After the treatment

the gait disorder score

percentage of Bax positive cells and Bax mRNA expression were significantly down-regulated(P<0.01

P<0.05)

while the MPT and percentage of LC3 positive cells and LC3 mRNA expression were considerably increased(P<0.01

P<0.05) in both Moxi and Moxi+3-MA groups. The therapeutic effects of mild Moxi were remarkably superior to those of Moxi+3-MA in downregulating gait disorder score

Bax positive cell percentage and Bax mRNA expression

and in up-regulating MPT

LC3 positive cell percentage and LC3 mRNA expression(P<0.05)

suggesting a reduction of the function of mild Moxi after administration of 3-MA. Conclusion Mild Moxi at GV14 can relieve neuropathic pain in CSR rats

which may be related to its functions in up-regulating LC3 autophagy

thereby inhibiting the expression of Bax pro-apoptotic protein in spinal cord to reduce apoptosis and to repair nerve injury.