Impacts of curcumin on the inflammation and activation of microglia in dorsal horn of spinal cord in rats with lumbar disc herniation by regulating the CXCL12/CXCR4 signaling pathway

ZHANG Xiaolin; ZHAO Li'na; KONG Linglei

doi:10.13431/j.cnki.immunol.j.20250047

Abstract：Objective To analyze the impacts of curcumin on the inflammation and activation of microglia in dorsal horn of spinal cord in rats with lumbar disc herniation(LDH)by regulating the CXC chemokine ligand 12(CXCL12)/CXC chemokine receptor 4(CXCR4)signaling pathway.Methods Rats were randomly separated into sham surgery group,model group,curcumin low,medium,and high-dose groups,and curcumin high-dose+NUCC-390(CXCL12/CXCR4 signaling pathway activator)group.The motor function and scores of rats in each group were observed.Pain hypersensitivity experiment was applied to determine the mechanical stimulation foot contraction reflex threshold(PWMT)and the thermal stimulation foot contraction reflex latency(PWTL).HE staining was applied to observe pathological changes in the spinal dorsal horn tissue.Immunofluorescence staining was applied to observe the expression of Iba-1.ELISA was applied to detect levels of TNF-α,IL-8,and IL-2.Western blot was applied to detect the expression of Iba-1,CXCL12,and CXCR4 pathway proteins.Results Compared with the sham surgery group,the nerve cells of rats in the LDH group shrank,and the nuclei and Nissl bodies decreased,the motor function score,TNF-α,IL-8,IL-2,Iba-1,CXCL12,and CXCR4 expression elevated,PWMT and PWML decreased(P＜0.05).Compared with the LDH group,the morphology of nerve cells in the curcumin low,medium,and high dose groups recovered,nucleoli were clear,and Nissl bodies increased,the motor function score,TNF-α,IL-8,IL-2,Iba-1,CXCL12,and CXCR4 expression decreased,PWMT and PWML increased(P＜0.05).Compared with the curcumin high-dose group,the curcumin high-dose+NUCC-390 group showed nerve cell damage,the motor function score,TNF-α,IL-8,IL-2,Iba-1,CXCL12,and CXCR4 expression elevated,PWMT and PWML decreased(P＜0.05).Conclusion Curcumin can inhibit inflammatory response and the activation of microglia in spinal dorsal horn in LDH rats,and the mechanism of action may be related to the inhibition of the CXCL12/CXCR4 signaling pathway.