Anti-inflammatory And Analgesia Effects Of Soluble Epoxide Hydrolase Inhibition On Sciatica Rats

Part 1 Effect of soluble epoxide hydrolase inhibitors on pain behaviors of sciatica SD rats Objective To evaluate the effects of soluble epoxide hydrolase inhibition on pain behaviors of sciatica SD rats,and to compare its analgesia effects on sciatica with celecoxib.Methods Forty female SD rats were randomly divided into four groups as follows(n=10,each):sham-operated group,model group,AUDA group and celecoxib group.In the sham-operated group,sciatic nerves were exposed but not ligatured.Other groups were set up with the sciatica model.From the second day after operation,soluble epoxide hydrolase inhibition AUDA and celecoxib,were injected intraperitoneally at the dose of 10mg/kg in the AUDA group and celecoxib group respectively.Normal saline 2ml were injected intraperitoneally in the sham-operated group and the model group.Behavior tests,including Paw withdraw mechanical threshold(PWMT)and Paw withdraw thermal latency(PWTL),were performed on all rats before operation and 1,2,3,5,7 days after operation.Results The PWMT and PWTL were significantly decreased in the model group compared with the sham-operated group.The PWMT and PWTL of AUDA group and Celecoxib group were significantly higher than those of the model group and lower than those of the sham-operated group.No significant difference was observed between the PWMT and PWTL of the AUDA group and the Celecoxib group.Conclusion AUDA,a type of soluble epoxide hydrolase inhibition,can increase the PWMT and PWTL of sciatica SD rats.Its analgesia effects have no significant difference with celecoxib.Part 2 Effect of soluble epoxide hydrolase inhibitors on the expression of TNF-?,IL-1? and COX-2 in the dorsal root ganglion of sciatica SD ratsObjective To evaluate the effect of soluble epoxide hydrolase inhibition on the expression of tumor necrosis factor-alpha(TNF-a),interleukine-1 beta(IL-1?)and cyclooxygenase-2(COX-2)in sciatica SD rats.To explore the anti-inflammatory and analgesia effect of soluble epoxide hydrolase inhibition on sciatica.Methods Forty female SD rats were randomly divided into four groups as follows(n=10,each):sham-operated group,model group,AUDA group and celecoxib group.In the sham-operated group,sciatic nerves were exposed but not ligatured.Other groups were set up with the sciatica model.From the second day after operation,soluble epoxide hydrolase inhibition AUDA and celecoxib,were injected intraperitoneally at the dose of 10mg/kg in the AUDA group and celecoxib group respectively.Normal saline 2ml were injected intraperitoneally in the sham-operated group and the model group.All rats were sacrificed after the behavior test on the 7th day after operation and the dorsal root ganglion were extracted.The expression of TNF-?,IL-1? and COX-2 in the DRG were detected by immunohistochemistry method.The expression of TNF-?mRNA,IL-1?mRNA and COX-2mRNA were assayed with real-time Polymerase Chain Reaction.Results The immunohistochemical results showed that the expression of TNF-?,IL-1? and COX-2 in the DRG in the model group significantly increased compared with that in sham-operated group.The expression of TNF-?,IL-1? and COX-2 in the AUDA group and Celecoxib group were lower than those in the model group,but higher than those in the sham-operated group.The PCR results showed that the expression of TNF-?mRNA,IL-1?mRNA and COX-2mRNA in the model group significantly increased compared with that in sham-operated group.The expression of TNF-?mRNA,IL-1?mRNA and COX-2mRNA in the AUDA group and Celecoxib group were lower than those in the model group,but higher than those in the sham-operated group.Conclusion AUDA,a type of soluble epoxide hydrolase inhibition,can decrease the expression of TNF-?,IL-1? and COX-2 in the dorsal root ganglion of sciatica rats.Inhibition of soluble epoxide hydrolase may induce the anti-inflammatory and analgesia effects on sciatica.