Abstract:
OBJECTIVE To study the effects of Qingluo Tongbi Compound(QLT) on pain behavior and COX-2 mRNA expression in dorsal root ganglion(DRG) and blood PGE
2 concentration, and to explore the mechanisms of pain in rheumatoid arthritis. METHODS The mice were randomly divided into control group, celecoxib 30mg/kg,QLT 4.35g/kg, QLT 8.70g/kg and QLT 17.4g/kg groups. The mice pain threshold change were measured by hot plate method, and body torsion times were tested by acetic acid twisting method. The collagen-induced arthritis(CIA) was induced by collagenⅡ in DBA/1 mice. The mice were randomly divided into control group, CIA group, celecoxib 30mg/kg group, QLT 8.70g/kg. The paws swelling, mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) were recorded. After treated with corresponding drugs by intragastric administration for four weeks, COX-2 mRNA in DRG and PGE
2 in mice were quantified. RESULTS QLT reduced pain threshold and body torsion times in pain model mice(P<0.01); compared with the CIA group, the QLT group decreased the paws swelling(P<0.05), up-regulated MWT(P<0.01) and PWL(P<0.05), down-regulated the expression level of COX-2 mRNA in DRG and PGE
2 concentrations in blood. CONCLUSION QLT shows certain analgesic action, which might be related to the inhibitory effect of COX-2 mRNA expression in DRG and PGE
2 in blood.