Dragon's blood inhibits chronic inflammatory and neuropathic pain responses by blocking the synthesis and release of substance P in rats

As a traditional chinese medicine,dragon's blood (db) is widely used in treating various pains for thousands of years due to its potent anti-inflammatory and analgesic effects. in the present study,we observed that intragastric administration of db at dosages of 0.14,0.56,and 1.12 g/kg potently inhibited paw edema,hyperalgesia,cyclooxygenase-2 (cox-2) protein expression,or preprotachykinin-a mrna expression in carrageenan-inflamed or sciatic nerve-injured (chronic constriction injury) rats,respectively. a short-term (15 s or 10 min) pre-exposure of cultured rat dorsal root ganglion (drg) neurons to db (0.3,3,and 30 μg/ml) or its component cochinchinenin b (cb; 0.1,1,and 10 μm) blocked capsaicin-evoked increases in both the intracellular calcium ion concentration and the substance p release. moreover,a long-term (180 min) exposure of cultured rat drg neurons to db or cb significantly attenuated bradykinin-induced substance p release. these findings indicate that db exerts anti-inflammatory and analgesic effects by blocking the synthesis and release of substance p through inhibition of cox-2 protein induction and intracellular calcium ion concentration. therefore,db may serve as a promising potent therapeutic agent for treatment of chronic pain,and its effective component cb might partly contribute to anti-inflammatory and analgesic effects. © the japanese pharmacological society.