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.