Analgesic Effect of DA-5018, a New Capsaicin Derivative, against Experimental Acute Pain

새로운 캅사이신 유도체 DA-5018의 급성통증 모델에서의 진통작용

Analgesic effect of DA-5018, a new capsaicin derivative, was evaluated in various rat models of experimentally induced acute pain. DA-5018(0.2∼10.0 mg/kg, p.o.) prevented the writhing syndromes induced by acetic acid or phenol-p-benzoquinone(PBQ). It increased the pain threshold of inflamed paw when tested by the Randall-Selitto method at the dose of 2.0∼20.0 mg/kg by oral administration. And also it showed antinociceptive activities in tail-pinch(1.0∼20.0 mg/kg, p.o.) and tail-flick test(5.0∼50.0 mg/kg, p.o.). the potency and efficacy of DA-5018 were comparable to morphine · HCI in all the models mentioned above. Acetaminophen exhibited the inhibition of acetic acid-induced writhing syndromes and also analgesic activity in Randall-Selitto test, but it showed the limited efficacy in tail-pinch and tail-flick test. These results mean that DA-5018 has a broader analgesic activity profile than acetaminophen. And we found out that the analgesic activity of DA-5018 was 100 times more potent when administered centrally than administered orally in tail-flick test. These results suggest that DA-5018 has an orally active analgesic activity, and central nervous system may be involved in the action of DA-5018.