A study of analgesic effect of Zanthoxylum bungeanum Maxim pharmacopuncture

Objectives :This study was carried out to evaluate analgesic effects of Zanthoxylum bungeanum Maxim (ZM) pharmacopuncture on formalin-induced pains in Sprague-Dawley (SD) rats and ICR-mice. Methods : The subjects were divided 8 weeks aged rats with constant pain sensitivity into five groups; normal (treated with normal saline at Taegye (KI3) and before injected with normal saline at hindpaw), Con-1 (treated with normal saline at KI3 before injected with formalin at hindpaw), Lido-1 (treated with lidocaine at KI3), ZMWG-1 (treated with Hot water extraction pharmacopuncture of Zanthoxylum bungeanum Maxim at KI3), ZMEG-1 (treated with ethanol extraction pharmacopuncture of Zanthoxylum bungeanum Maxim at KI3). After 35 minutes, we measured ultrasonic vocalization (USV) and enzyme activities of both Aspartate aminotransferase (AST), Alanine aminotransferase (ALT) in rat serum. In addition, Tail flick test is performed by injecting ICR mice at 5 weeks of age. And it classified into 4 groups (Con-2, Lido-2, ZMWG-2, ZMEG-2) according to the kind of drug (normal saline, lidocaine, ZMW, ZME). After each drug injection, we examined the reaction by placing the tail in water at 50°C. Results : ZME had analgesic effects in the early and late phase of USV during the formalin test. There were no significant differences between ZMEG-1 and Lido-1 in early and late phase of USV. Also, No significant differences observed in serum AST and ALT activity in ZMWG-1 and ZMEG-1 compared with Con-1. For tail-flick test, analgesic effect on warmth significantly increased in Lido-2 and ZMEG-2 compare to that of Con-2. Conclusion : ZME pharmacopuncture had analgesic effects on formalin-induced pain without liver toxicity. Also, tail-flick test suggest that ZME pharmacopuncture could be useful technique on analgesic effect on warmth and treatment of pains.