Anti-nociceptive effects of DAACS water extract

Direct reflux and TLC methods were used to isolate and identify de-aristolochic acid Aristolochia tuberosa C. F. Liang et S. M. Hwang (DAACS). Different doses of DAACS were administered intragastricly (i.g) and methods of hotplate, writhing, hot-bathing and tail-flick method were used to observe anti-nociceptive effects of DAACS; β-Endorphin (β-EP) and prostaglandin E2 (PGE2) contents of mice were detected with radioimmunoassay (RIA) to explore the anti-nociceptive mechanisms of DAACS. The results showed that DAACS (0.4, 0.8, 1.6 g·kg-1) could prolong mice´ responsive latencies to hotplate significantly compared with those in the control group, delay writhing latencies of mice and reduce their writhing times, delay tail-flick latencies of mice, and reduce contents of β-EP in brain and PGE2 in liver tissue of formalin-treated mice significantly. DAACS would produce anti-nociceptive effects and its anti-nociceptive mechanism may be related to its effect on β-EP in brain and PGE2 in liver tissue of mice.