Study on the Antinociceptive Effects of Herba Epimedium in Mice.

The present study was conducted to investigate the antinociceptive action of relationship between Herba Epimedium (HE) and 5-HT1A receptor, between Herba Epimedium (HE) and 5-HT2A receptor. We used the hot-plate method and the writhing assay in mice by the intracerebroventricular (i.c.v.) injection and observed the analgesic effect of HE. Furthermore, through the i.c.v. injection, 5-HT1A receptor partial agonist Buspirone, antagonist Propranolol, the adrenaline ß 1-receptor selective blocking agent Metoprolol, and 5-HT2A receptor agonist hydrochloride DOI and antagonist Ketanserin were used, and, 5 min later, HE was used to investigate the impacts of drugs on the analgesic effect in the same way. Results showed that HE had fast and significant antinociception in nervous system, and the effects can persist for a long time. Buspirone and Hydrochloride DOI can remarkably increase the antinociception of HE in nervous system. Ketanserin leads to a significant decrease in its antinociception in nervous system; Metoprolol also has antinociceptive action in nervous system, but it can inhibit the antinociceptive effect of Herba Epimediumin peripheral region. These results suggest that HE has significant antinociception effect and its mechanism is related with 5-HT1A receptor, 5-HT2A receptor, and adrenaline ß 1-receptor.