Analgesic roles of aspirin eugenol ester and its mechanisms

The analgesic roles of aspirin eugenol ester(AEE) were investigated by using Writhing test and Hot plate test,while the influence of some drugs,including Diethyldithiocarbamate(DDC),haloperidol(Hal),L-tryptophan(L-Trp) and cyproheptadine(Cyp),on the analgesic effects under heat stimulation were examined.Also,the contents of PGE2 in the whole brain of mice were measured by ultraviolet spectrophotometry.The result showed that both the writhing induced by acetic acid and the paining by thermal stimulation in mice were significantly eased by AEE;the contents of PGE2 in the whole brain of mice were decreased;the algesa induced by DDC was inhibited;a combined effect between Hal and AEE existed,while L-Trp/CYP had significant antagonism to AEE.It suggested that AEE has an obvious analgesic effect which may be related to decreasing the production of the PGE2 in the whole brain of rats,raising the contents of norepinephrine(NE) and blocking-up the dopamine(DA) receptor.