A comparison Comparison between analgesic effects of aqueous ethanolic extract of mentha longifolia and morphine in male rats

Long-term consumption of many drugs followed by reduction of their effectiveness has necessitated performing research on new analgesics. Thus، the present study was conducted to evaluate the analgesic effects of mentha longifolia and morphine in mice using writhing and hot plate tests. In this experimental study، 70 male rats were divided into 7 equal groups. The groups included the control، three experimental groups receiving 400، 800، or 1600 mg/kg of mentha extract and three experimental groups which received 2، 4، or 8 mg/kg of morphine. In order to measure pain، the two acceptable tests، writhing and hot plate tests، were applied. Pain scores were measured at 0، 15، 30، 45 or 60 min after administration of algogenic stimulus. It was found that in hot plate test، only the dose of 1600mg/kg of Mentha extract after 60 minutes was significantly able to exert an analgesic effect (P<0. 05). In wrighting test، mentha extract at different doses significantly reduced the number and time of wrightes in the rats، comparable to morphine (P<0. 05). It seems that all doses of mentha extract in wrighting test have analgesic effects which indicate chronic pain inhibition of mentha hydroalcholic extract.