A comparison between the analgesic effect of tragacanth gum, diclofenac and morphine in mice using writhing and hot-plate analgesic tests

Some of medicinal plants have been used for pain reliving in Iarnian ancient medicine. Astragalus gummifer (AG) is one of them and its gum (tragacanth gum) were used for several health purposes. The present study was conducted to evaluate the analgesic effects of this gum in mice. In this study, the analgesic effect of tragacanth gum was determined using hot-plate and writhing tests. Mice were injected with tragacanth gum at doses of 125, 250 or 500 µg/kg i.p. as treatment groups. Morphine at doses of 2, 4 or 8 µg/kg i.p., and diclofenac at doses of 10, 20 or 30 µg/kg i.p. were used as control groups. In writhing test, gum tragacanth at different doses (125, 250, and 500 µg/kg) significantly reduced the number of writhings in mice as compared to control group (p<0.05). In hot-plate test, maximum possible effect of tragacanth gum significantly increased only after 15 minutes but not in other time periods. In two models of pain assesment, both morphine sulfate and diclofenac sodium had also pain relieving potential. Coclusion: The present study indicated that tragacanth gum elicits prominent analgesic effects in an experimental model of acute and chronic pain. Additionally, data obtained in this study indicated the presence of some constituents with pain releiving properties that confirms the traditional use of the gum for pain relieving purposes.