A study on the site of antinociceptive effect of Trigonella foenum graecum (TFG) leaves extract in phasic and tonic models of pain

  There are several reports on the therapeutic effects of TFG in Iranian traditional medical literature such as antinociceptive, antipyretic, and anti-inflammatory, antidiabetic and antidiuretic effects. The anti-inflammatory and anti-pyretic effects of TFG have been confirmed in experimental models. In the present study, the antinociceptive effect of TFG extract in formalin and tail flick tests and its site of action were investigated on NMRI rats (220 ± 20 g). The TFG extract was administered by three routes, i.e. i.c.v., i.t. and i.p. at different doses. The effect of i.p. administration was also examined in tail flick test. The results showed that i.p. administration of aqueous extract of TFG leaves induced analgesia in tail flick and both phases of formalin test. The i.t. administration at doses of 0.5, 1, 2 and 3 mg/rat showed significant antinociceptive effect in formalin test, however i.c.v. administration of extract had no antinociceptive effect. The results of the present study supported the facts that: 1) TFG extract has antinociceptive effect in first and second phases of formalin and tail flick tests and 2) the site of its action in the first and second phase of formalin test might be at spinal cord and with regard to its anti-inflammatory effect, peripheral mechanisms may be involved in its analgesic effect in the second phase of formalin test.