Introduction: The application of herbal plants instead of synthetic drugs is increasing in recent years because of their lower side-effects and high varieties of efficient components. The aim of the present study was to evaluate the antinociceptive effects of hydroalcholic extract of grape seed using hot plate and formalin test.

  Methods: This experimental study has been done on 56 NMRI male mice
(28±3 g) (n = 7 in each group) in weight. The hot plate and formalin test were used for acute and chronic pain. After preparation of extract, to evaluate the effect of pain related behaviors on antinociception, animals systemically received grape seed extract (75, 150, 300, mg/kg) and after 30 min pain related behaviour was monitored in formalin and for hotplate tests. The data was analyzed using SPSS software and ANOVA at significance level p < 0/05.

  Results: The results showed that hydroalcholic Grape seed extract (75, 150, 300, mg/kg), significantly can induce antinociception in both phases of formalin test. Also, the Grape seed extract caused delay in painful behaviours (licking and jumping) in hot-plate test.

  Conclusion: The present results show that hydroalcoholic extract of grape seed has analgesic properties in response to acute and chronic pain in the formalin with hot plate tests and can be substituted for chemical analgesic drugs.