Antinociceptive and anti-inflammatory effect of the Scutia buxifolia Reissek stem barks extract.

Abstract Background Scutia buxifolia (Rhamnaceae) has been extensively studied for its phenolics groups, which are able to capture free radicals; being therefore, considered promising as an antioxidant in preventing diseases resulting from oxidative stress. Hypothesis Scutia buxifolia extract (SBE) presents antinociceptive and anti-inflammatory effect in mice. Study Design SBE (400–800 mg/kg) was tested in different pain models to investigate its antinociceptive and anti-inflammatory action. Methods It was carried out the abdominal writhing test, capsaicin test, thermal hyperalgesia and incisional pain. The inflamed tissue by carrageenan was used for the analysis of interleukins (IL), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), c-reactive protein (CRP), nitrite and nitrate (NOx) determination and myeloperoxidase (MPO) activity. Furthermore, we evaluate the possible action mechanism of SBE using naloxone in capsaicin test. Results SBE prevented the nociception caused by acetic acid, formalin and capsaicin test. However, neither the SBE prevented the thermal hyperalgesia in hot-plate test, nor the naloxone reversed the SBE antinociceptive effect in capsaicin test. Furthermore, the administration of SBE prevented significantly the increase of MPO activity, the NOx content, and the levels of IL-1, IL-6, TNF-α, INF-γ and CRP and was able to increase the IL-10 levels after the inflammation induced by carrageenan in mice. In addition, SBE prevented mechanical hyperalgesia in a postoperative pain model. Conclusion The SBE presents great antinociceptive and anti-inflammatory activity in mice but this effect not seem to have its action mechanism like opioids. It is possible that its antinociceptive effects are associated with levels decrease of inflammatory mediators.