RESUMO
The present study was conducted to assess the anti-inflammatory effect of a crude aqueous extract of Blxa orellana leaves [AEBO] and to examine the possible involvement of nitric oxide [NO] in its anti-inflammatory mechanism. The air-dried, powdered leaves were soaked in distilled water [1:20 w/v] at 50°C for 24 h and the supernatant obtained was freeze-dried [yield 8.5% w/w]. The dosage was recorded as the mass of extract per kg b.w. of rats in all inflammatory assays [bradykinin-in-duced paw edema, peritoneal vascular permeability and NO assay]. Pretreatment with AEBO for 4 consecutive days exhibited significant inhibitory activity against inflammatory models, the bradykinin-induced hind paw edema model and bradykinininduced increased peritoneal vascular permeability at both doses in dose-dependent manner. In addition, AEBO was also found to significantly suppress the production of NO at doses of 50 and 150 mg/kg. This study provides scientific data to support the tradi-tional use of B. orellana leaves in treating inflammation. Results from this study suggest that AEBO exerts anti-inflammatory effects. Part of this anti-inflammatory effect may be associated with its antibradykinin activity and may be related to a reduction of the NO production