Anti-allergic effects of natural tetranortriterpenoids isolated from Carapa guianensis Aublet on allergen-induced vascular permeability and hyperalgesia

Abstract.

Objective: We investigated the anti-allergic and analgesic properties of an oil and a derived fraction of tetranortriterpenoids (TNTP) obtained from the seeds of Carapa guianensis Aublet.

Materials and methods: Pleurisy, paw and ear edema were induced in Swiss and C57/Bl10 mice mice, whereas thermal hyperalgesia was assessed in Wistar rats (n = 6−10 per group). Values of p < 0.05 were regarded as significant.

Results: C. guianensis oil (100 to 400 mg/kg, p.o.) and TNTP (12.5 to 100 mg/kg, p.o.) inhibited pleural exudation, paw and ear edema induced by ovalbumin (OVA) in sensitized mice. TNTP (12.5 to 100 mg/kg, p.o.) also inhibited paw edema induced by histamine, PAF and bradykinin. TNTP (100 mg/kg, p.o.) inhibited prostaglandin E₂ generation in the pleural cavity in response to antigenic challenge. Moreover, C. guianensis oil (100 to 400 mg/kg) and TNTP (12.5 to 100 mg/kg) decreased OVA- and histamine-induced hyperalgesia.

Conclusion: Taken together, these findings demonstrate the anti-edematogenic and analgesic effects of C. guianensis oil, and points out TNTP as the responsible bioactive compounds.