Anti-inflammatory and antipyretic effects of boldine.

Boldine, an antioxidant alkaloid isolated from Peumus boldus, exhibits a dose-dependent anti-inflammatory activity in the carrageenan-induced guinea pig paw edema test with an oral ED50 of 34 mg/kg. Boldine also reduces bacterial pyrogen-induced hyperthermia in rabbits to an extent which varied between 51% and 98% at a dose of 60 mg/kg p.o. In vitro studies carried out in rat aortal rings revealed that boldine is an effective inhibitor of prostaglandin biosynthesis, promoting 53% inhibition at 75 microM. The latter in vitro effect may be mechanistically linked to the anti-inflammatory and antipyretic effects of boldine exerted in vivo.