In vitro inhibitory activities of Lauraceae aporphine alkaloids.

The in vitro anti-inflammatory effect of eight aporphine alkaloids isolated from the leaves of two Lauraceae plants (Pleurothyrium cinereum and Ocotea macrophylla) was evaluated through inhibition of two isozymes of cyclooxygenase (COX-1 and COX-2), 5-lipoxygenase (5-LOX), and platelet aggregation induced by PAF, AA and ADP. All alkaloids exhibited inhibitory activities against COX-2 (IC50 25.9-116 microM range) and PAF- and AA-induced platelet aggregation, while only four and three of them were good COX-1 and 5-LOX inhibitors, respectively. (+)-N-acetyl-nornantenine 6 was the most potent COX-2, 5-LOX, AA and PAF inhibitor.