Liriodenine is a potent inhibitor of topoisomerase II (EC 5.99.1.3) both in vivo and in vitro, it has antitumor, antibacterial and antifungal activities, it can suppress ventricular arrhythmias induced by myocardial ischaemia reperfusion, through inhibition of Na+ and the Ito channel. Liriodenine also has antimuscarinic properties, the antimuscarinic characteristics are similar to those of 4-diphenylacetoxy-N-methylpiperidine (4-DAMP, smooth muscle selective M3 antagonist), it may act as a selective M3 receptor antagonist in canine tracheal smooth muscle.

The present study therefore investigated the potential antitumor effects of Liriodenine on HEp-2 human laryngocarcinoma cells in vitro and HEp-2-implanted nude mice in vivo. Liriodenine induced significant apoptosis and inhibition of cell migration in the HEp-2 cells. Furthermore, the rate of tumor growth in the HEp-2-implanted nude mice was inhibited by the administration of Liriodenine. The potential mechanism underlying the antitumor effects of Liriodenine may result from an upregulative effect upon p53 expression, which ultimately induces cellular apoptosis. By contrast, the downregulation of p53 significantly reduced the antitumor effects of Liriodenine[1]