Antiviral activity of scillarenin, a plant bufadienolide.

Abstract

Antiviral activity of scillarenin, a plant bufadienolide, and its mode of action were studied. Scillarenin selectively inhibited replication of picornaviruses, in particular, rhinovirus. At concentrations inhibiting rhinovirus replication, scillarenin had no effect on the synthesis of macromolecules in host cells. The action of scillarenin was not direct inactivation of virus. Scillarenin could inhibit virus replication when given at the latter half of latent period, although this treatment did not interfere with the normal level of viral RNA synthesis. The RNA synthesized in the presence of this compound showed the same sedimentation coefficient as normal viral RNA but possessed a reduced infectivity.