title: Mechanism of action of the antiherpesvirus biflavone ginkgetin.
abstract: Screening of plant extracts found that a biflavone from Cephalotaxus drupacea, which was found to be ginkgetin, is active against herpes simplex virus type 1 (HSV-1). This compound caused dose-dependent inhibition of virus replication with a 50% cytotoxic activity at 12.8 micrograms/ml and 50% anti-HSV-1 activity at 0.91 micrograms/ml, the therapeutic index being 14.1. Ginkgetin also showed inhibitory effects against HSV type 2 and human cytomegalovirus with therapeutic indices of 13.8 and 11.6, respectively. Ginkgetin had a weak virucidal activity against HSV-1 at more than 5 micrograms/ml. Both adsorption of HSV-1 to host cells and virus penetration into cells were unaffected by this agent. Ginkgetin suppressed viral protein synthesis when added at various steps of HSV-1 replication and exerted strong inhibition of transcription of the immediate-early genes.
authors.affiliation: Department of Virology, School of Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: N
authors.initials: N
authors.lastname: Morita
mesh_terms: D000327:Adsorption; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D044946:Biflavonoids; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D004279:DNA, Viral / Q000032:analysis / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D005419:Flavonoids / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D018139:Simplexvirus / Q000187:drug effects* / Q000502:physiology; D014709:Vero Cells; D014764:Viral Proteins / Q000096:biosynthesis; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D044946:Biflavonoids; D004279:DNA, Viral; D005419:Flavonoids; D014764:Viral Proteins; C077458:ginkgetin