title: Antiviral mode of action of a synthetic brassinosteroid against Junin virus replication.
abstract: The antiviral mode of action of the synthetic brassinosteroid (22S,23S)-3beta-bromo-5alpha,22,23-trihydroxystigmastan-6-one (6b) against Junin virus replication in Vero cells was investigated. Time-related experiments showed that 6b mainly affects an early event of virus growth cycle. Neither adsorption nor internalization of viral particles was the target of the inhibitory action. The analysis of the effect of 6b on viral RNA synthesis demonstrated that the presence of the compound adversely affects virus RNA replication by preventing the synthesis of full length antigenomic RNA. Although 6b was most effective the earlier it was added to the cells after infection with JV, a high level of inhibition of JV yield and fusion activity of newly synthesized viral glycoproteins was still detected when the compound was present during the last hours of infection. Therefore, we cannot rule out an inhibitory action of 6b on later events of JV replicative cycle.
authors.affiliation: Laboratorio de Virología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Piso 4, 1428 Buenos Aires, Argentina. viviana@qb.fcen.uba.ar
authors.forename: Viviana
authors.initials: V
authors.lastname: Castilla
authors.forename: Mariano
authors.initials: M
authors.lastname: Larzábal
authors.forename: Natalia Aguirre
authors.initials: NA
authors.lastname: Sgalippa
authors.forename: Mónica B
authors.initials: MB
authors.lastname: Wachsman
authors.forename: Celia E
authors.initials: CE
authors.lastname: Coto
mesh_terms: D000818:Animals; D000998:Antiviral Agents; D002459:Cell Fusion; D002460:Cell Line; D002522:Chlorocebus aethiops; D002778:Cholestanones / Q000138:chemical synthesis / Q000494:pharmacology*; D006224:Cricetinae; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D015726:Giant Cells / Q000187:drug effects; D047468:Immunoprecipitation; D018051:Junin virus / Q000187:drug effects*; D012367:RNA, Viral / Q000096:biosynthesis / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014709:Vero Cells; D014764:Viral Proteins / Q000096:biosynthesis; D014779:Virus Replication / Q000187:drug effects*
chemical_list: C493970:3-bromo-5,22,23-trihydroxystigmastan-6-one; D000998:Antiviral Agents; D002778:Cholestanones; D018076:DNA, Complementary; D012367:RNA, Viral; D014764:Viral Proteins