Antiviral effect of a synthetic brassinosteroid on the replication of vesicular stomatitis virus in Vero cells.

The antiviral mode of action of the synthetic brassinosteroid (22S,23S)-3beta-bromo-5alpha,22,23-trihydroxystigmastan-6-one (6b) against replication of vesicular stomatitis virus (VSV) in Vero cells was investigated. Time-related experiments showed that 6b mainly affects a late event of the virus growth cycle. Virus adsorption, internalisation and early RNA synthesis are not the target of the inhibitory action. Results obtained indicate that the antiviral compound adversely affects virus protein synthesis and viral mature particle formation.