In vitro antiviral activity of propolis

The in vitro effect of propolis on several DNA and RNA viruses including herpes simplex type 1, an acyclovir resistant mutant, herpes simplex type 2, adenovirus type 2, vesicular stomatitis virus and poliovirus type 2, was investigated. The inhibition of poliovirus propagation was clearly observed through a plaque reduction test and a multistep virus replication assay with a selectivity index equal to 5. At the concentration of 30 mu g/ml, propolis reduced the titer of herpes simplex viruses by 1,000, whereas vesicular stomatitis virus and adenovirus were less susceptible. In addition to its effect on virus multiplication, propolis was also found to exert a virucidal action on the enveloped viruses HSV and VSV.