Mechanisms of Antiviral Activity of the Polyphenol Complex from Seagrass of the Zosteraceae Family against Tick-Borne Encephalitis Virus.

Antiviral activity of the polyphenol complex from seagrass of the Zosteraceae family against highly pathogenic strain of the tick-borne encephalitis virus was studied on passaged culture of porcine embryo kidney cells. The antiviral effect of the test compound manifested in a decrease in the infectious titer of the virus and depended on the concentration and application schemes. Polyphenol complex in a concentration of 100 μg/ml suppressed accumulation of the pathogen in the cell culture: pretreatment of the virus reduced its titer by 4 log, pretreatment of cells by 1.4 log, and application of the compound 1 h after cell infection by 2.8 log. Antiviral action of the test compound is determined by direct inactivation of the virus and inhibition of virus replication at the early stage, which attests to potential of this compound in the treatment of tick-borne encephalitis.