The review considers potential opportunities of certain antioxidants as antiviral agents for flavivirus infections. Currently flavivirus infections represent a significant public health problem for various regions of the world, since they result in high morbidity and mortality. Oxidative stress induced by viruses, including the flaviviruses, not only interferes with the body's important metabolic processes, but also regulates replication of the virus. A broad spectrum of antiviral activity of the natural phenolic antioxidants, i.e. rosmarinic acid and luteolin as components of the polyphenol complex isolated from the seagrass family Zsteraceae is decribed. The antiviral activity of rosmarinic acid and luteolin is shown to be due to their high antioxidant, antiinflammatory and neuroprotective potential. Particular attention is paid to the analysis of the activity of the polyphenol complex and its components against the tickborne encephalitis virus. The antiviral properties of the compounds with a broad spectrum of the biological action provide an oppor- tunity to consider them as promising candidates for combined therapy of tick-borne encephalitis.