Antiviral Activity of Lady's Mantle (Alchemilla vulgaris L.) Extracts against Orthopoxviruses.

We studied toxicity and antiviral activity of bioactive substances extracted from the roots (ethylacetate extracts) and aerial parts (ethanol extracts) of lady's mantle (Alchemilla vilgaris L.). Plant extracts are characterized by low toxicity for continuous Vero cell culture, but inhibit the reproduction of orthopoxviruses (vaccinia virus and ectromelia virus) in these cells. Of all studied extracts, ethylacetate extract from lady's mantle roots characterized by the highest content of catechins in comparison with other samples demonstrated the highest activity in vitro towards the studied viruses (neutralization index for vaccinia and ectromelia viruses were 4.0 and 3.5 lg, respectively). The antiviral effect of Alchemilla vulgaris L. extracts was shown to be dose dependent.