In this study, 43 methanolic extracts from 41 different plant species belonging to 27 families (Table 1) were screened for their antiviral activity against herpes simplex virus and influenza virus A by dye uptake assay. By methanolic extraction, a broad spectrum of compounds with different polarity can be obtained. As prerequisite for antiviral tests, the cytotoxicity of the extracts against virus-host cells was investigated. The results are summarized in Table 2 .