Further investigations on the antiviral activities of medicinal plants of Togo

Further studies were done on the antiviral activities of 10 species of Togolese medicinal plants, previously shown to possess activity against herpes simplex virus (HSV). The dominant activity in all cases was virucidal (direct inactivation of virus particles), although Adansonia digitata extracts also appeared to have intracellular antiviral activities as well, which could indicate the presence of multiple antiviral compounds, or a single compound with multiple actions. In the seven most active extracts, the anti-HSV activity was considerably enhanced by light, especially UVA (long wavelength UV), although they all showed “dark” antiviral activity as well. Thus, all the extracts contained antiviral photosensitizers. In all tests, the root-bark and leaf extracts of A. digitata were the most potent.