Antiviral activity of Veronica persica Poir. on herpes virus infection

The lack of an effective anti-viral agent and the emergence of drug-resistant strains dictate a real need for discovery of novel therapies able to ameliorate viral infections. In this regards, medicinal plants and natural products offer safe and inexpensive platforms for discovery of efficient and novel anti-viral agents. We have investigated the potential anti-viral activities of Veronica persica Poir.  as a medicinal plant against herpes simplex viruses (HSVs). In vitro screening of the ethanol plant extract against HSV-1 and HSV-2 infected Vero cells revealed the extract to show a dose-dependent inhibitory activity against both virus strains. After fractionation of the extract by a stepwise methanol gradient and evaluation of each fraction, the 80% methanol fraction displayed a pronounced inhibitory activity against the herpes viruses. The highest antiviral activity was observed when the Vero cells were treated with the extract both during and after infection by viruses. Moreover, the extract showed a prominent synergistic activity in combination with acyclovir anti-HSV therapy. Our findings revealed the potential of V. persica extract, especially its 80% methanol fraction, in inhibition of herpes simplex viral infections.