Tanacetum vulgare: antiherpes virus activity of crude extract and the purified compound parthenolide.

The present study demonstrated that the ethyl acetate extract and the isolated compound, parthenolide, from aerial parts of Tanacetum vulgare L. (Asteraceae), protected Vero cells from herpes simplex virus (HSV-1) infection in vitro. The extract and parthenolide were assayed against HSV-1 by the sulforhodamine B colorimetric assay and exhibited anti-HSV-1 activity with an EC(50) of 40 microg/mL and 0.3 microg/mL, respectively. In order to determine which stage of the virus-cell interaction was affected by parthenolide, the pure compound was used. No effect was observed when both viruses and cells were pretreated, or during early stages of infection, suggesting that parthenolide interfered with virus replication after the penetration stage, inhibiting approximately 40% of plaques formed at a concentration of 2.5 microg/mL when compared with an untreated control. (c) 2009 John Wiley & Sons, Ltd.