Antiviral activity of seven iridoids, three saikosaponins and one phenylpropanoid glycoside extracted from Bupleurum rigidum and Scrophularia scorodonia

As part Of Our screening of antiviral agents from medicinal plants, 11 compounds from plant origin (Bupleurum rigidum and Scrophularia scorodonia), three saikosaponins, seven iridoids and one phenylpropanoid glycoside were tested in vitro against herpes simplex type 1 (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. Five of these compounds showed antiviral activity against VSV. The percentages of cellular viability at the non-toxic limit concentrations of the active compounds were: verbascoside 53.6% at 500mug/ml, 8-acetylharpagide 32.1% at 500 mug/ml, harpagoside 43.3 % at 450 mug/ml, scorodioside 47.8 % at 500 mug/ml and buddlejasaponin IV 56.9% at 25 mug/ml. Although none of the saikosaponins were active against HSV-1, the iridoid scorodioside showed moderate in vitro anti-HSV-1 activity (30.6% at 500 mug/ml). However, none of the compounds tested in this survey had any effect against poliovirus.