[Antiviral activity of plant components. 1st communication: Flavonoids (author's transl)]

Some drugs effective against influenza contain flavonoids. We therefore examined the antiviral effect of hesperidin, hesperidinmethylchalcon, trihydroxyethylrutin, catechol, quercitrin, rutin and aurantiin against vesicular stromatitis virus (VSV) action on mouse fibroblasts and that of hesperidin against influenza virus in HeLa cells system by means of dye uptake measurements (Finter) and by plaque reduction test, respectively. Preincubation of the cells with the flavonoids 6--8 h before virus addition was inevitable. Protection of cells against virus action persisted for about 24 h and it abruptly disappeared after an addition of hyaluronidase. Maximal inhibition of virus action was achieved with a concentration of 200 microgram/ml flavonoid.