IN VITRO ANTIVIRAL ACTIVITY OF CHESTNUT AND QUEBRACHO WOOD EXTRACTS

Avian reovirus (ARV) and avian metapneumovirus (AMPV) were chosen for an in vitro antiviral screening of three Chestnut (Castanea spp.) wood extracts and a Quebracho (Schinopsis spp.) wood extract, all containing tannins. The MTT assay was used to evaluate the 50% cytotoxic compound concentration (CC50) on Vero cells. Extracellular and intracellular antiviral activities were expressed as IC50 (compound concentration required to inhibit 50% of viral cytopathic effect). CC50s of tested compounds were > 200 µg/ml. All compounds had an extra-cellular antiviral effect against both ARV and AMPV with IC50 values ranging from 25 µg/ml to 66 µg/ml. Quebracho extract had also evident intracellular anti-ARV activity (IC50 24 µg/ml). These preliminary results suggest that the examined plant extracts might be good candidates in the control of some avian virus infections. Nevertheless further in vivo experiments are required to confirm these findings.