MECHANISMS OF ANTIVIRAL ACTION OF SEEDS FROM Guettarda angelica Mart. AGAINST BOVINE AND SWINE HERPESVIRUSES IN VITRO

Crude aqueous extract from seeds (AEs) of Guettarda angelica Mart. (Rubiaceae) presented in vitro antiviral activity against bovine (BoHV-1) and swine (SuHV-1) herpesviruses type 1 in our previous studies. The aim of the current work was to continue the studies with this extract in order to determine its mode of antiviral action on these two animal herpesviruses. For this, at non cytotoxic concentration (40 µg/mL), the AEs extract was added at different times to the cells or viruses during infection. The antiviral tests were performed using the viral titer reduction assay and expressed in inhibition percentage (IP). The mechanism studies showed that AEs blocked BoHV-1 binding to MDBK cells in 99%; inhibited both during and after virus adsorption by more than 97% for both viruses. Moreover, AEs inactivated both viruses extracellular and directly by 99%. These results indicate that AEs has a broad spectrum of action since it was able either to exert a direct virucidal effect or to present an antiviral activity before and after the attachment phase. Seeds of G. angelica might be a promising source of antiviral agents and merits further investigation. DOI:  http://dx.doi.org/10.17525/vrr.v15i2.46