Antiviral activities of natural compounds derived from traditional chinese medicines against porcine circovirus type 2 (PCV2)

Twenty natural compounds isolated from traditional Chinese medicines were examined for their antiviral activities against PCV2 in vitro . Antiviral activity was analyzed by the assays of blocking of virus entry, inhibition of virus replication and inactivation of virus particles in the virus suspension. 50% cytotoxic concentration (CC 50 ) and 50% effective concentration (EC 50 ) for each compound were determined by using the MTT method and immunofluorescence assay (IFA), respectively. The results obtained from the inhibition of virus replication and inactivation of virus particles showed that the maximum inhibition rates for matrine and scutellarin were 57 and 72.69% and their SI were 29.87 and 18.66, respectively. However, the results from the assays of inhibition of virus entry and inhibition of virus replication demonstrated that both aesculetin and arecoline hydrochloride stimulated PCV2 replication, with the maximum stimulation rate of 387.3 and 219.4%. In summary, both matrine and scutellarin had antiviral activity against PCV2, while aesculetin and arecoline hydrochloride promoted PCV2 infection replication in vitro .