e., against HIV, HSV, influenza virus Trichostatin A and HCV) by targeting virus entry, reverse transcription or gene expression. Aims. To investigate the potential antiviral effect of Flavocoxid (containing the natural flavonoids, baicalin and catechin) against HBV and

to verify whether the antiviral control exerted by Entecavir (ETV) in HBV-replicating cells may be enhanced by its use in combination with FLAV. Methods. HepG2 cells were transfected with linear wild-type HBV genomes. HBV replicating cells were treated with different dosages of Flavocoxid to determine the drug inhibitory concentrations (IC50). Treatment with Flavocoxid or ETV or with drugs combination started 3 hours after transfection and was renewed every other day for 7 days. Total HBV replicative intermediates, viral transcripts and cccDNA levels were evaluated in untreated and treated HepG2 cells by quantitative real-time PCR, Southern and Northern blots experiments. To

analyse AZD3965 supplier the epigenetic modulation of HBV cccDNA the cccDNA-ChIP assay was applied to untreated and treated cells Results. The analysis of HBV transcription/replication in the presence or absence of Flavocoxid enabled to determine that IC50 for the drug was 75 μg/mL. HBV replicative intermediates in cell treated with ETV, FLAV, or FLAV + ETV were decreased by 47%, 68%, and 83%, respectively,

compared with untreated HBV-replicating HepG2 cells. After exposure to ETV, FLAV or FLAV + ETV, Northern blot analysis showed that HBV pregenomic RNA levels were decreased this website by 31%, 87%, and 85% respectively, compared with untreated HBV-replicating cells. Levels of HBV cccDNA in the nuclei of cells treated with FLAV or FLAV + ETV were reduced by 34% and 23%, respectively, whereas treatment with ETV, failed to decrease cccDNA. HBsAg amount was reduced by 20%, 75%, and 60% in the supernatant of cells treated with ETV, FLAV, and FLAV + ETV, respectively, compared with untreated cells. Epigenetic analysis showed that cccDNA-bound H4 histones were hypoacetylated in cells treated with ETV, FLAV, or FLAV + ETV and that the recruitment of HDAC1 histone deacetylase was increased at higher levels both in FLAV and FLAV + ETV treated cells. The binding to the cccDNA of NFkB transcriptional regulator was strongly reduced in all treated cells Conclusions. The results of our study demonstrate that Flavocoxid: (a) is capable to inhibit HBV replication, (b) exerts its antiviral activity against HBV at multiple levels and (c) acts synergistically with ETV in a cell-based HBV replication system.