After further incubation for 24 h, the plates were then scanned by the Typhoon 9410 variable mode imager (Amersham Biosciences; Baie d’Urfe, Quebec, Canada) and VX-680 in vivo the EGFP expression was analyzed by ImageQuant TL software (Amersham Biosciences). Viral inhibition (%) and the EC50 for each compound based on viral EGFP expression were determined as previously reported [33]. For analyzing antiviral activities of the tannins on HCV infection, Huh-7.5 cells (1 × 104 cells/well) were seeded in 96-well plates and the cell monolayer was co-challenged with the viral inoculum and increasing concentration of the test compounds for 3 h. The inoculum and drug mixtures were removed from

the wells, followed by washing with PBS twice and overlaying with DMEM containing 2% FBS. After further incubation for 72 h, the supernatant was collected and then assayed selleck chemicals llc for luciferase activity using the BioLux™ Gaussia Luciferase

Assay Kit (New England Biolabs; Pickering, ON, Canada) and a luminometer (Promega; Madison, WI, USA). HCV infectivity was expressed as log10 of relative light units (RLU) for determining viral inhibition (%) and the EC50 of the drugs against HCV infection was calculated using GraphPad Prism 5 software (San Diego, CA, USA). All values were plotted against the DMSO control treatment of virus infection. Viral inactivation assays Viral inactivation assays were performed as previously described [33] and the incubation periods and viral dose used are listed in Figure 3A. Different viruses were mixed with the test compounds and incubated at 37°C (Figure 3A, long-term). The drug-virus mixtures were subsequently diluted (50 – 100 fold) to “sub-therapeutic” (ineffective) concentrations with low serum medium and then inoculated on to the respective host cells seeded in multiwell plates. The dilution

to sub-therapeutic concentration prevents effective interaction between the drugs and the host cell surface. For comparison, viruses were also mixed with test compounds and immediately diluted (no incubation period) to PJ34 HCl sub-therapeutic concentration prior to infection (Figure 3A, short-term). Following incubation for viral absorption, the diluted inocula were removed and the wells were washed with PBS twice before applying the overlay medium. The plates were further incubated before being subjected to assessment by plaque assays, EGFP expression analysis, or luciferase assay as described above. Figure 3 Inactivation of viral infections by CHLA and PUG. Different viruses were treated with the test compounds for a long period (incubated for 1.5 – 3 h before titration; light gray bars) or short period (immediately diluted; dark gray bars) at 37°C before diluting it 50 – 100 fold to sub-therapeutic concentrations and subsequent analysis of infection on the respective host cells.