Fig. 4.

Synergistic antiviral effects of nelfinavir and GNA in combination. To mimic the target cells present in the tissue of FCoV-infected cats, fcwf-4 cells were infected with MOI 0.1 of FCoV (20,000 PFU/mL) and then treated with a range of concentrations of each drug alone or in combination for 48 h. The mean plaque reduction rate in different combinations. The presence of the infectious virus in the culture supernatant was measured by plaque assay. When treating with the highest concentration of one of the agents and in combination with the other, a complete blockage was observed. All samples were analyzed in triplicate. Statistical analyses of synergism of antiviral activity were performed using two-way analysis of variance. *A synergistically antiviral effect (P < 0.05).