Fig. 3.

Antiviral activity of silvestrol against (+) ssRNA viruses that utilize canonical (cap-dependent) translation initiation (coronaviruses) or IRES-driven translation initiation mechanisms (members of the genus Enterovirus). Cells were infected with the indicated viruses at an MOI of 0.1 and grown in the presence of different concentrations of silvestrol. Supernatants collected at 24 h p.i. were used to determine viral titers. A, HCoV-229E, MRC-5 cells; B, MERS-CoV, MRC-5 cells; C, HRV A1, MRC-5 cells; D, PV, MRC-5 cells; E, HCoV-229E, PBMCs. Virus titers (in percent) were calculated in relation to infected controls without silvestrol treatment, and EC₅₀ values were calculated using non-linear regression analysis. Experiments were done in biological triplicate.