Broad-spectrum antiviral activity of the synthetic rocaglate zotatifin against Mayaro virus and other viruses.

Viruses pose a significant threat to global public health, yet therapeutic options remain limited. Zotatifin, a synthetic rocaglate targeting eukaryotic initiation factor 4A (eIF4A), inhibits viral protein synthesis and potentially triggers interferon responses; however, its broad-spectrum antiviral potential remains unclear. We evaluated zotatifin's cytotoxicity using MTT assays and assessed its antiviral activity through plaque-forming assays, Western blot analysis, immunofluorescence, and flow cytometry across multiple cell lines and virus strains. Zotatifin demonstrated superior tolerability compared to rocaglamide A and CR-1-31-B. The compound exhibited potent, dose-dependent inhibition of Mayaro virus, achieving a >4-log10 reduction in viral titers at 50 nM across all cell lines or virus strains tested. Zotatifin also effectively inhibited multiple arboviruses (Chikungunya, Una, and Zika viruses), influenza A virus, vesicular stomatitis virus, and vaccinia virus. Mechanistically, Zotatifin down-regulated viral protein synthesis for all viruses tested, and RT-qPCR analysis revealed activation of the type I interferon pathway in treated cells. Collectively, these results demonstrate that zotatifin exhibits broad-spectrum antiviral activity against five virus families, through different molecular mechanisms, supporting its potential therapeutic use as a pan-antiviral drug in humans.