Broad-spectrum antiviral activity of the synthetic rocaglate zotatifin against multiple viruses

Viruses pose a significant threat to global public health, yet therapeutic options are limited. Zotatifin, a synthetic rocaglate, targets eukaryotic initiation factor 4A (eIF4A), thereby inhibiting viral protein synthesis and triggering an interferon response. Whether zotatifin exhibits broad-spectrum antiviral activity is unknown. Here we evaluated zotatifin’s cytotoxicity using the MTT method and its antiviral activity using plaque-forming assays, Western blot analysis, immunofluorescence, and flow cytometry across multiple cell lines and virus strains. Zotatifin demonstrated better tolerability than rocaglates rocaglamide A and CR-1-31-B. The compound exhibited potent, dose-dependent inhibition of the Mayaro virus, achieving greater than a 4-log reduction in viral titers at a 50 nM dose, regardless of the cell line or virus strain tested. In addition, zotatifin was effective to inhibit multiple arboviruses (Chikungunya, Una, and Zika), influenza A virus, vesicular stomatitis virus, and vaccinia virus. Zotatifin down-regulated viral protein synthesis for all viruses tested and analysis of gene expression using RT-qPCR revealed activation of the type I interferon pathway in zotatifin-treated cells. Taken together, these results suggest that zotatifin exhibits broad-spectrum antiviral activity against five virus families, likely via several molecular mechanisms. This work supports the potential therapeutic use of zotatifin as a pan-antiviral drug in humans.