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

TL;DR

Zotatifin, a synthetic compound, shows strong antiviral effects against multiple viruses, including Mayaro, by inhibiting protein synthesis and activating immune responses.

Contribution

Zotatifin's broad-spectrum antiviral activity across five virus families is demonstrated, with distinct molecular mechanisms.

Findings

Zotatifin achieved a >4-log10 reduction in Mayaro virus titers at 50 nM across all cell lines.

The compound inhibited multiple arboviruses, influenza A, vesicular stomatitis, and vaccinia viruses.

Zotatifin down-regulated viral protein synthesis and activated the type I interferon pathway.

Abstract

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.

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