Antiviral Activity of the Polyene Macrolide Roseofungin Against Influenza a Virus: In Vitro, In Ovo, and Preliminary In Vivo Evaluation.

Roseofungin, a polyene macrolide antibiotic produced by Streptomyces roseoflavus, was evaluated for antiviral activity against Influenza A virus using complementary in vitro, in ovo, and preliminary in vivo toxicity models, supported by molecular docking and molecular dynamics simulations. The compound exhibited antiviral activity against multiple influenza A virus subtypes, including an oseltamivir-resistant H1N1 strain, with EC50 values ranging from 2.0 to 2.5 μg/mL and selectivity indices of 20-25. Functional assays demonstrated that roseofungin interfered with early stages of the viral life cycle by reducing viral adsorption and partially inhibiting neuraminidase activity. In virucidal assays, treatment with roseofungin resulted in a 1.5-2.5 log10 reduction in infectious viral titers. Acute toxicity studies in mice indicated low toxicity under the experimental conditions (LD50 > 25 mg/kg). Molecular docking predicted favorable interactions of roseofungin with multiple influenza A virus proteins. Subsequent molecular dynamics simulations of the hemagglutinin-roseofungin complex maintained the stability of the predicted binding mode across three independent 50 ns simulations (150 ns cumulative). Collectively, these findings demonstrate that roseofungin possesses broad-spectrum antiviral activity against genetically diverse Influenza A virus strains and represents a promising lead compound for the development of novel membrane-active antiviral agents. Further studies are warranted to elucidate its molecular mechanism of action and to evaluate its therapeutic potential in vivo.