Zingiber officinale Extract Inhibits Entry of SARS-CoV-2 D614G Virus-Like Particles to 6HBE14o-cells: In Vitro and In Silico Approaches

Global public health systems are facing challenges due to the COVID-19 pandemic, which is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Given increasing interest in plant-based antivirals, this study determined the potential of ethanol extract of red ginger (Zingiber officinale) to inhibit the attachment of SARS-CoV-2 virus-like particles (VLPs) to human bronchial epithelial cells. SARS-CoV-2 VLPs carrying the D614G spike mutation were generated in HEK293T cells using plasmids encoding the envelope (E), membrane (M), and spike-EGFP fusion proteins. EGFP was used to visualize and quantify VLP attachment. VLP formation was confirmed by fluorescence microscopy and transmission electron microscopy. Cells were exposed to 200 ng/mL of VLPs together with Z. officinale extract at 0.67 to 20 µg/mL for 24-48 h, and viral attachment was quantified via EGFP fluorescence intensity. For in silico analysis, identified compounds of Z. officinale extract were screened based on drug-likeness parameters for further processing to molecular docking and molecular dynamics simulations. The results showed that treatment with Z. officinale extract significantly reduced VLP attachment at concentrations of 0.67–10 µg/mL after 24 h. After 48 h, the lowest concentrations (0.67 and 1.25 µg/mL) maintained inhibitory effects from SARS-CoV-2 VLP, as indicated by reduced EGFP fluorescence. Of the 22 initially screened compounds, 9 met drug-likeness parameters. Among these, (2E)-3-(3,4-dimethoxyphenyl)prop-2-enoic acid and ferulic acid exhibited the strongest binding affinities to the SARS-CoV-2 spike protein (-5.3 and-5.5 kcal/mol, respectively). These findings suggest that Z. officinale contains bioactive compounds with potential as antiviral agents targeting SARS-CoV-2 variants.