Efficacy of sodium polyanethol sulfonate on herpes simplex virus-1 infection in vitro

Objective: To investigate the effect of sodium polyanethol sulfonate (SPS) on herpes simplex virus type 1 (HSV-1) infection in vitro. METHODS: Human corneal epithelial (HCE-T) cells and Vero cells were infected with HSV-1 [HSV-1 f strain, HSV-1f; HSV-1-H129 with green fluorescent protein (GFP) knock-in, HSV-1g]. SPS was added to the culture medium at various concentrations in time-of-addition assay. Experiments including photography of fluorescence in HSV-1g or plaque formation by HSV-1f, western blot assays, real-time RT–PCR assays, cytopathic effect inhibition assays, cytotoxicity assays, and viral absorption and penetration assays were performed to explore the antiviral effect and mechanism of the compounds. RESULTS: We identified that SPS reduced the replication of HSV-1 in HCE-T and Vero cells in a dose-dependent manner. HSV-1g fluorescence was reduced by 66.3% and 65.4% in HCE-T and Vero cells, respectively, after treatment with 0.4 µg/ml SPS. Furthermore, the viral fluorescence intensities were inhibited by SPS in a dose-dependent manner when the viruses or cells were preincubated with SPS. Relative levels of the ICP4 protein and VP16 mRNA were decreased by SPS in a dose-dependent manner. Moreover, the IC(50) values of SPS for HSV-1g and HSV-1f in HCE-T cells were 0.69±0.09 μg/ml and 1.63±0.44 μg/ml, respectively. Even 10,000 µg/ml SPS had no obvious cytotoxicity toward HCE-T and Vero cells. Importantly, viral absorption and penetration assays showed that the relative fluorescence intensity of HSV-1g was significantly reduced by SPS in a dose-dependent manner in the absorption test, but no change was observed in the penetration test. CONCLUSIONS: SPS inhibits HSV-1 replication in HCE-T and Vero cells, indicating that SPS has the potential for treating HSV-1 infection, particularly HSV-1 keratitis.