In Vitro Antiviral Activities of Scutellaria rubicunda Hornem. subsp. pannosula and Scutellaria salviifolia Extracts against Respiratory Syncytial Virus (RSV)

Abstract

In this study, the antiviral activities of the water extracts of two Turkey-endemic species Scutellaria rubicunda subsp. pannosula and Scutellaria salviifolia against human respiratory syncytial virus (RSV), using XTT-based colorimetric cytotoxicity test were investigated for the first time. For this purpose, Hep-2 cells were infected with RSV and then were cultured with hot water extract of S. rubicunda subsp. pannosula or S. salviifolia. The antiviral activity of EC₅₀ was defined as the concentration achieved 50% cyto-protection against virus infection and the selectivity index (SI) was determined by the ratio of CC₅₀ (concentration of 50% cellular cytotoxicity) to EC₅₀. Results showed that water extract of S. rubicunda subsp. pannosula has not anti-RSV activity.  In contrast, the water extract of S. salviifolia exhibited a significant  antiviral effect against RSV with a CC₅₀ value of 94.18 µg/ml and a SI value of 34.16. We suggest that S. salviifolia might be a useful medicinal plant against infection of RSV.

Keywords: Scutellaria species, Colorimetric XTT assay, Antiviral activity, Human respiratory syncytial virus