Evaluation of the In Vitro Antiviral Activity of Salvia halophila and Salvia sclarea Extracts against Human Respiratory Syncytial Virus (HRSV)

Abstract

This study was conducted to investigate the anti-RSV activities of crude methanol and aqueous extracts prepared from Salvia halophila Hedge and Salvia sclarea L. plant species grown in Turkey. Extracts were tested by colorimetric XTT assay. EC50 was defined as the concentration required to achieve 50% protection against virus-induced cytopathic effects, and the selectivity index (SI) was determined as the ratio of CC50 (concentration of 50% cellular cytotoxicity) to EC50. Results showed that methanol extract of Salvia halophila Hedge (EC50: 916.39 ± 5.32 μg/mL and SI: 0.83) and its aqueous extract (EC50: 582.72 ± 11.67 μg/mL and SI: 1.72), likewise methanol extract of Salvia sclarea L. (EC50: 1773.80 ± 3.57 μg/mL and SI: 0.51) and its aqueous extract (EC50: 732.41 ± 11.20 μg/mL and SI: 1.44) values possessed an anti-RSV activity that could be considered weaker than ribavirin (EC50 = 3.46±1.22 μg/mL, SI = 38.73) used as a positive control.