Exploring the potent in vitro antiviral activity of Faramir®: A tailored Salvia officinalis extraction utilizing the sequential solvent polarity method

Abstract

Salvia officinalis, known as Sage, serves as a rich source of natural compounds that exhibit antioxidant, anti-inflammatory activities. Antioxidant activity has been demonstrated to be enhanced when medicinal herbs are extracted using sequential polar solvents, as revealed by previous studies. In this study, we examined the antiviral potential of Sage extract through successive extractions using organic solvents of increasing polarity (hexane, chloroform, ethanol, acetone, methanol, and water). The antiviral effectiveness of the selected extract fraction, Faramir®, was assessed against human immunodeficiency virus using ELISA and MTT assays conducted on Jurkat cells. Moreover, Faramir® antiviral activity was also examined against SARS-CoV-2 and Influenza viruses using the TCID50 assay, employing Vero E6 and MDCK cell lines, respectively. The findings indicated that the inhibitory effects of Faramir® on HIV replication are dependent on the concentration, as demonstrated through serial dilutions (0.25, 0.5, 1, 2, and 4 mg/mL). The highest inhibitory effect was observed at a concentration of 0.25 mg/mL. Furthermore, the TCID50 assay demonstrated that the antiviral activity of Faramir® is time-dependent. The highest level of antiviral activity was observed at the 5-minute mark following treatment. Subsequently, the extract fraction exhibiting the highest antiviral activity (Faramir®) was subjected to analysis using HPLC and GC-MS and found to contain three classes of phenolic molecules, namely flavonoids (such as Apigenin), hydroxylated compounds (including rosmarinic acid), and terpenes (such as alpha pinene). Based on these findings, it is suggested that Faramir® holds great potential as a novel natural therapeutic extract for combating viral infections.