Molecular docking and dynamics supported investigation of antiviral activity of Lichen metabolites of Roccella montagnei: an in silico and in vitro study

Abstract

Lichens are symbiotic organisms that have been traditionally used for treating different kinds of ailments. As there are only a few reports on the antiviral activity of lichens, we thought of evaluating the anti-Herpes simplex virus-1 (HSV-1) activity of methanolic extract of Roccella montagnei and their isolated compounds. Fractionation of crude methanolic extract of Roccella montagnei by column chromatography isolated two pure compounds. Antiviral activity was assessed using a CPE inhibition assay at non-cytotoxic concentrations on Vero cells. Molecular docking and dynamics studies were carried out against Herpes simplex type-1 thymidine kinase to understand the binding interactions of the isolated compounds with reference to acyclovir. Isolated compounds were characterized as methyl orsellinate and montagnetol by spectral methods. Methanolic extract of Roccella montagnei exhibited an EC₅₀ value of 56.51 µg/ml, while the compounds methyl orsellinate and montagnetol offered EC₅₀ values of 13.50 µg/ml and 37.52 µg/ml, respectively, against HSV-1 viral infection on Vero cell lines. The selectively index (SI) of montagnetol (10.93) was found to be higher when compared to that of methyl orsellinate (5.55), indicating its better anti-HSV-1 activity. The docking and dynamics studies showed montagnetol was stable throughout the 100 ns, having better interactions and docking scores with HSV-1 thymidine kinase than methyl orsellinate, as well as the standard. To understand the mechanism of montagnetol’s anti-HSV-1 activity, more research is required, and this could lead to the discovery of new and effective antiviral agents.

Communicated by Ramaswamy H. Sarma

Keywords:

• Antiviral activity
• Lichen
• Roccella montagnei
• CPE inhibition assay
• molecular docking
• molecular dynamics

Acknowledgements

The authors thank the Innovation center, Manipal Institute of Technology, Manipal for NMR spectra and the authors also express gratitude to the Manipal-Schrodinger Centre for Molecular Simulations. We are also grateful to the Principal, Manipal College of Pharmaceutical Sciences, and Head, Dept. of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, MAHE, for providing the necessary research facilities. We authors would like to thank The Dean of Melaka Manipal Medical College (Manipal Campus) for allowing us to carry out our study at the institute.

Disclosure statement

No potential conflict of interest was reported by the authors.

Authors’ contributions

Nishanth B Bhat: Conceptualization, analysis and interpretation of data, original draft preparation. Subham Das: Conceptualization, in silico modeling, interpretation of data, data curation, manuscript editing. Balireddy V S Sridevi: Interpretation of data. Raghu Chandrashekhar H: Interpretation of data. Sanjeeva Nayaka: Interpretation of data. Narasimhan S: Interpretation of data. Sumit Raosaheb Birangal: Interpretation of data. G Gautham Shenoy: Interpretation of data. Alex Joseph: Interpretation of data, manuscript editing and supervision.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.