Dietary factors and SARS-CoV-2 contagion: in silico studies on modulation of viral and host proteins by spice actives

Abstract

The SARS-CoV-2 contagion has had a huge impact on world population. It has been observed that despite massive spread of the contagion in India particularly during the second wave, the overall case fatality rates remain low. This prompted us to look into dietary factors that can possibly modulate the viral impact and/or host response. In silico studies were carried out on forty-two commonly used spices and their 637 known active compounds with an aim of identifying such compounds that may have propensity to reduce viral impact or boost host immune response. We chose to study SARS-Cov-2 helicase on account of its functional importance in maintaining viral load within the host, and the human tank binding protein (TBK1) for its important role in host immunity. We carried out in silico virtual screening, docking studies with 637 phytochemical against these two proteins, using in silico methods. Upon assessing the strength of the ligand-target interactions and post simulation binding energy profile, our study identifies procyanidin-B4 from bay leaf, fenugreekine from fenugreek seed and gallotannin from pomegranate seed as active interactors that docked to viral helicase. Similarly, we identified eruboside B from garlic, gallotannin from pomegranate seed, as strong interacting partners to human TBK1. Our studies thus present dietary spice constituents as potential protagonists for further experimentation to understand how spices in the diet might help the hosts in countering the viral assault and mount a robust protective response against COVID and other infections.

Communicated by Ramaswamy H. Sarma

Keywords:

• SARS-CoV-2
• Nsp13
• TBK1
• virtual screening
• spices
• phytochemicals
• immunity

Acknowledgments

We are grateful to CSIR mission directorate for initiating us in this area by funding the projects under Nutraceutical and Immunity Missions. We are also grateful to the chairman of the CSIR Mission mode monitoring committee Dr. V. Prakash, CSIR Mission on Nutraceuticals and Nutritionals/Immunity Mission; Dr. Sanjay Kumar, Director of IHBT, Palampur and all the members of the committee for their valuable advice and initiating this new idea. Our gratitude for encouraging us in its periodical review of the project with innovative ideas about the active constituents of spices and their potential beneficial effects and fruitful discussions; held as part of the monitoring committee meetings that periodically reviewed our project on spices. Those learnings and top of the line suggestions eventually motivated us to carry out the studies reported in this manuscript. An institutional grant to IBAB from the department of IT, BT, Science, and Technology, the Government of Karnataka is acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors of this manuscript wish to acknowledge gratefully the top driven project concept on Mission Mode from CSIR on this idea of spices in the prevention of diseases (HCP0019WP7 and HCP0035). IBAB is also supported by DST-FIST vide sanction no SR/FST/LSI-536/2012. CSIR-CDRI manuscript number is 10260.