[Paper Review] On the Inhibition of COVID-19 Protease by Indian Herbal Plants: An In Silico Investigation

Ambrish Kumar Srivastava, Abhishek Kumar+1 more|arXiv (Cornell University)|Apr 5, 2020

Phytochemicals and Medicinal Plants15 references38 citations

TL;DR

The study screened 18 compounds from 11 Indian medicinal plants using in silico methods to evaluate their potential to inhibit the COVID-19 main protease, identifying harsingar, aloe vera, and giloy as the most promising based on binding affinity.

ABSTRACT

COVID-19 has quickly spread across the globe, becoming a pandemic. This disease has a variable impact in different countries depending on their cultural norms, mitigation efforts and health infrastructure. In India, a majority of people rely upon traditional Indian medicine to treat human maladies due to less-cost, easier availability and without any side-effect. These medicines are made by herbal plants. This study aims to assess the Indian herbal plants in the pursuit of potential COVID-19 inhibitors using in silico approaches. We have considered 18 extracted compounds of 11 different species of these plants. Our calculated lipophilicity, aqueous solubility and binding affinity of the extracted compounds suggest that the inhibition potentials in the order; harsingar > aloe vera > giloy > turmeric > neem > ashwagandha > red onion > tulsi > cannabis > black pepper. On comparing the binding affinity with hydroxychloroquine, we note that the inhibition potentials of the extracts of harsingar, aloe vera and giloy are very promising. Therefore, we believe that these findings will open further possibilities and accelerate the works towards finding an antidote for this malady.

Motivation & Objective

• Motivate exploration of traditional Indian medicinal plants as potential COVID-19 protease inhibitors.
• Evaluate 18 extracted compounds from 11 plant species for binding to the COVID-19 main protease.
• Assess physicochemical properties (lipophilicity, aqueous solubility) and compare binding affinity to hydroxychloroquine.

Proposed method

• Use in silico approaches to assess binding potential of plant-derived compounds to the COVID-19 protease.
• Calculate lipophilicity and aqueous solubility of the compounds.
• Estimate binding affinity (in silico) and compare with hydroxychloroquine as a reference.
• Rank inhibition potential of compounds across the plant set.

Experimental results

Research questions

• RQ1 Which Indian herbal compounds show the strongest predicted binding to the COVID-19 main protease?
• RQ2 How do the binding affinities of these compounds compare to hydroxychloroquine?
• RQ3 Which plant species contribute the most promising inhibitors based on the calculated properties?
• RQ4 Do physicochemical properties support favorable drug-like behavior for the top candidates?

Key findings

• Inhibition potentials follow the order: harsingar > aloe vera > giloy > turmeric > neem > ashwagandha > red onion > tulsi > cannabis > black pepper.
• The extracts of harsingar, aloe vera, and giloy are noted as very promising when compared to hydroxychloroquine.
• 18 compounds from 11 species were evaluated for lipophilicity, solubility, and binding affinity.