Preventive Potential of Extracts of Some Dietary Plants against SARSCoV- 2 Infection

Abstract

Background: Coronavirus disease 2019 (COVID-19) had emerged as an unprecedented global health crisis. The pandemic resulted in over 672 million confirmed cases, and 6.84 million deaths till date. Several dietary plants are known for their beneficial health effects due to their diverse bioactive metabolites. Some of them are already reported for their therapeutic potential against respiratory viral infections with excellent safety profiles. Thus they can serve as sources of bioactive agents for the prevention and treatment of SARS-CoV-2 infection. Objective: With limited therapeutic options, the identification of safe, effective, and affordable medicines for the SARS-CoV-2 infection are urgently needed. The primary aim of the current study is to identify edible plant materials with preventive activity against SARS-CoV-2 infection. Method: Extracts of 30 dietary plants were evaluated for their in cellulo anti-SARS-CoV-2 potential. The antiviral activity was evaluated on SARS-CoV-2, propagated in Vero cell line (ATCCCCL- 81), followed by isolation of viral RNA, and its confirmation by qRT-PCR. Cytotoxicity of extracts was evaluated by using MTT assay in the Vero cell line, while the reduction in viral load was measured through plaque reduction assay. Furthermore, evaluations of the plant extracts on various treatment targets were also performed in cellulo. Results: An extract of Trigonella foenum-graecum L. (Fenugreek leaves) (part of the plant: leaves) was identified as a promising inhibitor of SARS-CoV-2 propagation with 98.7% reduction in the formation of plaques at 50 μg mL−1. Moreover, Trapa natans L. (Water caltrop, fruit) (part of the plant: fruit) also showed a 55.0% reduction in viral load at 50 μg mL−1. Both dietary plants exhibited prophylactic effects against SARS-CoV-2 infection. Conclusion: Trigonella foenum-graecum L., and Trapa natans L. and their bioactive metabolites can be used as preventive agents against SARS-CoV-2 infection. These results can form the basis for the development of anti-viral nutraceutical formulations.