Anti-SARS-CoV Natural Products With the Potential to Inhibit SARS-CoV-2 (COVID-19)

Abstract

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), known to cause the disease COVID-19, was declared a pandemic in early 2020. The objective of this review was to collate information regarding the potential of plants and natural products to inhibit coronavirus and targets associated with infection in humans and to highlight known drugs, which may have potential activity against SARS-CoV-2. Due to the similarity in the RNA genome, main proteases, and primary host receptor between SARS-CoV and SARS-CoV-2, a review was conducted on plants and secondary metabolites, which have shown activity against SARS-CoV. Numerous scientific reports on the potential of plants and secondary metabolites against SARS-CoV infection were found, providing important information on their possible activity against SARS-CoV-2. Based on current literature, 83 compounds have been identified with the potential to inhibit COVID-19. The most prominent selectivity was found for the alkaloid, lycorine, the lignan, savinin, and the abietane terpenoid, 8-beta-hydroxyabieta-9(11),13-dien-12-one with selectivity index values greater than 945, 667, and 510, respectively. Plants and their secondary metabolites, with activity against targets associated with the SARS-CoV infection, could provide valuable leads for the development into drugs for the novel SARS-CoV-2. The prospects of using computational methods to screen secondary metabolites against SARS-CoV targets are briefly discussed, and the drawbacks have been highlighted. Finally, we discuss plants traditionally used in Southern Africa for symptoms associated with respiratory viral infections and influenza, such as coughs, fever, and colds. However, only a few of these plants have been screened against SARS-CoV. Natural products hold a prominent role in discovering novel therapeutics to mitigate the current COVID-19 pandemic; however, further investigations regarding in vitro, in vivo, pre-clinical, and clinical phases are still required.

Current Updates on Naturally Occurring Compounds Recognizing SARS-CoV-2 Druggable Targets

“…Since SARS-CoV-2 has become a pandemic infection with relevant health issues, the scientific community carried out much effort for the identification of potential drug targets to tackle this virus infection. Recently, several articles have been published, most of them based on the virtual screening of natural occurring compounds towards viral target proteins [ 152 , 153 , 154 , 155 ].…”

Identification of Small Molecule Inhibitors of the Deubiquitinating Activity of the SARS-CoV-2 Papain-Like Protease: in silico Molecular Docking Studies and in vitro Enzymatic Activity Assay

“…(-)-Epigallocatechin gallate, rutin and cyanidin-3-O-glucoside are flavonoids, a biologically active class of the phenolic compounds (Bonvino et al, 2018 ). In a recent literature review conducted by Verma et al, the flavonoids were found to be the largest class of compounds with potential activity against coronaviruses (Verma et al, 2020 ).…”

Natural and Nature-Derived Products Targeting Human Coronaviruses

“…It was found that NPs/SMs are a rich source of drug potential leads against coronaviruses due to their pronounced structural diversity and complexity. Several compilations of pre-2020 findings on NPs/SMs with activity against coronaviruses were recently reported, some of which could serve as leads for the development of new drugs [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. Among the identified molecules the majority is represented by NPs ( Figure 2 a) and most of them have been found as inhibitors of SARS-CoV ( Figure 2 b).…”