Phytomolecules Repurposed as Covid-19 Inhibitors: Opportunity and Challenges

Abstract

The SARS-CoV-2 virus has spread worldwide to cause a full blown pandemic since 2020. To date, several promising synthetic therapeutics are repurposed and vaccines through different stages of clinical trials were approved and being administered, but still the efficacy of the drugs and vaccines are yet to be decoded. This article highlights the importance of traditional medicinal plants and the phytomolecules derived from them, which possess in vitro antiviral and anti-CoV properties and further explores their potential as inhibitors to molecular targets of SARS-CoV-2 that were evaluated by in silico approaches. Botanicals in traditional medicinal systems have been investigated for anti-SARS-CoV-2 activity through in silico and in vitro studies. However, information linking structure of phytomolecules to their antiviral activity is limited. Most phytomolecules with anti-CoV activity were studied for inhibition of the human ACE2 receptor through which the virus enters host cells, and non-structural proteins 3CL pro and PL pro . Although the proteases are ideal anti-CoV targets, information on plant-based inhibitors for the CoV structural proteins, e.g., spike, envelope, membrane, nucleocapsid required further investigations. In absence of scientific evaluations through in vitro and biocompatibility studies, plant-based antivirals fall short as treatment options. Plant-based anti-SARS-CoV-2 therapeutics can be promising alternatives to their synthetic counterparts as they are economical and bear fewer chances of toxicity, side effects, and viral resistance. Our review could provide a systematic overview of the potential phytomolecules which can be repurposed and subjected to further modes of experimental evaluation to qualify for use in treatment and prophylaxis of SARS-CoV-2 infections.

Role of ethno-phytomedicine knowledge in healthcare of COVID-19: advances in traditional phytomedicine perspective

“…Several plant biometabolites including extracts have been reported previously for in vivo and in vitro anti-coronavirus properties such as lectins, saikosaponins, emodin, quercetin derivatives, lectin, ethanolic, and water extract of the plant parts or whole plant [81]. Traditional medicinal plants and their secondary metabolites have been evaluated by an in silico approach against coronavirus for the inhibition of hACE2 receptor that facilitates virus entry into host cells, also studied for inhibition of non-structural proteins 3CL pro and PL pro [33]. Molecular docking was conducted to investigate compounds of selected South African traditional medicinal plants and their potential inhibitory activities against SARS-CoV-2 RDRP, 3CL pro , and SARS-CoV-2 RBD.…”

Pharmacokinetics of Curcumin Delivered by Nanoparticles and the Relationship with Antitumor Efficacy: A Systematic Review

“…Phytotherapy has found a place worldwide, with about 35,000 herbal species showing anticancer properties, according to the National Cancer Institute (NCI) in the USA [ 2 ]. Phytomolecules have unique advantages, such as low price, fewer adverse effects, and lower toxicity [ 3 ].…”

Bioprospecting phytochemicals of Rosmarinus officinalis L. for targeting SARS-CoV-2 main protease (Mpro): a computational study

“…Even though synthetic antiviral agents are efficacious against COVID-19, they cause several side effects and viral complications. The ineffectiveness of these antivirals is due to the latency and recurrence problems seen in immunosuppressed hosts, as it limits their effectual lifespan [ 23 ]. Consequently, recent studies support the use of traditional medications and natural sources as a remedy against COVID-19 [ 3 ].…”