A Comprehensive Update of Various Attempts by Medicinal Chemists to Combat COVID-19 through Natural Products

Abstract

The ongoing COVID-19 pandemic has resulted in a global panic because of its continual evolution and recurring spikes. This serious malignancy is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the outbreak, millions of people have been affected from December 2019 till now, which has led to a great surge in finding treatments. Despite trying to handle the pandemic with the repurposing of some drugs, such as chloroquine, hydroxychloroquine, remdesivir, lopinavir, ivermectin, etc., against COVID-19, the SARS-CoV-2 virus continues its out-of-control spread. There is a dire need to identify a new regimen of natural products to combat the deadly viral disease. This article deals with the literature reports to date of natural products showing inhibitory activity towards SARS-CoV-2 through different approaches, such as in vivo, in vitro, and in silico studies. Natural compounds targeting the proteins of SARS-CoV-2—the main protease (Mpro), papain-like protease (PLpro), spike proteins, RNA-dependent RNA polymerase (RdRp), endoribonuclease, exoribonuclease, helicase, nucleocapsid, methyltransferase, adeno diphosphate (ADP) phosphatase, other nonstructural proteins, and envelope proteins—were extracted mainly from plants, and some were isolated from bacteria, algae, fungi, and a few marine organisms.

nCoV-19 therapeutics using cucurbitacin I structural derivatives: an in silico approach

“…One of the alternatives to existing pharmaceuticals is the phytochemical-based therapeutics that need to be designed and developed for proper treatment and cure of the disease in a costeffective manner. Various natural products have been reviewed in terms of their potential to fight the disease, taking into consideration the specific targets [5]. Cucurbitacins, tetracyclic triterpenoids occur in regularly consumed vegetables like cucumber, gourds, squash, and pumpkins as secondary metabolites and act in the plant's defense mechanisms [6].…”

A Comprehensive Update of Anti-COVID-19 Activity of Heterocyclic Compounds

“…Thymohydroquinone, dithymoquinone, ginger, strychnine bush, and pineapple ingredients are used as natural enemies of SARS-CoV-2. [47][48][49] Remdesivir XIV is an adenosine analogue RNA-dependent RNA polymerase (RdRp) inhibitor used for the treatment of SARS-CoV-2-infected patients. 50 Remdesivir, which has been recommended by the FDA for emergency use, can be injected intravenously into hospitalized patients.…”