Coronaviruses (CoVs) are associated with several infectious outbreaks in
humans, beginning with severe acute respiratory syndrome (SARS) in 2003 and Middle
East respiratory syndrome (MERS) in 2012. Recently, the World Health Organization
(WHO) announced the global outbreak of coronavirus disease 2019 (COVID-19)
caused by SARS-CoV-2 in December 2019. There are currently no natural or synthetic
drugs that inhibit SARS-CoV2. Because of the COVID-19 outbreak, many people have
returned to the use of complementary or traditional medicinal therapies for prophylaxis
or treatment. Herbal extracts and their purified natural compounds provide a platform
for the development of novel antiviral candidates. Effective drugs may be designed
based on the chemical structure of natural compounds that exhibit potential effects.
Researchers have primarily focused on 3-chymotrypsin-like protease (3CLpro),
papain-like protease (PLpro), RNA-dependent RNA polymerase, and spike (S) proteins
as drug targets for SARS-CoV. Furthermore, phylogenetic studies of the viral genome
have provided evidence of a close similarity between SARS-CoV2 and SARS-CoV1.
Here, we review the literature with respect to plant extracts from different families that
have been examined for antiviral activity against coronavirus diseases and explore the
underlying mechanisms. We also discuss the structures of promising natural
compounds representing different categories that serve as SARS-CoV chemical
inhibitors. Hopefully, this chapter will provide a valuable tool for scientists interested
in developing effective naturally derived anti-SARS-CoV-2 drugs for the management
of COVID-19 development and progression.
Keywords: Antiviral, Coronavirus, Outbreak, Protease, Respiratory, Traditional
medicine.
