Using natural compounds to fight disease is not something new. Using novel screening methods, it is possible to isolate useful compounds that have the potential to be used as therapeutics. Three natural compounds have been found that may have potential in fighting coronaviruses. In a new study, researchers have screened a large library of natural substances using X-ray and found that they bound to an enzyme which is essential for replication of the coronavirus (Figure 1). Importantly, these compounds are already being used in drugs today however targeting coronavirus directly still remains an important goal.
The researchers tested 500 substances from the Karachi Library of Natural Compounds if they bind to the papain-like protease of the novel coronavirus, whereby the papain-like protease (PLpro) is crucial for viral replication and it also blocks an important immune system protein, ISG15 which is important for the cells defence.
From the screening the researchers were able to identify three phenols that bind the enzyme, i.e; hydroxyethylphenol (YRL), (from Lawsonia alba), which can be found in virgin olive oil and wine; Hydroxybenzaldehyde (HBA) an anti-tumor agent from Acalypha torta and Methyldihydroxybenzoate (HE9) from Tagetes patula, which servese as an anti-oxidant with anti-inflammatory effects.
This study is important in highlighting natural compounds for drug development.
Journal article: Srinivasan, V, et al., 2022. Antiviral activity of natural phenolic compounds in complex at an allosteric site of SARS-CoV-2 papain-like protease. Communications Biology.
Summary by Stefan Botha