Unraveling the anti-influenza effect of flavonoids: Experimental validation of luteolin and its congeners as potent influenza endonuclease inhibitors
Language English Country France Media print-electronic
Document type Journal Article
PubMed
32883638
DOI
10.1016/j.ejmech.2020.112754
PII: S0223-5234(20)30726-1
Knihovny.cz E-resources
- Keywords
- Influenza, Neuraminidase, PA(N) endonuclease Inhibitors, Polyphenols, RNA polymerase,
- MeSH
- Antiviral Agents chemistry metabolism MeSH
- Endonucleases antagonists & inhibitors chemistry metabolism MeSH
- Enzyme Assays methods MeSH
- Flavonoids chemistry metabolism MeSH
- Enzyme Inhibitors chemistry metabolism MeSH
- Crystallography, X-Ray MeSH
- Microbial Sensitivity Tests MeSH
- Molecular Structure MeSH
- Drug Evaluation, Preclinical MeSH
- Protein Domains MeSH
- RNA-Dependent RNA Polymerase antagonists & inhibitors chemistry metabolism MeSH
- Protein Binding MeSH
- Viral Proteins antagonists & inhibitors chemistry metabolism MeSH
- Influenza A virus enzymology MeSH
- Structure-Activity Relationship MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Antiviral Agents MeSH
- Endonucleases MeSH
- Flavonoids MeSH
- Enzyme Inhibitors MeSH
- RNA-Dependent RNA Polymerase MeSH
- Viral Proteins MeSH
The biological effects of flavonoids on mammal cells are diverse, ranging from scavenging free radicals and anti-cancer activity to anti-influenza activity. Despite appreciable effort to understand the anti-influenza activity of flavonoids, there is no clear consensus about their precise mode-of-action at a cellular level. Here, we report the development and validation of a screening assay based on AlphaScreen technology and illustrate its application for determination of the inhibitory potency of a large set of polyols against PA N-terminal domain (PA-Nter) of influenza RNA-dependent RNA polymerase featuring endonuclease activity. The most potent inhibitors we identified were luteolin with an IC50 of 72 ± 2 nM and its 8-C-glucoside orientin with an IC50 of 43 ± 2 nM. Submicromolar inhibitors were also evaluated by an in vitro endonuclease activity assay using single-stranded DNA, and the results were in full agreement with data from the competitive AlphaScreen assay. Using X-ray crystallography, we analyzed structures of the PA-Nter in complex with luteolin at 2.0 Å resolution and quambalarine B at 2.5 Å resolution, which clearly revealed the binding pose of these polyols coordinated to two manganese ions in the endonuclease active site. Using two distinct assays along with the structural work, we have presumably identified and characterized the molecular mode-of-action of flavonoids in influenza-infected cells.
References provided by Crossref.org
Nitrogen-Containing Flavonoids-Preparation and Biological Activity
