bims-antpol Biomed News
on Antiviral properties of polyphenols
Issue of 2023–07–16
four papers selected by
Rick Sheridan, EMSKE Phytochem



  1. Crit Rev Food Sci Nutr. 2023 Jul 10. 1-22
      Flavonoid compounds exhibit a wide range of health benefits as plant-derived dietary components. Typically, co-consumed with the food matrix,they must be released from the matrix and converted into an absorbable form (bioaccessibility) before reaching the small intestine, where they are eventually absorbed and transferred into the bloodstream (bioavailability) to exert their biological activity. However, a large number of studies have revealed the biological functions of individual flavonoid compounds in different experimental models, ignoring the more complex but common relationships established in the diet. Besides, it has been appreciated that the gut microbiome plays a crucial role in the metabolism of flavonoids and food substrates, thereby having a significant impact on their interactions, but much progress still needs to be made in this area. Therefore, this review intends to comprehensively investigate the interactions between flavonoids and food matrices, including lipids, proteins, carbohydrates and minerals, and their effects on the nutritional properties of food matrices and the bioaccessibility and bioavailability of flavonoid compounds. Furthermore, the health effects of the interaction of flavonoid compounds with the gut microbiome have also been discussed. HIGHLIGHTSFlavonoids are able to bind to nutrients in the food matrix through covalent or non-covalent bonds.Flavonoids affect the digestion and absorption of lipids, proteins, carbohydrates and minerals in the food matrix (bioaccessibility).Lipids, proteins and carbohydrates may favorably affect the bioavailability of flavonoids.Improved intestinal flora may improve flavonoid bioavailability.
    Keywords:  Dietary flavonoids; bioaccessibility; bioavailability; food matrix; gut microbiome
    DOI:  https://doi.org/10.1080/10408398.2023.2232880
  2. Eur J Med Chem. 2023 Jul 07. pii: S0223-5234(23)00595-0. [Epub ahead of print]258 115629
      The current Coronavirus Disease 2019 (COVID-19) pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is highly contagious infection that breaks the healthcare systems of several countries worldwide. Till to date, no effective antiviral drugs against COVID-19 infection have reached the market, and some repurposed drugs and vaccines are prescribed for the treatment and prevention of this disease. The currently prescribed COVID-19 vaccines are less effective against the newly emergent variants of concern of SARS-CoV-2 due to several mutations in viral spike protein and obviously there is an urgency to develop new antiviral drugs against this disease. In this review article, we systematically discussed the anti-SARS-CoV-2 and anti-inflammatory efficacy of two flavonoids, baicalein and its 7-O-glucuronide, baicalin, isolated from Scutellaria baicalensis, Oroxylum indicum, and other plants as well as their pharmacokinetics and oral bioavailability, for development of safe and effective drugs for COVID-19 treatment. Both baicalein and baicalin target the activities of viral S-, 3CL-, PL-, RdRp- and nsp13-proteins, and host mitochondrial OXPHOS for suppression of viral infection. Moreover, these compounds prevent sepsis-related inflammation and organ injury by modulation of host innate immune responses. Several nanoformulated and inclusion complexes of baicalein and baicalin have been reported to increase oral bioavailability, but their safety and efficacy in SARS-CoV-2-infected transgenic animals are not yet evaluated. Future studies on these compounds are required for use in clinical trials of COVID-19 patients.
    Keywords:  Baicalein; Baicalin; COVID-19; Host immunomodulators; SARS-CoV-2; Virus entry blockers; Virus replication inhibitors
    DOI:  https://doi.org/10.1016/j.ejmech.2023.115629
  3. Luminescence. 2023 Jul 08.
      The interactions of human CYP3A4 with three selected isomer flavonoids, such as astilbin, isoastilbin and neoastilbin, are clarified using spectral analysis, molecular docking and molecular dynamics simulation. During binding with the three flavonoids, the intrinsic fluorescence of CYP3A4 is statically quenched in static mode with non-radiative energy conversion. The fluorescence and UV/Vis data reveal that the three flavonoids have moderate and stronger binding affinity with CYP3A4 due to the order of Ka1 and Ka2 values ranged from 104 to 105 L·mol-1 . In the meantime, astilbin has the highest affinity with CYP3A4, then isoastilbin and neoastilbin at the three experimental temperatures. Multispectral analysis confirms that the binding of the three flavonoids results in clear changes in the secondary structure of CYP3A4. It can be found from fluorescence, UV/Vis and molecular docking that these three flavonoids strongly bind to CYP3A4 by the means of hydrogen bond and van der Waals forces. The key amino acids around the binding site are also elucidated. Furthermore, the stabilities of the three-CYP3A4 complexes are evaluated by molecular dynamics simulation.
    Keywords:  CYP3A4; flavonoid; molecular docking; molecular dynamics simulation; spectral analysis
    DOI:  https://doi.org/10.1002/bio.4553
  4. Int J Pharm. 2023 Jul 07. pii: S0378-5173(23)00636-1. [Epub ahead of print] 123216
      In this study, the ability of zein nanospheres (NS) and zein nanocapsules containing wheat germ oil (NC) to enhance the bioavailability and efficacy of quercetin was evaluated. Both types of nanocarriers had similar physico-chemical properties, including size (between 230 and 250 nm), spherical shape, negative zeta potential, and surface hydrophobicity. However, NS displayed a higher ability than NC to interact with the intestinal epithelium, as evidenced by an oral biodistribution study in rats. Moreover, both types of nanocarriers offered similar loading efficiencies and release profiles in simulated fluids. In C. elegans, the encapsulation of quercetin in nanospheres (Q-NS) was found to be two twice more effective than the free form of quercetin in reducing lipid accumulation. For nanocapsules, the presence of wheat germ oil significantly increased the storage of lipids in C. elegans; although the incorporation of quercetin (Q-NC) significantly counteracted the presence of the oil. Finally, nanoparticles improved the oral absorption of quercetin in Wistar rats, offering a relative oral bioavailability of 26% and 57% for Q-NS and Q-NC, respectively, compared to a 5% for the control formulation. Overall, the study suggests that zein nanocarriers, particularly nanospheres, could be useful in improving the bioavailability and efficacy of quercetin.
    Keywords:  antihyperlipidemic effect; bioavailability; nanocapsules; nanospheres; quercetin; zein
    DOI:  https://doi.org/10.1016/j.ijpharm.2023.123216