Centrifugal Filters Aid COVID-19 Research on Phytomedicines

A collaborative research group headed by Harvard Medical School in Boston cites using Pall Nanosep® devices in a new publication on the potential treatment of COVID-19 with phytomedicines.

March 4, 2021

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Flavonoid compounds are often used as the active ingredient in plant-based medicines (phytomedicines) because they have been shown to have pharmacological effects, including anti-coronavirus and anti-inflammatory activity.  



Research has shown that certain flavonoid-based phytomedicines can bind with high affinity to the SARS-CoV-2 spike protein. This is important to COVID-19 research because the spike protein is used by the SARS-CoV-2 virus to bind the angiotensin-converting enzyme 2 (ACE2) receptors abundant on the surface of many respiratory tract cells. It is through this mechanism that the virus fuses with the cell membrane and ultimately infects cells.  



The Harvard-based researchers theorized that if flavonoid-based phytomedicines could be used to interfere with SARS-CoV-2 binding and fusion, they could potentially be used as prophylactics or therapeutics against COVID-19. Furthermore, phytomedicines are a more widely accepted form of medication in many undeveloped nations, where there is a rich tradition of using medicinal plants. Developing a phytomedicine which is effective at treating COVID-19 may help speed treatment adoption in these areas.

To investigate the potential of flavonoid-based phytomedicines1 to treat COVID-19, the authors used computer simulations to determine the predicted binding affinity of flavonoid-based phytomedicines caflanone, Equivir, hesperetin, myricetin, and Linebacker to SARS-CoV-2 spike protein. Their analysis showed that these molecules are predicted to bind with high affinity to the SARS-CoV-2 spike protein, as well as to protease sites on the ACE2 receptor used by the SARS-CoV-2 virus to infect cells. In vitro studies demonstrated that caflanone in particular displayed the potential to inhibit a number of different viral entry factors, including a factor known to facilitate mother-to-fetus transmission of coronavirus. 



While these findings were promising, the authors felt that the most important argument in favor of developing phytomedicine-based treatments would be showing that they could be successfully targeted to the respiratory system in vivo.

For these experiments, the authors devised what they refer to as “smart” nanoparticles to improve bioavailability of the proposed treatment. They used Pall Nanosep centrifugal devices to purify the flavonoid-linked nanoparticles prior to their introduction into mice bearing SARS-CoV-2 lung lesions. The Nanosep centrifugal filter rapidly concentrates  50-500 μL sample volumes. For larger sample volumes, Pall also make additional centrifugal devices: the Microsep™ for 0.5 to 5 mL sample volume, the Macrosep® for 5 to 20 mL sample volume, and the Jumbosep™ for 20 to 60 mL sample volume. 


The results were very encouraging. Flavanoid-linked nanoparticles were successfully targeted to afflicted lung cells at significantly higher levels than control nanoparticles, binding and blocking ACE2 receptors on the lung cell surface. The findings in this paper justify further research on the use of phytomedicines in the fight against COVID-19. Pall is dedicated to assist researchers in this fight by supporting COVID-19 related research workflows.  


Please visit our dedicated COVID-19 information to learn more about solutions to support COVID-19 research. 



Ngwa W. et al. Potential of Flavonoid-Inspired Phytomedicines against COVID-19. Molecules. (25) 2707. June 2020.


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