Since COVID-19 took the world by storm, healthcare professionals have been tasked with finding ways to manage it.
Along with vaccines against the SARS-CoV-2 virus, the virus that causes COVID-19, researchers are working towards alternate prevention methods.
A recent study shows that naturally sourced ionophoric polyphenols with metal ions have the potential to significantly reduce the transmissibility of a wide variety of respiratory viruses, including SARS-CoV-2.1
Dietary supplements may act as an antiviral therapeutic agent
Zinc, a metal found in small doses in the human diet, has been found to inhibit the activity of select respiratory viruses.2
For instance, zinc ions (the charged form of zinc) inhibit the SARS-CoV-2 RNA-dependent RNA polymerase, which is responsible for the creation of new viral proteins.
Polyphenols are biochemicals that show antiviral properties.
Types of polyphenols, called flavonoids, are sourced from vegetables and fruits.
The research group, led by professors at Tel-Aviv University in Israel, created dietary supplements that included zinc picolinate, which is composed of zinc ions bound to picolinic acid.
Being attached to picolinic acid helps the body absorb zinc easier.
The dietary supplement also contained the flavonoids Quercetin, Taxifolin, Naringenin, and Epigallocatechin-3-gallate (EGCG).1
The flavonoids acted as zinc ionophores, which help transport zinc across cell membranes and enter cells.
Zinc, when combined with flavonoids, reduced viral replication
The dietary supplement was administered in vitro – in the lab – on different cell types, including human lung cells and kidney cells.
Cell cultures were infected with different viruses; each virus was tagged with fluorescent proteins that would allow viral presence to be detected throughout the study.
qRT-PCR (real-time quantitative reverse transcription PCR) was used; this process measures the production of viral proteins and, thus, viral replication.
Researchers observed that in cells treated with dietary supplements, viral replication was reduced by 50-95%.
These results correspond to the respiratory RNA viruses of coronavirus OC43 (causes the common cold), influenza A virus, and human metapneumovirus.
The study used coronavirus OC43 to represent the SARS-CoV-2 virus.
Eran Bacharach is a professor at Tel-Aviv University and co-author of the study.
He commented on the wide applicability of flavonoids in preventing respiratory viruses: “The interesting aspect is the treatment’s potential flexibility: we found that a combination of several flavonoids with zinc helps protect cells against a wide range of RNA viruses. We believe that the product can serve as a supplementary treatment to enhance the effect of existing anti-viral vaccines and medications.”3
Results also showed that combining zinc with flavonoids provided a more significant antiviral effect than if either were used independently.
Increased levels of zinc were found in treated cells
Zinc can inhibit viral replication and transmission.
When cells were treated with a combination of zinc and flavonoids, the level of zinc within cells was approximately three times greater than cells treated with only zinc.1
This finding suggests that respiratory viral replication can be inhibited using zinc and zinc ionophores because these agents increase cellular zinc levels and can, therefore, inhibit viral replication.
But how exactly can these findings help the fight against COVID-19 and other respiratory viruses?
Antiviral therapeutic agents could address vaccine limitations
COVID-19 vaccines were created to help control the infection rate of the SARS-CoV-2 virus.
However, reaching the level of vaccination that would result in population immunity has posed a challenge due to the rapid evolution of the virus.1
New mutants of the SARS-CoV-2 virus, such as Omicron and Delta, contain genetic mutations within their spike proteins.
The vaccines that are currently available target these spike proteins; thus, the more mutations, the less effective the vaccines may become.1
To help accelerate the response to the evolving virus, creating antiviral therapeutic agents has been a focus for many pharmaceutical companies.
However, most of the therapeutic agents found need to be administered in a hospital setting, which limits their accessibility.4
Having access to a dietary supplement that helps fight SARS-CoV-2, then, could potentially address this limitation.
SARS-CoV-2 variants have increased transmissibility
One study has shown that SARS-CoV-2 can suppress the human immune system.5
The ability of the virus to suppress immunity appears to increase as the virus mutates. Reduced immunity may lead to enhanced human-to-human transmissibility.
While the world has coped with the spread of COVID-19 by socially distancing, other respiratory viruses, including adenovirus, rhinovirus, influenza, and parainfluenza virus, have surfaced in an unusual way.
Specifically, cases have occurred during the off-season and have been linked to SARS-CoV-2 infection.6,7
The dietary supplement, created by the researchers at Tel-Aviv University, could potentially address this increase in respiratory viral infections seen in recent months.
A combination dietary supplement should be available to help fight COVID-19
There is a complementary relationship between zinc and zinc ionophores in containing viral infection within the cell and inhibiting viral replication for numerous respiratory viruses.1
Although this research has been limited to laboratory-based studies, they hope to extend their research to human-based experiments.
Professor Daniel Segal, the co-author of the study, commented, “These results are very promising, possibly enabling the development of an orally administered biological shelf treatment. Such a product will be safe, natural, and effective against several types of viruses, including new mutations and variants – clearly an important step forward.”3
- Kreiser, T. et al. (2022). Inhibition of Respiratory RNA Viruses by a Composition of Ionophoric Polyphenols with Metal Ions. Pharmaceuticals; 15(3): 377. Doi: 10.3390/ph15030377.
- Read, S.A. et al. (2019). The Role of Zinc in Antiviral Immunity. Advances in Nutrition; 10(4): 696–710. Doi: 10.1093/advances/nmz013.
- Shahar, N. (2022). Researchers: We’ve found a “Healthy Weapon” Against Covid-19-dietary supplements found in pumpkin and peas. EurekAlert! Accessed Apr. 15, 2022. Retrieved from https://www.eurekalert.org/news-releases/949367.
- Hwang, Y.C et al. (2022). Monoclonal antibodies for COVID-19 therapy and SARS-CoV-2 detection. Journal of Biomedical Science; 29(1). Doi: 10.1186/s12929-021-00784-w.
- Thorne, L.G. et al. (2021). Evolution of enhanced innate immune evasion by the SARS-CoV-2 B.1.1.7 UK variant. Nature; 602: 487–495. Doi: 10.1038/s41586-021-04352-y.
- Jones, N. (2021). Why easing COVID restrictions could prompt a fierce flu rebound. Nature; 598: 395.
Lu, D. (2021). Children’s immunity at risk. New Scientist; 250(3332): 8-9. Doi:10.1016/S0262-4079(21)00716-8.
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