MIDDLE EAST RESPIRATORY SYNDROME CORONAVIRUS—OR JUST “CORONAVIRUS” AS IT HAS BEEN DUBBED IN THE MEDIA—IS AN EMERGING VIRAL PATHOGEN THAT CAUSES SEVERE MORBIDITY AND MORTALITY. ACCORDING TO THE CDC, “THERE IS CURRENTLY NO VACCINE TO PREVENT CORONAVIRUS DISEASE.”¹ TO PREVENT ITS TRANSMISSION, THE CDC RECOMMENDS EVERYDAY PREVENTIVE ACTIONS TO HELP PREVENT THE SPREAD OF ANY RESPIRATORY DISEASE:

• Avoid close contact with people who are sick.
• Avoid touching your eyes, nose, and mouth.
• Stay home when you are sick.
• Cover your cough or sneeze with a tissue, then throw the tissue in the trash.
• Clean and disinfect frequently touched objects and surfaces using a regular household cleaning spray or wipe.

Naturally these are good recommendations, but shouldn’t there be something else we can do to help prevent the transmission of coronavirus? In my opinion, there is. Let’s start with resveratrol.

Resveratrol and the coronavirus

In 2006 an in-vitro study² was undertaken in China to examine the effects of “stilbene derivatives” to inhibit coronavirus replication. What are stilbene derivatives? They are an important family of bioactive molecules that are normally associated with plants. Stilbenes are produced in response to injury or attack by pathogens.^{3, 4} The most extensively studied stilbene is resveratrol. In any case, the 2006 study found that various stilbene compounds were able to inhibit coronavirus replication. This may have included resveratrol, but the study details made it somewhat difficult to determine.

Then, in 2017, another in-vitro study⁵ was conducted to specifically examine the antiviral effect of resveratrol against coronavirus. In this study, cells from coronavirus infected patients were given resveratrol. The results were that resveratrol significantly inhibited coronavirus infection and prolonged cellular survival after virus infection. In addition, resveratrol decreased the replication of nucleocapsid, a protein essential for coronavirus replication. Furthermore, resveratrol down-regulated apoptosis (i.e. cellular death) induced by coronavirus. This study clearly demonstrated that resveratrol is a potent anti-coronavirus agent in-vitro. The study’s authors suggested that resveratrol can be a potential antiviral agent against coronavirus in the near future.

Resveratrol and the immune system

So why was resveratrol effective against coronavirus? Although we can’t say for certain, we do know that resveratrol can increase certain circulating immune cells known as gamma delta T cells. Human research⁶ was conducted to assess the effects of repeated doses of resveratrol (1000mg/day for 28 days) on circulating immune cells in healthy individuals. The results were that resveratrol was safe and well tolerated and was associated with significant increases in the numbers of circulating gamma delta T cells (functioning as a first line of defense and a bridge between innate and adaptive responses) and regulatory T cells. Now consider that analyses of T cell repertoires in health care workers who survived coronavirus infection during the 2003 outbreak revealed that their gamma delta T cell populations were selectively expanded about 3 months after the onset of disease. The expansion of the gamma delta T cell population was associated with higher production of anti-coronavirus immunoglobulin G titers. In addition, in-vitro experiments demonstrated that stimulated gamma delta T cells display an interferon- gamma -dependent anti-coronavirus activity and are able to directly kill coronavirus-infected target cells. These findings suggest that gamma delta T cells play a protective role during coronavirus⁷—and resveratrol increases the numbers of circulating gamma delta T cells. So, pending human clinical trials on the effects of resveratrol against coronavirus, what is a good dose of resveratrol to be used for protective effects? My suggestion is to use 1,000 mg of resveratrol daily, which is consistent with the amount used in human clinical research in which delta T cells were effectively increased.

Black elderberry protection

In addition to resveratrol, black elderberry may also offer a degree of protection against coronavirus—although it has yet to be tested for this purpose. My rationale for this is based upon black elderberry’s success in treating influenza.

The flu virus invades cells by puncturing their walls with tiny spikes called hemagglutinin that cover its surface. In-vitro research found that natural components of black elderberry (Sambucus nigra) actually disarm the spikes. It binds to them, thus preventing them from piercing the cell membrane. The viral spikes are covered with an enzyme called neuraminidase. This enzyme acts to break down the cell wall.

To test how black elderberry would work in actual people with the flu, a team of Israeli scientists and physicians conducted placebo-controlled, double blind study on patients infected with the flu virus during an epidemic in Southern Israel. The results were that within twenty-four hours the symptoms—fever, cough, and muscle pain had significantly improved in twenty percent of the patients. After the second day, another seventy five percent were clearly much improved, and in three days a complete cure was achieved in over ninety percent of the patients studied. Among the control group only eight percent of patients showed an improvement after 24 hours, and for the remaining 92 percent, improvement was observed within six days or more. Tests were also conducted on patients to determine the presence of influenza antibodies. It was found that the level of antibodies was higher in patients receiving the black elderberry extract versus those receiving the placebo, indicating an enhanced defense response in those patients.⁸

Other research⁹ has also shown that a black elderberry extract effectively treated and helped relieve symptoms of influenza when taken in doses of 175 mg four times daily.

So, what’s the relationship to coronavirus? Just this: hemagglutinin is also found on the surface of coronavirus. In fact, coronavirus may have actually evolved from a certain type of influenza.¹⁰ Consequently, it’s not much of a stretch to imagine that black elderberry may also have application against coronavirus. Pending human clinical trials on the effects of black elderberry against coronavirus, my suggestion is to use 175 mg of black elderberry extract daily, as a prophylactic dose rather than a treatment for actual coronavirus.

Conclusion

Currently there are no vaccines to prevent coronavirus. However, research suggests that 1000 mg of resveratrol daily, and 175 mg of black elderberry extract may have a protective effect against the coronavirus. Until such time as other proven prevention methods come to fruition, it seems prudent to consider the regular use of these nutraceuticals.

References

1. Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention. Page last reviewed: February 15, 2020. Retrieved February 28, 2020 from https://www.cdc.gov/coronavirus/2019-ncov/about/prevention-treatment.html.
2. Li Y, Li ZL, Zhao WJ, Wen RX, Meng QW, Zeng Y. Synthesis of stilbene derivatives with inhibition of SARS coronavirus replication. Eur J Med Chem. 2006 Sep;41(9):1084–9.
3. Higdon J, Drake VJ, Steward WP. Resveratrol. Micronutrient Information Center. Linus Pauling Institute, Oregon State University, Corvallis, OR; 2016.
4. Fremont L. Biological Effects of Resveratrol. Life Sci. 2000;66(8):663–73.
5. Lin SC, Ho CT, Chuo WH, Li S, Wang TT, Lin CC. Effective inhibition of MERS-CoV infection by resveratrol. BMC Infect Dis. 2017 Feb 13;17(1):144.
6. Espinoza JL, Trung LQ, Inaoka PT, Yamada K, An DT, Mizuno S, Nakao S, Takami A. The Repeated Administration of Resveratrol Has Measurable Effects on CirculatingT-Cell Subsets in Humans. Oxid Med Cell Longev. 2017;2017:6781872.
7. Poccia F, Agrati C, Castilletti C, Bordi L, Gioia C, Horejsh D, Ippolito G, Chan PK, Hui DS, Sung JJ, Capobianchi MR, Malkovsky M. Anti-severe acute respiratory syndrome coronavirus immune responses: the role played by V gamma 9V delta 2 T cells. J Infect Dis. 2006 May 1;193(9):1244–9.
8. Zakay-Rones Z, et al, J Altern Complement Med 1995; 1(4):361–9.
9. Kong F. Pilot Clinical Study on a Proprietary Elderberry Extract: Efficacy in Addressing Influenza Symptoms, Online J Pharmacol Pharmacokin 5:32– 43, 2009.
10. Zeng Q, Langereis MA, van Vliet AL, Huizinga EG, de Groot RJ. Structure of coronavirus emagglutinin-esterase offers insight into corona and influenza virus evolution. Proc Natl Acad Sci U S A. 2008 Jul 1;105(26):9065–9.

Last Updated: March 14, 2020