Preliminary results of using CBD to inhibit SARS-CoV-2

Disclaimer: This article is a pre-print and has not officially finished going through peer-review. It should not be regarded as conclusive evidence. See the funding agency (NIH’s) explanation of this.

It’s no secret that the novel 2019 coronavirus has been the center of a global pandemic that has accounted for millions of deaths, and shut down parts of the world for weeks, even months at a time. Scientists and medical professionals have developed vaccines, and have been able to test the effects of different compounds for treating infections of the virus. A team at the University of Chicago (UC) found that a metabolite of Cannabidiol (CBD), called 7-OH-CBD, may be able to inhibit SARS-CoV-2 infection.

By exposing human lung cells to the virus, the team at University of Chicago were able to target the cells most vulnerable to infection by the virus. These cells have receptors on their surfaces, called ACE-2, that act as binding sites for the coronavirus.

This research was done in conjunction with a study conducted on CBD users, who showed lower COVID infection rates than the general population. CBD is available in many forms because of its popularity as an over-the-counter medicine. Oral solutions of CBD are approved by the FDA as treatment for seizures in people with epilepsy.

In this paper, researchers conducted multiple experiments comparing CBD use and coronavirus infection rates. In one experiment, they used human lung cells that expressed the ACE-2 receptor to see if the coronavirus would enter the cell through this receptor after being treated with CBD. The cells were treated with CBD at concentrations ranging from 0.0-10 micromolars (µM) for 2 hours, then introduced to the coronavirus for a period of 48 hours. 

They measured the infection level by detecting the amount of viral spike protein in the culture. The infection rate, or the amount of spike protein recovered, decreased as CBD dosage increased. The results of the experiment supported their hypothesis that CBD inhibited the infection, but they needed more information.

To pinpoint exactly what compound is responsible for inhibiting SARS-CoV-2 from infecting the cells, the researchers compared how different cannabinoid compounds, such as CBG and CBD-A, affected spike protein levels. They also tested THC, the psychoactive compound in marijuana. Their results suggested that CBD, and its metabolite 7-OH-CBD were associated with reduced expression of the viral spike protein and reduced rate of infection. In fact, the presence of other compounds seemed to reduce the ability of the CBD to shield the cells from infection.  

In the human body, our cells don’t take up CBD directly. Instead, our body breaks down CBD into two molecules, 7-OH-CBD and 7-COOH-CBD.  The metabolite 7-OH-CBD, the same compound effective in treating epilepsy, was included in testing.  Researchers were able to identify that 7-OH-CBD is responsible for actively helping the cells prevent infection. The molecule does this by signaling to the body that a virus is present, as well as causing other changes within the cell. In addition, CBD, while not present at high concentrations in the human body, did show the ability to prevent cell infection and reverse the effect of the virus on the cell.

It seems that CBD may have a role in preventing the infection and replication of COVID-19 and other virus infections. Because these were cell culture experiments, more research is needed to know what effect CBD has on the coronavirus in the human body. The researchers were careful to note that they do not suggest self-treatment of the coronavirus with commercially available CBD products. As of now, CBD products are widely available and come in many forms such as tinctures, lotions, foods, and nasal sprays. However, the sources, quality, and concentration of these products can vary widely.

Conflict of interest statement by the authors: Five of the authors (MRR, GR, LCN, DY and JMM) filed a provisional patent entitled “Method of use of Cannabidiol as an antiviral agent”. Receipt of the provisional patient was acknowledged by the USPTO on November 30, 2020. S.A.O. is a cofounder and consultant at OptiKira., L.L.C. (Cleveland, OH).