CBD has potential as COVID-19 treatment, but more study needed, experts say

NEW YORK, Feb. 3 (UPI) -- Marijuana and its derivatives, including cannabidiol, have been touted as potential treatments for everything from anxiety and sleep problems to chronic pain conditions.

And because COVID-19 has been the health condition on the top of virtually everyone's mind for nearly three years, it should come as no surprise that momentum is building for a potential role for marijuana, in particular cannabidiol, or CBD, as a treatment.

However, unlike some treatments that have been promoted without scientific evidence behind them, studies exist that suggest the drug may have properties to counteract the virus' effects on the body and perhaps, prevent infection in some cases.

If someone becomes infected with COVID-19, Is it time to head to the local CBD dispensary? Not yet, experts say.

"We don't know yet if CBD can prevent or treat COVID-19, but our results provide a strong case for conducting a clinical trial, such as those done for vaccines, to determine whether this is the case," Marsha Rosner, a co-author of one CBD study, told UPI in a phone interview.

"Having said that, we do not advise anyone to run out and get CBD products from a local dispensary, because we were using very pure, very high-quality CBD in our study," said Rosner, a professor of cancer research at the University of Chicago.

CBD: 'Of Mice and Men'

CBD is a chemical component of the marijuana plant, known scientifically as cannabis sativa.

However, it is not that ingredient that gives marijuana its intoxicating effect, or high. That comes from tetrahydrocannabinol, or THC.

For their study, which was published Jan. 20 by the journal Science Advances, Rosner and her colleagues used a form of commercially available CBD oil approved by the FDA in 2018 to treat epilepsy in children.

In experiments with mice, the drug appeared to prevent the virus that causes COVID-19 from infecting cells, including those in the lungs, according to Rosner.

The research team replicated these experiments in several human subjects and had similar results, she said.

In addition, in a separate component of the study, the researchers found that COVID-19 infection rates were lower in people who reported using CBD oil for other purposes, compared with those who did not use the oil, Rosner said.

Exactly how the drug works against the virus remains unclear, though it is possible that its anti-inflammatory properties -- the same ones that make it effective against pain -- also could prevent some of the organ damage caused by infection, she said.

The drug also may work to reduce production of angiotensin-converting enzyme 2, or ACE-2, an enzyme found in cells in the intestines, kidney, testis, gallbladder and heart that helps the virus spread throughout the body, studies suggest.

However, by themselves, these findings do not prove that CBD can prevents COVID-19 -- only that the drug may have some effect against the virus, according to Rosner.

Any curative properties will need to be confirmed in clinical trials designed to compare results with its use against those of other treatments or a placebo, a "sham" drug that provides no clinical benefit.

Still, the results of the study suggest that a clinical trial is worthwhile, and the researchers involved are in the planning stages right now, Rosner said.

Other research with CBD

Other studies have also explored the potential value for CBD to treat COVID-19.

In research published in December by the journal Cannabis and Cannabinoid Research, scientists at St. John's University College of Pharmacy and Health Sciences in New York City found that the drug boosted the effectiveness of Remdesivir, a medication that has been used to treat the virus.

CBD essentially slowed the process by which the liver metabolized, or processed, Remdesivir, an antiviral originally developed to treat Ebola, allowing it to remain in the body and work against COVID-19 for a longer period.

In addition, in another study published in October of last year, by the journal Phytotherapy Research, researchers in Italy found that treatment with CBD, at a specific dose and purity, prevented some of the cell damage and inflammation caused by the virus.

However, in perhaps the only clinical trial of CBD's use in COVID-19 to date, the results of which were published in Cannabis and Cannabinoid Research in October, infected patients with mild to moderate symptoms treated with the drug actually took longer to recover than those given placebo.

The 91 participants in this trial received either 300 milligrams of CBD or a placebo, plus steroids and other treatments, for 14 days, though it is unclear how the CBD used in the study was produced.

Is there a future for CBD in COVID-19?

Even after the promising results from Rosner and her colleagues and others, the question remains: Is CBD a viable treatment for COVID-19?

The short answer is: Maybe.

Just because the drug shows promise in laboratory experiments does not mean it will perform well in more stringent clinical trials, according to Peter Cogan, an associate professor of pharmaceutical sciences at Regis University in Denver, who has studied its medical use.

CBD, like many drugs with limited water solubility, will form nanosized waxy globules called "colloids" that interfere with a number of chemicals used in experiments and "tend to give false positive results simply because they stick to everything in the dish," he said.

For this and other reasons, researchers may not be able to replicate the findings with CBD in the lab in human study subjects, Cogan said.

And that is why, although he described the findings of Rosner and her colleagues as "intriguing," he is not "super optimistic" CBD will see widespread use as a treatment for COVID-19, "though it certainly warrants more research," including clinical trials with large patient populations, he said.

"CBD should be treated like any other chemical being investigated for therapeutic purposes, which is to say we should probably figure out what it actually does before planning the parade," Cogan said.

"The nice thing about CBD, though, is that it appears, generally speaking, to be safe, so it could be argued that there isn't any good reason to not put together a clinical trial to see if it has any effect," he said.