Cannabidiol, or CBD, may help reduce the cytokine storm and excessive lung inflammation that is killing many patients with COVID-19, researchers say.
While more work, including clinical trials to determine optimal dosage and timing, is needed before CBD becomes part of the treatment for COVID-19, researchers have early evidence it could help patients showing signs of respiratory distress avoid extreme interventions like mechanical ventilation.
Laboratory studies by The Dental College of Georgia and Medical College of Georgia indicate pure CBD can help the lungs recover from the overwhelming inflammation, or cytokine storm, caused by the COVID-19 virus, and restore healthier oxygen levels in the body.
The laboratory model, which takes advantage of the large, unique genetic structure of the novel coronavirus, produced classic symptoms of the overwhelming, destructive immune response, and then CBD significantly downregulated classic indicators of the excess, like inflammation-promoting cytokines – as it improved oxygen levels in the blood and enabled the lungs to recover from the structural damage.
A major problem with SARS-CoV-2 is instead of just killing the virus, the over-the-top immune response can quickly disable the lungs, transforming them to a place where virus is replicated, rather than a place that makes oxygen available for our bodies and eliminates potentially harmful gases like carbon dioxide.
Mechanical ventilators can take over these vital functions for a while, and enable critically ill people to use less energy to just breathe and have more energy to fight infection, while ideally the lungs recover from the assault. However evidence suggests 30-50% of patients who get to the point of mechanical ventilation, don’t survive.
They looked at objective measures of lung function in mice like levels of proinflammatory cytokines, oxygen levels in the blood before and after treatment, as well as temperature, an indicator of inflammation. Oxygen levels went up, while temperatures and cytokine levels went down with CBD therapy. Days later, a more detailed analysis of the lungs, reinforced reduction of key indicators of destructive inflammation, which their model, like the virus, drove way up including reduced levels infiltrating neutrophils.
In fact, both clinical symptoms and physical lung changes resulting from ARDS were reversed with CBD treatment, they say.
Their model was created with the help of a synthetic analog of double-stranded RNA called POLY (I:C). In humans, our double-stranded DNA contains our genetic information and our single-stranded RNA carries out the instruction of our DNA to make certain proteins. In the family of coronaviruses, the double-stranded RNA carries the genetic material needed to reproduce the viruses and hijacks the cell machinery of our body to do that.
Mice received three, once-a-day doses of POLY (I:C) in the nasal passageway. CBD was given by a shot in the abdomen, the first dose two hours after the second POLY (I:C) treatment, then every other day for a total of three days in a process that sought to mimic mice getting treatment about the time a human would begin to experience trouble breathing and likely seek medical care. Given too early, CBD might actually interfere with a proper immune response against the virus, Yu says.
CBD quickly improved the clinical symptoms, then later detailed studies of the lungs showed damage to their structure, like tissue overgrowth, scarring and swelling, also had totally or partially resolved. Their next steps include doing similar studies on other organs impacted by COVID-19 including the gut, heart and brain, Baban says.
At least one way CBD is thought to calm the immune response is because it looks similar to endocannabinoids, a natural cell signaling system in our bodies believed to be involved in a wide variety of functions from sleep to reproduction to inflammation and immune response.
CB1 and CB2, the main receptors for this system, are found extensively throughout the body including the brain and respiratory system, where we breathe in manmade and natural irritants in the air—as well as viruses and bacteria—that might inflame. While understanding the workings of the natural endocannabinoid system is still very much a work in progress, it’s thought that one way CBD works to reduce seizures, for example, is indirectly through the large number of CB1 receptors in the brain, says Yu.
ARDS is a rapid, severe infection of the lungs that results in widespread inflammation, shortness of breath, rapid breathing and the inability to sustain adequate oxygen levels to the body and brain. Shortness of breath or difficulty breathing are some of the early signs of COVID-19. ARDS is a major cause of death in patients who are critically ill for a variety of reasons, including common sepsis.