Statement on Covid-19 and the CB2 Receptors
There is great hope that medicines that stimulate the CB2 receptor will be found useful in treating Covid-19. At present, we lack clear evidence that they do. It would be irresponsible to promote the use of any substance for treating Covid-19 without evidence.
The 'Cytokine Storm' hypothesis that is widely held proposes that much of the damage in Covid-19 is not directly caused by the virus... it states that some people over-respond to the virus, and their own immune system causes damage while fighting the virus. This hypothesis is supported by research showing that dexamethasone (a powerful steroid and immunosuppressant) can reduce the death rate when given to people who were hospitalized with Covid-19.
Activating the CB2 receptor can lead to profound anti-inflammatory effects. There are many studies in test-tubes and animals that show that this is the case. But we cannot say yet with any certainty that a CB2 medicine will reduce inflammation in exactly the right way that is needed when a person is infected with SARS-2 virus and develops Covid-19.
One Canadian company is moving forward on testing a selective CB2 agonist for Covid-19. Tetra Bio-Pharma has obtained FDA approval for phase I clinical trials for what they call ARDS-003 (which is HU-308).
It is conceivable that activating the CB2 receptors early in a viral infection could actually make disease worse. It may be that inflammation is good early on, and that such inflammation helps the body control the infection. Such a bi-phasic response has been seen for viruses and anti-inflammatory cannabinoids with other diseases ... cannabinioids seem to be beneficial for the inflammation associated with chronic inflammation (as with multiple sclerosis) but they can also make an acute viral infection worse in some cases. A more detailed discussion of this dynamic is found in the article *Effects of cannabinoids and their receptors on viral infections.