With all that’s going on in the world these days, the need to find an effective treatment for severe respiratory complications has never been more pressing. Fortunately, the solution may be right under our noses, as new research reveals that THC could potentially save the lives of those suffering from the kinds of symptoms regularly associated with coronavirus.
Publishing their work in the journal Frontiers in Pharmacology[i], the study authors explain that the majority of people who die from COVID-19 develop something called Acute Respiratory Distress Syndrome (ARDS), which is caused by excessive inflammation in the lungs. This usually occurs when the body’s immune system overreacts to an infection, releasing an excessive amount of messenger proteins called pro-inflammatory cytokines – a response known as a cytokine storm.
As we reported in an earlier blog, smoking cannabis has been found to reduce cytokine production in healthy adults, although no information is available regarding how this may help to reduce ARDS in those infected with coronavirus or other pathogens. Furthermore, given the plant’s known anti-inflammatory properties, many have speculated that it could be used to treat ARDS by reducing inflammation in the lungs.
To finally add some substance to these claims, the researchers used a toxin called Staphylococcus enterotoxin B (SEB) to induce ARDS in mice. Doing so resulted in “acute mortality” as every mouse died, indicating just how fatal a cytokine storm can be. However, after being treated with THC, 100 percent of the mice survived.
The suggestion here is that while THC may not be a cure for coronavirus, it could help patients to survive the severe respiratory complications that tend to occur in fatal cases, thereby giving their immune system the time it needs to fight off the virus.
More research will be needed before we can say for sure that THC works as effectively in humans suffering from ARDS, or how it interacts with COVID-19. However, by digging deeper into the mechanisms behind THC’s action in mice, the researchers noted that it ticks many of the boxes that a coronavirus antidote would need to tick.
Firstly, they found that it “significantly suppressed inflammatory cytokines,” indicating that it may help to extinguish a cytokine storm and thereby nip the main problem in the bud. Even more impressively, THC was found to help treat any existing inflammation in the lungs by stimulating the production of two different kinds of anti-inflammatory cells, known as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs).
This response is facilitated by the fact that cannabinoid receptors are found in the lungs and bronchial tissue, although the study authors were interested to find that the anti-inflammatory effects of THC are mediated via the CB2 receptor, rather than the CB1 receptor.
Typically, THC is associated with CB1, as most of its psychoactive effects are produced when it binds to this receptor[ii]. Yet the researchers found that by chemically disabling CB2 receptors in the rodents’ lungs, they were able to reduce the efficacy of THC treatment for ARDS.
Because of this, they suggest that other cannabinoids with a higher affinity for CB2 receptors may prove even more effective at treating ARDS, although they are keen to stress that rigorous research will be needed in order to confirm this.
Finally, it’s important to note that the mice in this study obviously did not smoke a spliff, but were injected with pure THC. No research has yet been conducted in order to determine how different delivery methods may influence the efficacy of THC treatment in humans, although it seems sensible to assume that anyone suffering from ARDS should avoid smoking.
[i] Mohammed A, Alghetaa H, Sultan M, Singh NP, Nagarkatti P, Nagarkatti M. Administration of Δ9‐Tetrahydrocannabinol (THC) Post‐Staphylococcal Enterotoxin B Exposure Protects Mice From Acute Respiratory Distress Syndrome and Toxicity. Frontiers in Pharmacology. 2020 Jun 16;11:893. – https://www.frontiersin.org/articles/10.3389/fphar.2020.00893/full
[ii] Jung SW, Cho AE, Yu W. Exploring the ligand efficacy of cannabinoid receptor 1 (CB1) using molecular dynamics simulations. Scientific reports. 2018 Sep 13;8(1):1-1. – https://www.nature.com/articles/s41598-018-31749-z