Since Covid-19 first became a dangerous pandemic, many have wondered how cannabis use might factor into risk or healing for the deadly disease. While some immediately assumed cannabis was harmful, like tobacco, and others assumed it could cure or prevent the disease, scientists quickly began to explore the question.
Early research focused on the cannabinoid CBD as a potential treatment for cytokine storms and acute respiratory distress syndrome (ARDS) – a symptom in severe cases of Covid-19, which can lead to death. The results suggested that CBD may be an effective treatment, although human studies need to be conducted to confirm.
Now, researchers are exploring whether another popular cannabinoid, THC, might help with treating the novel coronavirus. And they suggest THC may actually be able to prevent Covid-19 from escalating into a fatal condition.
The new research from the University of South Carolina, Columbia investigated whether using THC might be able to prevent Covid-19 deaths. THC is the notorious chemical in cannabis that produces psychoactive effects like feeling ‘high’ or having an elevated mood. But it is also a highly medicinal chemical with potent anti-inflammatory and pain relieving traits.
In this case, researchers were looking to see if THC’s anti-inflammatory powers might be able to fight against cytokine storms and ARDS.
Cytokine storms are a dangerous symptom of Covid-19 (and other severe infections) which happens when the immune system goes overboard in its attempt to fight off an infection. Cytokines are normally part of a healthy immune response – triggering inflammation to fight against an infection. But when the infection is severe enough, our bodies can release way too many cytokines, and thus create a dangerous level of inflammation. This leads to ARDS, where breathing becomes difficult or even impossible. And cytokine storms can also lead to death from organ failure.
Several studies point to CBD as a potential treatment for ARDS, and the FDA recently greenlighted clinical trials for a synthetic cannabinoid treatment for ARDS.
In the new research, scientists explored whether THC might be able to treat cytokine storms and ARDS, by studying its effects on mice.
In this animal model, researchers exposed two groups of healthy mice to a bacterial infection called Staphylococcus aureus or SEB. SEB is known to cause cytokine storms and ARDS in mice, and it almost always leads to death for those exposed. In this case, however, the researchers gave one group of mice a treatment of THC right after they infected them with SEB, along with doses 24 and and 48 hours afterward.
Amazingly, 100% of the mice who were given THC before being infected survived having SEB. Meanwhile, 100% of the mice who weren’t given THC died from the ARDS that resulted from their infection.
While some researchers suggested early on that cannabis’ anti-inflammatory effects could potentially be dangerous in early phases of an infection – suppressing the immune system when it should be defending against attack. This study suggests that using THC early in the infection drastically improved the prognosis and avoided damage to the lungs. While the results need to be confirmed by human research, it could be good news for cannabis users who fear ongoing cannabis use could increase their risk of infection with Covid-19. For mice with SEB, THC helped even when administered immediately after the infection.
Researchers also found that THC was also able to significantly suppress the inflammatory cytokines that are involved with ARDS. It also was able to elevate regulatory T cells which help suppress inflammation. Interestingly, researchers also noticed a shift in the expression of miRNA in cells in the lungs – which may play an important role in suppressing cytokine storms, reducing lung injury and preventing death from ARDS.
In a follow up study, the same researchers went a step further, exploring whether the results from the first study are relevant to those suffering from ARDS as a result of Covid-19. While both Covid-19 and SEB lead to cytokine storms and ARDS, it’s not clear that this happens in the same way. So, given the way THC acted on RNA in mice, these researchers decided to perform an analysis comparing gene expression in Covid-19 patients with ARDS and mice with ARDS from SEB. They found similarities suggesting THC may work well in both cases.
The researchers explain that “Collectively, this study suggests that the activation of cannabinoid receptors may serve as a therapeutic modality to treat ARDS associated with Covid-19.”
While this is a very early study, and more studies should be conducted in human populations with Covid-19, the research suggests that cannabis’ active ingredient THC could be able to prevent Covid-19 from escalating to ARDS – or treat it if it does.