SARS-CoV-2 is responsible for the ongoing COVID -19 pandemic which has caused and continues to cause widespread morbidity and mortality across the world. SCIENCE ADVANCES published an exciting research article last Friday reporting CBD as a potential preventative agent by blocking SARS-CoV-2 infection in host cells at early and even later stages of infection.
CBD and its metabolite 7-OH-CBD, but not THC, CBDA, CBDV, CBC, or CBG, potently blocked SARS-CoV-2 replication in lung epithelial cells. CBD was not able to block viral entry into host cells as no decrease in ACE2 expression was observed, where ACE2 is the SARS-CoV-2 receptor into host cells. However, CBD effectively blocked viral RNA expression, including RNA coding for spike, membrane, envelope and nucleocapsid proteins after viral entry into cells. CBD also reversed many viral-induced changes in the host genes, including those associated with chromatin modification and transcription.
One mechanism contributing to the antiviral activity of CBD is the induction of the interferon pathway both directly and indirectly following activation of the host immune response to the viral pathogen, where interferons have been tested clinically as potential treatments for COVID-19. CBD was also able to suppress cytokine production in recruited immune cells such as macrophages within lungs and other affected tissues. Notably, combining CBD with THC (1:1) significantly suppressed the antiviral efficacy of CBD.
In addition to the cell study, pre-clinical studies show that CBD treatment reduced viral titers in the lungs and nasal turbinates of SARS-CoV-2 infected mice. This study also showed that a national sample of patients from the National COVID Cohort Collaborative with medication record of an oral solution of 100 mg/mL CBD (CBD100) had a significant lower rate of SARS-CoV-2 infection.
This study highlights CBD as a potential preventative agent for early-stage COVID infection and calls for future clinical trials. However, it also cautions against use of non-medical CBD formulations including edibles, inhalants or topicals as a preventative or treatment therapy due to the quality and inactive carriers and formulation adjuvants, which may limit the amount of drug available to tissues after administration.
Reference :
Nguyen, L. C. et al. Cannabidiol inhibits SARS-CoV-2 replication through induction of the host ER stress and innate immune responses. Sci. Adv. (2022). https://www.science.org/doi/10.1126/sciadv.abi6110
