Researchers in the United States have conducted a study showing that a cannabis plant compound inhibited infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human lung cells.
SARS-CoV-2 is the agent responsible for the coronavirus disease 2019 (COVID-19) pandemic that continues to sweep the globe posing a threat to global public health and the worldwide economy.
Marsha Rosner from the University of Chicago in Illinois and colleagues found that cannabidiol (CBD) and its metabolite 7-OH-CBD potently blocked SARS-CoV-2 replication in lung epithelial cells.
The CBD inhibited viral gene expression and reversed many of the effects the virus has on host gene transcription.
The compound also induced the expression of interferons – cell signaling proteins that are produced by host cells as an early response to viral invasion.
Furthermore, the incidence of SARS-CoV-2 infection was up to an order of magnitude lower in a cohort of patients who had been taking CBD, compared with matched patients who had not been taking CBD.
“This study highlights CBD, and its active metabolite, 7-OH-CBD, as potential preventative agents and therapeutic treatments for SARS-CoV-2 at early stages of infection,” says Rosner and the team
A pre-print version of the research paper is available on the bioRxiv* server, while the article undergoes peer review.
Rapid spread of SARS-CoV-2 highlights the need for new treatments
Since the COVID-19 outbreak first began in Wuhan, China, in late December 2019, the rapid spread of SARS-CoV-2 has led to more than 119.5 million infections and caused more than 2.64 million deaths.
Although recently-approved vaccines are now being rolled out in many countries, the virus is still spreading rapidly. Rosner and colleagues say this highlights the need for alternative approaches, particularly among populations with limited access to vaccines.
More about SARS-CoV-2 and CBD
The SARS-CoV-2 virus primarily enters host cells through the binding of a surface viral protein called spike to the human host cell receptor angiotensin-converting enzyme 2 (ACE2).
The viral genome is then translated into two large polypeptides that are cleaved by the viral proteases MPro and PLPro to produce the proteins required for viral replication, assembly, and budding.
Rosner and colleagues say that, although limited, some studies have reported that certain cannabinoids have antiviral effects against hepatitis C virus and other viruses.
Furthermore, an oral solution of CBD is already approved by the US food and Drug Administration for the treatment of epilepsy.
What did the current study involve?
To test the effect of CBD on SARS-CoV-2 replication, the researchers pretreated A549 human lung carcinoma cells expressing ACE-2 (A549-ACE2) with 0-10μM CBD for 2 hours before infecting them with SARS-CoV-2.
Analysis of the cells 48 hours later showed that CBD had potently inhibited viral replication in the cells.
Since CBD is often consumed as part of a Cannabis sativa extract, the team investigated whether other cannabinoids could also inhibit SARS-CoV-2 infection, especially those with closely related structures.
Remarkably, the only agent that potently inhibited viral replication was CBD; limited or no antiviral activity was exhibited by the other structurally similar cannabinoids tested.
Furthermore, the CBD metabolite 7-OH-CBD, the active ingredient in the CBD treatment of epilepsy, also effectively inhibited SARS-CoV-2 replication in the A549-ACE2 cells.
Read more: News-Medical.net