A recent study published in the journal ACS Infectious Diseases has indicated that a common cannabinoid, cannabigerol (CBG), may hold the key to combating drug-resistant superbugs. Researchers from McMaster University in Canada screened 18 different cannabinoids in their investigation of their antibacterial properties. The study revealed that all cannabinoids tested showed antibiotic activity, with CBG proving to be the most effective at tackling pathogenic bacteria. Tests showed that CBG was able to reduce biofilm formation by 50% with as little as 0.5 micrograms per millilitre. Biofilms produced by methicillin-resistant Staphylococcus aureus (MRSA) are particularly dangerous, as they are extremely difficult to remove and can form on medical implants and the skin leading to recurrent infections and spread.
Following these promising results, researchers decided to assess the efficacy of CBG using a mouse model. The results showed that CBG was able to combat MRSA with its efficacy directly comparable to that of vancomycin, an antibiotic commonly used in the treatment of superbugs. The researchers also believe that CBG could be developed further into a more general-use antibiotic.
The McMaster University researchers found CBG and other cannabinoids to be relatively ineffective at inhibiting drug-resistant gram-negative bacteria such as E.coli in initial tests. However, when used in conjunction with small quantities of the antibiotic polymyxin B, which disrupts the outer membrane of such bacteria, CBG was able to combat drug-resistant gram-negative pathogens.
Despite the potential demonstrated by CBG in this study, researchers emphasise that it is not an immediate ‘readymade’ fix for antibiotic resistance. CBG exhibited some toxicity towards otherwise ‘good’ host cells, making it more of an important lead or starting point rather than a finished pharmaceutical product.
Other cannabinoids have previously shown promise as antibiotics candidates. Dr Mark Blaskovich from the University of Queensland explained that it may not be necessary to understand an antibiotic’s mechanism of action in order to progress with its development. If an antibiotic is effective at killing bacteria and not inducing resistance, such as CBD, there should not be significant roadblocks in advancing it further from a regulatory perspective.