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20th January 2020

Cannabis compound proves potent against superbugs

Cannabigerol offers new weapon against drug-resistant bacteria

Following lab testing on five cannabis compounds for their antibiotic properties, Cannabigerol (CBG) has been found to be particularly effective in killing drug-resistant strains of bacteria, such as the common hospital superbug MRSA.
Tests reveal that CBG, which is not psychoactive, was able to kill methicillin-resistant Staphylococcus aureus microbes and ‘persistent’ cells, which are known for their resistance to antibiotics and which often drive repeat infections. 
The compound also cleared up hard-to-shift “biofilms” of MRSA that can form on the skin and on medical implants.
With antibiotic resistance on the rise, the lack of effective treatments pose a significant threat to public health, with patients at risk of dying from simple infections and routine operations becoming too dangerous to perform. England’s former chief medical officer Dame Sally Davies believes the risk is so severe that she has gone as far as to suggest that ‘apocalyptic scenarios’ may be awaiting us if alternatives can’t be found.
In a 2013 interview with The Guardian, she said: “There are few public health issues of potentially greater importance for society than antibiotic resistance. It means we are at increasing risk of developing infections that cannot be treated – but resistance can be managed.”
Among antibiotics in use today, the newest date back to discoveries made more than 30 years ago.
An unpublished study will examine CBG’s ability to treat infections outside of a lab, after further testing showed positive results for mice infected with MRSA, with the compound holding its own against vancomycin, a drug currently used as the last line of defence against drug-resistant microbes.
The study is under review at the ACS Infectious Diseases journal.
Eric Brown, a microbiologist who led the work at McMaster University in Hamilton, Ontario, said cannabinoids were “clearly great drug-like compounds”, but noted it was early days in assessing the compounds for use in the clinic. “There is much work to do to explore the potential of the cannabinoids as antibiotics from the safety standpoint,” he said.
Brown found that CBG and other cannabinoids did not work well against gram negative multi-drug resistant bugs. But the team went on to show that when CBG was used with small quantities of polymyxin B, an existing antibiotic that disrupts the outer membrane of gram negative bacteria, the cannabis compound wiped out the drug-resistant pathogens.
Bacteria fall into two classes depending on the makeup of their cells. MRSA bugs are known as gram positive bacteria, and have a single, thick cell membrane. Gram negative bugs differ in having inner and outer cell membranes, and these infections can be harder to treat. In the World Health Organization’s priority list of drug-resistant bacteria, all three ranked as a “critical” priority are gram negative, namely Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacteriaceae.
Cannabis plants are thought to make the compounds to fight off invading pathogens, but there are other ways to produce CBG. To study the compound, Brown’s team synthesised it in the lab using the chemicals olivetol and geraniol. “We are now pursuing the required paperwork to work with a wide variety of cannabinoids,” he said.
Mark Blaskovich, who studies antibiotic cannabis compounds at the University of Queensland, said cannabis seemed to be particularly rich in antibiotics, though other plants such as tea tree, garlic and spices turmeric and curcurmin also contained antibacterials.
“These are likely made as a defence mechanism to protect the plant from bacterial and fungal infections, but to date have not been very useful for human infections as they really only work outside the body,” he said. “That’s what makes this new report potentially exciting – evidence that cannabigerol is able to treat a systemic infection in mice.”
About Medical Cannabiz World:
In November 2019, Medical Cannabiz World opened its doors to the medicinal cannabis industry, supported by the Maltese government’s commitment to legislation for this high growth sector.  Medical Cannabiz World summit 2020 will focus on the Malta medical cannabis industry as well as global opportunities in the sector, attracting investors, medical researchers, policy makers and entrepreneurs looking to forge exciting new opportunities.