Study: CBG can help fight antibiotic-resistant superbugs

Researchers at McMaster University in Hamilton, Ontario, recently conducted a study exploring the antibiotic properties of five cannabinoids. During laboratory tests, the research team discovered that the cannabigerol (CBG) was capable of killing the Staphylococcus aureus methicillin-resistant (MRSA), a form of drug-resistant bacteria responsible for a growing number of life-threatening infections.

According to researchers, CBG, a non-intoxicating cannabinoid, killed MRSA microbes as well as «persistent» cells that are resistant to traditional antibiotics. CBG also helped eliminate treatment-resistant MRSA «biofilms» that can develop on the skin or on medical implants. Inspired by the success of their initial study, the researchers conducted a second experiment to determine whether CBG could treat MRSA infections in mice.

The results of this second study are also promising. Researchers found that CBG was just as effective at treating MRSA infections as vancomycin, an antibiotic that doctors often use as a last resort to kill bacteria that have become resistant to all other drugs. This new study has not yet been published, but is currently under review by the journal ACS Infectious Diseases.

The researchers also wondered whether the cannabinoids could kill Gram-negative bacteria, particularly the superbugs that top the World Health Organization’s (WHO) priority list of drug-resistant microbes. The study reports that cannabinoids alone were ineffective against these bacteria, but a combination of CBG and polymyxin B, a common antibiotic, was able to destroy these dangerous microorganisms, which act as pathogens in a wide variety of infections.

Eric Brown, a principal investigator and microbiologist at McMaster, said in The Guardian that this study demonstrated that cannabinoids were «clearly important drug-like compounds.» However, he cautioned that research on these natural compounds found in cannabis is still in its infancy. «There is a lot of work to be done to explore the potential of cannabinoids as antibiotics from a safety perspective,» he explained.

Although the cannabis is legal in Canada, the researchers chose to synthesize CBG in the lab from olivetol and geraniol—the precursors of CBG—rather than extracting a natural, plant-based version. «We are currently reviewing the documentation required to work with a wide variety of cannabinoids,» Brown said.

This study is of particular interest to the medical community, as drug-resistant bacteria are becoming increasingly prevalent in hospitals. Over the years, bacteria have developed mutations that protect them from traditional antibiotics, making infections that were once easy to treat difficult to cure. In 2008, a study revealed that another cannabinoid, CBN, might also be effective against MRSA.

Mark Blaskovich, a researcher on the Cannabis at the University of Queensland, told The Guardian that cannabis plants likely produce antibacterial compounds «as a defense mechanism to protect the plant against bacterial and fungal infections.» Prior to this study, researchers had had little success using these natural antibiotics to treat infections.

«That’s what makes this new report potentially exciting,» Blaskovich said, «the evidence that cannabigerol is capable of treating a systemic infection in mice.»