Antibiotic resistance currently poses a major threat to global healthcare systems, but a new study in the journal Nature Communications Biology suggests that a compound found in cannabis may provide a solution. Known as cannabidiol (CBD), the non-psychoactive cannabinoid was found to destroy numerous highly resistant bacteria, including those that cause gonorrhea, meningitis, and MRSA.
Bacteria fall into two broad categories, known as gram-positive and gram-negative. Previous research has shown that CBD is effective at destroying numerous types of gram-positive bacteria, although it had been assumed that the compound would not work against gram-negative species, as their sturdier outer membranes make them more difficult to kill. This extra layer of protection also renders many antibiotics ineffective against gram-negative bacteria.
To conduct their research, the study authors applied synthetic CBD – as well as a range of slightly altered CBD analogs – to various samples of pig skin that had been infected with a range of different bacteria.
Results indicated that the cannabinoid is able to penetrate and kill a much wider range of gram-positive bacteria than previously thought. These include antibiotic-resistant strains such as Methicillin-resistant Staphylococcus aureus (MRSA), which has proved difficult to treat in humans.
More significantly, however, CBD was also able to destroy a range of gram-negative bacteria, including Neisseria gonorrhoeae, which causes gonorrhea, and Neisseria meningitides, which is responsible for meningitis.
The World Health Organization (WHO) has designated N. gonorrhoeae as a high-priority pathogen due to its increasing resistance to existing antibiotics, leading to fears that a “super gonorrhea” could be on the rise. The fact that CBD displayed no propensity to induce resistance is therefore extremely promising and prompted the researchers to suggest that a more effective treatment for certain highly problematic pathogens may be on the horizon.
“We think that cannabidiol kills bacteria by bursting their outer cell membranes, but we don’t know yet exactly how it does that, and need to do further research,” explained study author Mark Blaskovich, associate professor at the University of Queensland, in a statement.
However, while topical CBD showed great promise, the compound was found to be ineffective when it was injected into mice that had been infected with various bacteria. This is due to the fact that the cannabinoid has a very high tendency to bind to compounds in blood plasma, and is therefore largely unavailable at the systemic level to fight off infections.
Fortunately, numerous CBD analogs proved to be equally potent at killing bacteria, leading to renewed hope that it may be possible to create a slightly altered version of the compound with increased systemic availability.
“This is particularly exciting because there have been no new molecular classes of antibiotics for Gram-negative infections discovered and approved since the 1960s, and we can now consider designing new analogs of CBD within improved properties,” explained Blaskovich.
On a related note, a separate study recently showed that treating strawberries with CBD increases their shelf-life by inhibiting the growth of mold and yeast, further highlighting the compound’s antimicrobial potential.