Since 1987, only one new class of antibiotic has been found. This is a frightening fact, as bacteria are some of the fastest evolving organisms on the planet. Already, several common strains of bacteria have become resistant to antibiotics, putting patients at risk of dying from once treatable diseases like staph infection and tuberculosis. Now, researchers are turning to the natural world in hopes of finding novel antibiotics, and cannabis is a major plant of interest.
The antibacterial properties of cannabis
The wonders of the cannabis plant continue to amaze both the medical community and herb lovers alike. Thus far, phytochemicals found only in cannabis have successfully reduced epileptic seizures, eased chemotherapy-induced nausea and vomiting, and provided relief to those with chronic pain and muscle spasms caused by multiple sclerosis.
However, there is another major medical use for the plant that researchers are only just beginning to explore. The crystally, psychoactive resin that coats cannabis flowers and leaves happen to contain potent antibiotics.
Thus far, scientists have only examined the antibacterial properties of the plant in the laboratory. Yet, several of the plant’s active compounds, called cannabinoids, have successfully beaten the dreaded methicillin-resistant Staphylococcus aureus (MRSA).
Effective throughout history
Back in the 1950s, before chemist Dr. Rafael Mechoulam and his team first isolated tetrahydrocannabinol (THC), researchers looked heavily into topical antiseptic applications of cannabis for both the mouth and the skin.
While it sounds impressive, the antibacterial properties of cannabis aren’t all that surprising. The cannabis plant is thought to have developed cannabinoids as a type of external immune system, protecting the herb from environmental threats.
As reported by MIT Technology Review, Simon Gibbons of the School of Pharmacy at the University of London is optimistic, though perplexed, about the novel ways cannabis compounds seem to kill bacteria. He explains,
Everything points towards these compounds having been evolved by the plants as antimicrobial defenses that specifically target bacterial cells, but the actual mechanism by which they kill the bugs is still a mystery.
We’ve tested whether the cannabinoids affect common antibiotic targets like fatty acid synthesis or the [DNA-bending enzyme] DNA gyrase, but they don’t.
I really cannot hazard a guess how they do it, but their high potency as antibiotics suggests there must be a very specific mechanism
Simply stated, the cannabis plant has proven to be a powerful antibiotic, but just how it works is a bit of a mystery. The cannabis plant produces over 100 of these potential antimicrobial cannabinoids overall, plus a few hundred more aroma and flavor molecules that may boost the plant’s antimicrobial potential.
Here’s the scoop on the top five antibacterial compounds in the cannabis plant.
1. Tetrahydrocannabinol (THC)
Soon after psychoactive THC was first isolated, researchers stumbled upon the chemical’s antibacterial effects. A paper published in 1976 found that a dose as small as 1-5 micrograms per milliliter of THC successfully killed streptococci and staphylococci two bacteria that cause strep through and the much-feared staph infection.
Though, the effective concentration jumped to 50 micrograms when tested in blood. Interestingly, the study found that gram-negative bacteria like E. coli and helicobacter pylori, which causes stomach ulcer, were resistant to isolated THC.
In a more recent study published in 2012, a full extract taken from cannabis seed and plants showed a moderate effectiveness against E. coli and a high effectiveness against Pseudomonas aeruginosa, a gram-negative bacteria that can cause respiratory, skin, and urinary tract infections.
The full extract also was highly effective against Bacillus subtilis, a pathogen that causes food poisoning.
2. Cannabinol (CBN)
CBN is a breakdown product of THC. As cannabis plants age, more THC transforms into the less psychoactive CBN. Like THC, however, this aged cannabinoid has some potent antimicrobial properties.
In 2008, researchers Giovanni Appendino and Simon Gibbons treated MRSA with different cannabinoids in the lab.
MRSA is a very difficult to treat infection in humans since the pathogenic staphylococcus bacteria is no longer killed by antibiotics. They found that CBN was one of the five cannabinoids common cannabinoids that were effective against MRSA, the others included THC, CBD, CBC, and CBG.
3. Cannabidiol (CBD)
Amazingly, not only did CBD and other cannabinoids effectively kill MRSA, but they don’t seem to respond to the traditional ways that bacteria evade death by an antibiotic. According to Gibbons, the cannabinoids,
…appear to be unaffected by the mechanism that superbugs like MRSA use to evade existing antibiotics.
To make matters even better, medical professionals and researchers in the future may not even need to use psychoactive THC to treat potential infections. Rather, CBD, along with CBN, CBC, and CBG, do not cause the mind-altering high that cannabis is so famous for. Gibbons explains,
What this means is, we could use fiber hemp plants that have no use as recreational drugs to cheaply and easily produce potent antibiotics.
4. Cannabichromene (CBC)
While not often discussed, CBC is one of the most common cannabinoids in the cannabis plant. In some strains, particularly those of Afghani and Pakistani origin, CBC and CBD have been found in almost equal ratios. In 2008, Appendino and Gibbons found that CBC was also effective against MRSA.
Yet, they weren’t the only researchers to discover the bacteria-fighting potential of this chemical. Back in 1981, scientists discovered that CBC had strong antibacterial properties and mild antifungal properties against common bugs like E. coli and Candida albicans.
A year later, researchers again showed that CBC demonstrated strong antifungal and antibacterial properties in the laboratory.
5. Cannabigerol (CBG)
CBG is the cannabinoid that fosters all other cannabinoids, like a stem cell or a template. Both THC, CBD, and CBC are breakdown products of CBG acid, which is most abundant early on in the growth cycle. As cannabis plants age and mature, this CBG differentiates into different cannabinoids.
In early research, this nonpsychoactive cannabinoid demonstrated modest antibacterial and antifungal effects. Now, like the other cannabinoids on this list, CBG has been found effective against MRSA.