Researchers at Canadian University, McMaster University, recently released their findings in which they described cannabigerol, a cannabinoid more commonly known as CBG, as able to kill a variety of strains of MRSA – an antibiotic-resistant staph bacteria.
Led by Eric Brown, researchers went further than studies in the past by moving beyond the petri dish and testing on rodents. Their findings here may take cannabis one step closer to the antibiotic market.
MRSA Impact in Hospitals
MRSA is a well known issue in hospitals around the world. 1 in 3 people carries staph bacteria – Staphylococcus aureus – in their noses. S.aureus is a common bacteria which is usually harmless, unless it enters an open wound where it can sometimes start a deadly infection.
Most staph infections are simply treated with antibiotics, but a new antibiotic resistant strain has become a real danger and is known as MRSA, or Methicillin-resistant Staphylococcus aureus.
Roughly 5 in every 100 people carry MRSA. Although they are generally mild, if they are difficult to treat or not done in time it can be deadly. This is particularly true in instances where MRSA is introduced to someone with a weak or suppressed immune system, like those in hospitals.
MRSA is most commonly observed as a skin infection or an infection of soft tissues. These are seen on the skin as pus filled bumps and/or sores. It can even cause festering wounds which slowly kill the tissue that the bacteria live on.
Things tend to get a bit spongy when MRSA enters the body. “Necrotizing” is used in numerous ways to describe the effects caused by these infections. MRSA can degrade and kill your bones, tear holes in your lungs, and cause infections of the heart and blood that could be deadly. With these terrifying effects, doctors are looking for treatment options that can stop MRSA in its tracks – but these are, unfortunately, extremely difficult to come by.
Cannabis’ Antibacterial Properties
Cannabis has been known to be an antibacterial for some time now. The first researchers didn’t know what compounds were actually responsible for the effects they had observed – but more recent research has started to break it all down and make things clearer. Especially when trying to determine which cannabinoid is effective against certain bacteria.
The McMaster Uni team tested 18 cannabinoids against the more common variations of MRSA. What they found is that nearly all had some sort of positive effect on the bacteria. Interestingly, 11-OH-THC, the compound which Δ9-THC breaks down into when eaten, was not particularly effective against MRSA. This leads us to believe that THC treatments may not be viable for the future of cannabis as an MRSA treatment.
Several other cannabinoids, such as CBG, CBD, CBN, CBCA, Δ9-THC and Δ8-THC were the most effective. These destroyed bacteria at concentrations low enough to warrant deeper investigation – with CBD being the most promising.
CBG’s Dominance over MRSA
One main reason why MRSA is so difficult to address is the biofilm that bacterial cells develop as a defence mechanism.
Biofilm acts as an armour of sorts. CBG, in a way, prevents this protective shield from forming – as well as stripping it away if it does form. This is why it may be so effective in tackling MRSA at relatively low concentrations.
The next question is whether CBG could do the same for blood cells? Doing so would be an indication of toxicity and would send a signal to halt further research. Researchers also exposed human red blood cells to CBG, and noted that the cells remained happy and healthy. This leads us to believe that CBG can remove MRSA’s armour, while keeping our blood cells defences intact.
The Matter of Persistence
One of the major concerns with potential antibiotics is the trickery of certain bacteria, where they can fool antibiotics into being less effective. The first of these include dormant bacterial cells known as persister cells. These are heavily resistant to antibiotics and have the potential to reactivate after the antibiotic is gone, causing reinfection. CBG was observed to destroy these persistent cells within 30 minutes, after being observed in a petri dish.
Another way in which bacteria make it hard for antibiotics to function is by rapidly mutating defences against particular drugs. This is how relatively simple and harmless bacteria such as staph have evolved into something deadly like MRSA overtime.
Researchers created models as a way to observe how quickly MRSA would adapt to CBG. Guess what – it didn’t. CBG remained effective even when researchers did their best to force a mutation of MRSA bacteria to become resistant to CBG. This strength is vital in developing an antibiotic that will be effective in the long term.
How soon until we can start using CBG to address MRSA in humans? Once a compound has shown potential in the petri dish, the next phase is to start testing it on animals. This is exactly what the researchers as McMaster did – they treated mice with CBG and observed a reduction in the animals bacterial load by roughly half.
The most efficient dose to kill the bacteria was 100 mg/kg of injected CBG. This is actually a rather large dose if scaled up to human size. This measure would be a little over 700 grams of pure CBG with a 70kg human. Another point worth making is that humans often don’t inject cannabinoids. Common cannabinoid administration is done orally, oromucosal, or intranasal. These are issues we hope will be addressed once further studies are conducted.
Balancing Effectiveness & Safety
Even though “antibiotics are commonly given at much higher doses than other medicines and are typically dosed to obtain much higher levels in humans than most other drugs,” lead researcher Eric D. Brown wrote that “the need for high doses of antibiotics to achieve efficacy is often at odds with the competing need for safety and tolerability. Indeed, this is one of the reasons that there is so much failure in antibiotic drug discovery and development. It’s hard to achieve both efficacy and tolerability. This, of course, is why MRSA remains such a problem in the clinic.”
CBG may have a long way to travel before it becomes a common and viable treatment for MRSA bacteria, we may be able to see the day where cannabis can put a halt to flesh eating bacteria.