Over 2,500 years ago, funerals in Central Asia were conducted in the intoxicating haze of cannabis smoke to calm mourners. China’s ancient pharmacopoeias dispensed cannabis for a wide range of physical and emotional ailments.

Ever since then, humans in many parts of the world have drawn on the cannabis plant in similar ways. They didn’t know exactly how it worked, but they knew the smoke and oil it produced improved their mood and dulled their aches and pains.

It’s only in the last 40 years or so that scientists have figured out exactly how cannabis interacts with our biology. They’ve identified around 100 cannabinoids, the active ingredient in the plant that can interact with cell receptors in our bodies.

They also discovered the endocannabinoid system (ECS), a sort of communications network for the brain and body that influences a wide range of bodily functions, including how we feel, move and react. The ECS and how it works was the subject of our previous article.

How exactly phytocannabinoids (or phytocoids) which come from plants like cannabis sativa influence our biology, is still the subject of intense study. Here’s what we know so far.

Of the cannabinoids scientists have identified, two are best understood and considered to have the most potential for medicinal use - delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is known to be psychoactive when it binds to the neuroreceptors in our brain. It is responsible for the high that cannabis smokers experience. CBD may have some psychoactive properties but doesn’t have the same sort of intoxicating effect. 

Neurotransmitters in reverse 

Our brain on average contains 86 billion brain cells (neurons) that talk to each other via chemical messengers known as neurotransmitters. They are constantly sending and receiving information that allows us to think, breathe, move and function. 

The neuron sending a chemical message is considered to be presynaptic and the neuron receiving the message, once it has crossed a short pathway in the brain known as the synapse, is a postsynaptic cell. The message chain carries on between neurons across the brain to our nervous system.

Cannabinoids are also chemical messengers, but in contrast work in reverse. When a postsynaptic neuron lights up, endocannabinoids are created from the fats within the cell and travel backwards to the presynaptic neuron.

They can effectively go back to the source, influencing the messaging that is sent out across the brain. That’s done naturally in our brain all the time by our internal endocannabinoids. But introducing phytocannabinoids can supercharge or modify the process. 

THC, for instance, binds to the CB1 cannabinoid receptors in the brain and body. It can have an overwhelming effect, as anyone who has smoked cannabis can attest to. The potentially anxiety-inducing impairment caused by THC is the main reason cannabis was and continues to be classed as an illegal drug in many countries for recreational use.

Suppressing enzymes

CBD is different. It doesn’t interact with our receptors in the same way, but is believed to have antioxidant and anti-inflammatory properties that medical studies suggest can offer treatment for a range of neurological disorders, from psychosis to multiple sclerosis.

Phytocannabinoids may also act to suppress the role enzymes play in our body to break down the endocannabinoids once they have fulfilled their intended role. That could allow them to carry on for longer and have more of a beneficial impact. CBD in particular has been studied for its potential to interact with the ECS to produce health effects such as reduced anxiety. THC has been more cautiously approached as prolonging its psychoactive effects can have negative consequences.

The science underpinning how THC and CBD work on the body is developing rapidly. In the next article, we’ll look at what the evidence suggests about how effective and safe Cannabinoids are for treating a wide range of conditions and ailments.

Sources:

Review of the neurological benefits of phytocannabinoids
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5938896/

Phytocannabinoids explains - a video guide https://www.metagenicsinstitute.com/video/phytocannabinoids/

What are phytocannabinoids?
https://www.sydney.edu.au/lambert/medicinal-cannabis/phytocannabinoids.html

Phytocannabinoids and endocannabinoids
https://pubmed.ncbi.nlm.nih.gov/19630737/