The cannabis plant is a botanical universe unto itself with more than 400 active compounds. Over 100 of these come in the form of cannabinoids, with the most abundant being THC and CBD. But that still leaves a whole bunch of other stuff in the plant to discover, with terpenes in particular garnering interest in the scientific community.
What are terpenes?
But what exactly are terpenes? They provide the distinctive smell not only in cannabis, but also all herbs, flowers and plants in nature. Most of us have heard of the therapeutic benefits of aromatherapy oils such as lavender for relaxation, and rosemary for relief from muscle soreness. But did you know the oils extracted from household herbs and flowers contain many of the same terpenes found in cannabis?
That’s not to say that terpenes exist just for the benefit of mankind to help rid us of our woes and ailments. Terpenes are in fact a plant’s way of protecting itself against pests, and to help it survive in high temperatures.
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Terpenes in the cannabis plant
The cannabis plant contains around 200 terpenes, which along with cannabinoids are produced in the sticky resin of the trichomes. Terpenes only make up about 1% of overall cannabis samples, but about 10% of trichome content.
They evaporate at high temperatures, explaining why cannabis plants smell most pungent in the morning. This also makes early in the day the best time for harvesting to ensure maximum terpene availability.
The most abundant terpenes in cannabis are myrcene, pinene, limonene, linalool, eucalyptol and caryophyllene, with the variation between them dictating a strain’s distinctive smell. Steephill Labs in California have even gone as far as suggesting that the difference between Cannabis Sativa and Indica is down to its terpene content saying, “if a sample has over 0.5% myrcene, it will have indica, or ‘couch-lock’ effects. If a sample has less than 0.5%, it will have the soaring sativa effect.”
In cannabis products that have been decarboxylated (which are the majority), it’s the heat resistant terpene caryophyllene that is most abundant, which is why sniffer dogs are trained to detect it when searching for cannabis.
Ok, so terpenes smell kind of nice, but do they really do anything to our bodies?
As it happens, science backs up what aromatherapists have known for years – that terpenes can bring about physiological changes in the body. In the seminal paper ‘Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects,’ author Dr Ethan Russo describes how “terpenoid components in concentrations above 0.05% are considered of pharmacological interest,” and how “mice exposed to terpenoid odours inhaled from ambient air for 1 h demonstrated profound effects on activity levels, suggesting a direct pharmacological effect on the brain, even at extremely low serum concentrations.”
So, as it’s clear that terpenes are not just ‘extra’ ingredients in cannabis products, let’s take a whistle stop tour around the main aromatic contenders, concentrating in particular on the terpenes found in our Endoca CBD oil products.
Myrcene is the most abundant terpene in cannabis and provides an earthy, spicy and clove-like aroma. As well as the cannabis plant, it can be found in wild thyme, hops, lemongrass, basil and mango. It is purported to have several therapeutic effects with studies suggesting that it can fight the effects of diabetes, is a pain reliever and a sedative. According to Fundación Canna in their very comprehensive article on terpenes, “it has also been shown that the myrcene alters the blood-brain barrier, favouring the penetration of cannabinoids in the brain and increasing the effects.” This suggests that a higher myrcene content will promote better cannabinoid bioavailability.
D-Limonene is one of the most common terpenes found in nature. Ever noticed how your hemp oil tastes a bit orangey or citrusy? Well, that would be the limonene content. It’s been found to dissolve cholesterol containing gallstones, relieve heartburn, prevent certain types of cancer, cause cancer cell death, is anti-inflammatory, and has both antifungal and antibacterial properties.
Mood enhancing, anti-anxiety effects have been noted in both animal models and humans. One small study in which patients hospitalized for depression were exposed to citrus aromas, saw depression reduced, and 9 out of the 12 patients discontinuing with their antidepressants.
Alpha and Beta Pinene
As the name would suggest pinene is the terpene found in pine resin and conifers. Not only is it encountered in the plant kingdom, but also in the insect world where it is part of their chemical communication system.
If you think of the fresh alpine smell of pinene, one can’t help but think of cleaning products and detergents. It’s no surprise then that pinene is anti-microbial, showing effectiveness even against antibiotic resistant pathogens. Nor is it surprising that pinene should be a bronchodilator when inhaled in low concentrations.
Not only that, but pinene has been found to have anti-inflammatory properties. In a 2014 study on humans, it was even found to be a potential candidate for a new osteoarthritis drug.
You don’t have to be an aromatherapy expert to know that lavender has calming sedative effects, aids sleep and can even help with depression. That’s probably because it contains the terpene Linalool. Legend goes that lavender’s healing properties were discovered when a perfumier plunged his severely burned hand into a vat of lavender oil, only to discover that the essential oil speeded up the healing process, most probably because of Linalool’s anti-inflammatory and analgesic properties.
A further intriguing aspect of Linalool is that it appears to have anti-seizure capacities, which according to Fundación Canna “inhibit glutamatergic activity and is also able to decrease the release of neurotransmitters of the neurons under glutamate stimulation. In this way, we could argue that the sedative, anxiolytic and anti-seizure effects have their mechanism of action based on the modulation of the glutamate and GABA neurotransmitters, similarly to the way the cannabinoides act.”
Perhaps the terpene with the most pharmacological potential is β-caryophyllene, found in black pepper, leafy greens, cloves and of course, cannabis. It is unique amongst terpenes in the cannabis plant as it is also considered cannabinomimetic, meaning it acts like a cannabinoid by activating the CB2 receptor. This explains why β-caryophyllene has an anti-inflammatory and immunomodulating effect, with a studyshowing it to be more effective than synthetic cannabinoids. Like the cannabinoids THC and CBD, β-caryophyllene is a powerful antioxidant, with a one paper declaring it to have “tremendous therapeutic potential in a multitude of diseases associated with inflammation and oxidative stress.”
This wonder terpene has also been found to ease anxiety and depression, stimulate the death of cancer cells, and may even be a possible treatment for alcoholism. While much of the research has been on animal models rather than humans, the anti-inflammatory and antioxidant nature of the terpene makes it an exciting nutraceutical compound of the future.
Terpenes and the entourage effect
So, if each terpene found in cannabis has such a vast array of pharmacological effects, what implication does this have on the plant as a whole? Especially as no other plant in nature has as many terpenes as cannabis.
Well, as ever no one is really sure. According to Ethan Russo, terpenes “may contribute meaningfully to the entourage effects of cannabis-based medicinal extracts.” By the entourage effect he refers to the synergy between the various compounds in the plant, so that as Aristole put it, “the whole is greater than the sum of its parts.”
Indeed, studies show that medical cannabis containing the full spectrum of active components is more effective than isolated or synthetic versions, and terpenes almost certainly perform an important role in that therapeutic plant synergy.
However, the whole plant cannabis is not a viable option for most pharmaceutical companies who are racing to patent single cannabinoids or their synthetic variants. It would be all too easy for the role of terpenes in the plant’s therapeutic synergy to go unexplored, ignored, or even forgotten. In the end it’s up to us, the consumers to keep demanding full spectrum cannabis, with all its mysterious whistles and bells intact