What Are Cannabis Terpenes?

There are over 200 terpenes in the cannabis plant, but due to testing limitations only a few have been studied in great detail. Terpenes are largely responsible for the aroma or fragrance of the cannabis plant and give off unique flavors when tasted. Terpenes and cannabinoids are different yet work together to create a unique physiological effect utilizing what we call the entourage effect. Individually and as a group, they are more than likely what is responsible for the difference between “strains” of marijuana plants as well as a variety of proposed medicinal effects. Terpene essential oils (EO) are fast becoming the next big product market after CBD.

What is a Terpene?

Terpenes are unsaturated hydrocarbons present widely in plants and fruits. They are what gives the plant aroma, color and flavor. They have two important functions – to protect plants from predators and to produce resin. 

What are Cannabis Terpenes?

Cannabis terpenes are indigenous to the cannabis plant not only providing pungent aromatic smells but potential medicinal qualities as well. These unique cannabinoid/terpene profiles of cannabis plants are termed their “chemotype” and might be thought of as the plant’s personality.

 A chemotype is a chemical profile of the plant identifying specific cannabinoids and specific terpenes. Each plant has a unique chemotype.

Where are Terpenes Produced?

Terpenes are produced in the secretory cells of the mature un-fertilized female trichomes or resin producing structures of the cannabis plant. Trichomes are on the leaves and buds of the plant, are sticky and look like little crystals. Cannabinoids and flavones are produced here as well.

What is the Difference Between Cannabinoids and Terpenes?

There are about 480 active compounds within cannabis sativa and about 66 have been classified as cannabinoids. The two most well-known cannabinoids are THC and CBD. Cannabinoids are compounds that exert their effects through cannabinoid receptors while terpenes have an entourage effect on the endocannabinoid system mediating its effects through multiple mechanisms that may or may not affect the receptors.

 Other cannabinoids identified include Cannabigerols (CBG), Cannabichromenes (CBC), Cannabinol (CBN), cannabinodiol (CBDL), cannabicyclol (CBL), cannabielsoin (CBE), cannabitriol (CBT) and other miscellaneous types. Cannabinoids are similar in chemical structure to our neurotransmitters such as dopamine and serotonin.

Terpenes are not unique to marijuana but may be found throughout the plant kingdom. Terpenes and cannabinoids work together to produce a specific taste, aroma and high, a process called the entourage effect as mentioned earlier.

Prevalent Terpene Strains in Cannabis Plants

The following terpenes are among the most researched in the literature:

    1. α-pinene (PNE)

This terpene is known for its pine tree aroma. It is found in other plants such as basil, rosemary, parsley, dill and pine needles. 

   2. Caryophylline (CYE)

The aroma associated with this terpene is spicy, woody, cloves. It is found in other plants such as black pepper, cloves and cinnamon.

   3. Humulene (HUM)

Smells like hops or perhaps a woody aroma. Is also found in hops, coriander, basil.

   4. Limonene (LME)

Exudes the aroma of citrus. Is present in fruit rinds, rosemary, juniper and peppermint. Limonene has been used in an animal model to control anxiety as well as depression through the use of aromatherapy.

   5. Linolool (LNL)

A floral odor is predominant in this terpene. It is present in the lavender flower and essence oil.

   6. Myrcene (MYR)

Smells of cardamom, cloves, musky, herbal. Can also be found in mango, lemongrass, hops.

   7. Ocimene (OCM)

Has a sweet woody aroma. Is found in parsley, kumquats, mangos, orchids, parsley, mint.

   8. Terpinolene (TPE)

Smells piney, floral, herbal. It is also found in tea tree, nut meg, lilacs, apples.

Terpene Function

Terpenes in concentrations of 0.05% or above are considered of pharmacological interest as possible drug treatment therapies.

One of the most important functions of the terpenes is to speed up the passing of the cannabinoids into our bloodstream. Terpenes also interact with THC to either antagonize its effects or stimulate it.

Terpenes and the entourage effect

 While the literature is contradictory as to whether terpenes do or don’t act on the CB1 or CB2 receptors, it is clear they do have the following functions as to the entourage effect:

• Being lipophilic (fat combining/attracting) they interact with cell membranes as well as neural and muscle ion channels.
• They interact with neurotransmitter receptors.
• They function at G-coupled protein receptors.
• They are active as second messengers.
• They interact with enzymes.

They essentially interact with all the other cannabinoids, flavones, terpenes, and chemicals in the cannabis plant to produce a synergistic and unique effect all working in concert to produce a unique effect dependent on the chemotype of the product being consumed. For example, PNE prevents the breakdown of acetylcholine, a molecule involved in memory impairment which is a side-effect of THC administration. So, finding a product with a high PNE content may help with finding a product that helps you stay alert and focused.

Functions of terpenes independently of entourage effect

antioxidant

Terpenes have been found to have effects on their own accord aside from the entourage effect. They have far reaching anti-oxidant functions in both the cannabis plant and other terpene containing plants, fruits and vegetables. Oxidative stress diseases which terpenes may be effective for include atherosclerosis, heart disease, high blood pressure, diabetes, obesity, Parkinson’s Disease and Alzheimer’s Disease.

Antidepressant/psychopharmacology

Anti-depressant effects appear to be mediated through the interaction with the monoamines serotonin, dopamine and epinephrine. In addition, LNL induces sedative effects by acting on glutamate and GABA receptors. High GABA and glutamate are associated with anxiety.

inflammation

Inflammation is diminished by the terpenes effect on prostaglandins. Studies have shown CBD to have a prolonged effect on inflammation as opposed to terpenes which act in a quicker and shorter manner leading authors to conclude that terpenes might be more useful in acute inflammation. 

Antimicrobial

  Prominent activity against methicillin resistant staphylococcus as well as other diseases have been noted, especially with PNE. The bacterial, anti-fungal and anti-protozoal functions of some terpenes make them excellent candidates for broad spectrum antibiotics and novel insecticides.

Dermatology

  Skin permeability is enhanced making terpenes excellent delivery systems for medications such as hormones, medication, herbs or THC/CBD. 

What is the Difference in Terpene Chemotype in the Various Cannabis Strains?

When we talk about strains, we are primarily talking about 4 strains of cannabis:

Indica

Sativa

Hybrid

Cannabis ruderalis

Until just recently we have relied on popular literature and botanical differences to classify the strains. Technologically we now can test the chemotypes of the different strains to see if they are chemically different and, surprisingly, there is a lot of cross over.

A recent study showed that cannabis was effective regardless of strain for a wide range of conditions. For example, indica strains appeared better than sativa at improving appetite but no statistical difference was found between indica and sativa for pain, mood, nausea, muscle spasms, seizures, eye issues, insomnia, awareness or neuropathy.

A difference in the chemotype was found, however, between the indica and sativa strains. 

indica

Popular literature separates these strains based on both morphology and effects. Morphologically speaking, an indica strain is short and bushy and yields sedating, pain relieving effects. 

The chemotype in the indica plant was found to have a dominancy of myrcene with limonene or α-pinene as the second most dominant terpene present. 

sativa

sativa strains are tall and lanky with more of an energizing effect.

The mostly sativa strains were profiled as having a more complex array of terpenes with α-terpinolene or α-pinene as dominant and some strains having myrcene terpenes dominant with terpinolene or ocimene as second most dominant.

hybrids

 Hybrids are just that, a mixture of indica and sativa traits with each individual hybrid said to have its own unique “chemotype”. Scientists do not consider it to be a separate strain.

ruderalis

  Cannabis ruderalis is a said to be a wild form of cannabis believed to be a direct descendant of the indica plant. Ruderalis was identified in 1924 where it was widespread in central Europe and Russia.

 The primary difference between ruderalis and the other strains is that the budding cycle is initiated by maturity and not by photoperiod, or light dependent, meaning it will flower regardless of the light cycle. This is called auto flowering. The THC content is low while the CBD content is relatively high in this strain.

Present studies suggest that there is a lack of evidence to recommend an indica or sativa strain to a patient but that a new classification system should be developed based on a strain’s individual chemotype.

CB1 and CB2 Receptors

THC binds to the CB1 receptor present in the brain and central nervous system. It is responsible for the high we feel when we consume THC. CBD, however, influences the CB2 receptor which is not psychoactive. CB2 receptors are located outside of the brain and central nervous system.

CB2 receptors regulate the immune system and the peripheral nervous system. Terpenes indirectly influence this receptor except for CYE which directly activates it giving it the name of a dietary cannabinoid. The dual action of CYE as a terpene and a CB2 activator underscores the importance of the synergistic interplay between the various cannabis compounds.

What Else Can Terpenes Do?

Terpenes and cannabinoids both increase capillary blood flow, enhance brain activity and kill respiratory pathogens including methicillin resistant staphylococcus aureus (MRSA). Terpenes buffer THCs psychoactivity by reducing THC’s anxiety producing effects.

Can Terpenes Get You High?

Consuming terpenes all on their own will not yield any psychoactive effects. Their actions are mainly via the entourage effect although individual terpenes can exert effects aside from their interactions with cannabinoids. For example, the essential oils from the citrus aurantium plant, rich in terpenes, has been shown to have an anti-anxiety effects mediated through the neurochemical system of communication. The essential oils consisted of PNE, MYR and LME.

Terpene Products

Terpenes are being added with great fervor to all kinds of edibles, beer, soda, teas, vaping cartridges, bath bombs, topical lotions and encapsulated products. It is being added for a multitude of reasons – to enhance flavor, for health benefits, for taste, for aromatherapy treatments and as a carrier for cannabinoids or medicinals in topical lotions.

 Terpenes help carry other molecules through the skin’s barrier membrane to act on deeper tissue layers in medicinal elixirs. Lilac aromatherapy has been known to have an antidepressant effect by acting on olfactory receptors that carry messages directly to the brain and is just one example of a novel terpene based aromatherapy product.  New and safer insecticides are being patented using terpenes as its base. The product market is virtually exploding!

Testing for Terpenes

A terpene test is like a fingerprint. It can tell the differences between strains and help with the mislabeling of strains by identifying key chemotype fingerprints. It may even form the basis for a new classification system for cannabis.

Are Terpenes Safe?

Of all the chemicals in the cannabis plant, terpenes are probably the safest. On the Generally Recognized as Safe list put out by the US Food and Drug Administration as well as the safety lists for Food and Drug Manufacturers Association and other world health organizations, their safety is well acknowledged by legal entities. Note that this is for oral consumption only. 

There is a question as to whether terpenes are safe as thinning agents added to vaping cartridges. We recently had a rash of lung injuries reported from people consuming mostly black-market vaping cartridges and inquiry led to the fact that the addition of vitamin E to the vaping cartridges caused a burning of the lung tissue. Speculation has been that terpenes need to come under the same scrutiny as vitamin E as inhalants and should be avoided at this time.

Summary

The study and application of terpene-based therapies is evolving at a rapid pace with many innovative products arriving on the scene with new technologies to prove their effectiveness in an evidence-based manner. Consequently, use of such products has rapidly become a multi-billion-dollar industry, one that admittedly needs more study, but is fast proving its place in the wellness industry.