Terpene Series: Linalool
What are Terpenes?
We’ve written about terpenes at length here but as a super-quick refresher:
Terpenes are a diverse class of organic hydrocarbon compounds that are primarily used as a means of defence by plants and insects.
The strong aroma of terpenes underpins their use as a defensive compound in nature; couple this with their inherent anti-bacterial and fungicidal properties and you have a set of diverse compounds that plans can use effectively to repel insect, fungal and bacterial attackers. Terpenes make up the bulk of “essential oils” found in many different plants and trees and are responsible for the unique smells of these organisms. Of particular note, Limonene and Citral have sharp and sweet smells and tastes that we associated with citrus fruits whereas terpenes like Humulene and pinene produce spiced and earthy tones.
Terpenes number in the multiple hundreds with probably many hundreds more that remain undiscovered. They are produced by a wide variety of plants including the cannabis plant which has one of the richest and most diverse terpene profiles currently known in the plant kingdom.
When it comes to cannabis/hemp-derived terpenes, they are produced and secreted alongside cannabinoids like THC and CBD by specialised glands. They are not only aromatic and but may also appear to alter or enhance the function of other cannabinoids as well as providing numerous physiological effects of their own. Much like the cannabinoids CBD and THC, terpenes appear to achieve at least some of their physiological effects by interacting with the Endocannabinoid System. However, unlike CBD and THC which are abundant in extracts, terpenes like pinene are secreted in much smaller quantity. To combat naturally low concentrations, we isolate terpenes from multiple species of plants and add increased quantities to our broad-spectrum CBD oils.
What is Linalool?
Linalool, unlike many terpenes in our Terpene Series, refers to two enantiomers of a naturally occurring terpene alcohol. The scent of Linalool is floral with hint of spice making the terpene very popular as a fragrance in a range of industries. Over 200 different species of plant produce Linalool, at varying quantities. These include mint, citrus fruits, lavender, coriander, rosewood and of course, cannabis.
The Science Behind Linalool
Anti-microbial: Like many terpenes, Linalool possess impressive anti-microbial properties stemming from its use as a natural defence for plants that produce it. This anti-microbial quality may potentially be used for therapeutic effect in humans.
Mood: Oil extracts with high concentrations of Linalool produce sedative-like effects and are also anxiolytic (anti-anxiety). Mice exposed to a vaporised form of this oil extract spend MORE time in fear-inducing environments and display less depressive behaviours. This is very unusual for mice which are naturally fearful and cautious, suggesting a calming and anxiety/fear-reducing effect. Although these data are far from concluding that Linalool could be an anxiety in therapy in humans; Linalool is certainly producing a real effect in mice that may translate to humans in the clinic.
Immunity: ‘Stress’ is known to impact immune system function negatively including altering the ratio of white blood cells as well as influencing their distribution in the body. Many other negative effects stem from a chronic overproduction of the ‘stress hormone’ cortisol, which is an important and useful hormone when secreted in appropriate quantities. While people differ quite larger in how their immune system responds to stress, by and large chronic stress is general not good for immune system health. Interestingly, one study conducted on rats showed that treatment with Linalool helps prevent this alteration in white blood cell ratio and distribution which is thought to be due to activation of the parasympathetic nervous system. Additionally, based on genetic expression profiles, Linalool treatment promotes downregulation of genes typically associated with stress exposure.
Alzheimer’s: This research is VERY early stage and Linalool is by no means a cure for this progressive brain disease however the compound has shown some promise in the potential reversal of cognitive decline associated with Alzheimer’s probably due to the compounds anti-inflammatory effects. This effect was shown in a very specific, genetically modified mouse model of the disease. Considering that Alzheimer’s has no cure and very few treatment options to slow the disease (with none reversing it), identifying new compounds with some promise is the main focus point for researchers at the moment. The authors of this paper conclude that Linalool is worthy of continued exploration, likely in human subjects.
Signalling and other Interactions: There is a huge amount we still do not know about terpenes such as Linalool. A range of papers and studies show true physiological effects, many linked to cell and neuronal signalling i.e. effects through the brain. Linalool appears to temporarily inhibit the receptors for glutamate, the primary excitatory neurotransmitter. In a similar vein, Linalool reduces the signalling strength of the neurotransmitter acetylcholine, critical for muscle movement and contraction- perhaps Linalool may find utility as a muscle relaxant? Linalool has also been shown to produce anaesthetic-like effects by reducing excitable cell signalling through the spinal cord thus dampening pain signalling. Furthermore, this observed effect on pain signalling may also involve an increase in adenosine levels when linalool is used as a treatment in numerous rodent models. In one of very few human studies, inhaled linalool significantly reduced the demand for post-operative pain control medications from 82% of the control group to 46% of the treated group. Additionally, when pain medications were taken by the treated group, the volume of morphine required was approximately half that of the control group. Although this study is small and limited in a large number of ways it remains interesting. Linalool targets multiple components of the nervous system simultaneously; many of which are involved in pain processing as well as mood regulation which likely explains emerging nociceptive and anxiolytic effects.
Pre-clinical research (mainly work on cells and specific animal models) into the beneficial physiological effects of Linalool do look promising and the research is perhaps more substantial for Linalool than it is for many other terpenes. However, as always, we require more clinical evidence before firm conclusions can be drawn about the effects of Linalool on human health.
Why We Use Linalool
Linalool can be found in modest quantities in our award-winning RELIEF oil. Linalool, Citral and Limonene are all fantastic and fresh tasting terpenes hence their varied inclusion in our oils. Along with other terpenes, Linalool imparts a delicious flavour to our RELIEF oil, helping to make it known as one of the best tasting oils on the market today.
Not only does Linalool impart a great taste, but the terpene’s anti-inflammatory effects make it a functionally powerful ingredient in our RELIEF blend. As always, if you have any technical questions about our products, please reach out to us directly on our website chat.