Terpene Series: Citral

What are Terpenes?

We’ve written a summary article on terpenes before which you can find here but as a quick refresher: terpenes are a diverse class of organic hydrocarbon compounds that are primarily used as a means of defence by plants and insects. Their use in defence stems from terpenes strong aromas as well as their inherent anti-bacterial and fungicidal properties.  They are the main component of “essential oils” found in many different plants and trees and are often responsible for the unique smells of plants – limonene and citral for example have sharp and pleasant ‘citrusy’ smells that we associated with oranges and lemons whereas pinene possesses ‘piney’ and ‘earthy’ tones and can be found, amongst other plants, in pine trees.

Terpenes number in the multiple hundreds with many hundreds more likely 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.

Terpenes are produced and secreted alongside cannabinoids like THC and CBD by specialised glands. They are not only aromatic and in some cases, very tasty, but may also alter or enhance the function of other cannabinoids as well as providing physiological effects of their own. They appear to achieve this by interacting with the Endocannabinoid System, much like CBD and other cannabinoids. 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 Citral?

Citral is technically a bonded pair of two terpene isomers, both of which are monoterpenes. Citral A also known as geranial (structure pictured below) and citral B also known as neral. Citral is well known for its fresh citrus aroma and taste. As can be expected, citral is found in many citrus fruits such as lemons and oranges although it is isn’t particularly concentrated in these fruits. However, citral is found in very high quantities in plants like lemongrass and lemon myrtle. The terpene is used commonly in the perfume industry but it has also found some fame amongst terpenes for it’s particularly strong anti-microbial properties.



The Science behind Citral

Research into terpenes like citral is generally not as advanced or established as cannabinoids such as THC and CBD. However, increased consumer and medical interest cannabis derived compounds has fuelled increased interest into cannabis derivates, and we are now seeing greater research effort placed on investigating the therapeutic effects of certain terpenes including citral.

The antimicrobial properties of citral have been known for decades. A study published in 1989 demonstrated that citral showed appreciable antimicrobial activity against a range of both gram positive and gram negative bacteria. The authors suggested it’s use as a new form of preservative in the cosmetic industry based on these findings. More recent work has explored the mechanism by which citral demonstrates bactericidal properties – it is thought that citral damages the cell envelope of bacterial thus leading to cell death. Additional research confirms the bactericidal effect of citral on a range of bacteria including MRSA.

Citral doesn’t just destroy certain bacterial but also has fungicidal properties. A study involving lemongrass and citral application to a species of fungus (Candida spp.) demonstrated potent in vitro activity against the fungus. The authors concluded that compounds like citral may be useful in the fight against common fungal infections to the skin.

Another vein of research looking at the potential anti-cancer effect of citral demonstrated that citral could induce apoptosis (controlled cell death) in numerous cancer cell lines. This particular linked study was small and of limited scope but interesting none the less.

Citral has demonstrated anti-inflammatory properties in a wide range of rodent studies:

Citral reduces nociceptive and inflammatory responses in rodents

Citral may produce anti-inflammatory effects by inhibiting immune factor Nf-Kb in murine models

Citral is both anti-inflammatory and anti-clastogenic in rodent models (Note: a ‘clastogen’ is a mutagenic agent that interferes with the  health of chromosomes)

Combining compounds like citral with Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) like Naproxen can increased the beneficial effects of the drug whilst reducing side effects.

Early research into the beneficial physiological effects of citral do look promising but as always, we require more clinical evidence before firm conclusions can be drawn about the effects of citral on human health. Most current research has been conducted in animal models and cell lines which don’t necessarily translate to similar findings in humans.


Why we use Citral

Citral can be found in our award-winning Relief Oil. Citral, in our opinion is one of the most pleasant tasting terpenes around and the flavour citral and other terpenes impart to our Relief Oil has made it known as one of the best tasting oils on the market today.

Not only does citral impart a great taste, but citral’s anti-inflammatory effects make it a functionally useful ingredient in our Relief Blend.

As always, if you are considering using CBD, gather as much information as you can before making a decision. Take a look at the peer-reviewed research about cannabinoids and terpenes, effects and side-effects on high-quality academic sites like PubMed


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