The substances of cannabis as a whole: the role of terpenes
Terpenes are biomolecules produced by many plants and which are the main compounds of their resins and essential oils and give to each of them their own characteristic odour.
Very common examples of terpenes are geraniol, menthol, limonene and camphor. At the moment, in the various strains, more than 100 terpenes have been identified in the cannabis plants and these are responsible for the different aromas, which can be appreciated.
The most abundant terpene in the Cannabis sativa plant is myrcene, common also in verbena or in citronella and used in the perfume industry, due to its particularly delightful scent. Limonene, instead, is the second terpene for quantity present in cannabis and is known for its citrus fruit aroma.
What is the entourage effect?
Until recently, scientific research concentrated exclusively on the investigation of the properties of cannabinoids present in the plant (like cannabidiol, CBD), while paying little attention to the role played by its terpenes. Today, instead, we know that the interaction between cannabinoids and terpenes of Cannabis sativa gives rise to what has been denominated the entourage effect: the combined action of the whole of substances which make up cannabis.
The entourage effect can significantly modify the action of the different active principles of cannabis. Some terpenes would bind to the CB1 and CB2 receptors of the endocannabinoid system, affecting some functions of our organism, others are said to modulate cell permeability controlling, for example, the absorption of THC.
Terpenes and cannabinoids: which benefits?
Myrcene, besides giving the plant a scent similar to that of cloves, has the capability of increasing cell permeability and, as a consequence, to make the absorption of cannabinoids faster. Limonene, instead, is widely studied by the scientific community and is used in many areas. Amongst these, the medical sector.
In 2014 a study published in Food Chemistry demonstrated how limonene had strong anti-inflammatory properties. Moreover, a study published in 1999 by researchers of the Indiana University-Purdue University of Indianapolis, demonstrated some chemo-preventive properties of limonene, arisen after the terpene was administered to some animals in the laboratory.
The most frequently used example to explain the concept underlying the entourage effect, is the story of the development of a medical drug containing cannabis for treating multiple sclerosis.
We are talking about Sativex, name of the pharmaceutical product developed by the British company GW Pharmaceuticals. The president of the company, Geoffrey Guy, declared in an interview with CNN that, after ten years of trials and evaluations, it became clear that the extract of the cannabis plant as a whole was much more effective in reducing the pain and spasms of multiple sclerosis than its compounds administered individually. Ethan B. Russo, researcher at GW Pharmaceuticals, published the results of his research studies on the interaction between cannabinoids and terpenes, in 2011.
His research – published on the pages of the leading magazine British Journal of Pharmacology – demonstrated how the data acquired up to that moment indicated that the full spectrum of substances present in cannabis were capable of strengthening and broaden clinical applications.