Scientists Find New Sources of Plant Cannabinoids
Monday, July 12th, 2010The British Journal of Pharmacology (link to article: BJP) has devoted another issue to the theme of cannabinoids. This issue contains numerous intriguing articles that you would be hard pressed to find discussed among media and science outlets. In a recent NPR Science Friday show on medical cannabis, Ira Flatow and guests suggested that there is a suppression of cannabis and cannabinoid research findings due to politics. This causes some journals to reject cannabinoid research without even reading the manuscript. Research journals are hesitant to publish research on cannabinoids, and many researchers often have to squander valuable funds re-submitting articles until they find a journal that will allow their research to be peer reviewed. The BJP deserves our attention for the great service it is doing for cannabinoid researchers—allowing our findings to be shared and discussed. One particular article in the BJP captured the imagination and wonder of cannabinoid science. The authors speculate on additional sources of plant cannabinoids, beyond the cannabis plant.
It appears that other plants produce things that directly and indirectly affect the Endocannabinoid system (ECS). The ECS is a system in our body which produces compounds or ligands that activate specific receptors. This system regulates important functions of mammals. If you have ever slept, eaten, forgot, or relaxed then you have used your ECS.
The receptors for cannabinoids are one of the most abundant receptors in the human brain and are expressed in nearly every tissue and cell. The two main receptors are the CB1 and CB2 receptor. CB1 is located in the brain and on neurons throughout the body, while the CB2 is mostly found in the immune system. Given the abundance of these receptors, it’s not hard to imagine that these receptors are important for something. However, THC and other cannabis parts are not the only plant compounds which can affect the ECS. Other plants produce compounds which can change the production and breakdown of Anandamide. Anandamide activates the same receptor as THC and is one of many endogenous cannabinoids produced by our body.
The recent discovery of different plants with compounds that can modulate this system means we can no longer simply define plant cannabinoids as merely a product of cannabis. The authors propose that the term phytocannabinoid is more appropriate now that scientists have discovered that Beta-Caryophyllene activates the CB2 receptor and is “among the most abundant plant essential oil component.” Beta-caryophyllene in found in nearly all plants, in fact it was proposed years ago that it is a “dietary cannabinoid.”
So, what else have you been eating that mimics the effects of molecules from cannabis?
Echinacea, Ruta graveolens (Citrus Family), and the Brassica genus (Mustard family, i.e. Broccoli) all contain compounds which may bind the CB2 receptor, some with an affinity or strength similar to THC. Note that unlike the CB1 receptor, the CB2 receptor does not cause psychotropic effects.
Even the Apiaceae family contains a compound which interacts with the CB1 receptor. Why should you care about the Apiacea family? Carrots.
Carrots and its relatives contain the compound falcarinol. This appears to interact with both cannabinoid receptors, undergoing a mysterious alkylation reaction at the CB1 receptor. The questions of how and what this compound is doing to the CB1 receptor still needs to be investigated before we can draw any conclusions about the similarities between cannabis and carrots.
Polyphenols are common components of tea and were speculated to interact with cannabinoid receptors. However, according to this article, Gertsch and collegues think that these may be non-specific interactions. The smelly molecular class of compounds known as terpenoids represents another potential group that can modulate the effects of cannabis and may affect the ECS. Terpenoids are abundant in vegetables and fruit.
One misconception or urban legend regarding cannabis is the presence of cannabinoids in chocolate. Sorry to disappoint some of you but that infamous research has never been duplicated… However what is true about chocolate and cannabinoids is far more fascinating and beautifully complex. There are fatty acid derivatives in chocolate and many other plants which inhibit the FAAH enzyme. The FAAH enzyme destroys or eats Anandamide. The blocking of this FAAH enzyme leads to an increase or elevation of the levels of Anandamide. That’s right chocolate, like aspirin, elevates the so called “natural THC” in your body. No wonder chocolate is so popular. Halloween will never be the same for this scientist.
It is obvious that phytocannabinoids are found in abundance in nature, is our next step to regulate these plants like cannabis, since large doses of the active ingredients may have some cannabis-like effects? Maybe less drastic actions should be taken.
A lot of work remains for scientists to determine the effectiveness of these phytocannabinoids and related compounds. If you want to engage in cannabis research, a great place to start would be looking at other ingredients of a healthy diet for new members of the phytocannabinoid family.
Nature has provided a single plant which produces THC-acid. THC-acid readily becomes THC, the most potent phytocannabinoid known to man. Why does nature not provide a single other plant that produces this compound? When all around us, we can find molecular messengers from plants that influence subtle components of the endcannabinoid system.
The take home message is that fatty acid derivatives, terpenes, and polyphenols are found in numerous plants. Fruits and veggies represent another source, if not treasure troves, of compounds which may interact with the endocannabinoid system.
I don’t know about you but I am certainly looking forward to having my next snack; maybe some fruit, a cup of tea, and just a few bites of chocolate.
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