The recent resurgence in the cannabis plant, as a result of many regions lessening prohibition, has caused a global shake-up in attitudes towards the plant and the products it provides for humans – largely for the better.
One of the most commonly-recited benefits of cannabis is the huge diversity of uses the plant has, from hemp-based supercapacitors and hemp clothing to high-value medicines from cannabinoid-rich cultivars, yet this almost exclusively refers to the aerial parts of the plant only. One aspect of the plant that seems to get little to no attention is the utilisation of the plant’s roots.
A Google Scholar and PubMed search provide some evidence that this is an understudied part of the plant (table 1). Although it is not an exact metric, nor is it highly scientific, the number of results is indicative of the number of publications, which gives some context to the point that the plant itself is understudied – but the roots have not been the feature of many studies, and in fact, have been largely ignored by those publishing in scientific journals.
Historically, the cannabis root has been used for numerous remedies, therefore the cannabis research community should be investigating the effectiveness of this relatively ignored plant part. Literature explaining the use of cannabis roots in a medical context spans back hundreds of years and covers a broad range of conditions (reviewed by Ryz et al 2017). From joint pain and gout to skin burns and childbirth, there exists numerous historical documentation of many different types of applications for many different conditions. Originating from all corners of the world, reports of using boiled cannabis roots in different applications are one of the more common preparation methods.
From cataplasm and compress to oral administration in various forms, many different cultures have documented the use of cannabis roots in their treatment of the sick (Ryz et al 2017). Despite this historical documentation, there has been a deafening silence on this subject since the recent resurgence. However, many of the molecules found in the root are described – admittedly via extraction from other plants – in other studies, and these provide the building blocks for studies going forward. Notably, the roots of Panax ginseng.
The cannabis plant produces hundreds, if not thousands, of phytochemicals which vary in concentration from cultivar to cultivar (Gould 2015).
The chemical composition of the root of the cannabis plant will no doubt also vary depending on the lineage of the cultivar, however, the phytochemicals which have been shown to constitute the chemical makeup of the roots include triterpenoids, monoterpenes, alkaloids and phytosterols (steroids) (Sethi et al 1977). Although rich in active molecules, a thesis out of King’s College London in 2009 by DJ Potter showed that the roots are practically devoid of cannabinoids.
The active ingredients in the plant’s roots are still to be fully investigated in terms of their effectiveness in treating human conditions, and much like many aerially produced phytochemicals, remain untested, especially at a clinical level. However, as the industry moves forward, more and more reports of clinical trials using full-spectrum extracts and isolates are coming through. Eventually, and hopefully, not in the distant future, there may be a time when the common phytochemicals are more fully explored, and focus starts to shift towards the lesser-known constitutes such as the triterpenoids.
The triterpenoids which have been found in cannabis plant roots include the molecules Friedelin and Epifriedelanol, and these have been shown to have many effects on mammalian biology. Friedelin, extracted from Azima tetracantha (Bee Sting Bush), has been shown to be effective in reducing inflammation, fever and certain types of pain in rodent studies (Antonisamy et al 2011). It has also shown promising signs as a powerful anti-diarrhetic, effective in treating gastric ulcers and in treating diabetes in rodents (Antonisamy et al 2015a, Antonisamy et al 2015b, Sunil et al 2021).
In addition, Friedelin has estrogenic activity and has been shown to improve sexual activity in rodents, and has been used to treat sexually transmitted diseases such as syphilis in humans (Aswar et al 2010). The other triterpenoid isolated from the cannabis root is Epifriedelanol. This has been shown as a powerful antitumor agent, as well as protecting against photoaging in humans and preventing human cell replication in vitro (Kundu et al 2000, Quan et al 2017, Li et al 2010). Epifriedelanol also shows anti-inflammatory activity and has been reported effective in ovarian cancer treatment as it has similar properties to an FDA-approved pharmaceutical used to treat the condition (Perumal et al 2016, Kim et al 2005).
There are many other phytochemicals extracted from cannabis roots such as the monoterpenes carvone and dihydrocarvone, phytosterols such as sitosterol and campesterol, and alkaloids such as cannabisativine and the nutrient choline (Ryz et al 2017). Each of these molecules has a story of its own in terms of its potential use in modern medicine and how it interacts with the human body, however, much like the full spectrum vs isolate argument, perhaps whole extract will provide a more potent effect than single-molecule extracts.
This leads to the question “if the entourage effect is indeed more powerful than any isolate, should this then be whole plant extract rather than just extraction of the aerial parts of the plant? Would that provide a greater effect than the sum of its parts?”
These are but a few of the areas needing further study, and although whole extract may provide a greater all-in-one medicine, each component of the plant’s chemistry will need to be examined individually to better understand what each is doing to the body. Again, this is something that will take a fair amount of time, money, and resources, but no doubt these studies will provide many alternatives to the pharmaceutical options currently positioned at the forefront of medical care.
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