In recent years, there has been increasing interest in cannabis for its potential therapeutic benefits. While there are numerous compounds in the plant, cannabinoids are the most abundant and have therefore elicited the highest level of interest. Most people are aware of THC and CBD, but in fact, there are more than 100 cannabinoids in the plant. Let’s take a closer look at some of the major cannabinoids in cannabis.
Delta-9-tetrahydrocannabinol (THC) is one of the most widely known and most abundant phytocannabinoids found in the cannabis plant. This cannabinoid is known for its psychoactive and intoxicating effects and therefore, plant strains containing high levels of THC are sought after by recreational users. However, strains grown for medicinal purposes have lower levels of THC, which are usually balanced by the presence of CBD and other cannabinoids. Nevertheless, patients taking medications containing THC cannot drive or operate machinery while on these medications. Studies in animals and humans have shown that THC can have anti-inflammatory, analgesic, and sedating properties, and can increase appetite, which is relevant to cancer or palliative care patients suffering from anorexia. However, higher concentrations of THC can lead to adverse effects and therefore, prescription medications containing THC must be titrated slowly in patients and the total daily limit must not be exceeded. Care must also be exercised in patients who have other conditions and who are on other medications, such as blood thinners, as THC can interact with these. To read some of the most recent research on THC and other cannabinoids, check out the information found here.
Cannabidiol (CBD) is the other major cannabinoid found in high concentrations within hemp cultivars and in varying concentrations of cannabis strains. This plant cannabinoid (or phytocannabinoid) has been shown to have a number of potential therapeutic properties as an antiepileptic, anti-inflammatory and anxiolytic . In Australia, the US and Europe, CBD is approved for use in severe and rare paediatric epilepsies that do not respond to conventional treatments. One of the advantages of CBD is that it is not psychoactive/intoxicating and therefore does not cause many of the unpleasant side effects and impairment associated with THC. Nevertheless, CBD is not without risk, and patients on high doses must be monitored for side effects and interactions with other medications.
Cannabigerol (CBG) is a non-acidic form of cannabigerolic acid (CBGA) which is the parent molecule from which every other phytocannabinoid is synthesized. In essence, it is the stem cell of cannabinoids. Every other cannabinoid found in the plant starts as CBGA before being chemically converted to a different compound. Animal studies have shown that when CBG is administered with CBD, it has anti-inflammatory activity, reducing expression of tumour necrosis factor (TNF), a molecule that drives inflammation . In addition to inhibiting inflammation, CBG has also exhibited antimicrobial and analgesic properties[3-4]. Further research will be needed to confirm the therapeutic efficacy of CBG and elucidate its mechanism of action.
Cannabinol (CBN) is considered to be mildly psychoactive but is only found in very small trace amounts in cannabis products on the market today. In aged cannabis, however, this cannabinoid is quite prevalent. This is because its levels increase as THC degrades over time. This cannabinoid may have antibacterial and neuroprotectant properties, but research is still in its infancy. It has also been found to stimulate appetite, and reduce inflammation as well as intraocular pressure in glaucoma patients . However, evidence is still limited.
Cannabichromene (CBC) acts as an agonist at cannabinoid 2 (CB2) receptors  and interacts with TRP channels which are present in cell membranes, suggesting therapeutic potential for the treatment of pain and inflammation . CBC has also been shown to have analgesic and anticonvulsant properties in animals [8, 9, 10]. Human studies into its therapeutic efficacy are still lacking.
Tetrahydrocannabivarin (THCV) is a minor cannabinoid found in cannabis and hemp cultivars. This slightly psychoactive phytocannabinoid is prevalent in sativa varieties of the plant. THCV is a homologue of tetrahydrocannabinol or THC, the most widely known psychoactive compound in the plant. It has shown some potential in reducing appetite .
2 Mammana S, Cavalli E, Gugliandolo A, Silvestro S, Pollastro F, Bramanti P, et al. Could the Combination of Two Non-Psychotropic Cannabinoids Counteract Neuroinflammation? Effectiveness of Cannabidiol Associated with Cannabigerol. Medicina (Kaunas). 2019;55(11).
3 Pellati F, Borgonetti V, Brighenti V, Biagi M, Benvenuti S, Corsi L. Cannabis sativa L. and Nonpsychoactive Cannabinoids: Their Chemistry and Role against Oxidative Stress, Inflammation, and Cancer. Biomed Res Int. 2018;2018:1691428.
4 Izzo AA, Borrelli F, Capasso R, Di Marzo V, Mechoulam R. Non-psychotropic plant cannabinoids: new therapeutic opportunities from an ancient herb. Trends Pharmacol Sci. 2009;30(10):515-27.
5 Alexander SP. Therapeutic potential of cannabis-related drugs. Prog Neuropsychopharmacol Biol Psychiatry. 2016;64:157-66.
6 Udoh M, Santiago M, Devenish S, McGregor IS, Connor M. Cannabichromene is a cannabinoid CB(2) receptor agonist. Br J Pharmacol. 2019;176(23):4537-47.
7 Natascia B, Carlo DP, Simonetta OB, Enrica P, Daniela D, Franco D. Cannabinoid Delivery Systems for Pain and Inflammation Treatment. 2018;23(10):2478.
8 Zagzoog A, Mohamed KA, Kim HJJ, Kim ED, Frank CS, Black T, et al. In vitro and in vivo pharmacological activity of minor cannabinoids isolated from Cannabis sativa. Sci Rep. 2020;10(1):20405.
9 Wong H, Cairns BE. Cannabidiol, cannabinol and their combinations act as peripheral analgesics in a rat model of myofascial pain. Arch Oral Biol. 2019;104:33-9.
10 Anderson LL, Ametovski A, Lin Luo J, Everett-Morgan D, McGregor IS, Banister SD, et al. Cannabichromene, Related Phytocannabinoids, and 5-Fluoro-cannabichromene Have Anticonvulsant Properties in a Mouse Model of Dravet Syndrome. ACS Chem Neurosci. 2021;12(2):330-9.
11 Abioye, A., Ayodele, O., Marinkovic, A. et al. Δ9-Tetrahydrocannabivarin (THCV): a commentary on potential therapeutic benefit for the management of obesity and diabetes. J Cannabis Res 2, 6 (2020). https://doi.org/10.1186/s42238-020-0016-7