The Science of CBD
Cannabidiol (CBD) is a non-intoxicating component of the Cannabis Sativa plant, and has generated significant interest among researchers in recent years. Although there is a current lack of high quality research proving its benefits, popularity is being driven strongly by consumer demand.
How CBD exerts its therapeutic effect is a topic great interest, and there are numerous molecular pathways that have been identified.
The Endocannabinoid System
There are cannabinoid receptors (CB1 and CB2) spread throughout the human body in skin, nervous system, and gastro-intestinal tract. The body naturally produces ‘endo-cannabinoids’ to maintain homeostasis. Stress levels, diet, sleep and exercise can all affect this system, either positively or negatively. In fact CBD doesn’t actually bind very well with either CB1 or CB2 receptors, yet it is able to exert an effect at relatively low concentrations.1 It is also known to have effects at many other receptor sites:
Serotonin receptors - At high concentrations, CBD directly activates serotonin receptors, conferring an anti-anxiety effect. This receptor is involved in a range of biological and neurological processes, including anxiety, addiction, appetite, sleep, pain perception, nausea and vomiting. A recent case series concluded CBD may be useful in the treatment of anxiety.2
Vanilloid Receptors - TRPV1 is known to mediate pain perception, inflammation and body temperature. CBD binds to TRPV1, which can influence pain perception.3
GPR55 Receptors - GPR55 receptors are widely expressed in the brain and cerebellum, and are involved in controlling blood pressure and bone density, among other physiological processes. Increased GPR55 activation is associated with cancer cell proliferation as well as osteoporosis, and blocking this receptor may have a future role in the treatment of osteoporosis and cancer. CBD is an antagonist (blocks the effect) at the GPR55 receptor, which seems to mediate its anti-epileptic effect.4
Allosteric Modulation - CBD can change the ‘shape’ of a receptor, which can either increase or decrease that receptors activity. Some of the anti-anxiety effect of CBD may come from positive allosteric modulation of the body’s own GABA channel.5 In other words, CBD enhances the effect of the body’s own calming neurotransmitter. Anandamide is one of the natural endo-cannabinoid molecules responsible for the ‘high’ that runners get after exercising.
PPARS - Activation of the receptor known as PPAR-gamma has an anti-proliferative effect and is being researched for its potential to develop new treatments for cancer and Alzheimers disease.