Pain is a sensory experience which instills anxiety and distress and can be acute or prolonged (chronic). Initially, the pain pathway seems to appear simple: pain signals develop in the periphery, moving mainly towards the spinal cord and therefrom to the brain. However, such a simple concept can be deceptive as pain is a complicated biological phenomenon that involves neurophysiological, psychosocial, neuroanatomical circuitry, behavioral, and affective elements.
Neuropathic pain management is completely different as the origin of pain seems to exist in the different segments of the nervous system itself. On the other hand, for treating a large proportion of chronic pain which originates within particular tissue or group of tissues targeting nociceptive activity inside the periphery can help indirectly regulating pain. Although chronic pain is pervasive within the population, the efficacy of present-day pharmacological therapies is sadly inadequate and lengthy treatment often results in harmful side effects. However, cannabinoids like cannabidiol (CBD) and cannabinol (CBN) have been found to work as peripheral analgesics with no adverse side effects.
This particular study examined whether local intramuscular injection of non-psychoactive cannabinoids, cannabidiol (CBD), cannabinol (CBN), cannabichromene (CBC) and their mixtures can reduce nerve growth factor (NGF) generated masticatory muscle sensitization in female rats. Nerve growth factor promotes the formation of substance P in afferent neurons, thereby increasing an individual’s pain sensitivity. They also play an integral part in redistributing or dispersing perceived pain signals.
In awake rats, alterations in mechanical sensitivity caused by intramuscular injection of NGF and cannabinoids were measured by using an electronic von Frey hair across the masseter muscle to determine the withdrawal reaction. The effect of CBD (5mg/ml) and CBN (1mg/ml) or their mixtures CBD/CBN (1:1mg/ml or 5:1mg/ml) were evaluated. To ascertain a peripheral action, electrophysiological tests were conducted in anesthetized rats to assess whether intramuscular injections of CBD (5mg/ml) and CBN (1mg/ml) modified the mechanical threshold of masticatory muscle mechanoreceptors.
In behavioral experiments, CBD (5mg/m/) or CBN (1mg/ml) reduced NFG-induced mechanical sensitization. Blends of CBD/CBN caused a decrease in mechanical sensitization for a longer duration than either compound alone. No prominent alterations in the contralateral masseter muscles and no damaged motor function was observed with the inverted screen test following any of the treatments. Invariable with behavioral results, CBD (5mg/ml), CBN (1mg/ml) and the mixture of CBD.CBN (1;1mg/ml) raised the mechanical threshold of masseter muscle mechanoreceptors. On the other hand, blending CBD/CBN (5:1mg/ml) at a higher ratio lessened the duration of this effect. This may suggest an inhibitory impact of higher concentrations of CBD on CBN.
Salient Features Of The Research
- Cannabidiol and Cannabinol in their individual capacity and in combination reversed sensitization of masseter muscle in a behavioral model of temporomandibular disorders
- Both cannabinoids reduced the mechanical sensitivity of masseter muscle afferent fibers.
- Though not as powerful as delta-9-tetrahydrocannabinol, these compounds are free from psychotropic effects.
These results indicate that peripheral application of both CBD and CBN, the non-psychoactive cannabinoids offers analgesic relief for chronic muscle pain disorders like fibromyalgia and temporomandibular afflictions without primary side effects.
Both CBD And CBN Can Attenuate Chronic Pain
CBD exhibits anti-inflammatory, analgesic, anti-epileptic, anticonvulsant and muscle relaxant properties among others. The anticonvulsant properties of CBD have potential worth in treating epilepsy, muscle spasms, and multiple sclerosis. Both CBD and CBN can attenuate inflammatory neuropathic pain. Moreover, CBD intake can alleviate pain without developing analgesic tolerance. The inherent analgesic attributes of CBD are associated with its interaction with the alpha 3 glycine receptor which is a well-recognized target for regulating pain. In addition, the effect of CBD on the anandamide levels as it augments the concentration of the endogenous cannabinoid, Anandamide by curbing its degradation which assists in reducing pain sensitivity. By altering the concentration of anandamide, CBD influences the endocannabinoid system which in turn enhances the muscle relaxant capabilities of CBD.
Likewise, Cannabinol (CBN) also interacts with particular sensory nerves within the body through the “release of sensory neuropeptides and vasorelaxation” as mentioned in research in the Journal of Neuroscience. Every nerve within the body transmits pain signals and contain receptors that can gain from the cannabinoids which have the capacity to block the pain receptors inside the nerves and lowering or removing the pain.
Opioids have been in use for a long time for treating chronic pain and in recent times, the opioid addiction rate is at an exponential high. Patients with opioid dependence experience a host of secondary side effects like dysphoria, motor deficits, nausea and addiction and are also unable to quit them even after their pain has subsided. Adjunct therapy to these opioids can be the natural alternatives like CBD and CBN which are non-addictive, non-intoxicating and presents nil side effects. In addition, they have the potential to release feel-good chemicals and attach with the endocannabinoid system making them a natural, actual therapy for pain and its management.