CBD or cannabidiol is a non-psychoactive compound extracted from the plant, Cannabis sativa.
The oil is produced by thinning this extract with a carrier oil like hemp seed oil.
CBD is a cannabinoid, which is a compound that binds to receptors of the endocannabinoid system (ECS) and regulates several physiological responses.
CBD oil is currently used in medical therapies as it confers a host of health benefits.
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Overview of Huntington’s Disease
Huntington’s disease (HD) or Huntington’s chorea denotes an inherited disorder which causes the death of brain cells. Mental disabilities and mood disorders occur in the initial phase followed by an unsteady gait.
The disease progression is often accompanied by a gradual lack of coordination in body movements. Dementia often occurs in the last stage of the disease.
Benefits of CBD in Huntington’s Disease
The major benefits of using CBD to treat Huntington’s disease are linked with its nature as a neuroprotective antioxidant. This cannabinoid helps in preventing neurodegenerative damage by improving synaptic plasticity and protecting the neurons from oxidative damage caused by free radicals. It also suppresses the inflammatory response of the microglia.
CBD also enhances the number and activity of the mitochondria and thereby, raises the cellular energy levels and lowers the generation of free radicals. The increased mitochondrial activity also prevents glutamate susceptibility. CBD also acts as a muscle relaxant and helps in combating a wide variety of movement disorders associated with HD.
1. CBD Is a Neuroprotective Agent
Huntington’s disease (HD) is a genetic disorder that is progressively neurodegenerative.
It is caused by an autosomal dominant mutation in either copy of the HTT gene which codes for the huntingtin protein.
An increase of cytosine-adenine-guanine (C-A-G) repeats in the gene is responsible for the mutation that results in the onset of neuronal loss.
According to research, the area of the brain that is most affected by Huntington’s is the basal ganglia which are responsible for motor function.
The major components of the basal ganglia include the striatum and the globus pallidus.
The cells in the striatum are affected by the development of this disorder.
As a result, the basal ganglia get heavily reduced and motor symptoms develop. Now, the reason behind neuronal loss is the presence of the abnormal huntingtin protein.
While the normal counterpart interacts with proteins found only in the brain, the mutated version disrupts this interaction leading to neuronal abnormalities and cell death.
Studies have shown that the normal huntingtin protein binds with two specific proteins namely the huntingtin’s interactor protein (HIP-1) and the huntingtin’s associated protein (HAP-1).
The number of C-A-G repeats in the HTT gene specifies how huntingtin will interact with HIP-1 and HAP-1.
Increase in the number of repeats changes enhances the specificity for HAP-1 as compared to that of HIP-1 which triggers a series of damaging reactions.
Protecting nerve cells in the striatum is the primary goal of medical research primed to treat HD.
A 2016 review undertaken by the University of São Paulo evaluated the role of the phytocannabinoid CBD in neuroprotection.
It was established that CBD prevents the nerve cell damage caused by the neurodegenerative conditions of HD by amplifying synaptic (nerve ending) plasticity and transmission as well by stimulating neurogenesis.
Phytocannabinoids like CBD weakens neurodegenerative damage caused by Huntington’s disease simply by enhancing the synaptic plasticity and preventing neuronal loss.
2. CBD Is an Antioxidant
The major hallmark of HD is the death of neurons in the striatum of the basal ganglia and the cortex (outer gray matter), particularly the motor cortex, resulting in impaired motor function.
The pathophysiology of disease encompasses a wide spectrum of reactions that trigger cell death owing to the presence of the altered huntingtin protein in the brain.
One of the major outcomes of neuronal loss is increased susceptibility to the excitatory neurotransmitter, glutamate.
Under the damaging conditions of HD, the mitochondria of the striatal cells get damaged by even normal levels of glutamate which acts as an excitotoxin.
Damage to the mitochondria results in the formation of toxic free radicals.
Free radicals contain unpaired electrons and therefore, are highly reactive atoms or molecules that can interact with cellular structures causing damage.
While they are generated naturally as a part of the metabolic or immune reactions, they can contribute to disease progression when they are formed indiscriminately.
Such atoms can react with cellular proteins, membranes, and even DNA and degrade them by a process known as oxidation.
When free radicals cause oxidative damage of important cellular constituents, the latter lose their abilities to function properly which initiates a chain of events leading to the breakdown of the cellular machinery and cell death.
Several studies have indicated the presence of free radicals in the pathophysiology of HD and how they contribute to nerve cell damage.
Research is being conducted to incorporate antioxidants in HD therapies which can scavenge such free radicals and destroy them.
A review by the National Institutes of Mental Health has studied the role of CBD as a neuroprotective antioxidant.
It states that CBD helps in combating free radical damage in HD by reducing glutamate toxicity.
CBD acts as an antioxidant and helps in combating oxidative nerve damage caused by lowering glutamate toxicity.
3. CBD Suppresses the Inflammatory Response
Inflammation refers to the spectrum of responses that involve redness, swelling, heat, and pain.
It is usually a response to any form of injury or pathogenic invasion and makes up the frontiers of natural defense mechanisms employed by the immune system.
The inflammatory process commonly protects the body from external threats and damage by secreting mediators that combat infection.
However, chronic inflammation can be deadly and damage the natural healing process of the body.
Studies have indicated that such persistent inflammation is common in the nerve tissue of patients suffering from HD and hence, the inflammatory response is a key mediator in disease progression and neurodegeneration.
Usually, the immune system primes the inflammatory response against foreign substances, but research has shown that the enhanced glutamine tract in the mutated huntingtin protein is viewed as a foreign threat by the immune system which initiates chronic inflammation to remove it.
The response is mediated via the microglial cells which are supporting cells that do not conduct nerve impulses but are involved in removing dying neurons and unwanted debris from the brain.
Research has shown that the number of activated microglia gets increased during HD and these cells get poised to engulf neighboring neurons which have accumulated the huntingtin protein.
These microglia also employ a wide variety of mediators like free radicals, cytokines, proteases, and complement proteins to exert the inflammatory response and continue to damage nerve cells.
Therefore, anti-inflammatory therapies are required to halt these mediators in order to treat HD.
A 2017 study by the University of Messina investigated the anti-inflammatory nature of CBD in prevent neurodegeneration.
The results of the clinical studies showed that CBD mediates its anti-inflammatory response by regulating several target sites in the brain which helps in delaying the progression of HD.
Phytocannabinoids like CBD modulate several receptors in the brain and thereby, suppress the inflammatory response as seen in HD progression.
4. CBD Increases Mitochondrial Activity
As mentioned earlier, one of the components in the pathophysiology of Huntington’s disease is the mitochondrial damage.
Mitochondria are cellular organelles involved in the production of energy.
Damage to these cellular components, therefore, diminishes the energy levels. Another outcome is the generation of reactive free radicals.
As per research, HD-associated mitochondrial dysfunction often leads to glutamate toxicity which is another mediator of nerve cell death.
The excitatory neurotransmitter, glutamate, damages cells whose mitochondria have been affected by HD progression.
A 2008 study by the Merck Research Laboratories has strived to establish a link between disease progression and mitochondrial dysfunction.
Animal models had been used to study the mechanisms that connect these two occurrences.
It was revealed that the mutated huntingtin protein interacts with the mitochondria in a way that triggers neuronal damage and degeneration.
Several studies have been conducted to develop therapeutic strategies that can sufficiently counter the mitochondrial damage and raise the cellular energy levels.
Cannabinoids like CBD have emerged popular as alternative lines of medicine in the treatment of HD owing to their role in neuroprotection.
A 2013 experimental study by the Universidade do Extremo Sul Catarinense investigated the ability of CBD to increase the activity of mitochondrial complexes in the brain.
The results revealed that the neuroprotective cannabinoid helps in increasing both the number and activity of mitochondria in rat brains thereby, helping in combating HD.
As CBD helps in increasing the number and activity of mitochondrial complexes, it helps in preventing the neurodegeneration as seen in HD.
5. CBD Oil Treats Movement Disorders
Movement disorders on account of impaired motor function are the most common manifestations of HD.
The progression of these disorders usually the categorize the disease into three stages: early stage which exhibits restlessness and some involuntary movements; the middle stage which includes dystonia, chorea, and disjointed gait; and late stage involving rigidity and bradykinesia.
While HD might not be fatal, these conditions eventually lead to death, particularly the inability to control throat muscles.
Swallowing becomes increasingly difficult and can often be fatal.
This is because the mechanism behind the sorting of food and air between the oesophagus (food pipe) and trachea (windpipe) becomes progressively impaired with the disease and can lead to choking.
HD is also referred to as Huntington’s chorea which denotes a neurological condition that is characterized by involuntary jerky movements of the face, shoulders, and hips.
Chorea can be manifested as jerks or twisting motions which occur unexpectedly.
These movement abnormalities often cause poor balance making it difficult to take a walk. Staggering, unsteady gaits are associated with HD.
Chorea occurs in 90% of the patients with HD and often lead to muscle rigidity and bradykinesia i.e. impaired capacity to move the body.
As a result, HD treatment often requires muscle relaxants which are capable of overcoming such problems of rigidity and stiffness.
A 2015 review by the University of Colorado School of Medicine established that CBD oil helps in treating movement disorders such as unsteady gaits and involuntary twitches via the endocannabinoid system (ECS) which improves motor function.
In a study reviewed by the National Academy of Sciences, CBD oil was revealed to be a muscle relaxant.
As CBD oil helps in improving motor function and relaxing muscle groups, it helps in treating involuntary movement disorders as seen in HD.
A healthcare provider should be consulted before beginning any therapy that might involve the ingestion of THC.
The dosage depends on the mode of delivery as the CBD products can be orally ingested or inhaled by a vaporizer.
There is no prescribed dosage for using CBD oil to treat Huntington’s disease as neurological disorders are degenerative.
To relieve symptoms and delay the progression of the disease, small doses of 90-100mg should be consumed initially.
The optimum dose should be decided according to the individual’s tolerance level.
The phytocannabinoid CBD has rarely produce side-effects. Daily oral doses of 500mg can be had for as long as 6 months without any unwanted complications.
A 2011 review stated that sufficiently high doses of 1500mg can be consumed daily for up to 3 months.
Maximum of the CBD products have varying amounts of the psychotropic compound tetrahydrocannabinol (THC) in them which might cause some side-effects.
While the quantity of THC is quite inadequate to produce a substantial effect, some individuals may be sensitive and hence, it is advisable, to begin with, small doses.
CBD often interacts with a class of liver enzymes (cytochrome p450) which are responsible for metabolizing drugs and hence, consumption of CBD might reduce the efficacies of such medications. E
xcessive THC-containing products might cause dizziness, disorientation, nausea, fatigue, confusion, impaired balance, hallucinations, and paranoia.
They might also raise the heart rates for a short duration and this condition is known as tachycardia.
Cannabis products containing high amounts of THC should also not be accompanied by alcohol.
Pregnant and lactating women should consult a gynaecologist before consuming CBD products.
Caution should also be maintained while administering THC-containing products to children and adolescents as it might affect their CNS differently.
To summarize, it can be said that CBD provides a host of neuroprotective benefits.
It helps in preventing rapid neuronal loss by enhancing synaptic plasticity and aiding neurogenesis.
Being an antioxidant, it helps in scavenging and destroying toxic free radicals which are involved in HD-mediated nerve damage.
CBD also suppresses the chronic inflammatory response initiated by the microglial cells and protect the neighbouring neurons from damage.
It also protects the nerve tissue by enhancing the activity of mitochondrial complexes and thus, preventing the cells from glutamate toxicity.
Finally, CBD acts as a muscle relaxant and helps in treating the movement disorders associated with HD.