“In this review article, we embark on a thorough exploration of cannabinoids, compounds that have garnered considerable attention for their potential therapeutic applications. Initially, this article delves into the fundamental background of cannabinoids, emphasizing the role of endogenous cannabinoids in the human body and outlining their significance in studying neurodegenerative diseases and cancer. Building on this foundation, this article categorizes cannabinoids into three main types: phytocannabinoids (plant-derived cannabinoids), endocannabinoids (naturally occurring in the body), and synthetic cannabinoids (laboratory-produced cannabinoids). The intricate mechanisms through which these compounds interact with cannabinoid receptors and signaling pathways are elucidated. A comprehensive overview of cannabinoid pharmacology follows, highlighting their absorption, distribution, metabolism, and excretion, as well as their pharmacokinetic and pharmacodynamic properties. Special emphasis is placed on the role of cannabinoids in neurodegenerative diseases, showcasing their potential benefits in conditions such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and multiple sclerosis. The potential antitumor properties of cannabinoids are also investigated, exploring their potential therapeutic applications in cancer treatment and the mechanisms underlying their anticancer effects. Clinical aspects are thoroughly discussed, from the viability of cannabinoids as therapeutic agents to current clinical trials, safety considerations, and the adverse effects observed. This review culminates in a discussion of promising future research avenues and the broader implications for cannabinoid-based therapies, concluding with a reflection on the immense potential of cannabinoids in modern medicine.”
“Marijuana, also known as cannabis, is a plant-based illicit drug notorious for its recreational purposes. However, in recent years its extracts are being extensively studied for their overall therapeutic effects. Active substances found in marijuana that interact with the endocannabinoid system are known as cannabinoids, the primary examples being 9-tetrahydrocannabinol (9-THC) and Cannabidiol (CBD). These cannabinoids ligand to receptors such as CB1 (found in CNS) and CB2 (found in immune system cells) to prevent the release of neurotransmitters and modulate immune cell migration as well as cytokine release, respectively (1). In recent years, there has been a surge of interest in the neuroprotective potential of marijuana; however, investigators could not make firm conclusions about the effectiveness of these treatments. A comprehensive review by Bahji A et al. (2022) found an evident link between cannabidiol-based products and relief from the motor as well as behavioural and psychological symptoms spanning Alzheimer’s disease (AD), Huntington’s disease (HD), and Parkinson’s disease (PD) (2). Here we discuss the effects of marijuana and its derivatives on the treating significant neurodegenerative disorders.
Dronabinol (2.5 mg) seemed to lessen the disordered behaviours as assessed by the Cohen-Mansfield Agitation Inventory in 12 patients of AD (p=0.05) (3). Sherman et al. (2018) reported the association of cannabis administration with weight and pain management in AD patients. The adverse effects are typically well tolerated at the levels supplied, even though cannabis is linked to an increased risk of euphoria, sleepiness and psychosis (1). On the other hand, for HD, nabilone (1 or 2 mg) had a substantial therapeutic benefit in a different 10-week placebo-controlled crossover experiment as determined by the overall motor and chorea score on the Unified Huntington’s Disease Rating Scale (UHDRS) (4). Available reviews revealed variable evidence suggesting the clinical benefits of cannabis in treating motor symptoms in patients with PD. A randomized trial found that compared to a placebo, giving a single dosage of 300 mg of CBD successfully decreased tremor amplitude (5).
Neurological diseases, including the neurodegenerative diseases, comprise 8.7% of the disease burden in lower- middle- income countries (such as Pakistan) (6). Currently, there is no real cure for neurodegenerative disorders, only symptomatic management, such as dopamine treatment for PD or cholinesterase inhibitors for dementia. Cannabinoids might be the lifeline all neurodegenerative disorder patients have been waiting for.”
“Dysregulated endocannabinoid (eCB) signaling and the loss of cannabinoid receptors (CB1Rs) are important phenotypes of Huntington’s disease (HD) but the precise contribution that eCB signaling has at the circuit level is unknown. Using a computational model of spiking neurons, synapses, and eCB signaling, we demonstrate that eCB signaling functions as a homeostatic control mechanism, minimizing excess glutamate. Furthermore, our model demonstrates that metabolic risk, quantified by excess glutamate, increases with cortico-striatal long-term depression (LTD) and/or increased cortico-striatal activity, and replicates a progressive loss of cannabinoid receptors on inhibitory terminals as a function of the excitatory/inhibitory ratio.”
“Neurodegenerative diseases are an increasing cause of global morbidity and mortality. They occur in the central nervous system (CNS) and lead to functional and mental impairment due to loss of neurons. Recent evidence highlights the link between neurodegenerative and inflammatory diseases of the CNS. These are typically associated with several neurological disorders. These diseases have fundamental differences regarding their underlying physiology and clinical manifestations, although there are aspects that overlap.
The endocannabinoid system (ECS) is comprised of receptors (type-1 (CB1R) and type-2 (CB2R) cannabinoid-receptors, as well as transient receptor potential vanilloid 1 (TRPV1)), endogenous ligands and enzymes that synthesize and degrade endocannabinoids (ECBs). Recent studies revealed the involvement of the ECS in different pathological aspects of these neurodegenerative disorders.
The present review will explore the roles of cannabinoid receptors (CBRs) and pharmacological agents that modulate CBRs or ECS activity with reference to Alzheimer’s Disease (AD), Parkinson’s Disease (PD), Huntington’s Disease (HD) and multiple sclerosis (MS).”
“Neurodegenerative diseases represent an important cause of morbidity and mortality worldwide. Existing therapeutic options are limited and focus mostly on improving symptoms and reducing exacerbations. The endocannabinoid system is involved in the pathophysiology of such disorders, an idea which has been highlighted by recent scientific work. The current work focusses its attention on the importance and implications of this system and its synthetic and natural ligands in disorders such as Alzheimer’s, Parkinson’s, Huntington’s and multiple sclerosis.”
“The cannabinoids are found to have particular application as neuroprotectants for mental and motor dysfuction in neurodegenerative diseases. The neuroprotective properties of cannabinoids suggest their therapeutic use for limiting neurological damage. The cannabinoids treatments should not only aim to alleviate specific symptoms but also attempt to delay/arrest disease progression and to repair the damaged structures. The author conducted a review of studies published between 1974 and 2011. The search was performed using the following PubMed search terms: “Cannabinoids” and “Neurodegenerative Diseases” and 287 papers were detected. The articles were examined and the overlapping or insufficiently clear works were excluded. Finally we chose 117 articles regarding the latest international guidelines, the pathophysiology of neurodegenerative diseases and the various therapeutic choices. The studies reported in the present review support the view that the cannabinoid signalling system is a key modulatory element in the activity of the basal ganglia. This idea is supported by different anatomical, electrophysiological, pharmacological and biochemical data. Furthermore, these studies indicate that the cannabinoid system is impaired in different neurological disorders that directly or indirectly affect the basal ganglia, which supports the idea of developing novel pharmacotherapies with compounds that selectively target specific elements of the cannabinoid system.”
“Three prevalent neurodegenerative diseases, Parkinson’s, Alzheimer’s, and Huntington’s are in need of symptomatic relief of slowing disease progression or both. This chapter focuses on the potential of cannabinoids to afford neuroprotection, i.e. avoid or retard neuronal death. The neuroprotective potential of cannabinoids is known from the work in animal models and is mediated by the two cannabinoid receptors (CB1/CB2) and eventually, by their heteromers, GPR55, orphan receptors (GPR3/GPR6/GPR12/GPR18), or PPARγ. Now, there is the time to translate the findings into patients. The chapter takes primarily into account advances since 2016 and addresses the issue of proving neuroprotection in humans. One recent discovery is the existence of activated microglia with neuroprotective phenotype; cannabinoids are good candidates to skew phenotype, especially via glial CB2 receptors (CB2R), whose targeting has, a priori, less side effects those targeting the CBs1 receptor (CB1R), which are expressed in both neurons and glia. The fact that a cannabis extract (SativexTM) is approved for human therapy, such that cannabis use will likely be legalized in many countries and different possibilities that cannabinoid pharmacology suggests a successful route of cannabinoids (natural or synthetic) all the way to be approved and used in the treatment of neurodegeneration.”
“The Endocannabinoid System (ECS) is primarily responsible for maintaining homeostasis, a balance in internal environment (temperature, mood, and immune system) and energy input and output in living, biological systems.
In addition to regulating physiological processes, the ECS directly influences anxiety, feeding behaviour/appetite, emotional behaviour, depression, nervous functions, neurogenesis, neuroprotection, reward, cognition, learning, memory, pain sensation, fertility, pregnancy, and pre-and post-natal development.
The ECS is also involved in several pathophysiological diseases such as cancer, cardiovascular diseases, and neurodegenerative diseases. In recent years, genetic and pharmacological manipulation of the ECS has gained significant interest in medicine, research, and drug discovery and development.
The distribution of the components of the ECS system throughout the body, and the physiological/pathophysiological role of the ECS-signalling pathways in many diseases, all offer promising opportunities for the development of novel cannabinergic, cannabimimetic, and cannabinoid-based therapeutic drugs that genetically or pharmacologically modulate the ECS via inhibition of metabolic pathways and/or agonism or antagonism of the receptors of the ECS. This modulation results in the differential expression/activity of the components of the ECS that may be beneficial in the treatment of a number of diseases.
This manuscript in-depth review will investigate the potential of the ECS in the treatment of various diseases, and to put forth the suggestion that many of these secondary metabolites of Cannabis sativa L. (hereafter referred to as “C. sativa L.” or “medical cannabis”), may also have potential as lead compounds in the development of cannabinoid-based pharmaceuticals for a variety of diseases.”
“Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment”
“Medical cannabis and individual cannabinoids, such as tetrahydrocannabinol (THC) and cannabidiol (CBD), are receiving growing attention in both the media and the scientific literature. The Cannabis plant, however, produces over 100 different cannabinoids, and cannabigerol (CBG) serves as the precursor molecule for the most abundant phytocannabinoids.
CBG exhibits affinity and activity characteristics between THC and CBD at the cannabinoid receptors, but appears to be unique in its interactions with alpha-2 adrenoceptors and 5-HT1A Studies indicate that CBG may have therapeutic potential in treating neurological disorders (e.g., Huntington’s Disease, Parkinson’s Disease, and multiple sclerosis), inflammatory bowel disease, as well as having antibacterial activity.
There is growing interest in the commercial use of this unregulated phytocannabinoid. This review focuses on the unique pharmacology of CBG, our current knowledge of its possible therapeutic utility, and its potential toxicological hazards.
Significance Statement Cannabigerol (CBG) is currently being marketed as a dietary supplement and, as with cannabidiol (CBD) before, many claims are being made about its benefits. Unlike CBD, however, little research has been performed on this unregulated molecule, and much of what is known warrants further investigation to identify potential areas of therapeutic uses and hazards.”
“The aberrant accumulation of disease-specific protein aggregates accompanying cognitive decline is a pathological hallmark of age-associated neurological disorders, also termed as proteinopathies, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis and multiple sclerosis.
Along with oxidative stress and neuroinflammation, disruption in protein homeostasis (proteostasis), a network that constitutes protein surveillance system, plays a pivotal role in the pathobiology of these dementia disorders.
Cannabidiol, a non-psychotropic phytocannabinoid of Cannabis sativa, is known for its pleiotropic neuropharmacological effects on the central nervous system, including the ability to abate oxidative stress, neuroinflammation, and protein misfolding. Over the past years, compelling evidence has documented disease-modifying role of cannabidiol in various preclinical and clinical models of neurological disorders, suggesting the potential therapeutic implications of cannabidiol in these disorders.
Because of its putative role in the proteostasis network in particular, cannabidiol could be a potent modulator for reversing not only age-associated neurodegeneration but also other protein misfolding disorders. However, the current understanding is insufficient to underpin this proposition. In this review, we discuss the potentiality of cannabidiol as a pharmacological modulator of the proteostasis network, highlighting its neuroprotective and aggregates clearing roles in the neurodegenerative disorders.
We anticipate that the current effort will advance our knowledge on the implication of CBD in proteostasis network, opening up a new therapeutic window for ageing proteinopathies.”
“Cannabidiol reduces oxidative stress and neuroinflammation of brain.”
“We aimed to comprehensively evaluate the effects of medical marijuana on symptoms that are relevant to movement disorders with a focus on Huntington disease (HD).
A systematic review by literature search through PubMed and EBSCO electronic databases was conducted for relevant studies reported after 2002 on the effects of medical marijuana or cannabis use on tremor, spasm, spasticity, chorea, sleep quality and HD-specific rating scales. Study selection, quality assessment and data extraction was performed by three reviewers. Outcome measures were changes in psychomotor, and sleep related symptoms. The methodological quality of the included studies was evaluated.
Results: A total of 22 studies were reviewed. There was strong evidence for significant improvement in the neurologic symptoms of spasms, tremors, spasticity, chorea, and quality of sleep following treatment with medical marijuana. Analysis of specific motor symptoms revealed significant improvement after treatment in tremors and rigidity. Furthermore, all pretreatment and post-treatment measures indicated a significant increase in average number of hours slept.
Conclusion: Larger scale studies are warranted to test the benefits of medical marijuana in HD patients. In the meanwhile, clinicians may consider prescribing medical marijuana as part of their strategy for better symptomatic treatment of patients with HD.”