Sativex® (nabiximols) cannabinoid oromucosal spray in patients with resistant multiple sclerosis spasticity: the Belgian experience

Clinical outcome analysis of patients with multiple sclerosis - Analysis from the UK Medical Cannabis Registry

INTRODUCTION

Whilst disease-modifying therapies are the cornerstone for treatment of multiple sclerosis (MS), there is a need to develop novel therapeutics for the symptomatic sequalae of the disease. Cannabis-based medicinal products (CBMPs) have been suggested as a potential therapy for the associated pain, spasticity, and mental health disorders. However, there is a paucity of clinical evidence on CBMPs in MS. The aim of this study is to assess changes in MS-specific and general health-related quality of life (HRQoL) outcomes alongside adverse event incidence in patients prescribed CBMPs for MS from the UK Medical Cannabis Registry (UKMCR).

METHOD

Patients prescribed CBMPs for MS symptoms for longer than one month were identified from the UKMCR. The primary outcomes were changes from baseline in MS Quality of Life-54 (MSQoL-54), Generalised Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), and EQ-5D-5L scales at one month, three months and six months. p < 0.050 was defined as statistically significant.

RESULTS

141 patients met the inclusion criteria for the study. There was an improvement in the following subscales of the MSQoL-54 at 6 months: change in health scale, cognitive function, mental health composition, physical health, role limitations due to physical limitation and due to emotional problems, as well as social and sexual function (p < 0.050). There were also improvements in the EQ-5D-5L index value, GAD-7 and SQS (p < 0.050). 146 (103.55 %) adverse events were reported in total. Most were considered mild (n = 47; 33.33 %) and moderate (n = 72; 51.06 %).

CONCLUSIONS

This preliminary analysis demonstrates a possible association with improved general health-related quality of life in those prescribed CBMPs for MS. Moreover, the results suggest that CBMPs are well-tolerated in the first 6 months of treatment. However, this must be interpreted with caution considering the limitations of the observational study design.

Anti-Cancer and Anti-Proliferative Potential of Cannabidiol: A Cellular and Molecular Perspective

Cannabinoids, the bioactive compounds found in Cannabis sativa, have been used for medicinal purposes for centuries, with early discoveries dating back to the BC era (BCE). However, the increased recreational use of cannabis has led to a negative perception of its medicinal and food applications, resulting in legal restrictions in many regions worldwide. Recently, cannabinoids, notably Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), have gained renewed interest in the medical field due to their anti-cancer properties. These properties include the inhibition of tumour growth and cell invasion, anti-inflammatory effects, and the induction of autophagy and apoptosis. As a result, the use of cannabinoids to treat chemotherapy-associated side effects, like nausea, vomiting, and pain, has increased, and there have been suggestions to implement the large-scale use of cannabinoids in cancer therapy. However, these compounds' cellular and molecular mechanisms of action still need to be fully understood. This review explores the recent evidence of CBD's efficacy as an anti-cancer agent, which is of interest due to its non-psychoactive properties. The current review will also provide an understanding of CBD's common cellular and molecular mechanisms in different cancers. Studies have shown that CBD's anti-cancer activity can be receptor-dependent (CB1, CB2, TRPV, and PPARs) or receptor-independent and can be induced through molecular mechanisms, such as ceramide biosynthesis, the induction of ER stress, and subsequent autophagy and apoptosis. It is projected that these molecular mechanisms will form the basis for the therapeutic applications of CBD. Therefore, it is essential to understand these mechanisms for developing and optimizing pre-clinical CBD-based therapies.

Effectiveness, Safety and Patients' Satisfaction of Nabiximols (Sativex®) on Multiple Sclerosis Spasticity and Related Symptoms in a Swiss Multicenter Study

Background: Cannabinoid oro-mucosal spray nabiximols is approved for patients with moderate to severe multiple sclerosis spasticity (MSS) resistant to other antispastic medications. Few real-world data are available on the effectiveness, safety and patients' satisfaction in MS patients treated with nabiximols as monotherapy. Methods: To investigate the effectiveness, tolerability and satisfaction of nabiximols in a real-life multicentric Swiss cohort as monotherapy or with stable doses of other antispastic medications, and explore clinical features which may predict treatment response. The following data were collected at treatment start (baseline) and 12 weeks thereafter: Modified Ashworth scale (MAS), scores at numerical rating scales ranging from 0 (absent) to 10 (considerable) for effect on spasticity (sNRS), pain (pNRS), gait (gNRS), urinary symptoms (uNRS), tolerability (tNRS) as assessed by the treating neurologist, and overall treatment satisfaction (TsNRS) and tolerability (tNRS) as assessed by the patient. Results: Ninety-five patients (44 relapsing remitting, 37 secondary progressive and 14 primary progressive MS; median age = 53 (IQR 45-62); female 70%; median EDSS 6 (IQR 4-6), concomitant antispastic treatments in 54% of patients) were included. From baseline to week 12, median MAS score decreased from 3.0 to 2.0 (p < 0.001). Median scores of the each NRS also significantly decreased (p < 0.001 for all comparisons). At week 12, the median TsNRS and tTS scores were 8/10 (IQR: 6-9) and 9/10 (IQR: 7-10), respectively, and 93.7% of patients continued to use nabiximols at the average dose of six sprays/day. No clinical factors, including use of nabiximols as add on vs. monotherapy, were associated with responder status. Conclusions: Our first Swiss, multicentric, observational, real-life study supports and enhances previous finding of nabiximols as monotherapy and as add-on therapy, being an effective, safe and well-tolerated treatment option for resistant MS spasticity and spasticity-related symptoms (pain, bladder dysfunction and gait).

Chemistry and pharmacological aspects of furanoid cannabinoids and related compounds: Is furanoid cannabinoids open a new dimension towards the non-psychoactive cannabinoids?

Cannabinoids have emerged as compelling candidates for medicinal applications, notably following the recent approval of non-psychoactive cannabidiol (CBD) as a medicine. This endorsement has stimulated a growing interest in this class of compounds for drug discovery. Within the cannabis plant, a rich reservoir of over 125 compounds exists. Tetrahydrocannabinol (THC), a member of the dibenzopyran class, is widely recognized for its psychoactive effects. Conversely, the furanoid class, represented by cannabielsoin-type (CBE) and cannabifuran-type (CBF) compounds, has not been reported with psychoactivity and demonstrates a spectrum of pharmacological potential. The transition from the pyran structure of THC to the furan structure of CBE seems to mark a shift from psychoactive to non-psychoactive properties, but a comprehensive examination of other members in this class is essential for a complete understanding. Building on these observations, our thorough review delves into the subject, offering a comprehensive exploration of furanoid cannabinoids, covering aspects such as their biosynthesis, classification, synthesis, and medicinal potential. The aim of this review is to encourage and catalyze increased research focus in this promising area of cannabinoid exploration.

Synthesis and Evaluation of Natural and Unnatural Tetrahydrocannabiorcol for Its Potential Use in Neuropathologies

(-)-trans-Δ9-Tetrahydrocannabinol (trans-(-)-Δ9-THC) has shown neuroprotective potential, but its medicinal benefits are not fully exploited due to the limitations of psychoactive properties. The lower homologues are non-psychoactive in nature but lack comprehensive scientific validation regarding neuroprotective potential. The present study describes the synthesis of non-psychoactive lower homologues of THC-type compounds and their neuroprotective potential. Both natural tetrahydro-cannabiorcol (trans-(-)-Δ9-THCO) and unnatural Δ9-tetrahydrocannabiorcol (trans-(+)-Δ9-THCO) were successfully synthesized starting from R-limonene and S-limonene, respectively, and investigated for neuroprotective potential in cellular models. The structures of both enantiomers were confirmed by NMR, HMBC, HQSC, NOESY, and COSY experiments. Results indicated that both enantiomers were nontoxic to the cells treated up to 50 μM. Neuroprotective properties of the enantiomers showed that treatments could significantly reverse the corticosterone-induced toxicity in SH-SY5Y cells and simultaneously cause elevated expression of brain-derived neurotrophic factor (BDNF). It was also observed that unnatural trans-(+)-Δ9-THCO displayed better activity than the natural enantiomer and can be further explored for its potential use in neuropathological ailments.

Effectiveness and Safety of Cannabinoids as an Add-On Therapy in the Treatment of Resistant Spasticity in Multiple Sclerosis: A Systematic Review

Background: Spasticity continues to be a very prevalent, highly invalidating, and difficult-to-manage symptom in patients with multiple sclerosis (MS). The aim of this systematic review is to evaluate the effectiveness of the use of cannabis and cannabinoids in these patients, evaluating its use as an additional therapy. Methods: We performed a systematic review of the literature searching in the major scientific databases (PubMed, Scopus, EMBASE, WOS, and Cochrane Library) for articles from January 2017 to May 2022 containing information about the effectiveness of cannabis and cannabinoids in patients with insufficient response to first-line oral antispastic treatment. Results: A total of five medium high-quality articles were selected to be part of the study and all evaluated the effectiveness of the tetrahydrocannabinol (THC) and cannabidiol (CBD) spray. The effectiveness of this drug and the significant improvements are produced on the patient-related spasticity assessment scales, obtaining improvement up to 45%; and on quality of life, producing a decrease in the appearance of symptoms related to spasticity, as well as an increase in the development of basic activities of daily living. The average dose is 5-7 sprays/day. The discontinuation rate for these treatments is around 40% due to lack of effectiveness and adverse events. All reported adverse effects are mild to moderate in severity and their incidence is ∼17%, although this figure tends to decrease with drug use. Conclusions: Adding the THC:CBD sprays have been shown to be more effective in treating MS spasticity than optimizing the dose of first-line antispastic drugs in selected responders patients. The safety and tolerability profiles remain in line with those obtained in other trials. More patients would benefit from treatment if the initial response search period was extended.

Cannabis and Cannabinoids in Multiple Sclerosis: From Experimental Models to Clinical Practice-A Review

BACKGROUND

As far as 80% of people diagnosed with multiple sclerosis (MS) experience disabling symptoms in the course of the disease, such as spasticity and neuropathic pain. As first-line symptomatic therapy is associated with important adverse reactions, cannabinoids have become increasingly popular among patients with MS. This review intends to provide an overview of the evidence of the role of cannabinoids in treating symptoms related to MS and to encourage further research on this matter.

AREAS OF UNCERTAINTY

To date, the evidence supporting the role of cannabis and its derivatives in alleviating the MS-related symptoms comes only from studies on experimental models of demyelination. To the best of our knowledge, relatively few clinical trials inquired about the therapeutic effects of cannabinoids on patients with MS, with variable results.

DATA SOURCES

We conducted a literature search through PubMed and Google Scholar from the beginning until 2022. We included articles in English describing the latest findings regarding the endocannabinoid system, the pharmacology of cannabinoids, and their therapeutic purpose in MS.

RESULTS

Evidence from preclinical studies showed that cannabinoids can limit the demyelination process, promote remyelination, and have anti-inflammatory properties by reducing immune cell infiltration of the central nervous system in mice with experimental autoimmune encephalomyelitis. Moreover, it has been established that experimental autoimmune encephalomyelitis mice treated with cannabinoids experienced a significant reduction of symptoms and slowing of the disease progression. Given the complexity of human immune and nervous systems, cannabinoids did not have the anticipated effects on human subjects. However, data obtained from clinical trials showed some beneficial results of cannabinoids as a single or as add-on therapy in reducing the spasticity and pain related to MS.

CONCLUSION

Considering their various mechanisms of action and good tolerability, cannabinoids remain an interesting therapy for spasticity and chronic pain related to MS.

Natural sources, biological effects, and pharmacological properties of cynaroside

Cynaroside is a flavonoid, isolated from several species belonging to the Apiaceae, Poaceae, Lamiaceae, Solanaceae, Zingiberaceae, Compositae and other families and it can be extracted from seeds, roots, stems, leaves, barks, flowers, fruits, aerial parts, and the whole plant of these species. This paper discloses the current state of knowledge on the biological/pharmacological effects and mode of action to better understand the numerous health benefits of cynaroside. Several research works revealed that cynaroside could have beneficial effects on various human pathologies. Indeed, this flavonoid exerts antibacterial, antifungal, antileishmanial, antioxidant, hepatoprotective, antidiabetic, anti-inflammatory, and anticancer effects. Additionally, cynaroside exhibits its anticancer effects by blocking MET/AKT/mTOR axis by decreasing the phosphorylation level of AKT, mTOR, and P70S6K. For antibacterial activity, cynaroside reduces biofilm development of Pseudomonas aeruginosa and Staphylococcus aureus. Moreover, the incidence of mutations leading to ciprofloxacin resistance in Salmonella typhimurium was reduced after the treatment with cynaroside. In addition, cynaroside inhibited the production of reactive oxygen species (ROS), which reduced the damage to mitochondrial membrane potential caused by hydrogen peroxide (H₂O₂). It also enhanced the expression of the anti-apoptotic protein Bcl-2 and lowered that of the pro-apoptotic protein Bax. Cynaroside abrogated the up-regulation of c-Jun N-terminal kinase (JNK) and p53 protein expression triggered by H₂O₂. All these findings suggest that cynaroside could be used to prevent certain human diseases.

Exploring the Potential of Cannabinoid Nanodelivery Systems for CNS Disorders

Cannabinoids have a major therapeutic value in a variety of disorders. The concepts of cannabinoids are difficult to develop, but they can be used and are advantageous for a number of diseases that are not sufficiently managed by existing treatments. Nanoconjugation and encapsulation techniques have been shown to be effective in improving the delivery and the therapeutic effectiveness of drugs that are poorly soluble in water. Because the bioavailability of cannabinoids is low, the challenge is to explore different administration methods to improve their effectiveness. Because cannabinoids cross the blood-brain-barrier (BBB), they modify the negative effects of inflammatory processes on the BBB and may be a key factor in the improvement of BBB function after ischemic disease or other conditions. This review discusses various types of cannabinoid administration, as well as nanotechnologies used to improve the bioavailability of these compounds in CNS diseases.

Targeting the endocannabinoid system for the treatment of abdominal pain in irritable bowel syndrome

The management of visceral pain in patients with disorders of gut-brain interaction, notably irritable bowel syndrome, presents a considerable clinical challenge, with few available treatment options. Patients are increasingly using cannabis and cannabinoids to control abdominal pain. Cannabis acts on receptors of the endocannabinoid system, an endogenous system of lipid mediators that regulates gastrointestinal function and pain processing pathways in health and disease. The endocannabinoid system represents a logical molecular therapeutic target for the treatment of pain in irritable bowel syndrome. Here, we review the physiological and pathophysiological functions of the endocannabinoid system with a focus on the peripheral and central regulation of gastrointestinal function and visceral nociception. We address the use of cannabinoids in pain management, comparing them to other treatment modalities, including opioids and neuromodulators. Finally, we discuss emerging therapeutic candidates targeting the endocannabinoid system for the treatment of pain in irritable bowel syndrome.

Nabiximols is Efficient as Add-On Treatment for Patients with Multiple Sclerosis Spasticity Refractory to Standard Treatment: A Systematic Review and Meta-Analysis of Randomised Clinical Trials

BACKGROUND

Spasticity affects 54% of multiple sclerosis (MS) patients at disease onset, but this rate gradually increases with disease progression. Spasticity does not fully respond to standard treatment in one-third of the patients.

OBJECTIVE

Our systematic review and meta-analysis assessed whether add-on nabiximols, can improve MS-associated refractory spasticity.

METHODS

The systematic literature search was performed in Web of Science, MEDLINE, Scopus, CENTRAL, and Embase, on 15/10/2021, without restrictions. We included in the review blinded, randomized, placebo-controlled trials evaluating the efficacy of nabiximols in adult MS patients with refractory spasticity, by comparison with placebo. The primary outcome was responder rate by spasticity numerical rating scale (NRS). Secondary outcomes were spasticity-related parameters. We used random effect models to calculate odds ratios (OR) or mean differences and the corresponding 95% CI. Bias-factors were assessed with Cochrane risk of bias tool (RoB2). (PROSPERO ID: CRD42021282177).

RESULTS

We identified 9 eligible articles, of which 7 (1128 patients) were included in the meta-analysis. The spasticity numerical rating scale (NRS) was significantly higher in the nabiximols group than in the placebo group (OR 2.41 (95% CI 1.39; 4.18)). Secondary outcomes were in accordance with our primary results. At least some concerns were detected in the risk of bias analysis.

CONCLUSION

Our results indicate that nabiximols is efficient in MS associated spasticity, refractory to standard treatment and it may be considered as add-on symptomatic therapy. Nevertheless, further studies are needed to establish the optimal treatment protocol - dose, duration, moment of initiation, disease type.

The Therapeutic Potential of the Endocannabinoid System in Age-Related Diseases

The endocannabinoid system (ECS) dynamically regulates many aspects of mammalian physiology. ECS has gained substantial interest since growing evidence suggests that it also plays a major role in several pathophysiological conditions due to its ability to modulate various underlying mechanisms. Furthermore, cannabinoids, as components of the cannabinoid system (CS), have proven beneficial effects such as anti-inflammatory, immunomodulatory, neuromodulatory, antioxidative, and cardioprotective effects. In this comprehensive review, we aimed to describe the complex interaction between CS and most common age-related diseases such as neuro-degenerative, oncological, skeletal, and cardiovascular disorders, together with the potential of various cannabinoids to ameliorate the progression of these disorders. Since chronic inflammation is postulated as the pillar of all the above-mentioned medical conditions, we also discuss in this paper the potential of CS to ameliorate aging-associated immune system dysregulation.

Positive Allosteric Modulators of Glycine Receptors and Their Potential Use in Pain Therapies

Glycine receptors are ligand-gated ion channels that mediate synaptic inhibition throughout the mammalian spinal cord, brainstem, and higher brain regions. They have recently emerged as promising targets for novel pain therapies due to their ability to produce antinociception by inhibiting nociceptive signals within the dorsal horn of the spinal cord. This has greatly enhanced the interest in developing positive allosteric modulators of glycine receptors. Several pharmaceutical companies and research facilities have attempted to identify new therapeutic leads by conducting large-scale screens of compound libraries, screening new derivatives from natural sources, or synthesizing novel compounds that mimic endogenous compounds with antinociceptive activity. Advances in structural techniques have also led to the publication of multiple high-resolution structures of the receptor, highlighting novel allosteric binding sites and providing additional information for previously identified binding sites. This has greatly enhanced our understanding of the functional properties of glycine receptors and expanded the structure activity relationships of novel pharmacophores. Despite this, glycine receptors are yet to be used as drug targets due to the difficulties in obtaining potent, selective modulators with favorable pharmacokinetic profiles that are devoid of side effects. This review presents a summary of the structural basis for how current compounds cause positive allosteric modulation of glycine receptors and discusses their therapeutic potential as analgesics. SIGNIFICANCE STATEMENT: Chronic pain is a major cause of disability, and in Western societies, this will only increase as the population ages. Despite the high level of prevalence and enormous socioeconomic burden incurred, treatment of chronic pain remains limited as it is often refractory to current analgesics, such as opioids. The National Institute for Drug Abuse has set finding effective, safe, nonaddictive strategies to manage chronic pain as their top priority. Positive allosteric modulators of glycine receptors may provide a therapeutic option.

Activating cannabinoid receptor 2 preserves axonal health through GSK-3β/NRF2 axis in adrenoleukodystrophy

Aberrant endocannabinoid signaling accompanies several neurodegenerative disorders, including multiple sclerosis. Here, we report altered endocannabinoid signaling in X-linked adrenoleukodystrophy (X-ALD), a rare neurometabolic demyelinating syndrome caused by malfunction of the peroxisomal ABCD1 transporter, resulting in the accumulation of very long-chain fatty acids (VLCFAs). We found abnormal levels of cannabinoid receptor 2 (CB2r) and related endocannabinoid enzymes in the brain and peripheral blood mononuclear cells (PBMCs) of X-ALD patients and in the spinal cord of a murine model of X-ALD. Preclinical treatment with a selective agonist of CB2r (JWH133) halted axonal degeneration and associated locomotor deficits, along with normalization of microgliosis. Moreover, the drug improved the main metabolic disturbances underlying this model, particularly in redox and lipid homeostatic pathways, including increased lipid droplets in motor neurons, through the modulation of the GSK-3β/NRF2 axis. JWH133 inhibited Reactive Oxygen Species elicited by excess VLCFAs in primary microglial cultures of Abcd1-null mice. Furthermore, we uncovered intertwined redox and CB2r signaling in the murine spinal cords and in patient PBMC samples obtained from a phase II clinical trial with antioxidants (NCT01495260). These findings highlight CB2r signaling as a potential therapeutic target for X-ALD and perhaps other neurodegenerative disorders that present with dysregulated redox and lipid homeostasis.

Phytocannabinoids and Cannabis-Based Products as Alternative Pharmacotherapy in Neurodegenerative Diseases: From Hypothesis to Clinical Practice

Historically, Cannabis is one of the first plants to be domesticated and used in medicine, though only in the last years the amount of Cannabis-based products or medicines has increased worldwide. Previous preclinical studies and few published clinical trials have demonstrated the efficacy and safety of Cannabis-based medicines in humans. Indeed, Cannabis-related medicines are used to treat multiple pathological conditions, including neurodegenerative disorders. In clinical practice, Cannabis products have already been introduced to treatment regimens of Alzheimer’s disease, Parkinson’s disease and Multiple Sclerosis’s patients, and the mechanisms of action behind the reported improvement in the clinical outcome and disease progression are associated with their anti-inflammatory, immunosuppressive, antioxidant, and neuroprotective properties, due to the modulation of the endocannabinoid system. In this review, we describe the role played by the endocannabinoid system in the physiopathology of Alzheimer, Parkinson, and Multiple Sclerosis, mainly at the neuroimmunological level. We also discuss the evidence for the correlation between phytocannabinoids and their therapeutic effects in these disorders, thus describing the main clinical studies carried out so far on the therapeutic performance of Cannabis-based medicines.

A real-world evidence study of nabiximols in multiple sclerosis patients with resistant spasticity: analysis in relation to the newly-described 'Spasticity-Plus syndrome'

Background and purpose

Nabiximols is a therapeutic option for patients with multiple sclerosis (MS) spasticity whose symptoms are poorly controlled by conventional oral first‐line medications. This study aimed to assess the relationship between changes in spasticity severity (measured on the 0–10 numeric rating scale [NRS]) and the presence of associated symptoms in patients treated with nabiximols, and to investigate the presence of the newly described ‘spasticity‐plus syndrome’.

Methods

We analyzed real‐world data from the Italian Medicines Agency e‐Registry on 1138 patients with MS spasticity who began treatment with nabiximols. Evaluation time points were baseline, 4 weeks, and 3, 6, 12 and 18 months after treatment start.

Results

Common symptoms associated with MS spasticity in this cohort were pain (38.4% at baseline), sleep disturbances (32.7%), and spasms/cramps (28.5%). Pain was frequently clustered with sleep disturbances (57.2% of pain cases) and spasms/cramps (43.9%). Approximately one‐third of patients with data at all evaluation time points maintained treatment at 18 months. Nabiximols reduced the baseline mean spasticity 0–10 NRS score by 24.6% at Week 4, and by 33.9% at 18 months in treatment continuers. Nabiximols resolved a range of MS spasticity‐associated symptoms at Week 4, and after 18 months in treatment continuers.

Conclusion

This real‐world analysis supports the concept of a spasticity‐plus syndrome and suggests that nabiximols can favorably impact a range of spasticity‐associated symptoms.

Evidence-based management of multiple sclerosis spasticity with nabiximols oromucosal spray in clinical practice: a 10-year recap

Effective symptomatic management of multiple sclerosis (MS) spasticity remains an unmet need for many patients. The second-line option nabiximols is the most widely investigated of the noninvasive antispasticity medications in this patient population. Clinical evidence accumulated with nabiximols since it was first approved in Europe in 2010 suggests that about 40% of initial responders (i.e., those with ≥20% improvement in their baseline 0-10 Numerical Rating Scale score) may expect to achieve clinically meaningful (≥30% Numerical Rating Scale response) and durable symptomatic improvement in MS spasticity. During 10 years' routine use of nabiximols, no new safety signals have emerged. Nabiximols-associated improvement in MS spasticity-related symptoms such as pain and sleep disruption suggests a need to track possible therapeutic effects beyond muscle tone control.

Carvone and its pharmacological activities: A systematic review

Natural products from plants have gained prominence in the search for therapeutic alternatives. Monoterpenes, such as carvone, are suggested as candidates for the treatment of several diseases. Therefore, the objective of this study is to review the pharmacological activities of carvone in experimental models in vitro and in vivo. For this, the searches were carried out in May 2020 (upgraded in July 2021) in the databases of PubMed, Web of Science and Scopus and gathered studies on the pharmacological activities of carvone. Two independent reviewers performed the selection of articles using the Rayyan application, extracted the relevant data and assessed the methodological quality of the selected studies using Syrcle's risk of bias tool. Ninety-one articles were selected that described 10 pharmacological activities of carvone, such as antimicrobial, antispasmodic, anti-inflammatory, antioxidant, antinociceptive, anticonvulsant, among others. The evaluation of the methodological quality presented an uncertain risk of bias for most studies. In light of that, carvone stands out as a viable and promising alternative in the treatment of several pathological conditions. However, carrying out studies to evaluate possible mechanisms of action and the safety of this monoterpene is recommended.

Neurological Benefits, Clinical Challenges, and Neuropathologic Promise of Medical Marijuana: A Systematic Review of Cannabinoid Effects in Multiple Sclerosis and Experimental Models of Demyelination

Despite current therapeutic strategies for immunomodulation and relief of symptoms in multiple sclerosis (MS), remyelination falls short due to dynamic neuropathologic deterioration and relapses, leading to accrual of disability and associated patient dissatisfaction. The potential of cannabinoids includes add-on immunosuppressive, analgesic, neuroprotective, and remyelinative effects. This study evaluates the efficacy of medical marijuana in MS and its experimental animal models. A systematic review was conducted by a literature search through PubMed, ProQuest, and EBSCO electronic databases for studies reported since 2007 on the use of cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) in MS and in experimental autoimmune encephalomyelitis (EAE), Theiler’s murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), and toxin-induced demyelination models. Study selection and data extraction were performed by 3 reviewers, and 28 studies were selected for inclusion. The certainty of evidence was appraised using the Cochrane GRADE approach. In clinical studies, there was low- and moderate-quality evidence that treatment with ~1:1 CBD/THC mixtures as a nabiximols (Sativex®) oromucosal spray reduced numerical rating scale (NRS) scores for spasticity, pain, and sleep disturbance, diminished bladder overactivity, and decreased proinflammatory cytokine and transcription factor expression levels. Preclinical studies demonstrated decreases in disease severity, hindlimb stiffness, motor function, neuroinflammation, and demyelination. Other experimental systems showed the capacity of cannabinoids to promote remyelination in vitro and by electron microscopy. Modest short-term benefits were realized in MS responders to adjunctive therapy with CBD/THC mixtures. Future studies are recommended to investigate the cellular and molecular mechanisms of cannabinoid effects on MS lesions and to evaluate whether medical marijuana can accelerate remyelination and retard the accrual of disability over the long term.