Phytocannabinoids for the Treatment of Neuropathic Pain: A Scoping Review of Randomised Controlled Trials Published Between 2012 and 2023

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“Purpose of review: Neuropathic pain (NP) remains a challenge to treat, with 50% of patients experiencing limited efficacy from current treatments. Medicinal cannabis, which contains tetrahydrocannabinol (THC), cannabidiol (CBD) and other minor cannabinoids, is garnering attention as an alternative treatment for NP. This paper reviews the clinical evidence for phytocannabinoid treatment of NP.

Recent findings: Seventeen randomised controlled trials (RCT) were identified for inclusion in this review. Of these, ten studies using phytocannabinoid preparations containing THC alone had the most evidence for pain relief. Four studies investigating THC/CBD combinations showed some reductions in pain scores, although not all findings were statistically significant, whereas studies investigating CBD (two studies) or cannabidivarin (one study) showed no analgesic effect over placebo. However, CBD studies were of small sample size when compared to other studies in the review and short duration. Results for treatment of diabetic peripheral neuropathy patients with THC showed better improvements over those for NP induced by chemotherapy and multiple sclerosis, with these trials using vaporised whole plant cannabis. This formulation may have trace amounts of other minor cannabinoids, compared with synthetic cannabinoids such as dronabinol or nabilone that were investigated in other studies. This review provides an overview of RCTs that have investigated phytocannabinoid use for the treatment of NP. There appears to be evidence to necessitate further high quality RCTs into novel formulations of phytocannabinoids for the treatment of NP.”

https://pubmed.ncbi.nlm.nih.gov/38095748/

https://link.springer.com/article/10.1007/s11916-023-01196-1

Medical Cannabis: A Review from the American Society of Pain and Neuroscience

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“Cannabinoids have recently gained a renewed interest due to their potential applicability to various medical conditions, specifically the management of chronic pain conditions.

Unlike many other medications, medical cannabis is not associated with serious adverse events, and no overdose deaths have been reported.

However, both safety and efficacy data for medical cannabis treatment of chronic, nonmalignant pain conditions are lacking. Therefore, representatives from the American Society of Pain and Neuroscience summarize the evidence, according to level and grade, for medical cannabis treatment of several different pain conditions. Treatment of cancer-related pain has prospective evidentiary support for the use of medical cannabis. Although 3 large and well-designed randomized controlled trials investigated cannabis treatment of cancer-related pain, the evidence yielded only a grade D recommendation. Neuropathic pain has been investigated in prospective studies, but a lack of high-quality evidence renders cannabis treatment for this indication a grade C recommendation. Both safety and efficacy data are lacking for use of medical cannabis to treat chronic nonmalignant pain conditions.”

https://pubmed.ncbi.nlm.nih.gov/38094100/

https://www.dovepress.com/medical-cannabis-a-review-from-the-american-society-of-pain-and-neuros-peer-reviewed-fulltext-article-JPR

Cannabis use and atherosclerotic cardiovascular disease: a Mendelian randomization study

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“Background: Association between cannabis use and development of atherosclerotic cardiovascular disease (ASCVD) is inconsistent and challenging to interpret, given existing study limitations.

Methods: Sixty five independent single-nucleotide polymorphisms (SNPs), obtained from a genome-wide association study on lifetime cannabis use, were employed as genetic instruments to estimate the effects of genetically indexed cannabis use on risk of coronary artery disease (CAD) and acute ischemic stroke (IS) using a two-sample Mendelian randomization (MR) approach. Summary statistics on CAD (CARDIoGRAMplusC4D; 60,801 cases and 123,504 controls) and IS (MEGASTROKE; 34,217 cases and 406,111 controls) were obtained separately. A comprehensive review of the observational literature on cannabis use and CAD or IS was also performed and contrasted with MR results.

Results: There was no causal effect of cannabis use on the risk of CAD (odds ratio (OR) per ever-users vs. never-users 0.93; 95% confidence interval (CI), 0.83 to 1.03) or IS (OR 1.05; 95%CI, 0.93 to 1.19). Sensitivity analyses yielded similar results, and no heterogeneity and directional pleiotropy was observed. Our meta-analysis of observational studies showed no significant association between ever use of cannabis with risk of CAD (k = 6 studies; ORpooled = 1.23, 95%CI 0.78 to 1.69), nor with IS (k = 6 studies; ORpooled = 1.22, 95%CI 0.95 to 1.50).

Conclusion: Using a genetic approach approximating a clinical trial does not provide evidence consistent with a causal effect of genetic predisposition to cannabis use on CAD or IS development. Further studies are needed to replicate our findinds, an to investigate more precisely the risk of ASCVD in relation to the quantity, type, route of administration, or the age at exposure to cannabis.”

https://pubmed.ncbi.nlm.nih.gov/38093188/

https://bmccardiovascdisord.biomedcentral.com/articles/10.1186/s12872-023-03641-w

Cannabis as a Source of Approved Drugs: A New Look at an Old Problem

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“Cannabis plants have been used in medicine since ancient times. They are well known for their anti-diabetic, anti-inflammatory, neuroprotective, anti-cancer, anti-oxidative, anti-microbial, anti-viral, and anti-fungal activities. A growing body of evidence indicates that targeting the endocannabinoid system and various other receptors with cannabinoid compounds holds great promise for addressing multiple medical conditions. There are two distinct avenues in the development of cannabinoid-based drugs. The first involves creating treatments directly based on the components of the cannabis plant. The second involves a singular molecule strategy, in which specific phytocannabinoids or newly discovered cannabinoids with therapeutic promise are pinpointed and synthesized for future pharmaceutical development and validation. Although the therapeutic potential of cannabis is enormous, few cannabis-related approved drugs exist, and this avenue warrants further investigation. With this in mind, we review here the medicinal properties of cannabis, its phytochemicals, approved drugs of natural and synthetic origin, pitfalls on the way to the widespread clinical use of cannabis, and additional applications of cannabis-related products.”

https://pubmed.ncbi.nlm.nih.gov/38067416/

https://www.mdpi.com/1420-3049/28/23/7686

THC improves behavioural schizophrenia-like deficits that CBD fails to overcome: a comprehensive multilevel approach using the Poly I:C maternal immune activation

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“Prenatal infections and cannabis use during adolescence are well-recognized risk factors for schizophrenia. As inflammation and oxidative stress (OS) contribute to this disorder, anti-inflammatory drugs have been proposed as potential therapies. This study aimed to evaluate the association between delta-9-tetrahydrocannabinol (THC) and schizophrenia-like abnormalities in a maternal immune activation (MIA) model. Additionally, we assessed the preventive effect of cannabidiol (CBD), a non-psychotropic/anti-inflammatory cannabinoid. THC and/or CBD were administered to Saline- and MIA-offspring during periadolescence. At adulthood, THC-exposed MIA-offspring showed significant improvements in sensorimotor gating deficits. Structural and metabolic brain changes were evaluated by magnetic resonance imaging, revealing cortical shrinkage in Saline- and enlargement in MIA-offspring after THC-exposure. Additionally, MIA-offspring displayed enlarged ventricles and decreased hippocampus, which were partially reverted by both cannabinoids. CBD prevented THC-induced reduction in the corpus callosum, despite affecting white matter structure. Post-mortem studies revealed detrimental effects of THC, including increased inflammation and oxidative stress. CBD partially reverted these pro-inflammatory alterations and modulated THC’s effects on the endocannabinoid system. In conclusion, contrary to expectations, THC exhibited greater behavioural and morphometric benefits, despite promoting a pro-inflammatory state that CBD partially reverted. Further research is needed to elucidate the underlying mechanisms involved in the observed benefits of THC.”

https://pubmed.ncbi.nlm.nih.gov/38064909/

https://www.sciencedirect.com/science/article/abs/pii/S0165178123005930?via%3Dihub

Effects of Full-Spectrum Cannabis Oil with a Cannabidiol:Tetrahydrocannabinol 2:1 Ratio on the Mechanisms Involved in Hepatic Steatosis and Oxidative Stress in Rats Fed a Sucrose-Rich Diet

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“Introduction: This study aimed to analyze the effects of cannabis oil (cannabidiol:tetrahydrocannabinol [CBD:THC], 2:1 ratio) on the mechanisms involved in hepatic steatosis and oxidative stress in an experimental model of metabolic syndrome (MS) induced by a sucrose-rich diet (SRD). We hypothesized that noninvasive oral cannabis oil administration improves hepatic steatosis through a lower activity of lipogenic enzymes and an increase in carnitine palmitoyltransferase-1 (CPT-1) enzyme activity involved in the mitochondrial oxidation of fatty acids. Furthermore, cannabis oil ameliorates liver oxidative stress through the regulation of the main regulatory factors involved, nuclear factor erythroid 2 (NrF2) and nuclear factor-kB (NF-κB) p65. For testing this hypothesize, a relevant experimental model of MS was induced by feeding rats with a SRD for 3 weeks.

Methods: Male Wistar rats were fed the following diets for 3 weeks: reference diet: standard commercial laboratory diet, SRD, and SRD + cannabis oil: noninvasive oral administration of 1 mg/kg body weight cannabis oil daily. The full-spectrum cannabis oil presents a total cannabinoid CBD:THC 2:1 ratio. Serum glucose, triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol, uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (AP), N-arachidonoylethanolamine or anandamide and 2-arachidonoylglycerol endocannabinoids levels, thiobarbituric acid reactive substance (TBARS) levels, and non-enzymatic antioxidant capacity (ferric ion-reducing antioxidant power [FRAP]) were evaluated. In the liver tissue: histology, nonalcoholic fatty liver disease activity score (NAS), triglycerides and cholesterol content, lipogenic enzyme activities (fatty acid synthase, acetyl-CoA carboxylase, malic enzyme, and glucose-6-phosphate dehydrogenase), enzyme related to mitochondrial fatty acid oxidation (CPT-1), reactive oxygen species, TBARS, FRAP, glutathione, catalase, glutathione peroxidase, and glutathione reductase enzyme activities. 4-hydroxynonenal, NrF2, and NF-κB p65 levels were analyzed by immunohistochemistry.

Results: The results showed that SRD-fed rats developed dyslipidemia, liver damage, hepatic steatosis (increase of key enzymes related to the novo fatty acid synthesis and decrease of key enzyme related to mitochondrial fatty acid oxidation), lipid peroxidation, and oxidative stress. Hepatic NrF2 expression was significantly decreased and NF-κB p65 expression was increased. Cannabis oil administration improved dyslipidemia, liver damage, hepatic steatosis, lipid peroxidation (improving enzymes involved in lipid metabolism), and oxidative stress. In the liver tissue, NrF2 expression increased, and NF-κB p65 expression was reduced.

Conclusion: The present study revealed new aspects of liver damage and steatosis, lipid peroxidation, and oxidative stress in dyslipidemic insulin-resistant SRD-fed rats. We demonstrated new properties and molecular mechanisms of cannabis oil (CBD:THC, 2:1 ratio) on lipotoxicity and hepatic oxidative stress in an experimental model of MS.”

https://pubmed.ncbi.nlm.nih.gov/38023489/

“our results suggest that full-spectrum cannabis oil with a CBD:THC 2:1 ratio may serve as a natural nutraceutical agent to prevent metabolic disorders related to hepatic steatosis, oxidative stress, and NASH. We cannot rule out the possibility that other components of cannabis oil, such as terpenes, flavonoids, and alkaloids, may also contribute to the beneficial effects found in the present study.”

https://karger.com/mca/article/6/1/170/869880/Effects-of-Full-Spectrum-Cannabis-Oil-with-a


An observational study of clinical outcome measures in patients treated with cannabis-based medicinal products on the UK Medical Cannabis Registry

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“Introduction: While there is increasing evidence of the effects of cannabis-based medicinal products (CBMPs) on health-related quality of life (HRQoL), a major limitation of the current literature is the heterogeneity of studied CBMPs. This study aims to analyze changes in HRQoL in patients prescribed a homogenous selection of CBMPs.

Methods: Primary outcomes were changes in patient-reported outcomes (PROMs) at 1, 3, 6, and 12 months from baseline. The secondary outcome was an adverse events analysis. Statistical significance was defined as p < 0.050.

Results: 1378 patients prescribed Adven® CBMPs (Curaleaf International, Guernsey, UK) were included in the final analysis. 581 (42.16%) participants were current users of cannabis at baseline. 641 (46.51%), 235 (17.05%), and 502 (36.43%) patients were treated with oils, dried flowers, or a combination of the two, respectively. Improvements were found in all PROMs in each route of administration at 1, 3, 6, and 12 months from baseline (p < 0.010). Those prescribed dried flower only or both oils and dried flower experienced greater improvements in GAD-7, SQS, and EQ-5D-5L index values at 12 months (p < 0.050). There was no difference in outcomes between those prescribed dried flower only or dried flower with oils (p > 0.050). 3663 (265.82%) adverse events were reported by 297 (21.55%) patients.

Conclusion: There was an associated improvement in self-reported anxiety, sleep quality, and HRQoL in patients treated with the CBMPs. Those prescribed treatment formulations including dried flower were most likely to show a clinical improvement. However, these results must be interpreted with caution given the limitations of study design.”

https://pubmed.ncbi.nlm.nih.gov/38057993/

“In conclusion, the CBMPs studied in this analysis were associated with an improvement in self-reported anxiety, sleep quality, and HRQoL, consistent with existing literature on CBMPs. Patients prescribed treatment formulations, including dried flowers, were most likely to show clinical improvement”

https://onlinelibrary.wiley.com/doi/10.1002/npr2.12403

UK Medical Cannabis Registry: An analysis of clinical outcomes of medicinal cannabis therapy for attention-deficit/hyperactivity disorder

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“Aim: This study aims to analyze the health-related quality of life (HRQoL) and safety outcomes in attention-deficit/hyperactivity disorder (ADHD) patients treated with cannabis-based medicinal products (CBMPs).

Methods: Patients were identified from the UK Medical Cannabis Registry. Primary outcomes were changes in the following patient-reported outcome measures (PROMs) at 1, 3, 6, and 12 months from baseline: EQ-5D-5L index value, generalized anxiety disorder-7 (GAD-7) questionnaire, and the single-item sleep quality score (SQS). Secondary outcomes assessed the incidence of adverse events. Statistical significance was defined as p < 0.050.

Results: Sixty-eight patients met the inclusion criteria. Significant improvements were identified in general HRQoL assessed by EQ-5D-5L index value at 1, 3, and 6 months (p < 0.050). Improvements were also identified in GAD-7 and SQS scores at 1, 3, 6, and 12 months (p < 0.010). 61 (89.71%) adverse events were recorded by 11 (16.18%) participants, of which most were moderate (n = 26, 38.24%).

Conclusion: An association between CBMP treatment and improvements in anxiety, sleep quality, and general HRQoL was observed in patients with ADHD. Treatment was well tolerated at 12 months. Results must be interpreted with caution as a causative effect cannot be proven. These results, however, do provide additional support for future evaluation within randomized controlled trials.”

https://pubmed.ncbi.nlm.nih.gov/38058251/

https://onlinelibrary.wiley.com/doi/10.1002/npr2.12400

Exploring the Antibacterial Potential of Semisynthetic Phytocannabinoid: Tetrahydrocannabidiol (THCBD) as a Potential Antibacterial Agent against Sensitive and Resistant Strains of Staphylococcus aureus

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“Antimicrobial resistance (AMR) is one of the most challenging problems and is responsible for millions of deaths every year. We therefore urgently require new chemical entities with novel mechanisms of action. Phytocannabinoids have been adequately reported for the antimicrobial effect but not seriously pursued because of either stringent regulatory issues or poor drug-like properties. In this regard, the current work demonstrated the antibacterial potential of tetrahydrocannabidiol (THCBD, 4), a semisynthetic phytocannabinoid, against Staphylococcus aureus, the second-most widespread bug recognized by the WHO. THCBD (4) was generated from cannabidiol and subjected to extensive antibacterial screening. In in vitro studies, THCBD (4) demonstrated a potent MIC of 0.25 μg/mL against Gram-positive bacteria, S. aureus ATCC-29213. It is interesting to note that THCBD (4) has demonstrated strong effectiveness against efflux pump-overexpressing (SA-1199B, SA-K2191, SA-K2192, and Mupr-1) and multidrug-resistant (MRSA-15187) S. aureus strains. THCBD (4) has also shown a good effect in kill kinetic assays against ATCC-29213 and MRSA-15187. In the checkerboard assay, THCBD (4) has shown additive/indifference effects with several well-known clinically used antibiotics, tetracycline, mupirocin, penicillin G, and ciprofloxacin. THCBD (4) also exhibited good permeability in the artificial skin model. Most importantly, THCBD (4) has significantly reduced CFU in mice’s in vivo skin infection models and also demonstrated decent plasma exposure with 16-17% oral bioavailability. Acute dermal toxicity of THCBD (4) suggests no marked treatment-related impact on gross pathophysiology. This attractive in vitro and in vivo profile of plant-based compounds opens a new direction for new-generation antibiotics and warrants further detailed investigation.”

https://pubmed.ncbi.nlm.nih.gov/38051636/

https://pubs.acs.org/doi/10.1021/acsinfecdis.3c00154

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Cancer-Cachexia-Induced Human Skeletal Muscle Myotube Degeneration Is Prevented via Cannabinoid Receptor 2 Agonism In Vitro

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“Cachexia syndrome, leading to reduced skeletal muscle and fat mass, is highly prevalent in cancer patients, resulting in further negative implications for these patients. To date, there is no approved therapy for cachexia syndrome. The objective of this study was to establish an in vitro model of cancer cachexia in mature human skeletal muscle myotubes, with the intention of exploiting the cell model to assess potential cachexia therapeutics, specifically cannabinoid related drugs. Having cultured and differentiated primary human muscle myoblasts to mature myotubes, we successfully established two cancer cachexia models using conditioned media (CM) from human colon adenocarcinoma (SW480) and from non-small-cell lung carcinoma (H1299) cultured cells. The cancer-CM-induced extensive myotube degeneration, demonstrated by a significant reduction in mature myotube diameter, which progressed over the period studied. Myotube degeneration is a characteristic feature of cancer cachexia and was used in this study as an index of cachexia. Expression of cannabinoid 1 and 2 receptors (CB1R and CB2R) was confirmed in the mature human skeletal muscle myotubes. Subsequently, the effect of cannabinoid compounds on this myotube degeneration were assessed.

Tetrahydrocannabinol (THC), a partial CB1R/CB2R agonist, and JWH133, a selective CB2R agonist, proved efficacious in protecting mature human myotubes from the deleterious effects of both (SW480 and H1299) cancer cachexia conditions.

ART27.13, a full, peripherally selective CB1R/CB2R agonist, currently being trialled in cancer cachexia (IRAS ID 278450, REC 20/NE/0198), was also significantly protective against myotube degeneration in both (SW480 and H1299) cancer cachexia conditions. Furthermore, the addition of the CB2R antagonist AM630, but not the CB1R antagonist Rimonabant, abolished the protective effect of ART27.13. In short, we have established a convenient and robust in vitro model of cancer-induced human skeletal muscle cachexia. The data obtained using the model demonstrate the therapeutic potential of ART27.13 in cancer-induced cachexia prevention and provides evidence indicating that this effect is via CB2R, and not CB1R.”

https://pubmed.ncbi.nlm.nih.gov/38004445/

“Several cannabinoid drugs have emerged as potential therapeutics for various conditions.”

https://www.mdpi.com/1424-8247/16/11/1580