Cannabinoid Therapeutics in Chronic Neuropathic Pain: From Animal Research to Human Treatment

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“Despite the importance of pain as a warning physiological system, chronic neuropathic pain is frequently caused by damage in the nervous system, followed by persistence over a long period, even in the absence of dangerous stimuli or after healing of injuries. Chronic neuropathic pain affects hundreds of millions of adults worldwide, creating a direct impact on quality of life. This pathology has been extensively characterized concerning its cellular and molecular mechanisms, and the endocannabinoid system (eCS) is widely recognized as pivotal in the development of chronic neuropathic pain. Scientific evidence has supported that phyto-, synthetic and endocannabinoids are efficient for pain management, while strong data arise from the therapeutic use of Cannabis-derived products. The use of medicinal Cannabis products is directed toward not only relieving symptoms of chronic pain, but also improving several aspects of patients’ welfare. Here, we review the involvement of eCS, along with other cellular and molecular elements, in chronic neuropathic pain pathology and how this system can be targeted for pain management.”

https://pubmed.ncbi.nlm.nih.gov/34916962/

“The role of eCS as a pharmacological target and the advantages of using medicinal Cannabis sp. to treat pain is remarkable, as described in this review.”

https://www.frontiersin.org/articles/10.3389/fphys.2021.785176/full


Cannabis sativa extracts protect LDL from Cu 2+-mediated oxidation

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“Background: Multiple therapeutic properties have been attributed to Cannabis sativa. However, further research is required to unveil the medicinal potential of Cannabis and the relationship between biological activity and chemical profile.

Objectives: The primary objective of this study was to characterize the chemical profile and antioxidant properties of three varieties of Cannabis sativa available in Uruguay during progressive stages of maturation.

Methods: Fresh samples of female inflorescences from three stable Cannabis sativa phenotypes, collected at different time points during the end of the flowering period were analyzed. Chemical characterization of chloroform extracts was performed by 1H-NMR. The antioxidant properties of the cannabis sativa extracts, and pure cannabinoids, were measured in a Cu2+-induced LDL oxidation assay.

Results: The main cannabinoids in the youngest inflorescences were tetrahydrocannabinolic acid (THC-A, 242 ± 62 mg/g) and tetrahydrocannabinol (THC, 7.3 ± 6.5 mg/g). Cannabinoid levels increased more than twice in two of the mature samples. A third sample showed a lower and constant concentration of THC-A and THC (177 ± 25 and 1 ± 1, respectively). The THC-A/THC rich cannabis extracts increased the latency phase of LDL oxidation by a factor of 1.2-3.5 per μg, and slowed down the propagation phase of lipoperoxidation (IC50 1.7-4.6 μg/mL). Hemp, a cannabidiol (CBD, 198 mg/g) and cannabidiolic acid (CBD-A, 92 mg/g) rich variety, also prevented the formation of conjugated dienes during LDL oxidation. In fact, 1 μg of extract was able to stretch the latency phase 3.7 times and also to significantly reduce the steepness of the propagation phase (IC50 of 8 μg/mL). Synthetic THC lengthened the duration of the lag phase by a factor of 21 per μg, while for the propagation phase showed an IC50 ≤ 1 μg/mL. Conversely, THC-A was unable to improve any parameter. Meanwhile, the presence of 1 μg of pure CBD and CBD-A increased the initial latency phase 4.8 and 9.4 times, respectively, but did not have an effect on the propagation phase.

Conclusion: Cannabis whole extracts acted on both phases of lipid oxidation in copper challenged LDL. Those effects were just partially related with the content of cannabinoids and partially recapitulated by isolated pure cannabinoids. Our results support the potentially beneficial effects of cannabis sativa whole extracts on the initial phase of atherosclerosis.”

https://pubmed.ncbi.nlm.nih.gov/33123676/

“Our findings support the beneficial effects of Cannabis sativa extracts on the initial phase of atherosclerosis. Since isolated cannabinoids were less effective preventing the oxidation of LDL, a synergistic effect between the diverse arrange of phytochemicals present in complex extracts is supported, reinforcing the entourage hypothesis and the use of whole medicinal cannabis extracts for therapeutic purposes.”

https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-020-00042-0

Tetrahydrocannabinol-Rich Extracts From Cannabis Sativa L. Improve Glucose Consumption and Modulate Metabolic Complications Linked to Neurodegenerative Diseases in Isolated Rat Brains

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“Reduced brain glucose consumption arising from impaired glucose uptake and utilization has been linked to the pathogenesis and complications of neurodegenerative diseases. The ability of Cannabis sativa L. tetrahydrocannabinol (THC)-rich extracts to stimulate brain glucose uptake and utilization as well as its modulatory effect on gluconeogenesis, antioxidative, purinergic and cholinergic activities were investigated in isolated rats’ brains. C. sativa leaves were sequentially extracted to yield the hexane and dichloromethane extracts. The extracts were incubated at 37°C with freshly harvested brains in the presence of glucose for 2 h. The control consisted of incubation without the extracts, while brains without the extracts and glucose served as the normal control. Metformin was used as the standard drug. C. sativa extracts caused a significant (p < 0.05) increase in brain glucose uptake, with concomitant elevation of glutathione level, superoxide dismutase, catalase, and ecto-nucleoside triphosphate diphosphohydrolase activities compared to the controls. Incubation with C. sativa extracts also led to depletion in malondialdehyde and nitric oxide levels, acetylcholinesterase, butyrylcholinesterase, glucose 6-phosphatase and fructose-1,6-biphosphatase activities. GC-MS analysis of the extracts revealed the presence of THC. In silico analysis predicted THC to be permeable across the blood-brain-barrier. THC was also predicted to have an oral LD50 and toxicity class values of 482 mg/kg and 4 respectively. These results indicate that C. sativa improves glucose consumption with concomitant suppression of oxidative stress and cholinergic dysfunction, and modulation of purinergic and gluconeogenic activities in brain tissues.”

https://pubmed.ncbi.nlm.nih.gov/33390972/

“As portrayed by these results, C. sativa improves glucose consumption with concomitant suppression of oxidative stress and cholinergic dysfunction, and modulation of purinergic and gluconeogenic activities in brain tissues. Further studies are recommended to decipher the molecular mechanisms that may be involved in these neuroprotective activities in in vivo studies.”

https://www.frontiersin.org/articles/10.3389/fphar.2020.592981/full

Cannabis sativa L. (var. indica) Exhibits Hepatoprotective Effects by Modulating Hepatic Lipid Profile and Mitigating Gluconeogenesis and Cholinergic Dysfunction in Oxidative Hepatic Injury

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“Cannabis sativa L. is a crop utilized globally for recreational, therapeutic, and religious purposes. Although considered as an illicit drug in most countries, C. sativa until recently started gaining attention for its medicinal application. This study sought to investigate the hepatoprotective effect of C. sativa on iron-mediated oxidative hepatic injury. Hepatic injury was induced ex vivo by incubating hepatic tissues with Fe2+, which led to depleted levels of reduced glutathione, superoxide dismutase, catalase and ENTPDase activities, triglyceride, and high-density lipoprotein-cholesterol (HDL-C). Induction of hepatic injury also caused significant elevation of malondialdehyde, nitric oxide, cholesterol, and low-density lipoprotein-cholesterol (LDL-C) levels while concomitantly elevating the activities of ATPase, glycogen phosphorylase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, amylase, and lipase. Treatment with the hexane, dichloromethane (DCM), and ethanol extracts of C. sativa leaves significantly (p < 0.05) reversed these levels and activities to almost near normal. However, there was no significant effect on the HDL-C level. The extracts also improved the utilization of glucose in Chang liver cells. High-performance liquid chromatography (HPLC) analysis showed the presence of phenolics in all extracts, with the ethanol extract having the highest constituents. Cannabidiol (CBD) was identified in all the extracts, while Δ-9-tetrahydrocannabinol (Δ-9-THC) was identified in the hexane and DCM extracts only. Molecular docking studies revealed strong interactions between CBD and Δ-9-THC with the β2 adrenergic receptor of the adrenergic system. The results demonstrate the potential of C. sativa to protect against oxidative-mediated hepatic injury by stalling oxidative stress, gluconeogenesis, and hepatic lipid accumulation while modulating cholinergic and purinergic activities. These activities may be associated with the synergistic effect of the compounds identified and possible interactions with the adrenergic system.”

https://pubmed.ncbi.nlm.nih.gov/34992528/

“The data obtained in this study indicate the ability of C. sativa to protect against oxidative-mediated hepatic injury by stalling oxidative stress, gluconeogenesis, and hepatic lipid accumulation while modulating cholinergic and purinergic activities. These activities may be associated with the synergistic effect of the identified phenolics, CBD, and Δ-9-THC and possible interactions with the adrenergic system.”

https://www.frontiersin.org/articles/10.3389/fphar.2021.705402/full

Healing of a Chronic Pressure Injury in a Patient Treated With Medical Cannabis for Pain and Sleep Improvement: A Case Report

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“Background: A small body of evidence suggests medical cannabis may facilitate wound healing, but the exact mechanism of this effect is unclear.

Purpose: This case report describes a patient with a pressure injury (PI) who received cannabis oil treatment for pain management and sleep improvement.

Methods: A 37-year-old woman with multiminicore disease, scoliosis, short-chain acyl-CoA dehydrogenase deficiency, and epilepsy presented to the Neurology Centre of Toronto with chronic pain and sleep disturbance, including difficulty initiating and maintaining sleep. She also had a 5-year history of a PI between her right iliac crest and right rib cage that had progressively worsened. The patient received a medical cannabis oil protocol that used a combination of cannabidiol and tetrahydrocannabinol.

Results: Cannabis oil was effective in treating pain and sleep difficulties. Unexpectedly, during the first 2 weeks of treatment, the PI started to heal and was almost completely closed at the 2-month follow-up.

Conclusion: Although it is unknown if the observed healing of this refractory PI was indirectly or directly related to the cannabidiol and tetrahydrocannabinol treatment, the potential relationships among pain, sleep disturbance, cannabis treatment, and healing should be explored.”

https://pubmed.ncbi.nlm.nih.gov/35030093/

“This case report provides an account of a patient who began using orally administered medical cannabis oil for sleep disturbances and pain management and subsequently experienced rapid healing of a chronic PI.”

https://www.hmpgloballearningnetwork.com/site/wmp/case-report/healing-chronic-pressure-injury-patient-treated-medical-cannabis-pain-and

Adherence, Safety, and Effectiveness of Medical Cannabis and Epidemiological Characteristics of the Patient Population: A Prospective Study

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“Background: Despite the absence of rigorous prospective studies, there has been an increase in the use of cannabis-based medicinal products. During the study period, the use of medical cannabis in Israel was tightly regulated by national policy. Through a prospective study of approximately 10,000 patients, we aimed to characterize the medical cannabis patient population as well as to identify treatment adherence, safety, and effectiveness.

Methods and findings: In this study of prescribed medical cannabis patients, adherence, safety, and effectiveness were assessed at 6 months. Treatment adherence was assessed by the proportion of patients purchasing the medication out of the total number of patients (excluding deceased cases and patients transferred to another cannabis clinic). Safety was assessed by the frequency of the side-effects, while effectiveness was defined as at least moderate improvement in the patient condition without treatment cessation or serious side-effects. The most frequent primary indications requiring therapy were cancer (49.1%), followed by non-specific pain (29.3%). The average age was 54.6 ± 20.9 years, 51.1% males; 30.2% of the patients reported prior experience with cannabis. During the study follow-up, 1,938 patients died (19.4%) and 1,735 stopped treatment (17.3%). Common side-effects, reported by 1,675 patients (34.2%), were: dizziness (8.2%), dry mouth (6.7%), increased appetite (4.7%), sleepiness (4.4%), and psychoactive effect (4.3%). Overall, 70.6% patients had treatment success at 6 months. Multivariable logistic regression analysis revealed that the following factors were associated with treatment success: cigarette smoking, prior experience with cannabis, active driving, working, and a young age. The main limitation of this study was the lack of data on safety and effectiveness of the treatment for patients who refused to undergo medical assessment even at baseline or died within the first 6 months.

Conclusions: We observed that supervised medical-cannabis treatment is associated with high adherence, improvement in quality of life, and a decrease in pain level with a low incidence of serious adverse events.”

https://pubmed.ncbi.nlm.nih.gov/35223923/


“This is a large study describing certain characteristics of medical cannabis users in a tightly regulated environment. The treatment appears to be safe and efficacious.”

https://www.frontiersin.org/articles/10.3389/fmed.2022.827849/full

Medical Cannabis for Gilles de la Tourette Syndrome: An Open-Label Prospective Study

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“Objectives: Assessing the effectiveness and tolerability of medical cannabis (MC) treatment on Gilles de la Tourette syndrome (GTS) patients.

Methods: We report on an open-label, prospective study on the effect of MC on adult GTS patients. MC mode of use was decided by the treating neurologist and the patient. Δ9-Tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) content within MC product and monthly dose were titrated during the study. Following treatment initiation, patients were assessed after 4 and 12 weeks for efficacy, tolerability, and side effects.

Results: Eighteen patients entered the study. Baseline Yale Global Tic Severity Scale- (YGTSS) Total (range 0-100) was 60.3 ± 17.1. Three patients did not reach the end of follow-up period. The most common mode of administration was smoking (80%). Following twelve weeks of treatment, a significant 38% average reduction (p = 0.002) of YGTSS-Total and a 20% reduction (p = 0.043) of Premonitory Urge for Tic Scale (PUTS) were observed. Common side effects were dry mouth (66.7%), fatigue (53.3%), and dizziness (46.7%). Three patients suffered from psychiatric side effects including worsening of obsessive compulsive disorder (stopped treatment), panic attack, and anxiety (resolved with treatment modification). Six patients (40%) reported cognitive side effects regarding time perception, visuospatial disorientation, confusion, slow processing speed, and attention.

Conclusions: MC treatment demonstrates good efficacy and tolerability in adult GTS patients. Predilection for smoking rather than using oil drops requires further comparative studies to evaluate the efficacy of each. Cognitive and psychiatric side effects have to be monitored and addressed.”

https://pubmed.ncbi.nlm.nih.gov/35310886/

“Our results are in line with a number of other studies suggesting that MC is effective and well tolerated in adults with GTS. From our data, it is suggested that MC might be a treatment option for resistant TS patients, and MC has a significant effect on tics, premonitory urges, and patients’ overall quality of life. In our sample, patients favored THC-rich cannabis strands and smoking/inhaling MC over sublingual oil.”

https://www.hindawi.com/journals/bn/2022/5141773/

Analogues of cannabinoids as multitarget drugs in the treatment of Alzheimer’s disease

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“Given that neuronal degeneration in Alzheimer’s disease (AD) is caused by the combination of multiple neurotoxic insults, current directions in the research of novel therapies to treat this disease attempts to design multitarget strategies that could be more effective than the simply use of acetylcholinesterase inhibitors; currently, the most used therapy for AD. One option, explored recently, is the synthesis of new analogues of cannabinoids that could competitively inhibit the acetylcholinesterase (AChE) enzyme and showing the classic neuroprotective profile of cannabinoid compounds. In this work, molecular docking has been used to design some cannabinoid analogues with such multitarget properties, based on the similarities of donepezil and Δ9-tetrahydrocannabinol. The analogues synthesized, compounds 1 and 2, demonstrated to have two interesting characteristics in different in vitro assays: competitive inhibition of AChE and competitive antagonism at the CB1/CB2 receptors. They are highly lipophilic, highlighting that they could easily reach the CNS, and apparently presented a low toxicity. These results open the door to the synthesis of new compounds for a more effective treatment of AD.”

https://pubmed.ncbi.nlm.nih.gov/33460612/

https://www.sciencedirect.com/science/article/abs/pii/S0014299921000285?via%3Dihub

Neuroprotection of retinal ganglion cells in vivo using the activation of the endogenous cannabinoid signaling system in mammalian eyes

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“Cannabinoid and glutamatergic signaling systems in the human retina coexist and greatly influence one another. Under glaucomatous conditions, excess levels of glutamate accrete in the retinal ganglion cell (RGC) layer. The present study tests the putative neuroprotective effect mediated by cannabinoids at the CB1 and CB2 receptors. In the first experiment, mice were given intravitreal injections of 160 nmol N-methyl-d-aspartic acid (NMDA) in one eye and saline in the paired eye. In the second experiment, both eyes were given NMDA, while one of the two was additionally given the cannabinoid agonist WIN 55,212-2. Ten days later, animals were perfused and the retinae were dissected as wholemounts and stained with Cresyl Violet. Quantitative analysis revealed that 70% of the neurons in the retinal ganglion cell (RGC) layer exposed to NMDA underwent cell death. The addition of the cannabinoid CB1/CB2 agonist doubled the number of neurons surviving the NMDA treatment. These data provide evidence that cannabinoids, either exogenous or endogenous, may be harnessed to provide protection from neurodegenerative diseases, including glaucoma, and from glutamate-induced, and potentially other forms of neurotoxicity, under chronic or acute conditions.”

https://pubmed.ncbi.nlm.nih.gov/35233292/

“In summary, we have demonstrated that the cannabimimetic drug, the CB1 and CB2 receptor agonist WIN55,212-2, acts to protect RGCs from NMDA-induced excitotoxicity in an in vivo mouse model. This further indicates the potential for therapeutic applications of cannabinoids in neurodegenerative diseases, including glaucoma.”

https://portlandpress.com/neuronalsignal/article/6/1/NS20210038/230703/Neuroprotection-of-retinal-ganglion-cells-in-vivo

Lower Rates of Hepatocellular Carcinoma Observed Among Cannabis Users: A Population-Based Study

“Background: Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and the fourth leading cause of cancer deaths in the world. The association between HCC and cannabis has been identified in mice; however, to our knowledge has not been identified in humans. Therefore, we aim to investigate the relation between HCC and cannabis use in humans.

Methods: Using data from the National Inpatient Sample (NIS) database between 2002 and 2014, we identified the patients with HCC and cannabis use diagnosis using the International Classification of Disease 9th version codes (ICD-9). Then, we identified patients without cannabis use as the control group. We adjusted for multiple potential confounders and performed multivariable logistic regression analysis to determine the association between cannabis abuse and HCC.

Results: A total of 101,231,036 patients were included in the study. Out of the total, 996,290 patients (1%) had the diagnosis of cannabis abuse versus 100,234,746 patients (99%) in the control group without cannabis abuse. We noticed that patients with cannabis abuse were younger (34 vs 48 years), had more males (61.7% vs 41.4%) and more African Americans (29.9% vs 14.2%) compared with the control group (P<0.001 for all). Besides, patients with cannabis use had more hepatitis B, hepatitis C, liver cirrhosis, and smoking, but had less obesity and gallstones, (P<0.001 for all). Using multivariable logistic regression, and after adjusting for potential confounders, patients with cannabis abuse were 55% less likely to have HCC (adjusted Odds Ratio {aOR}, 0.45, 95% Confidence Interval {CI}, 0.42-0.49, P<0.001) compared with patients without cannabis abuse.

Conclusion: Based on our large database analysis, we found that cannabis use patients were 55% less likely to have HCC compared to patients without cannabis use. Further prospective studies are needed to assess the role of cannabis use on HCC.”

“Our analysis revealed that cannabis users were 55% less likely to have HCC compared to non-cannabis users.”

https://www.cureus.com/articles/90568-lower-rates-of-hepatocellular-carcinoma-observed-among-cannabis-users-a-population-based-study