Therapeutic Potential of Cannabinoids in Counteracting Chemotherapy-induced Adverse Effects: An Exploratory Review

Early oral administration of THC:CBD formulations prevent pain-related behaviors without exacerbating paclitaxel-induced changes in weight, locomotion, and anxiety in a rat model of chemotherapy-induced neuropathy

RATIONALE

Paclitaxel-induced neuropathy stands out as the primary, dose-limiting side effect of this extensively used chemotherapy agent. Prolonged hypersensitivity and pain represent the most severe clinical manifestations. Effective preventive and therapeutic strategies are currently lacking.

OBJECTIVES

Our study aimed to assess the impact of early oral administration of pharmaceutical-grade formulations containing the phytocannabinoids THC and CBD in a rat model of paclitaxel-induced neuropathy.

METHODS

The experimental design involved the co-administration of paclitaxel and cannabinoid formulations with different THC to CBD ratios (THC:CBD 1:1 and THC:CBD 1:20) to adult male rats. Mechanical and thermal sensitivity, locomotor activity, vertical exploratory behaviors, anxiety-related parameters, weight gain, food and water consumption, and liver functionality were assessed.

RESULTS

Daily administration of THC:CBD 1:1 successfully prevented paclitaxel-induced cold allodynia, while THC:CBD 1:20 effectively prevented both thermal and mechanical hypersensitivities. Additionally, THC:CBD 1:1 formulation restored rearing behavior, significantly reduced by paclitaxel. Conversely, neither cannabinoid formulation was able to counteract paclitaxel-induced hypo-locomotion, reduced vertical exploratory activity, increased anxiety-like behaviors, attenuated weight gain, or decreased food and water intakes. However, the formulations employed did not induce further alterations or toxicity in animals receiving paclitaxel, and no signs of liver damage were detected.

CONCLUSIONS

Our results suggest a differential therapeutic effect of two THC:CBD formulations on pain-related behaviors and spontaneous activities, particularly in the context of peripheral neuropathy. These formulations represent a promising therapeutic strategy not only to managing pain but also for enhancing daily activities and improving the quality of life for cancer patients.

Investigation of the cytotoxicity induced by cannabinoids on human ovarian carcinoma cells

Cannabinoids have been shown to induce anti-tumor activity in a variety of carcinoma cells such as breast, prostate, and brain. The aim of the present study is to investigate the anti-tumor activity of cannabinoids, CBD (cannbidiol), and CBG (cannabigerol) in ovarian carcinoma cells sensitive and resistant to chemotherapeutic drugs. Sensitive A2780 cells and resistant A2780/CP70 carcinoma cells and non-carcinoma cells were exposed to varying concentrations of CBD, CBG, carboplatin or CB1 and CB2 receptor antagonists, AM251 and AM630, respectively, alone or in combination, at different exposure times and cytotoxicity was measured by MTT assay. The mechanism of action of CBD and CB in inducing cytotoxicity was investigated involving a variety of apoptotic and cell cycle assays. Treatment with CBD and CBG selectively, dose and time dependently reduced cell viability and induced apoptosis. The effect of CBD was stronger than CBG in all cell lines tested. Both CBD and CBG induced stronger cytotoxicity than afforded by carboplatin in resistant cells. The cytotoxicity induced by CBD was not CB1 or CB2 receptor dependent in both carcinoma cells, however, CBG-induced cytotoxicity may involve CB1 receptor activity in cisplatin-resistant carcinoma cells. A synergistic effect was observed when cannabinoids at sublethal doses were combined with carboplatin in both carcinoma cells. The apoptotic event may involve loss of mitochondrial membrane potential, Annexin V, caspase 3/7, ROS activities, and cell cycle arrest. Further studies are required to investigate whether these results are translatable in the clinic. Combination therapies with conventional cancer treatments using cannabinoids are suggested.

Potential, Limitations and Risks of Cannabis-Derived Products in Cancer Treatment

The application of cannabis products in oncology receives interest, especially from patients. Despite the plethora of research data available, the added value in curative or palliative cancer care and the possible risks involved are insufficiently proven and therefore a matter of debate. We aim to give a recommendation on the position of cannabis products in clinical oncology by assessing recent literature. Various types of cannabis products, characteristics, quality and pharmacology are discussed. Standardisation is essential for reliable and reproducible quality. The oromucosal/sublingual route of administration is preferred over inhalation and drinking tea. Cannabinoids may inhibit efflux transporters and drug-metabolising enzymes, possibly inducing pharmacokinetic interactions with anticancer drugs being substrates for these proteins. This may enhance the cytostatic effect and/or drug-related adverse effects. Reversely, it may enable dose reduction. Similar interactions are likely with drugs used for symptom management treating pain, nausea, vomiting and anorexia. Cannabis products are usually well tolerated and may improve the quality of life of patients with cancer (although not unambiguously proven). The combination with immunotherapy seems undesirable because of the immunosuppressive action of cannabinoids. Further clinical research is warranted to scientifically support (refraining from) using cannabis products in patients with cancer.

Scoping Review and Meta-Analysis Suggests that Cannabis Use May Reduce Cancer Risk in the United States

Introduction:Cannabis smoke contains carcinogens similar to tobacco, in addition to compounds with antitumor activity. Cannabis use reduces the risk of obesity and cannabinoids inhibit chronic inflammation, known causes of cancer. The net effect of Cannabis use on cancer risk is not known. Objective: To examine the association between Cannabis use and cancer risk in the United States. Methods: Identify and analyze published data on cancer risk in Cannabis users. Results: A total of 55 data points, consisting of risk ratios of cancer in Cannabis users and nonusers, were identified from 34 studies. Of these, 5 did not contain data essential for inclusion in the meta-analysis. The remaining data showed a nonsignificant trend to an association with reduced risk (relative risk [RR]=0.90, p>0.06, N=50) although heterogeneity is high (I2=72.4%). Removal of data with high risk of selection bias (defined as those from North Africa and those that failed to adjust for tobacco) and data with high risk of performance bias (defined as those with fewer than 20 cases or controls among Cannabis users) resulted in an RR <1.0 (RR=0.86, p<0.017, N=24) and large effect size (Hedges g=0.66), but did not decrease heterogeneity (I2=74.9). Of all cancer sites, only testicular cancer showed an RR value >1, although this was not significant and had a negligible effect size (RR=1.12, p=0.3, Hedges g=0.02). Following removal of testicular cancers the remaining data showed a decrease in risk (RR=0.87, p<0.025, N=41). Cancers of the head and neck showed a negative association with cancer risk (RR=0.83, p<0.05), with a large effect size (Hedges g=0.55), but high heterogeneity (I2=79.2%). RR did not reach statistical significance in the remaining cancer site categories (lung, testicular, obesity-associated, other). The data are consistent with a negative association between Cannabis use and nontesticular cancer, but there is low confidence in this result due to high heterogeneity and a paucity of data for many cancer types.

Natural Products Counteracting Cardiotoxicity during Cancer Chemotherapy: The Special Case of Doxorubicin, a Comprehensive Review

Cardiotoxicity is a frequent undesirable phenomenon observed during oncological treatment that limits the therapeutic dose of antitumor drugs and thus may decrease the effectiveness of cancer eradication. Almost all antitumor drugs exhibit toxic properties towards cardiac muscle. One of the underlying causes of cardiotoxicity is the stimulation of oxidative stress by chemotherapy. This suggests that an appropriately designed diet or dietary supplements based on edible plants rich in antioxidants could decrease the toxicity of antitumor drugs and diminish the risk of cardiac failure. This comprehensive review compares the cardioprotective efficacy of edible plant extracts and foodborne phytochemicals whose beneficial activity was demonstrated in various models in vivo and in vitro. The studies selected for this review concentrated on a therapy frequently applied in cancer, anthracycline antibiotic-doxorubicin-as the oxidative stress- and cardiotoxicity-inducing agent.

Topical Costus sp. Preparation as Palliative Care for Chemotherapy-Induced Peripheral Neuropathy of Patients: A Randomized Placebo-Controlled Pilot Trial

Objectives: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of various anticancer regimens with different sensory-motor abnormalities in patients. The aim of this study was to examine the feasibility of using Costus sp. oil as a palliative treatment in such patients. Design: This was a pilot randomized placebo-controlled double-blind clinical study. Settings/Location: Imam Hossein Hospital, Tehran, Iran. Subjects: Patients 18-80 years of age undergoing chemotherapy treatment recently or during the last 6 months were enrolled after meeting the inclusion criteria. Interventions: The intervention group used Costus sp. as a topical ointment and the placebo group used topical paraffin for 4 weeks. Outcome measures: Feasibility of recruitment, including treatment acceptability (evaluated as number of patients leaving the study early), and compliance (defined as consumption of a minimum 80% of the ointment) with the intervention were assessed. Neuropathic pain change was defined as the secondary outcome, too. Results: Totally, 50 out of 73 participants were identified eligible and were randomly divided into intervention or placebo groups. There was no significant difference between groups in terms of sociodemographic data. At the end of the study, 24% (confidence interval [95% CI]: 9-45) (intervention group) and 12% (95% CI: 2-31) (placebo group) of patients revealed treatment unacceptability. Meanwhile, 12% (95% CI: 2-31) in the intervention group and 28% (95% CI: 12-49) in the placebo group did not show the compliance. Moreover, according to patients' records, pain reduction was higher in the intervention group compared to the placebo group (p = 0.001). Conclusions: This preliminary study showed that topical use of Costus sp. was feasible and acceptable in patients suffering from CIPN.

Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review

BACKGROUND

Medicinal cannabis has received increased research attention over recent years due to loosening global regulatory changes. Medicinal cannabis has been reported to have potential efficacy in reducing pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and intractable childhood epilepsy. Yet its potential application in the field of psychiatry is lesser known.

METHODS

The first clinically-focused systematic review on the emerging medical application of cannabis across all major psychiatric disorders was conducted. Current evidence regarding whole plant formulations and plant-derived cannabinoid isolates in mood, anxiety, sleep, psychotic disorders and attention deficit/hyperactivity disorder (ADHD) is discussed; while also detailing clinical prescription considerations (including pharmacogenomics), occupational and public health elements, and future research recommendations. The systematic review of the literature was conducted during 2019, assessing the data from all case studies and clinical trials involving medicinal cannabis or plant-derived isolates for all major psychiatric disorders (neurological conditions and pain were omitted).

RESULTS

The present evidence in the emerging field of cannabinoid therapeutics in psychiatry is nascent, and thereby it is currently premature to recommend cannabinoid-based interventions. Isolated positive studies have, however, revealed tentative support for cannabinoids (namely cannabidiol; CBD) for reducing social anxiety; with mixed (mainly positive) evidence for adjunctive use in schizophrenia. Case studies suggest that medicinal cannabis may be beneficial for improving sleep and post-traumatic stress disorder, however evidence is currently weak. Preliminary research findings indicate no benefit for depression from high delta-9 tetrahydrocannabinol (THC) therapeutics, or for CBD in mania. One isolated study indicates some potential efficacy for an oral cannabinoid/terpene combination in ADHD. Clinical prescriptive consideration involves caution in the use of high-THC formulations (avoidance in youth, and in people with anxiety or psychotic disorders), gradual titration, regular assessment, and caution in cardiovascular and respiratory disorders, pregnancy and breast-feeding.

CONCLUSIONS

There is currently encouraging, albeit embryonic, evidence for medicinal cannabis in the treatment of a range of psychiatric disorders. Supportive findings are emerging for some key isolates, however, clinicians need to be mindful of a range of prescriptive and occupational safety considerations, especially if initiating higher dose THC formulas.

Role of cannabis in digestive disorders

Cannabis sativa, a subspecies of the Cannabis plant, contains aromatic hydrocarbon compounds called cannabinoids. [INCREMENT]-Tetrahydrocannabinol is the most abundant cannabinoid and is the main psychotropic constituent. Cannabinoids activate two types of G-protein-coupled cannabinoid receptors: cannabinoid type 1 receptor and cannabinoid type 2 receptor. There has been ongoing interest and development in research to explore the therapeutic potential of cannabis. [INCREMENT]-Tetrahydrocannabinol exerts biological functions on the gastrointestinal (GI) tract. Cannabis has been used for the treatment of GI disorders such as abdominal pain and diarrhea. The endocannabinoid system (i.e. endogenous circulating cannabinoids) performs protective activities in the GI tract and presents a promising therapeutic target against various GI conditions such as inflammatory bowel disease (especially Crohn's disease), irritable bowel syndrome, and secretion and motility-related disorders. The present review sheds light on the role of cannabis in the gut, liver, and pancreas and also on other GI symptoms, such as nausea and vomiting, cannabinoid hyperemesis syndrome, anorexia, weight loss, and chronic abdominal pain. Although the current literature supports the use of marijuana for the treatment of digestive disorders, the clinical efficacy of cannabis and its constituents for various GI disorders remains unclear.

Cannabinoid hyperemesis syndrome masquerading as an eating disorder

The case of a 22 year old woman with cannabinoid hyperemesis syndrome (CHS) presenting as an eating disorder is described. The importance of recognizing chronic cannabis use as a cause of episodic vomiting is emphasized, given that CHS can be confused with self-induced purging and cyclic vomiting. This case was further complicated by the well-defined history of anorexia nervosa (binge-purge type), major depressive disorder, obsessive-compulsive disorder, migraine headache, and the initial denial of cannabis use. However, collateral history and a positive drug screen confirmed the diagnosis. The signs, symptoms and pathophysiological mechanisms of CHS are reviewed in light of clinical presentations that mimic eating disorder phenomenology complicated by addiction. Given the trend for increasing legalization of recreational marijuana as well as medical marijuana, CHS is an important and potentially complicating disorder that eating disorder clinicians need to be aware of. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:826-829).

Recruitment, Follow-Up and Characteristics of HIV Infected Adults who Use Illicit Drugs in Southern Africa

BACKGROUND

With one of the worst HIV prevalence rates in the world, Botswana has made great strides in addressing AIDS. Nevertheless, to fully contain the epidemic, outreach to marginalized groups, including illicit drug users, is critical.

OBJECTIVE

To conduct targeted outreach within an intervention trial to recruit HIV-infected drug users and assess HIV disease and nutritional status.

METHOD

Recruitment strategies included safeguarding confidentiality, involving ocal health-care professionals, advertising, and participation incentives. Urine toxicology, CD4 cell count, HIV viral load, blood chemistry, plasma micronutrients, dietary history, drug use and morbidity were assessed for two years.

RESULTS

Targeted outreach identified 138 HIV-infected persons who used marijuana; 18.1% had CD4 cell counts ≤ 350 cells/μL and 39.9% had low BMI. Eligible marijuana users (N=52) had significantly lower BMI (21.8 3.7 vs. 24.3 ± 5.3 kg/m², P=0.001), higher HIV viral load (4.36 ± 0.89 vs. 4.09 ± 0.89 log₁₀, P=0.018), and higher kilocalorie intake (1924 ± 1055 vs. 1620 ± 926 Kcalories, P=0.025) than those who did not use marijuana (N=748) with similar CD4 cell count. Marijuana users ≥ 40 years old had more opportunistic diseases (P=0.020) than non-users of the same age. Benzodiazepine use was detected among 57 participants and they had higher BMI than marijuana users (24.4 ± 6.8 vs. 21.8 ± 3.7 kg/m², P= 0.017).

CONCLUSION

A population stigmatized by illicit drug use and HIV-infection can be brought into a clinical research setting in Africa. HIV-infected marijuana users were at a risk for higher HIV viral load, lower BMI and more comorbidities than nonusers. Outreach to this marginalized group is important for containing the HIV epidemic.