Article

Identification of cytochrome P450 enzymes responsible for metabolism of cannabidiol by human liver microsomes

June 2011
Life Sciences 89(5-6):165-70

DOI: 10.1016/j.lfs.2011.05.018

Source
PubMed

Authors:

Rongrong Jiang

CosMED Pharmaceutical Co. Ltd.,Japan, Kyoto

Satoshi Yamaori

Shinshu University

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Cannabidiol (CBD), one of the major constituents in marijuana, has been shown to be extensively metabolized by experimental animals and humans. However, human hepatic enzymes responsible for the CBD metabolism remain to be elucidated. In this study, we examined in vitro metabolism of CBD with human liver microsomes (HLMs) to clarify cytochrome P450 (CYP) isoforms involved in the CBD oxidations. Oxidations of CBD in HLMs and recombinant human CYP enzymes were analyzed by gas chromatography/mass spectrometry. CBD was metabolized by pooled HLMs to eight monohydroxylated metabolites (6α-OH-, 6β-OH-, 7-OH-, 1″-OH-, 2″-OH-, 3″-OH-, 4″-OH-, and 5″-OH-CBDs). Among these metabolites, 6α-OH-, 6β-OH-, 7-OH-, and 4″-OH-CBDs were the major ones as estimated from the relative abundance of m/z 478, which was a predominant fragment ion of trimethylsilyl derivatives of the metabolites. Seven of 14 recombinant human CYP enzymes examined (CYP1A1, CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) were capable of metabolizing CBD. The correlations between CYP isoform-specific activities and CBD oxidative activities in 16 individual HLMs indicated that 6β-OH- and 4″-OH-CBDs were mainly formed by CYP3A4, which was supported by inhibition studies using ketoconazole and an anti-CYP3A4 antibody. The correlation and inhibition studies also showed that CBD 6α-hydroxylation was mainly catalyzed by CYP3A4 and CYP2C19, whereas CBD 7-hydroxylation was predominantly catalyzed by CYP2C19. This study indicated that CBD was extensively metabolized by HLMs. These results suggest that CYP3A4 and CYP2C19 may be major isoforms responsible for 6α-, 6β-, 7-, and/or 4″-hydroxylations of CBD in HLMs.

Role of Cannabidiol for Improvement of the Quality of Life in Cancer Patients: Potential and Challenges

Article

Full-text available

Oct 2022
INT J MOL SCI

There is currently a growing interest in the use of cannabidiol (CBD) to alleviate the symptoms caused by cancer, including pain, sleep disruption, and anxiety. CBD is often self-administered as an over-the-counter supplement, and patients have reported benefits from its use. However, despite the progress made, the mechanisms underlying CBD’s anti-cancer activity remain divergent and unclear. Herein, we provide a comprehensive review of molecular mechanisms to determine convergent anti-cancer actions of CBD from pre-clinical and clinical studies. In vitro studies have begun to elucidate the molecular targets of CBD and provide evidence of CBD’s anti-tumor properties in cell and mouse models of cancer. Furthermore, several clinical trials have been completed testing CBD’s efficacy in treating cancer-related pain. However, most use a mixture of CBD and the psychoactive, tetrahydrocannabinol (THC), and/or use variable dosing that is not consistent between individual patients. Despite these limitations, significant reductions in pain and opioid use have been reported in cancer patients using CBD or CBD+THC. Additionally, significant improvements in quality-of-life measures and patients’ overall satisfaction with their treatment have been reported. Thus, there is growing evidence suggesting that CBD might be useful to improve the overall quality of life of cancer patients by both alleviating cancer symptoms and by synergizing with cancer therapies to improve their efficacy. However, many questions remain unanswered regarding the use of CBD in cancer treatment, including the optimal dose, effective combinations with other drugs, and which biomarkers/clinical presentation of symptoms may guide its use.

Pharmacokinetics of cannabidiol in a randomized crossover trial in senior horses

Article

Full-text available

Jul 2022

Objective: To determine the pharmacokinetics, bioavailability, and pharmacological effects of cannabidiol (CBD) in senior horses. Animals: 8 university-owned senior horses. Procedures: In this randomized, crossover study, horses were assigned to receive either a single oral dose of 2 mg/kg CBD in oil or a single IV dose of 0.1 mg/kg CBD in DMSO between August 10 and September 4, 2020. Blood samples were collected before and then 0.5, 1, 4, 8, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, and 264 hours after CBD administration. Serum biochemical analyses and CBCs were performed. Plasma concentrations of CBD and its metabolites were determined with the use of liquid chromatography-tandem mass spectrometry. Results: Concentrations of CBD and metabolites (7-COH CBD and 7-COOH CBD) were detected in all plasma samples up to 8 hours after dosing (oral and IV), with 7-COOH CBD being the most predominant metabolite. Pharmacokinetic results for CBD oral dosing at 2 mg/kg were mean ± SD half-life of 7.22 ± 2.86 hours, maximum concentration of 18.54 ± 9.80 ng/mL, and time to maximum concentration of 2.46 ± 1.62 hours. For both oral and IV administrations, 7-COOH CBD did not fall below the limit of quantification for the times reported. Oral bioavailability for CBD was 7.92%. There was no meaningful effect of CBD on results for CBC, serum biochemical analyses, or vital signs for any horse. Clinical relevance: Pharmacokinetics and bioavailability of CBD in senior horses were determined, and there were no adverse effects of administering either the oral or IV dose of CBD evaluated.

Label accuracy of unregulated cannabidiol (CBD) products: measured concentration vs. label claim

Article

Full-text available

Dec 2022

Background The legalization of hemp in the USA has led to tremendous growth in the availability of hemp-derived products, particularly cannabidiol (CBD) products. The lack of regulatory oversight in this industry has resulted in the marketing and sale of CBD products with questionable ingredients and quality. The aim of the current study was to examine the CBD content in 80 commercially available hemp-derived CBD products purchased from online and local retailers. Epidiolex® was also included in the study as a positive control. Methods Hemp-derived CBD products were selected to represent products readily available to residents of Central Kentucky. The samples were comprised of local and national brands produced in a variety of locations inside and outside of Kentucky. The products were analyzed by liquid chromatography-tandem mass spectrometry (LC–MS/MS), and the analytical findings were compared to the label claims for CBD content. Descriptive statistics and normal-based confidence intervals were calculated using Microsoft Excel. Results The label claims for CBD content ranged from 7.5 to 60 mg/mL, while LC–MS/MS analysis detected a range of 2.9 to 61.3 mg/mL. Of the 80 products evaluated, 37 contained CBD concentrations that were at least ± 10% different than the concentration listed on the label (range of 0.9 to 30.6 mg/mL from label claim) — 12 products contained < 90%, while 25 products contained > 110%. The degree of concordance for the samples tested using ± 10% tolerance from label claim was 54%. Conclusions These data suggest that additional regulation is required to ensure label accuracy as nearly half of the products in this study were not properly labelled (i.e., not within a ± 10% margin of error). Consumers and practitioners should remain cautious of unregulated and often-mislabeled CBD products due to the risks of taking too much CBD (e.g., drug-drug interactions, liver enzyme elevations, increased side effects) and the consequences of taking too little (e.g., no clinical benefits due to underdosing). The results of this study support the continued need for good manufacturing practices and testing standards for CBD products.

Phase I-metabolism studies of the synthetic cannabinoids PX-1 and PX-2 using three different in vitro models

Article

Full-text available

Dec 2021

Purpose Synthetic cannabinoids (SCs), highly metabolized substances, are rarely found unmodified in urine samples. Urine screening relies on SC metabolite detection, requiring metabolism knowledge. Metabolism data can be acquired via in vitro assays, e.g., human hepatocytes, pooled human liver microsomes (pHLM), cytochrome P450 isoforms and a fungal model; or in vivo by screening, e.g., authentic human samples or rat urine. This work describes the comprehensive study of PX-1 and PX-2 in vitro metabolism using three in vitro models. 5F-APP-PICA (PX-1) and 5F-APP-PINACA (PX-2) were studied as they share structural similarity with AM-2201, THJ-2201 and 5F-AB-PINACA, the metabolism of which was described in the literature. Methods For SC incubation, pHLM, cytochrome P450 isoenzymes and the fungal model Cunninghamella elegans LENDNER ( C. elegans ) were used. PX-1 and PX-2 in vitro metabolites were revealed comprehensively by liquid chromatography–high-resolution mass spectrometry measurements. Results In total, 30 metabolites for PX 1 and 15 for PX-2 were detected. The main metabolites for PX-1 and PX-2 were the amide hydrolyzed metabolites, along with an indole monohydroxylated (for PX-1) and a defluorinated pentyl-monohydroxylated metabolite (for PX-2). Conclusions CYP isoforms along with fungal incubation results were in good agreement to those obtained with pHLM incubation. CYP2E1 was responsible for many of the metabolic pathways; particularly for PX-1. This study shows that all three in vitro assays are suitable for predicting metabolic pathways of synthetic cannabinoids. To establish completeness of the PX-1 and PX-2 metabolic pathways, it is not only recommended but also necessary to use different assays.

Skin Applications of Cannabidiol: Sources, Effects, Delivery Systems, Marketed Formulations and Safety

Article

Full-text available

Mar 2023
Phytochemistry Rev

In recent decades, the therapeutic potential of cannabinoids and analogous compounds has been intensively investigated. The endocannabinoid system has already been identified in the skin and, although much remains to be discovered about its contribution and importance for the maintenance of skin homeostasis, it has been increasingly associated as promising for dermatological disorders’ management. Cannabidiol (CBD), the main non-intoxicating phytocannabinoid in cannabis, has been shown to have hydrating, sebostatic, antipruritic, antimicrobial, anti-inflammatory, antioxidant, wound healing, photoprotective, anti-fibrotic and antitumoral, as well as modulating hair growth. Thus, CBD has gained attention concerning its application in cutaneous pathologies such as atopic dermatitis, psoriasis, acne, epidermolysis bullosa, systemic sclerosis, seborrheic dermatitis, androgenetic alopecia and cutaneous melanoma, although its bioactivities still lack scientific evidence and some of its mechanisms of action remain to be elucidated. Given its physicochemical characteristics, its topical administration becomes challenging, and it is necessary to develop new technological strategies to overcome the skin intact barrier. This review describes the latest evidence that exists on the application of CBD to the skin, the problems inherent to its chemical structure and that compromise its cutaneous administration, and the different strategies and formulations that have been studied to improve it, also clarifying some CBD-containing cosmetics products that are already available on the market.

Enhanced Skin Penetration of Cannabidiol Using Organosilane Particles as Transdermal Delivery Vehicles

Article

Full-text available

Feb 2023

There is potential for cannabidiol to act as an analgesic, anxiolytic and antipsychotic active ingredient; however, there is a need to find alternate administration routes to overcome its low oral bioavailability. In this work, we propose a new delivery vehicle based on encapsulation of cannabidiol within organosilica particles as drug delivery vehicles, which are subsequently incorporated within polyvinyl alcohol films. We investigated the long-term stability of the encapsulated cannabidiol, as well as its release rate, in a range of simulated fluids with different characterization techniques, including Fourier Transform Infrared (FT-IR) and High-performance Liquid Chromatography (HPLC). Finally, we determined the transdermal penetration in an ex vivo skin model. Our results show that cannabidiol is stable for up to 14 weeks within polyvinyl alcohol films at a range of temperatures and humidity. Release profiles are first-order, consistent with a mechanism involving diffusion of the cannabidiol (CBD) out of the silica matrix. The silica particles do not penetrate beyond the stratum corneum in the skin. However, cannabidiol penetration is enhanced and is detected in the lower epidermis, which was 0.41% of the total CBD in a PVA formulation compared with 0.27% for pure CBD. This is partly due to an improvement of its solubility profile as it is released from the silica particles, but we cannot rule out effects of the polyvinyl alcohol. Our design opens a route for new membrane technologies for cannabidiol and other cannabinoid products, where administration via non-oral or pulmonary routes can lead to better outcomes for patient cohorts in a range of therapeutics.

A Phase I Randomized, Double-blind, Placebo-controlled Study on Efficacy and Safety Profile of a Sublingually Administered Cannabidiol /Delta 9-tetrahydrocannabidiol (10: 1) Regimen in Diabetes Type 2 Patients

Article

Full-text available

Feb 2023
IRAN J PHARM RES

: The current study aimed to evaluate the safety profile and efficacy of a cannabis-based sublingual spray, CBDEX10® (containing 100 µg cannabidiol and 10 µg Δ9-tetrahydrocannabinol per puff; CBD/Δ9-THC 10:1), in improving lipid profile and glycemic state of the diabetic patients. Fifty diabetic patients were randomly allocated to the treatment (n = 25; receiving two puffs of CBDEX10® twice daily) or the control groups (n = 25; receiving two puffs of placebo). The primary endpoint of the study was to evaluate the efficacy of the CBDEX10® adjunctive therapy in improving the lipid profile and glycemic state of diabetic patients; the secondary endpoint was to assess the safety profile and tolerability of the spray. A statistically significant decline in total cholesterol [estimated treatment difference (ETD) = −19.73 mg/dL; P < 0.05], triglyceride (ETD = −27.84 mg/dL; P < 0.01), LDL-C (ETD = −5.37 mg/dL; P < 0.01), FBS (ETD = −12 mg/dL; P < 0.01), HbA1c (ETD = −0.21 mg/dL; P < 0.01) and insulin secretion (ETD = -5.21 mIU/L; P < 0.01) was observable in the patients treated with CBDEX10® at the end of the 8-week treatment period. Regarding safety, the mentioned adjunctive regimen was well, and there were no serious or severe adverse effects. Overall, CBDEX10® sublingual spray could be a new therapeutic agent for lipid and glycemic control in diabetic patients.

An update of nano-based drug delivery systems for cannabinoids: Biopharmaceutical aspects & therapeutic applications

Article

Feb 2023
INT J PHARMACEUT

Nanotechnology has been widely used to improve stability, efficacy, release control and biopharmaceutical aspects of natural and synthetic cannabinoids. In this review, the main types of cannabinoid-based nanoparticles (NPs) reported so far are addressed, taking into account the advantages and disadvantages of each system. Formulation, preclinical and clinical studies performed with colloidal carriers were individually analyzed. Lipid-based nanocarriers have been recognized for their high biocompatibility and ability to improve both solubility and bioavailability. Δ9-tetrahydrocannabinol-loaded lipid systems designed to treat glaucoma, for example, showed superior in vivo efficacy in comparison to market formulations. The analyzed studies have shown that product performance can be modulated by varying particle size and composition. In the case of self-nano-emulsifying drug delivery systems, the reduced particle size shortens the time to reach high plasma concentrations while the incorporation of metabolism inhibitors extend the plasma circulation time. The use of long alkyl chain lipids in NP formulations, in turn, is strategized to achieve intestinal lymphatic absorption. Polymer NPs have been prioritized when a sustained or site-specific cannabinoid release is desirable (e.g., CNS-affecting diseases/cancer). The functionalization of the surface of polymer NPs makes their action even more selective whereas surface charge modulation is highlighted to provide mucoadhesion. The present study identified promising systems for targeted applications, making the process of optimizing new formulations more effective and faster. Although NPs have shown a promising role in the treatment of several difficult-to-treat diseases, more translational studies should be performed to confirm the benefits reported here.

Adverse Effects of Oral Cannabidiol: An Updated Systematic Review of Randomized Controlled Trials (2020-2022)

Article

Full-text available

Nov 2022

(1) Background: With the massive demand for the use and commercialization of medicinal cannabidiol (CBD) products, new randomized clinical trials (RCTs) are being published worldwide, with a constant need for safety and efficacy evaluation. (2) Methods: We performed an update on a systematic review published in 2020 that focused on analyzing the serious adverse effects (SAEs) of CBD in RCTs and its possible association with drug interactions. We also updated the report of the most prevalent CBD adverse effects (AEs). We systematically searched EMBASE, MEDLINE/PubMed, and Web of Science without language restriction for RCTs that reported adverse effects after repeated oral CBD administration for at least one week in healthy volunteers or clinical samples published from January 2019 to May 2022. The included studies were assessed for methodological quality by the Quality Assessment of Controlled Intervention Studies tool. The present review is registered on PROSPERO, number CRD42022334399. (3) Results: Twelve studies involving 745 randomized subjects analyzed were included (range 1.1–56.8 y). A total of 454 participants used CBD in the trials. The most common AEs of CBD were mild or moderate and included gastrointestinal symptoms (59.5%), somnolence (16.7%), loss of appetite (16.5%), and hypertransaminasemia (ALT/AST) (12.8%). Serious adverse effects include mainly hypertransaminasemia with serum levels elevations greater than three times the upper limit of the normal (6.4%), seizures (1.3%), and rash (1.1%). All SAEs reported in the studies were observed on CBD as an add-on therapy to anticonvulsant medications, including clobazam and valproate. (4) Conclusion: Recent RCTs involving oral CBD administration for at least a week suggest that CBD has a good safety and tolerability profile, confirming previous data. However, it can potentially interact with other drugs and its use should be monitored, especially at the beginning of treatment

A Systemic Review of Medical Cannabinoids Dosing in Human

Article

Dec 2022
CLIN THER

Purpose This systemic review assesses currently available clinical information on which cannabinoids and what range of doses have been used to achieve positive effects in a diversity of medical context. Methods The data were collected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol guidelines. Inclusion criteria were articles that assessed administration of any cannabinoid to any clinical population, reported in the ClinicalTrials.gov or PubMed databases, that involved a comparison with other treatment or placebo and a result measurement to assess the effectiveness or ineffectiveness of the cannabinoid. Exclusion criteria were review or letter; articles not in the English language; not full-text articles; not a clinical trial, case report, case series, open-label trial, or pilot study; administration in animals, in vitro, or in healthy participants; cannabinoids administered in combination with other cannabinoids (except for cannabidiol [CBD] or tetrahydrocannabinol [THC]) or as whole cannabis extracts; no stated concentration; inhalation or smoke as a route of administration; and no results described. The articles were assessed by the risk of bias. Finding In total, 1668 articles were recovered, of which 55 studies met the inclusion criteria for 21 diseases. Positive effects were reported in clinical studies: 52% with THC (range, 0.01–0.5 mg/kg/d [0.62–31 mg/d]), 74% with CBD (range, 1–50 mg/kg/d [62–3100 mg/d]), 64% with THC-CBD (mean, 1:1.3 mg/kg/d [ratio, 1:1]), and 100% with tetrahydrocannabivarin (THCV) (0.2 mg/kg/d). Implications THC, CBD, and THCV can regulate activity in several pathologies. New studies of cannabinoids are highly encouraged because each patient is unique and requires a unique cannabinoid medication.

Cover Image

Article

Full-text available

Nov 2022

The cover image is based on the Original Article Phytocannabinoids regulate inflammation in IL‐1β‐stimulated human gingival fibroblasts by Ammaar H. Abidi et al., https://doi.org/10.1111/jre.13050

Specific Gene Duplication and Loss of Cytochrome P450 in Families 1-3 in Carnivora (Mammalia, Laurasiatheria)

Article

Full-text available

Oct 2022

Cytochrome P450s are among the most important xenobiotic metabolism enzymes that catalyze the metabolism of a wide range of chemicals. Through duplication and loss events, CYPs have created their original feature of detoxification in each mammal. We performed a comprehensive genomic analysis to reveal the evolutionary features of the main xenobiotic metabolizing family: the CYP1-3 families in Carnivora. We found specific gene expansion of CYP2Cs and CYP3As in omnivorous animals, such as the brown bear, the black bear, the dog, and the badger, revealing their daily phytochemical intake as providing the causes of their evolutionary adaptation. Further phylogenetic analysis of CYP2Cs revealed Carnivora CYP2Cs were divided into CYP2C21, 2C41, and 2C23 orthologs. Additionally, CYP3As phylogeny also revealed the 3As’ evolution was completely different to that of the Caniformia and Feliformia taxa. These studies provide us with fundamental genetic and evolutionary information on CYPs in Carnivora, which is essential for the appropriate interpretation and extrapolation of pharmacokinetics or toxicokinetic data from experimental mammals to wild Carnivora.

Hyponatremic Cognitive Dysfunction Resulting from Drug-Drug-Gene Interaction between Sertraline and Cannabidiol in an Intermediate CYP2C19 Metabolizer Patient

Article

Full-text available

Sep 2022

Background: Pharmacogenomics (PGx) can provide more precision in determining causation of adverse drug reactions (ADRs) from drug-drug-gene interaction clinical application. Case Summary: Patient was an intermediate CYP2C19 metabolizer on stable therapy taking a low but therapeutic dose of sertraline for depression and anxiety over a period of 20 years. The patient then became hyponatremic and cognitively impaired after addition of cannabidiol (CBD) to this sertraline regimen. The proposed mechanism was drug-drug-gene interaction of CBD further inhibiting the CYP2C19 metabolism of sertraline and increasing drug exposure to produce moderate to severe hyponatremia and subsequent cognitive dysfunction. Practice Implications: Pharmacogenomics (PGx) testing may assist in etiology of patient symptoms from adverse drug reactions (ADRs) or drug-drug interactions by combining these with detection and application of drug-gene interactions. This case shows inhibition of CYP2C19 by CBD to further increase sertraline exposure, producing hyponatremia and subsequent cognitive dysfunction through CYP2C19 phenoconversion by CBD.

Long-term daily feeding of cannabidiol is well-tolerated by healthy dogs

Article

Full-text available

Sep 2022

Cannabidiol (CBD) containing dog food and treats are widely commercially available, mirroring the growing popularity of CBD as a supplement for humans. Despite this, experimental evidence of the safety and efficacy of long-term oral exposure in dogs is lacking. The purpose of this study was to address the gap in knowledge around the longer-term suitability and tolerance of a broad-spectrum CBD (THC-free) distillate in clinically healthy dogs. The study was a randomized, placebo-controlled, and blinded study where one group of twenty dogs received daily CBD capsules at a dose of 4 mg/kg of body weight (BW) for a period of 6 months. The control group of twenty dogs received placebo capsules. A comprehensive suite of physiological health measures was performed throughout the study at baseline, and after 2, 4, 10, 18, and 26 weeks of exposure, followed by 4 weeks of washout. CBD concentrations were measured at the same cadence in plasma, feces and urine. Health measures included biochemistry, hematology, urinalysis, in addition to fortnightly veterinary examinations, twice daily well-being observations, and a daily quality-of-life survey. Biochemistry and hematology showed no clinically significant alterations apart from a transient elevation in alkaline phosphatase (ALP) in just over half of the dogs receiving CBD. This elevation was observed in the absence of concurrent elevations of other liver parameters, and without any adverse effects on health and wellbeing. Furthermore, bone alkaline phosphatase (BALP) was simultaneously elevated with a significant, strong ( r > 0.9) positive correlation between the two measures, suggesting that the elevation of total ALP was at least partly due to the bone-derived isoform. This study provides evidence that a once-daily oral dose of 4 mg CBD/kg BW is well tolerated in clinically healthy dogs for a duration of 6-months.

Oral lipid-based drug delivery approaches to improve the intestinal lymphatic transport and systemic bioavailability of a highly lipophilic drug cannabidiol

Article

Jul 2022

Wanshan Feng

Lipid-based formulations play a significant role in oral delivery of lipophilic drugs. Previous studies have shown that natural sesame oil promotes the intestinal lymphatic transport and oral bioavailability of highly lipophilic drug cannabidiol (CBD). However, both lymphatic transport and systemic bioavailability were also associated with considerable variability. The first aim of this thesis was to test the hypothesis that pre-digested lipid formulations (oleic acid, linoleic acid, oleic acid with 2-oleoylglycerol, oleic acid with 2-oleoylglycerol and oleic acid with glycerol) could reduce variability and increase the extent of the intestinal lymphatic transport and oral bioavailability of CBD. In vivo studies in rats showed that pre-digested or purified triglyceride did not improve the lymphatic transport and bioavailability of CBD in comparison to sesame oil. Moreover, the results suggest that both the absorption of lipids and the absorption of co-administered CBD were more efficient following administration of natural sesame oil vehicle compared with pre-digested lipids or purified trioleate. However, this natural oil-based formulation also leads to considerable variability in absorption of CBD [1]. Therefore, the second approach in this thesis was to test the performance of lipid-based formulations with the addition of medium-chain triglyceride (MCT) or surfactants to the sesame oil vehicle in vitro and in vivo using CBD as a model drug. The in vitro lipolysis has shown that addition of the MCT leads to a higher distribution of CBD into the micellar phase. Further addition of surfactants to MCT-containing formulations did not improve distribution of the drug into the micellar phase. In vivo, formulations containing MCT led to lower or similar concentrations of CBD in serum, lymph and mesenteric lymph nodes (MLN), but with reduced variability. MCT improves the emulsification and micellar solubilisation of CBD, but surfactants did not facilitate further the rate and extent of lipolysis. Even though addition of MCT reduces the variability, the in vivo performance for the extent of both lymphatic transport and systemic bioavailability remains superior with a pure natural oil vehicle [2]. These results lead to the hypothesis that differences in composition of vegetable oils lead to differences in promotion of intestinal lymphatic transport of lipophilic drugs. Therefore, the differences in composition of sesame, sunflower, peanut, soybean, olive and coconut oils and their corresponding role as vehicles in promoting CBD lymphatic targeting and bioavailability were investigated in this thesis. The comparative analysis suggested that the fatty acids profile of vegetable oils is overall similar to the fatty acids profile in the corresponding chylomicrons in rat lymph. However, arachidonic acid (C20:4), was introduced to chylomicrons from endogenous nondietary sources in all cases. Overall, fatty acid composition of natural vegetable oils vehicles affected the intestinal lymphatic transport and bioavailability of CBD following oral administration in this work. Olive oil led to the highest concentration of CBD in the lymphatic system and systemic circulation and low variability in comparison to other natural vegetable oils following oral administration in rats. The natural rapeseed oil bodies also used as lipid-based vehicles to facilitate CBD oral bioavailability and lymphatic transport in this thesis. The oral bioavailability of CBD was 1.7-fold higher in oil bodies-based formulation than rapeseed oil-based formulation in rats. This finding indicates that oil bodies could potentially to improve lipophilic drug systemic exposure and lymphatic targeting in comparison to simple oils, and their other pharmaceutical properties as a drug delivery carrier needs to be further investigated. Overall in this thesis, olive oil and oil bodies are preferred lipid vehicles for improving intestinal lymphatic transport and bioavailability of co-administered CBD following oral administration.

Cannabidiol for the treatment of autism spectrum disorder: hope or hype?

Article

Full-text available

Jul 2022
PSYCHOPHARMACOLOGY

Rationale Autism spectrum disorder (ASD) is defined as a group of neurodevelopmental disorders whose symptoms include impaired communication and social interaction, restricted and repetitive patterns of behavior, and varying levels of intellectual disability. ASD is observed in early childhood and is one of the most severe chronic childhood disorders in prevalence, morbidity, and impact on society. It is usually accompanied by attention deficit hyperactivity disorder, anxiety, depression, sleep disorders, and epilepsy. The treatment of ASD has low efficacy, possibly because it has a heterogeneous nature, and its neurobiological basis is not clearly understood. Drugs such as risperidone and aripiprazole are the only two drugs available that are recognized by the Food and Drug Administration, primarily for treating the behavioral symptoms of this disorder. These drugs have limited efficacy and a high potential for inducing undesirable effects, compromising treatment adherence. Therefore, there is great interest in exploring the endocannabinoid system, which modulates the activity of other neurotransmitters, has actions in social behavior and seems to be altered in patients with ASD. Thus, cannabidiol (CBD) emerges as a possible strategy for treating ASD symptoms since it has relevant pharmacological actions on the endocannabinoid system and shows promising results in studies related to disorders in the central nervous system. Objectives Review the preclinical and clinical data supporting CBD’s potential as a treatment for the symptoms and comorbidities associated with ASD, as well as discuss and provide information with the purpose of not trivializing the use of this drug.

On-Line Solid Phase Extraction High Performance Liquid Chromatography Method Coupled With Tandem Mass Spectrometry for the Therapeutic Monitoring of Cannabidiol and 7-Hydroxy-cannabidiol in Human Serum and Saliva

Article

Full-text available

Jun 2022

Cannabidiol is a novel antiseizure medication approved in Europe and the US for the treatment of seizures associated with Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex. We describe in this article a new and simple liquid chromatography-mass spectrometry method (LC-MS/MS) for the determination of cannabidiol and its active metabolite 7-hydroxy-cannabidiol in microvolumes of serum and saliva (50 μl), to be used as a tool for therapeutic drug monitoring (TDM) and pharmacokinetic studies. After on-line solid phase extraction cannabidiol, 7-hydroxy-cannabidiol and the internal standard cannabidiol-d3 are separated on a monolithic C18 column under gradient conditions. Calibration curves are linear within the validated concentration range (10–1,000 ng/ml for cannabidiol and 5–500 ng/ml for 7-hydroxy-cannabidiol). The method is accurate (intraday and interday accuracy within 94–112% for cannabidiol, 91–109% for 7-hydroxy-cannabidiol), precise (intraday and interday precision <11.6% for cannabidiol and <11.7% for 7- hydroxy-cannabidiol) and sensitive, with a LOQ of 2.5 ng/ml for cannabidiol and 5 ng/ml for 7-hydroxy-cannabidiol. The stability of the analytes was confirmed under different storage conditions. Extraction recoveries were in the range of 81–129% for cannabidiol and 100–113% for 7-hydroxy-cannabidiol. The applicability of the method to TDM was demonstrated by analysis of human serum and saliva samples obtained from patients with epilepsy treated with cannabidiol.

Cannabidiol and the possibilities of its use in veterinary medicine of dogs and horses: A brief review

Article

Full-text available

Jun 2022
VET MED-CZECH

In connection with the use of cannabinoids for therapeutic purposes in human medicine, there is increased attention for their use in veterinary medicine, particularly by the owners of companion animals and horses. Therefore, veterinarians are expected to face this interest and have the corresponding knowledge on these substances. Presently, it is not possible to use medical marijuana (in terms of the dried cannabis flowers) for veterinary purposes in many countries, but there is increasing evidence that isolated cannabinoids also have beneficial effects (namely cannabidiol – CBD). Thus, this review summarises the possible therapeutic implications of CBD within the scope of evidence-based medicine, particularly in dogs and horses in association with the treatment of pain, epilepsy and anxiety in order to provide veterinarians with a concise overview of scientific findings in this field.

The Endocannabinoid System: A Potential Therapeutic Target for Coagulopathies

Article

Full-text available

Jun 2022

Abnormal blood coagulation or coagulopathy is a common manifestation of many pathological conditions. It occurs when there is an imbalance between the activities of the coagulation system and the fibrinolytic system, leading to excessive or impaired intravascular blood clot formation, which can disturb blood flow causing ischemia or hemorrhage in the affected tissues. A growing body of evidence has demonstrated blood coagulation abnormalities in association with cannabinoid use, suggesting the involvement of the endogenous cannabinoid system (ECS) in modulating blood coagulation. However, the evidence in the literature has been controversial on whether cannabinoids promote or inhibit blood coagulation. The ECS has been extensively studied in recent years for its potential as a therapeutic target for many diseases. This review provides a brief introduction to the ECS and discusses the reported anticoagulatory and procoagulatory effects of various cannabinoids, highlighting some possible mechanisms that might underlie the observed effects. Understanding the coagulatory effects of cannabinoids and the interaction between the coagulation system and the ECS is vital for developing novel therapeutics for coagulopathies.

Implications and quantifications of marijuana use regarding neonatal outcomes

Article

Full-text available

Jun 2022

Background : Legalization of marijuana is increasingly steadily which supports more widespread use and a growing perception of less risk of harm, however study of its effects on newborns when used by pregnant women is still lacking. Current physicians and health care practitioners are not fully informed to advise best practice regarding marijuana use during pregnancy. Additionally, methods to measure marijuana usage and effects are still limited and require further development, therefore assessment of whether not pregnant women should use marijuana products is timely and important. Methods : This paper questioned whether or not pregnant women should use marijuana products, firstly through review of available peer-reviewed literature. Secondly, by review of how its effects are quantified and captured, including International Disease Classification codes (ICD). Lastly, assessing the bioactivity of marijuana by in-silico analysis of the four key cannabinoids CBC, CBG, CBN and THC. Results : Findings of this study confirm that research the neonatal effects on offspring from pregnant women using marijuana is still non-conclusive and in many instances contradictory. This research field is highly confounded by multiple sociological, economic, political and experimental factors. Further complicated by the common use of alcohol, tobacco, and other drugs by marijuana. Conclusion : Therefore, more study quantifying the dose-effect relationship of marijuana in pregnant women and potential implications for their offspring is needed before safe use during pregnancy can be advised to avail of its apparent its positive benefits. Longer-term and follow-up studies are required to reduce confounding factors apparent in current studies relating to marijuana use. This study finds multiple adverse effects and bioactivities of marijuana could have neonatal implications. Therefore, the cessation of marijuana during pregnancy is recommended to provide the least risk and highest safety profile for mothers and their infants, until future research proves otherwise.

Effects of Cannabidiol on Locomotor Activity

Article

Full-text available

Apr 2022

Cannabidiol (CBD) is the second cannabinoid, in order of importance after Δ9-tetrahydrocannabinol (THC), from Cannabis sativa. Unlike THC, CBD does not cause psychotomimetic effects, and although these compounds have the same chemical formula, their pharmacological characteristics are not equivalent. Preclinical studies suggest that CBD has anti-inflammatory, analgesic, anxiolytic, antiemetic, anticonvulsant, and antipsychotic properties and influences the sleep–wake cycle. The evaluation of effects on spontaneous motor activity is crucial in experimental pharmacology, and the careful measurement of laboratory animal movement is an established method to recognize the effects of stimulant and depressant drugs. The potential influence of CBD on locomotor activity has been investigated through numerous in vivo experiments. However, there is no clear picture of the impact of CBD on these issues, even though it is administered alone for medical uses and sold with THC as a drug for pain caused by muscle spasms in multiple sclerosis, and it was recently licensed as a drug for severe forms of infantile epilepsy. On this basis, with the aim of developing deeper knowledge of this issue, scientific data on CBD’s influence on locomotor activity are discussed here. We conducted research using PubMed, Scopus, Google Scholar, and a search engine for literature between January 2009 and December 2021 on life sciences and biomedical topics using the keywords “motor activity”, “locomotor activity”, and “locomotion” in combination with “cannabidiol”. In this article, we discuss findings describing the effects on locomotor activity of the CBD precursor cannabidiolic acid and of CBD alone or in combination with THC, together with the effects of CBD on locomotor modifications induced by diseases and on locomotor changes induced by other substances.

A critical review of cannabis in medicine and dentistry: A look back and the path forward

Article

Full-text available

Apr 2022

Introduction: In the last two decades, our understanding of the therapeutic utility and medicinal properties of cannabis has greatly changed. This change has been accompanied by widespread cannabis use in various communities and different age groups, especially within the United States. With this increase, we should consider the potential effects of cannabis-hemp on general public health and how they could alter therapeutic outcomes. Material and methods: The present investigation examined cannabis use for recreational and therapeutic use and a review of pertinent indexed literature was performed. The focused question evaluates "how cannabis or hemp products impact health parameters and do they provide potential therapeutic value in dentistry, and how do they interact with conventional medicines (drugs)." Indexed databases (PubMed/Medline, EMBASE) were searched without any time restrictions but language was restricted to English. Results: The review highlights dental concerns of cannabis usage, the need to understand the endocannabinoid system (ECS), cannabinoid receptor system, its endogenous ligands, pharmacology, metabolism, current oral health, and medical dilemma to ascertain the detrimental or beneficial effects of using cannabis-hemp products. The pharmacological effects of pure cannabidiol (CBD) have been studied extensively while cannabis extracts can vary significantly and lack empirical studies. Several metabolic pathways are affected by cannabis use and could pose a potential drug interaction. The chronic use of cannabis is associated with health issues, but the therapeutic potential is multifold since there is a regulatory role of ECS in many pathologies. Conclusion: Current shortcomings in understanding the benefits of cannabis or hemp products are limited due to pharmacological and clinical effects not being predictable, while marketed products vary greatly in phytocompounds warrant further empirical investigation. Given the healthcare challenges to manage acute and chronic pain, this review highlights both cannabis and CBD-hemp extracts to help identify the therapeutic application for patient populations suffering from anxiety, inflammation, and dental pain.

Cannabidiol on the Path from the Lab to the Cancer Patient: Opportunities and Challenges

Article

Full-text available

Mar 2022

Cannabidiol (CBD), a major non-psychotropic component of cannabis, is receiving growing attention as a potential anticancer agent. CBD suppresses the development of cancer in both in vitro (cancer cell culture) and in vivo (xenografts in immunodeficient mice) models. For critical evaluation of the advances of CBD on its path from laboratory research to practical application, in this review, we wish to call the attention of scientists and clinicians to the following issues: (a) the biological effects of CBD in cancer and healthy cells; (b) the anticancer effects of CBD in animal models and clinical case reports; (c) CBD’s interaction with conventional anticancer drugs; (d) CBD’s potential in palliative care for cancer patients; (e) CBD’s tolerability and reported side effects; (f) CBD delivery for anticancer treatment.

Short term feeding of industrial hemp with a high cannabidiolic acid (CBDA) content increases lying behavior and reduces biomarkers of stress and inflammation in Holstein steers

Article

Full-text available

Mar 2022

Industrial hemp (IH) is defined as Cannabis sativa containing < 0.3% delta-9 tetrahydrocannabinol (THC) and was legalized in the 2018 Farm Bill. The impact of cannabinoids in IH fed to livestock, especially after repeat exposure, has not been thoroughly investigated. Sixteen male castrated Holstein cattle weighting (± SD) 447 ± 68 kg were enrolled onto the study. Cattle were allocated into two treatment groups either receiving IH (HEMP, n = 8) or a control (CNTL, n = 8). Cattle in the HEMP group were fed 25 g IH mixed in 200 g of grain once a day for 14 days to target a daily dose of 5.5 mg/ kg of cannabidiolic acid (CBDA). Behavior was continuously monitored with accelerometers and blood samples were collected at predetermined time points for plasma cannabinoid, serum cortisol, serum haptoglobin, liver enzymes, serum amyloid A, and prostaglandin E 2 concentrations. The HEMP group spent a mean 14.1 h/d (95% CI 13.6-14.6 h/d) lying compared to the 13.4 h/d (95% CI 12.9-13.8 h/d) for the CNTL cattle (P = 0.03). Cortisol concentrations in the HEMP group were lower than the CNTL group (P = 0.001). Cattle in the HEMP group demonstrated an 8.8% reduction in prostaglandin E 2 concentrations from baseline compared to a 10.2% increase from baseline observed in the CNTL group. No differences for haptoglobin or serum amyloid A were observed. These results suggest that feeding IH with a high CBDA content for 14 days increases lying behavior and decreases biomarkers of stress and inflammation in cattle.

Drug-Drug Interaction Between Orally Administered Hydrocodone-Acetaminophen and Inhalation of Cannabis Smoke: A Case Report

Article

Dec 2021
Hosp Pharm

Objective To determine if a 2-day protocol measuring pharmacokinetic and pharmacodynamic characteristics can demonstrate drug-drug interactions when smoked cannabis is added to orally administered hydrocodone/acetaminophen combination products. Case Summary A 51-year-old non-Hispanic white male with chronic pain diagnoses participated in a 2-day pilot protocol. The participant attended two 7-hour in-lab days where he received 10 blood draws each day and completed self-administered pain and anxiety surveys. For both days, the participant took his prescribed dose of hydrocodone/acetaminophen (1/2 tablet of 7.5 mg/325 mg combination product) with the addition of 1 smoked pre-rolled marijuana cigarette (labeled as 0.5 g; 22.17% Δ9-tetrahydrocannabinol; 0.12% cannabidiol) on Day 2. Blood specimens were analyzed using mass spectrometry to quantify the difference of plasma hydrocodone levels between Day 1 and Day 2. Results Compared to Day 1, lower levels of pain and anxiety were reported during Day 2 with the addition of cannabis to oral hydrocodone/acetaminophen. Day 2 pharmacokinetic analysis also revealed more rapid absorption and overall lower levels of hydrocodone in plasma. Discussion Lower hydrocodone plasma levels in Day 2 may indicate cannabis’s effect on metabolism and reduce the risk of opioid toxicity. The quicker absorption rate of hydrocodone could explain lower pain and anxiety scores reported on the second day. Conclusion and Relevance A 2-day protocol was able to capture differences across time in pharmacokinetic and pharmacodynamic measurements. Larger studies can be designed to better characterize the potential drug-drug interaction of cannabis and opioids.

In vitro effects of cannabidiol and its main metabolites in mouse and human Sertoli cells

Article

Dec 2021
FOOD CHEM TOXICOL

Cannabidiol (CBD) is a major cannabinoid present in extracts of the plant Cannabis sativa (marijuana). While the therapeutic effects of CBD on epilepsy have been demonstrated, less is understood regarding its potential adverse effects. Recent studies revealed that CBD induced toxicity in the male reproductive system of animal models. In this study, we used TM4, an immortalized mouse Sertoli cell line, and primary human Sertoli cells to evaluate the toxicities of CBD and its main metabolites, 7-carboxy-CBD and 7-hydroxy-CBD. CBD induced concentration- and time-dependent cytotoxicity in mouse and human Sertoli cells, which mainly resulted from the inhibition of the G1/S-phase cell cycle transition. CBD also inhibited DNA synthesis and downregulated key cell cycle proteins. Moreover, CBD reduced the mRNA and protein levels of a functional marker, Wilms’ tumor 1. Similar to CBD, 7-carboxy-CBD and 7-hydroxy-CBD inhibited cellular proliferation and decreased DNA synthesis. 7-Carboxy-CBD was less cytotoxic than CBD, while 7-hydroxy-CBD showed comparable cytotoxicity to CBD in both mouse and human Sertoli cells. Compared to mouse Sertoli cells, CBD, 7-hydroxy-CBD, and 7-carboxy-CBD were more cytotoxic in human Sertoli cells. Our results indicate that CBD and its main metabolites can inhibit cell proliferation in mouse and human Sertoli cells.

Biological activity of Cannabis compounds: a modern approach to the therapy of multiple diseases

Article

Full-text available

Oct 2021
Phytochemistry Rev

Cannabis spp. are some of the most controversial medicinal plants in the world. They contain great amounts of biologically active secondary metabolites, including the typical phenolic compounds called cannabinoids. Because of their low toxicity and complex biological activities, cannabinoids can be useful in the therapy of various diseases, but adverse psychological effects (of Δ9-THC in particular) raise concerns. This review summarizes the current knowledge of selected active C. indica compounds and their therapeutic potential. We summarize the main compounds contained in cannabis, the mechanisms of their effects, and their potential therapeutic applications. Further, we mention some of the clinical tests used to evaluate the efficacy of cannabinoids in therapy.

Cannabis Dopaminergic Effects Induce Hallucinations in a Patient with Parkinson’s Disease

Article

Full-text available

Oct 2021
MED LITH

Cannabis products that contain the tetrahydrocannabinol (THC) cannabinoid are emerging as promising therapeutic agents for the treatment of medical conditions such as chronic pain. THC elicits psychoactive effects through modulation of dopaminergic neurons, thereby altering levels of dopamine in the brain. This case report highlights the complexity associated with medicinal cannabis and the health risks associated with its use. A 57-year-old male with Parkinson’s disease was experiencing worsening tremors and vivid hallucinations despite therapy optimization attempts. It was discovered that the patient took cannabis for chronic back pain, and a pharmacogenomics (PGx) test indicated the presence of variants for the COMT and HTR2A genes. These variants could increase dopamine levels and predispose patients to visual hallucinations. Once the cannabis was discontinued, the patient’s hallucinations began to slowly dissipate. Cannabis use continues to expand as it gains more acceptance legally and medicinally, but cannabis can affect the response to drugs. This patient case suggests that cannabis use in combination with dopamine-promoting drugs, especially in a patient with genetic variants, can increase the risk for vivid hallucinations. These conditions support the importance of considering herb–drug interactions and PGx data when performing a medication safety review.

Genetic polymorphism of CYP2C19 and subcortical variability in the human adult brain

Article

Full-text available

Sep 2021

Pharmacogenetic studies have shown involvement of cytochrome P450 enzymes in the metabolism of psychotropic drugs. However, expression and activity on endogenous substrates in the brain may underlie a constitutive role of these enzymes beyond drug metabolism. CYP2C19, which is expressed in the human fetal brain during neurodevelopment, shows affinity for endogenous compounds including monoaminergic neurotransmitters, steroid hormones, and endocannabinoids. In this study ( N = 608), we looked at the genetic polymorphism of CYP2C19 and its potential associations with structural phenotypes of subcortical brain volume with structural imaging. Using two independent volume estimation techniques, we found converging evidence for a positive association between CYP2C19 activity scores, as inferred from the genotype, and basal ganglia and hippocampal volume. This association was present only in female individuals, raising the possibility that effects on brain morphology may arise through a mechanism involving the metabolism of estrogen steroids.

Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions

Article

Full-text available

Sep 2021

The legalization of cannabis in many parts of the United States and other countries has led to a need for a more comprehensive understanding of cannabis constituents and their potential for drug-drug interactions. While (-)-trans-Δ⁹-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) are the most abundant cannabinoids present in cannabis, THC metabolites are found in plasma at higher concentrations and for a longer duration than that of the parent cannabinoids. To understand the potential for drug-drug interactions, the inhibition potential of major cannabinoids and their metabolites on major hepatic cytochrome P450 (CYP) enzymes was examined. In vitro assays with CYP-overexpressing cell microsomes demonstrated that the major THC metabolites 11-hydroxy-∆9-tetra-hydrocannabinol (11-OH-THC) and 11-COO-Δ9-THC-glucuronide (THC-COO-Gluc) competitively inhibited several major CYP enzymes, including CYP2B6, CYP2C9, and CYP2D6 (apparent Ki,u values = 0.086 {plus minus} 0.066 µM and 0.90 {plus minus} 0.54 µM, 0.057 {plus minus} 0.044 µM and 2.1{plus minus} 0.81 µM, 0.15 {plus minus} 0.067 µM and 2.3 {plus minus} 0.54 µM, respectively). 11-nor-9-carboxy-Δ9- tetrahydrocannabinol (THC-COOH) exhibited no inhibitory activity against any CYP450 tested. THC competitively inhibited CYPs 1A2, 2B6, 2C9, and 2D6, CBD competitively inhibited CYPs 3A4, 2B6, 2C9, 2D6, and 2E1, and CBN competitively inhibited CYPs 2B6, 2C9, and 2E1. THC and CBD showed mixed-type inhibition for CYP2C19 and CYP1A2, respectively. These data suggest that cannabinoids and major THC metabolites are able to inhibit the activities of multiple CYP enzymes, and basic static modelling of these data suggest the possibility of pharmacokinetic interactions between these cannabinoids and xenobiotics extensively metabolized by CYP2B6, CYP2C9 and CYP2D6. Significance Statement Major cannabinoids and their metabolites found in the plasma of cannabis users inhibit several CYP enzymes, including CYP2B6, CYP2C9, and CYP2D6. This study is the first to show the inhibition potential of the most abundant plasma cannabinoid metabolite, THC-COO-Gluc, and suggests that circulating metabolites of cannabinoids play an essential role in CYP450 enzyme inhibition as well as drug-drug interactions.

Pharmacotherapy for Seizures in Tuberous Sclerosis Complex

Article

Aug 2021

Epilepsy is one of the main symptoms affecting the lives of individuals with tuberous sclerosis complex (TSC), causing a high rate of morbidity. Individuals with TSC can present with various types of seizures, epilepsies, and epilepsy syndromes that can coexist or appear in relation to age. Focal epilepsy is the most frequent epilepsy type with two developmental and epileptic encephalopathies: infantile spasms syndrome and Lennox–Gastaut syndrome. Active screening and early management of epilepsy is recommended in individuals with TSC to limit its consequences and its impact on quality of life, cognitive outcome and the economic burden of the disease. The progress in the knowledge of the mechanisms underlying epilepsy in TSC has paved the way for new concepts in the management of epilepsy related to TSC. In addition, we are moving from traditional “reactive” and therapeutic choices with current antiseizure medications used after the onset of seizures, to a proactive approach, aimed at predicting and preventing epileptogenesis and the onset of epilepsy with vigabatrin, and to personalized treatments with mechanistic therapies, namely mechanistic/mammalian target of rapamycin inhibitors. Indeed, epilepsy linked to TSC is one of the only epilepsies for which a predictive and preventive approach can delay seizure onset and improve seizure response. However, the efficacy of such interventions on long-term cognitive and psychiatric outcomes is still under investigation.

Medicinal Cannabis for Alzheimer's Disease

Chapter

Dec 2022

Alzheimer's disease (AD) is the most common form of dementia, and currently there is no cure. New therapeutic strategies that have the potential to address the complex pathophysiology of AD are urgently required; medicinal cannabis offers this possibility. Several potential leads can be extracted from Cannabis sativa (cannabis) that can target AD pathophysiology and alleviate symptoms, making it a prime candidate for AD drug discovery research. To date, most cannabis and AD research has focused on the major cannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), paying little attention to other plant constituents with therapeutic properties for AD. This chapter will highlight emerging evidence on the therapeutic potential of medicinal cannabis going beyond CBD and THC to discuss cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), cannabinoid acids, and other cannabinoid homologs, terpenes, and flavonoids that may have relevance to AD therapy. Further, the entourage effect, clinical implications, and directions for future research will be discussed.

Twice-daily oral administration of a cannabidiol and cannabidiolic acid-rich hemp extract was well tolerated in orange-winged Amazon parrots (Amazona amazonica) and has a favorable pharmacokinetic profile

Article

Full-text available

Feb 2023

Objective: To determine the pharmacokinetics of 8 cannabinoids and 5 metabolites after oral administration of single and multiple doses of a cannabidiol (CBD)-cannabidiolic acid (CBDA)-rich hemp extract to orange-winged Amazon parrots (Amazona amazonica) as well as to evaluate the extract's adverse effects. Animals: 12 birds. Procedures: Based on pilot studies, a single-dose study based on 30/32.5 mg/kg of cannabidiol/cannabidiolic acid of a hemp extract was administered orally to 8 fasted parrots, and 10 blood samples were collected over 24 hours after administration. After a 4-week washout period, the hemp extract was administered orally to 7 birds at the previous dose every 12 hours for 7 days, and blood samples were collected at the previous time points. Cannabidiol, Δ9-tetrahydrocannabinol, cannabinol, cannabichromene, cannabigerol, cannabidiolic acid, cannabigerolic acid, Δ9-tetrahydrocannabinolic acid, and 5 specific metabolites were measured by liquid chromatography-tandem/mass-spectrometry, and pharmacokinetic parameters were calculated. Adverse effects and changes in the plasma biochemistry and lipid panels were evaluated. Results: Pharmacokinetic parameters for cannabidiol, cannabidiolic acid, Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabinolic acid, and the metabolite 11-hydroxy-9-tetrahydrocannabinol were established. For the multiple-dose study, cannabidiol/cannabidiolic acid mean Cmax was 337.4/602.1 ng/mL with a tmax of 30 minutes and a terminal half-life of 8.6/6.29 hours, respectively. No adverse effects were detected during the multidose study. The predominant metabolite was 11-hydroxy-9-tetrahydrocannabinol. Clinical relevance: Twice daily oral administration of the hemp extract based on 30 mg/kg/32.5 mg/kg of cannabidiol/cannabidiolic acid was well tolerated and maintained plasma concentrations considered to be therapeutic in dogs with osteoarthritis. Findings suggest different cannabinoid metabolism from mammals.

Verifying in vitro‐determined enzyme contributions to cannabidiol clearance for exposure predictions in human through physiologically‐based pharmacokinetic modeling

Article

Full-text available

Dec 2022

Cannabidiol (CBD) is approved for treatment of seizures associated with two forms of epilepsy that become apparent in infancy or early childhood. To consider an adult physiologically based pharmacokinetic (PBPK) model for pediatric scaling, we assessed in vitro‐derived cytochrome P450 (CYP) and uridine 5´‐diphospho‐glucuronosyltransferase (UGT) enzyme contributions to CBD clearance in human. An IV PBPK model was constructed using CBD physicochemical properties and knowledge of disposition. IV datasets were used for model building and evaluation. Oral PBPK models for CBD administered in fasted and fed states were developed using single dose oral datasets and parameters optimized from the IV model and evaluated with multiple dose datasets. Relative contributions of CBD metabolizing enzymes were partitioned according to in vitro studies. Clinical drug‐drug interaction (DDI) studies were simulated using CBD fed state, itraconazole, fluconazole, and rifampicin PBPK models. Linear mixed effect modelling was used to estimate AUC0‐∞ perpetrator + CBD vs CBD alone. The IV and oral datasets used in model evaluation produced acceptable average fold error (AFE) of 1.28 and absolute AFE of 1.65. Relative contributions of drug‐metabolizing enzymes to CBD clearance were proposed from in vitro data: UGT1A7 4%, UGT1A9 16%, UGT2B7 10%, CYP3A4 38%, CYP2C19 21%, and CYP2C9 11%. The simulated DDI studies using the in vitro‐derived values produced mean AUC0‐∞ ratios comparable to observed: itraconazole 1.24 vs 1.07, fluconazole 1.45 vs 1.22, and rifampicin 0.49 vs 0.69. The constructed CBD PBPK models can predict adult exposures and have potential for use in pediatrics where exposure estimates are limited.

Advances and Challenges of Cannabidiol as an Anti-Seizure Strategy: Preclinical Evidence

Article

Full-text available

Dec 2022
INT J MOL SCI

The use of Cannabis for medicinal purposes has been documented since ancient times, where one of its principal cannabinoids extracted from Cannabis sativa, cannabidiol (CBD), has emerged over the last few years as a promising molecule with anti-seizure potential. Here, we present an overview of recent literature pointing out CBD’s pharmacological profile (solubility, metabolism, drug-drug interactions, etc.,), CBD’s interactions with multiple molecular targets as well as advances in preclinical research concerning its anti-seizure effect on both acute seizure models and chronic models of epilepsy. We also highlight the recent attention that has been given to other natural cannabinoids and to synthetic derivatives of CBD as possible compounds with therapeutic anti-seizure potential. All the scientific research reviewed here encourages to continue to investigate the probable therapeutic efficacy of CBD and its related compounds not only in epilepsy but also and specially in drug-resistant epilepsy, since there is a dire need for new and effective drugs to treat this disease.

Isobolographic analysis of adjunct Antiseizure activity of the FDA-approved cannabidiol with neurosteroids and benzodiazepines in adult refractory focal onset epilepsy

Article

Dec 2022
EXP NEUROL

Epilepsy is a serious neurological disorder associated with recurrent and unpredictable seizures and extensive neuropsychiatric comorbidities. There is no cure for epilepsy, and over one third of epileptic patients have been diagnosed with drug-refractory epilepsy, indicating the critical need for novel antiseizure medications (ASMs). Cannabidiol (CBD) has been shown to decrease seizures in pediatric epilepsies, such as Dravet and Lennox-Gastaut syndromes; however, it has not been rigorously tested for adult seizures or in models of refractory focal epilepsy. Although the exact mechanism is unknown, it is likely to act in a way that is unique to certain GABA-A receptor-modulating drugs, such as neurosteroids and benzodiazepines. In this study, we sought to determine the adjunct antiseizure activity of a clinical CBD product in an adult 6-Hz model of focal refractory epilepsy. CBD was evaluated alone in both a dose-response and time-course manner and in an adjunct combination with two ASMs ganaxolone (neurosteroid) and midazolam (benzodiazepine) against 6-Hz-induced refractory focal onset, generalized seizures. In pharmacological studies, CBD produced dose-dependent protection against seizures (ED50, 53 mg/kg, i.p.) without any side effects. CBD significantly reduced both electrographic activity and behavioral ictal responses with no apparent sex differences. CBD was evaluated in an isobologram design in conjunction with ganaxolone or midazolam at three standard ratios (1:1, 1:3, 3:1). Isobolographic analysis shows the combination regimens of CBD + ganaxolone and CBD+ midazolam exerted combination index of 0.313 and 0.164, indicating strong synergism for seizure protection, with little to no toxicity. Together, these results demonstrate the therapeutic potential of CBD monotherapy and as an adjunct therapy for adult focal refractory epilepsy in combination with GABAergic ASMs.

Pharmacodynamic synergism contributes to the antiseizure action of cannabidiol and clobazam

Article

Nov 2022
EXP NEUROL

The management of refractory epilepsy involves treatment with more than one antiseizure medication (ASM). Combination of ASMs with distinct mechanisms of action are hypothesized to improve overall treatment effectiveness. In clinical trials, concomitant use of cannabidiol (CBD) and clobazam (CLB) was associated with increased seizure reduction and bidirectional elevation in levels of their active metabolites, 7-hydroxy-cannabidiol (7-OH-CBD) and nor-clobazam (n-CLB). Using isobolographic analysis, we investigated whether CBD and CLB interacted pharmacodynamically. In the mouse maximal electroshock seizure (MES) test, brain tissue levels of CBD and CLB corresponding to seizure prevention in 50% of animals (brain Effective Exposure, bEE50) were 7.9 μM and 1.6 μM, respectively. In the 6 Hz psychomotor seizure model, 7-OH-CBD displayed a 5-fold greater potency than CBD (b-EE50, 8.7 μM vs 47.3 μM). Isobolographic analysis performed on combination of CBD/CLB at 1:1, 3:1, and 1:3 ratios based on equi-effective bEE50 values revealed synergism at all doses with combination indices (CI) of 0.43, 0.62 and 0.75 respectively. These outcomes were independent of pharmacokinetic interaction between CBD and CLB. These findings identify pharmacodynamic synergism as an important factor underlying enhanced antiseizure effect during concomitant CBD and CLB use.

Identification of Cannabidivarin Metabolites in Different Mouse Organs Using Ultra-Performance Liquid Chromatography Coupled to a Quadrupole Time-of-Flight Mass Spectrometer

Article

Nov 2022

Background and Objectives: As a natural analog of cannabidiol (CBD), nonpsychoactive cannabidivarin (CBDV) has therapeutic potential. However, the precise metabolism of CBDV either in vivo or in vitro has not been fully understood. Objective and Experimental Approach: Therefore, mice were intragastrically administered CBDV, and metabolite-rich and potential target organs and tissues were collected and analyzed by ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. The metabolic pathways of CBDV in mice were illustrated more comprehensively for the first time. Results: Twenty-one metabolites were found, all of which, except decarbonylated CBDV, were initially identified. Compared with CBD, the newly identified metabolic pathways were single dehydrogenation, combined decarbonylation and monohydroxylation, and glutathione conjugations of CBDV and its phase I metabolite. Conclusions: According to the very low response in plasma and the extremely high response in intestinal contents 1 h later after the administration, it was assumed that the oral bioavailability of CBDV was as poor as that of CBD, and the major forms to excrete were conjugates of glutathione and glucuronic acid. In contrast to CBDV, decarbonylated CBDV in the keto form and enol form had considerable responses in plasma and preferred to target fatty tissues and organs owing to their higher lipophilicity. Whether these forms can function as genuine active substances in vivo instead of CBDV is worthy of investigation. These results and supposes contribute notable information regarding the pharmacokinetics and pharmacodynamics of CBDV.

Pharmacokinetics of Cannabidiol in Sprague-Dawley Rats After Oral and Pulmonary Administration

Article

Oct 2022

Introduction: Cannabidiol (CBD) is primarily consumed through ingestion and inhalation. Little is known about how CBD pharmacokinetics differ between routes of administration, and duration of pulmonary exposure. Methods: Pharmacokinetics, brain distribution, and urinary elimination of CBD and its major metabolites (6-hydroxy-cannabidiol [6-OH-CBD], 7-hydroxy-cannabidiol [7-OH-CBD], 7-carboxy-cannabidiol [7-COOH-CBD], and CBD-glucuronide) were evaluated in adult Sprague-Dawley rats following a single oral CBD ingestion (10 mg/kg in medium chain triglyceride oil; 24 male animals), and 1 or 14 days of repeated inhalation (0.9-13.9 mg/kg in propylene glycol [41%/59% by weight]; 5 male and 5 female animals per dose). Blood and brain tissue were collected at a single time point from each animal. Collection times were staggered from 5 min to 24 h postoral gavage or first (blood only) and final inhalation. Urine was collected 24 h postoral gavage or final inhalation. Samples were analyzed through liquid chromatography-mass spectrometry (LC-MS/MS). Results: CBD was more rapidly absorbed following inhalation than ingestion (Tmax=5 min and 2 h, respectively). Inhalation resulted in a dose-responsive increase in CBD Cmax and AUClast. CBD Cmax was 24-fold higher following the highest pulmonary dose (13.9 mg/kg) versus an oral dose of comparable concentration (10 mg/kg). Cmax and AUClast (0-16 h) trended higher following repeated exposure. Elimination was notably faster with repeated CBD inhalation (t1/2=5.3 and 2.4 h on days 1 and 14, respectively). While metabolites were detectable in plasma, AUClast (0-2 h) was at least 10- (7-OH-CBD, 7-COOH-CBD) to 100- (6-OH-CBD) fold lower than the parent compound. Metabolite concentration trended higher following repeated inhalation (6.7 mg/kg CBD); AUClast (0-16 h) was ∼1.8-, ∼1.4-, and ∼2.4-fold higher following 14 days of exposure for 6-OH-CBD, 7-OH-CBD, and 7-COOH-CBD, respectively. CBD was detectable in brain homogenate tissue 24-h after 14-day inhalation (>3.5 mg/kg deposited dose) or a single oral administration. CBD metabolites were only measurable in brain tissue following the highest inhaled dose (13.9 mg/kg CBD). CBD, but not metabolites, was detectable in urine for all dose groups following 2 weeks of CBD inhalation. Neither CBD nor metabolites were present in urine after oral administration. Conclusion: CBD pharmacokinetics differ across oral and pulmonary routes of administration and acute or repeated dosing.

Metabolites of Cannabigerol Generated by Human Cytochrome P450s Are Bioactive

Article

Oct 2022
BIOCHEMISTRY-US

The phytocannabinoid cannabigerol (CBG) is the central biosynthetic precursor to many cannabinoids, including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Though the use of CBG has recently witnessed a widespread surge because of its beneficial health effects and lack of psychoactivity, its metabolism by human cytochrome P450s is largely unknown. Herein, we describe comprehensive in vitro and in vivo cytochrome P450 (CYP)-mediated metabolic studies of CBG, ranging from liquid chromatography tandem mass spectrometry-based primary metabolic site determination, synthetic validation, and kinetic behavior using targeted mass spectrometry. These investigations revealed that cyclo-CBG, a recently isolated phytocannabinoid, is the major metabolite that is rapidly formed by selected human cytochrome P450s (CYP2J2, CYP3A4, CYP2D6, CYP2C8, and CYP2C9). Additionally, in vivo studies with mice administered with CBG supported these studies, where cyclo-CBG is the major metabolite as well. Spectroscopic binding studies along with docking and modeling of the CBG molecule near the heme in the active site of P450s confirmed these observations, pointing at the preferred site selectivity of CBG metabolism at the prenyl chain over other positions. Importantly, we found out that CBG and its oxidized CBG metabolites reduced inflammation in BV2 microglial cells stimulated with LPS. Overall, combining enzymological studies, mass spectrometry, and chemical synthesis, we showcase that CBG is rapidly metabolized by human P450s to form oxidized metabolites that are bioactive.

Strategies for enhancing the oral bioavailability of cannabinoids

Article

Jul 2022

Introduction: Oral administration of cannabinoids is a convenient route of administration in many cases. To enhance the poor and variable bioavailability of cannabinoids, selected strategies utilizing proper delivery systems have been designed. Low solubility in the GI aqueous media is the first and most critical barrier. Thereafter, cannabinoids can reach the systemic blood circulation via the portal vein that is associated with significant hepatic first pass metabolism (FPM) or bypass it via lymphatic absorption. Areas covered: The solubility obstacle of cannabinoids is mainly addressed with lipid-based formulations such as self-nanoemulsifying drug delivery systems (SNEDDS). Certain lipids are used to overcome the solubility issue. Surfactants and other additives in the formulation have additional impact on several barriers, including dictating the degree of lymphatic bioavailability and hepatic FPM. Gastro-retentive formulation is also plausible. Expert opinion: Comparison of the role of the same SNEDDS formulation, cyclosporine vs. cannabinoids, when used to elevate the oral bioavailability of different compounds, is presented. It illustrates some similarities and major mechanistic differences obtained by the same SNEDDS. Thus, the different influence over the absorption pathway illuminates the importance of understanding the absorption mechanism and its barriers to properly select appropriate strategies to achieve enhanced oral bioavailability.

Metabolites of Cannabigerol (CBG) Generated by Human Cytochrome P450s are Bioactive

Preprint

Jul 2022

The phytocannabinoid cannabigerol (CBG) is the central biosynthetic precursor to many cannabinoids, including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Though the use of CBG has recently witnessed a widespread surge because of its beneficial health effects and lack of psychoactivity, its metabolism by human cytochrome P450s is largely unknown. Herein, we describe comprehensive in vitro and in vivo cytochrome P450 (CYP)-mediated metabolic studies of CBG, ranging from LC-MS/MS-based primary metabolic site determination, synthetic validation, and kinetic behavior using targeted mass spectrometry. These investigations revealed that cyclo-CBG, a recently isolated phytocannabinoid, is the major metabolite that is rapidly formed by selected human cytochrome P450s (CYP2J2, CYP3A4, CYP2D6, CYP2C8, and CYP2C9). Additionally, in vivo studies with mice administered with CBG, supported these studies, where cyclo-CBG is the major metabolite as well. Spectroscopic binding studies along with docking and modeling of CBG molecule near the heme in the active site of P450s confirmed these observations, pointing at the preferred site-selectivity of CBG metabolism at the prenyl chain over other positions. Importantly, we found out that CBG and its oxidized CBG metabolites reduced inflammation in BV2 microglial cells stimulated with LPS. Overall, combining enzymological studies, mass spectrometry, and chemical synthesis, we showcase that CBG is rapidly metabolized by human P450s to form oxidized metabolites that are bioactive. The study reveals the structure-activity relationship of CBG metabolites and analogs to their anti-inflammatory activity.

Physiologically-based pharmacokinetic model for predicting blood and tissue tetrahydrocannabinol concentrations

Research

Nov 2021

Prediction of Carboxylesterase 1 (CES1)-mediated In Vivo Drug Interaction between Methylphenidate and Cannabinoids using Static and Physiologically Based Pharmacokinetic Models

Article

May 2022

The use of cannabis products has increased substantially. Cannabis products have been perceived and investigated as potential treatments for attention-deficit/hyperactivity disorder (ADHD). Accordingly, co-administration of cannabis products and methylphenidate (MPH), a first-line medication for ADHD, is possible. Oral MPH undergoes extensive pre-systemic metabolism by carboxylesterase 1 (CES1), a hepatic enzyme which can be inhibited by two prominent cannabinoids, ∆9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This prompts further investigation into the likelihood of clinical interactions between MPH and these two cannabinoids through CES1 inhibition. In the present study, inhibition parameters were obtained from a human liver S9 system and then incorporated into static and physiologically-based pharmacokinetic (PBPK) models for prediction of potential clinical significance. The inhibition of MPH hydrolysis by THC and CBD was reversible, with estimated unbound inhibition constants (Ki,u) of 0.031 and 0.091 µM, respectively. The static model predicted a mild increase in MPH exposure by concurrent THC (34%) and CBD (94%) from smoking a cannabis cigarette and ingestion of prescriptive CBD, respectively. PBPK models suggested no significant interactions between single doses of MPH and CBD (2.5 - 10 mg/kg) when administered simultaneously, while a mild interaction (AUC increased by up to 55% and Cmax by up to 45%) is likely if multiple doses of CBD (10 mg/kg twice daily) are administered. In conclusion, the pharmacokinetic disposition of MPH can be potentially influenced by THC and CBD under certain clinical scenarios. Whether the magnitude of predicted interactions translates into clinically relevant outcomes requires verification in an appropriately designed clinical study. Significance Statement This work demonstrated a potential mechanism of drug-drug interactions between methylphenidate (MPH) and two major cannabinoids (∆9-tetrahydrocannabinol [THC] and cannabidiol [CBD]) not previously reported. We predicted a mild interaction between MPH and THC when the cannabinoid exposure occurred via cannabis smoking. Mild interactions between MPH and CBD were predicted with multiple oral administrations of CBD.

Para‐phenylenediamine deteriorates oocyte quality by impairing mitochondrial function

Article

Apr 2022

Several studies demonstrate that para‐phenylenediamine (PPD) is often added to permanent oxidative hair dyes. Sub‐chronic topical exposure to PPD in male rats damages their testicular function; however, little is known about the effects of PPD exposure on the female reproductive system, especially on oocyte quality. In this study, we found that PPD can affect the meiotic capacity of oocytes and their fertilization potential. In particular, PPD can damage the spindle/chromosome structure and prevent oocytes from developing and maturing normally. Furthermore, PPD exposure compromised the dynamics of cortical granules and their component, ovastacin. In addition to the protein level of Juno, the sperm receptors on the egg membrane, were substantially impaired in PPD‐administered oocytes, thus leading to fertilization failure. Finally, we found that PPD exposure resulted in abnormal mitochondrial function, which led to oocyte degeneration, apoptosis, and increased ROS levels. Altogether, our study illustrates that mitochondrial dysfunction and redox perturbation are the major causes of the poor quality of oocytes exposed to PPD.

Cannabinoid-Based Medicine: Pharmacology and Drug Interactions

Chapter

Feb 2022

Mellar P. Davis

Cannabis use for cancer symptom management is increasing and is becoming part of polypharmacy that patients with advanced cancer are often subjected to. Drug-drug interactions depend in part on the schedule of administration, absorption, method of administration, the capacity of either the drug and cannabinoids to inhibit CYP enzymes (inhibitory constant) or the ability to upregulate CYP enzymes. Phytocannabinoids and endocannabinoids are both metabolized by CYP450 enzymes, though endocannabinoids also have their own specific metabolic pathways. In general, endocannabinoids influence responses to various drug classes such as antiseizure medications, antidepressants, and opioids. Both tetrahydrocannabinol (THC) and cannabidiol (CBD) concentrations in blood are dependent on dose, diet(fat), route of administration, vehicle, and disease state. The more important cannabis-induced drug interactions are largely inhibitory in nature and encountered through the CYP2C family. Other drug interactions via immunomodulatory mechanisms have been shown to reduce efficacy of check-point inhibitors and are a reminder that cannabis use should be closely monitored in cancer patients.KeywordsCytochromeCompetitiveInhibitionDrug interactionsEndocannabinoidsAnandamide2-AGFAAHMAGLCheckpoint inhibitor

Comprehensive Predictions of Cytochrome P450 (P450)-Mediated In Vivo Cannabinoid-Drug Interactions Based on Reversible and Time-Dependent P450 Inhibition in Human Liver Microsomes

Article

Feb 2022
DRUG METAB DISPOS

We previously reported the unbound reversible (IC50,u) and time-dependent (KI,u) inhibition potencies of cannabidiol (CBD), delta-9-tetrahydrocannabinol (THC), and THC metabolites (11-OH THC, 11-COOH THC) against the major cytochrome P450 (CYP) enzymes (1A2, 2C9, 2C19, 2D6, 3A). Here, using human liver microsomes, we determined the CYP2A6, 2B6, and 2C8 IC50,u values of the aforementioned cannabinoids and the IC50,u and KI,u of the circulating CBD metabolites, 7-OH CBD and 7-COOH CBD, against all the CYPs listed above. The IC50,u of CBD, 7-OH CBD, THC, and 11-OH THC against CYP2B6 was 0.05, 0.34, 0.40, and 0.38 µM, respectively and against CYP2C8 was 0.28, 1.02, 0.67, and 4.37 µM, respectively. 7-COOH CBD, but not 11-COOH THC, was a weak inhibitor of CYP2B6 and 2C8. All tested cannabinoids except 11-COOH THC were weak inhibitors of CYP2A6. 7-OH CBD inhibited all CYPs examined (IC50,u<2.5 µM) except CYP1A2 and inactivated CYP2C19 and CYP3A, with inactivation efficiencies (kinact/KI,u) of 0.10 and 0.14 min-1µM-1, respectively. Using several different static models, we predicted the following maximum pharmacokinetic interactions (affected CYP probe drug and AUC ratio) between oral CBD (700 mg) and drugs predominantly metabolized by CYP3A (midazolam, 14.8) >2C9 (diclofenac, 9.6) >2C19 (omeprazole, 7.3) >1A2 (theophylline, 4.0) >2B6 (ticlopidine, 2.2) >2D6 (dextromethorphan, 2.1) >2C8 (repaglinide, 1.6). Oral (130 mg) or inhaled (75 mg) THC was predicted to precipitate interactions with drugs predominately metabolized by CYP2C9 (diclofenac, 6.6 or 2.3, respectively) >3A (midazolam, 1.8) >1A2 (theophylline, 1.4). In vivo drug interaction studies are warranted to verify these predictions. Significance Statement This study, combined with our previous findings, provides for the first time a comprehensive analysis of the potential for cannabidiol, delta-9-tetrahydrocannabinol, and their metabolites to inhibit cytochrome P450 enzymes in a reversible or time-dependent manner. These analyses enabled us to predict the potential of these cannabinoids to produce drug interactions in vivo at clinical or recreational doses.

Palmitoylethanolamide: A Potential Alternative to Cannabidiol

Article

Full-text available

Nov 2021

The endocannabinoid system (ECS) is a widespread cell signaling network that maintains homeostasis in response to endogenous and exogenous stressors. This has made the ECS an attractive therapeutic target for various disease states. The ECS is a well-known target of exogenous phytocannabinoids derived from cannabis plants, the most well characterized being Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). However, the therapeutic efficacy of cannabis products comes with a risk of toxicity and high abuse potential due to the psychoactivity of THC. CBD, on the other hand, is reported to have beneficial medicinal properties including analgesic, neuroprotective, anxiolytic, anticonvulsant, and antipsychotic activities, while apparently lacking the toxicity of THC. Nevertheless, not only is the currently available scientific data concerning CBD’s efficacy insufficient, there is also ambiguity surrounding its regulatory status and safety in humans that brings inherent risks to manufacturers. There is a demand for alternative compounds combining similar effects with a robust safety profile and regulatory approval. Palmitoylethanolamide (PEA) is an endocannabinoid-like lipid mediator, primarily known for its anti-inflammatory, analgesic and neuroprotective properties. It appears to have a multi-modal mechanism of action, by primarily activating the nuclear receptor PPAR-α while also potentially working through the ECS, thus targeting similar pathways as CBD. With proven efficacy in several therapeutic areas, its safety and tolerability profile and the development of formulations that maximize its bioavailability, PEA is a promising alternative to CBD.

Routes of Administration, Pharmacokinetics and Safety of Medicinal Cannabis

Chapter

Oct 2021

There are four main routes of administration of medicinal cannabis: inhalation, the oral route, topical applications and ‘other routes’ (eg. suppositories, intranasal delivery). Each is associated with different onsets of action and durations of action due to their pharmacokinetic profiles. There are some safety issues associated with cannabis. Many of the safety concerns such as associations between cannabis use and conditions such as cannabis use disorder and various mental health conditions that have been raised in the literature relate to recreational smoking of cannabis. Cannabis is associated with a range of negative side effects that are typically dose-dependent, most of which relate to the tetrahydrocannabinol (THC) component. Cannabidiol (CBD) has less serious side effects than THC. In general, CBD has been found to be well tolerated and safe and does not cause addiction. Both CBD and THC can potentially interact with a range of pharmaceuticals because they are metabolised by many of the cytochrome P450 enzymes that metabolise pharmaceuticals. Clinical trials in epilepsy in which high doses of CBD are used in conjunction with typically several anti-epileptic medications have demonstrated that side effects can occur with certain drugs. However, whether drug-cannabis interactions are common in clinical practice has not been well established.

Pharmacogenetic predictors of cannabidiol (CBD) response and tolerability in treatment‐resistant epilepsy

Article

Aug 2021

In patients with treatment‐resistant epilepsy (TRE), cannabidiol (CBD) produces variable improvement in seizure control. Patients in the University of Alabama at Birmingham CBD Expanded Access Program (EAP) were enrolled in the genomic study and genotyped using the Affymetrix Drug Metabolizing Enzymes and Transporters plus array. Associations between variants and CBD response (≥50% seizure reduction) and tolerability (diarrhea, sedation, abnormal liver function) was evaluated under dominant and recessive models. Expression quantitative trait loci (eQTL) influencing potential CBD targets was evaluated in Braineac, and genetic co‐expression examined. Of 169 EAP patients, 112 (54.5% pediatric; 50.0% female) were included in the genetic analyses. Patients with AOX1 rs6729738 CC (aldehyde oxidase; OR 6.69, 95%CI 2.19‐20.41; p=0.001) or ABP1 rs12539 (diamine oxidase; OR 3.96, 95%CI 1.62‐9.73; p=0.002) were more likely to respond. Conversely, patients with SLC15A1 rs1339067 TT had lower odds of response (OR 0.06, 95%CI 0.01‐0.56; p=0.001). ABCC5 rs3749442 was associated with lower likelihood of response and abnormal LFTs, and higher likelihood of sedation. EQTL revealed that rs1339067 decreased GPR18 expression (endocannabinoid receptor) in white matter (p=5.6x10‐3), and rs3749442 decreased hippocampal HTR3E expression (serotonin 5‐HT3E; p=8.5x10‐5). Furthermore, 75% of genes associated with lower likelihood of response were co‐expressed. Pharmacogenetic variation is associated with CBD response and influences expression of CBD targets in TRE. Implicated pathways, including cholesterol metabolism and glutathione conjugation, demonstrate potential interactions between CBD and common medications (e.g. statins, acetaminophen) that may require closer monitoring. These results highlight the role of pharmacogenes in fundamental biologic processes and potential genetic underpinnings of treatment‐resistance.

Pharmacology and Toxicology of Major Constituents of Marijuana—On the Metabolic Activation of Cannabinoids and Its Mechanism

Article

Full-text available

Nov 2003

Many oxidative metabolites of tetrahydrocannabinols (THCs), active components of Cannabis sativa L. (Cannabinaceae), were pharmacologically potent, and 11‐hydroxy‐THCs, 11‐oxo‐Δ8‐THC, 7‐oxo‐Δ8‐THC, 8β,9β‐epoxyhexahydrocannabinol (EHHC), 9α,10α‐EHHC and 3'‐hydroxy‐Δ9‐THC were more active than THC in pharmacological effects such as catalepsy, hypothermia and barbiturate synergism in mice, indicating that these metabolites are active metabolites of THCs. Cannabidiol (CBD), another major component, was biotransfomred to two novel metabolites, 6‐hydroxymethyl‐Δ9‐THC and 3‐pentyl‐6, 7, 7a, 8, 9, 11a‐hexahydro‐1, 7‐dihydroxy‐7,10‐dimethyldibenzo[b,d]oxepin (PHDO) through 8R,9‐epoxy‐CBD and 8S, 9‐epoxy‐CBD as intermediates, respectively, identified by us. Both metabolites have some pharmacological effects comparable to Δ9‐THC. Cannabinol (CBN), the other major component, was mainly metabolized to 11‐hydroxy‐CBN by hepatic microsomes of animals including humans. The pharmacological effects of the metabolite were higher than those of CBN demonstrating that 11‐hydroxylation of CBN is an activation pathway of the cannabinoid as is the case in THCs. Tolerance developed to catalepsy, hypothermia and pentobarbital‐induced sleep prolonging effects of Δ8‐THC and its active metabolite, 11‐hydroxy‐Δ8‐THC. Reciprocal cross‐tolerance also developed to pharmacological effects and the magnitude of tolerance development produced by the metabolite was significantly higher than that by Δ8‐THC indicating that 11‐hydroxy‐Δ8‐THC has important role not only in the pharmacological effects but also its tolerance development of Δ8‐THC. THCs and their metabolites competed with the specific binding of CP‐55,940, an agonist of cannabinoid receptor, to synaptic membrane from bovine cerebral cortex. The Ki value of THCs and their metabolites were closely parallel to their pharmacological effects in mice. A novel cytochrome P450 (cyp2c29) was purified and identified for the first time by us as a major enzyme responsible for the metabolic activation of Δ8‐THC at the 11‐position in the mouse liver. cDNA of cyp2c29 was cloned from a mouse cDNA library and its sequence was determined. All of major P450s involving the metabolic activation of Δ8‐THC at the 11‐position are belonging to CYP2C subfamily in mammalian liver.

Meta-analysis of the efficacy and safety of Sativex (nabiximols), on spasticity in people with multiple sclerosis

Article

Full-text available

Jun 2010
MULT SCLER

To determine the efficacy of Sativex (USAN: nabiximols) in the alleviation of spasticity in people with multiple sclerosis. The results from three randomized, placebo-controlled, double-blind parallel group studies were combined for analysis. 666 patients with multiple sclerosis and spasticity. A 0-100 mm Visual Analogue Scale (VAS, transformed to a 0-10 scale) or a 0-10 Numerical Rating Scale (0-10 NRS) was used to measure spasticity. Patients achieving a > or =30% improvement from baseline in their spasticity score were defined as 'responders'. Global impression of change (GIC) at the end of treatment was also recorded. The patient populations were similar. The adjusted mean change of the numerical rating scale from baseline in the treated group was -1.30 compared with -0.97 for placebo. Using a linear model, the treatment difference was -0.32 (95% CI -0.61, -0.04, p = 0.026). A statistically significant greater proportion of treated patients were responders (odds ratio (OR) = 1.62, 95% CI 1.15, 2.28; p = 0.0073) and treated patients also reported greater improvement: odds ratio 1.67 (95% CI 1.05, 2.65; p = 0.030). High numbers of subjects experienced at least one adverse event, but most were mild to moderate in severity and all drug-related serious adverse events resolved. The meta-analysis demonstrates that nabiximols is well tolerated and reduces spasticity.

Randomized Placebo-Controlled Double-Blind Clinical Trial of Cannabis-Based Medicinal Product (Sativex) in Painful Diabetic Neuropathy

Article

Full-text available

Oct 2009

To assess the efficacy of Sativex, a cannabis-based medicinal extract, as adjuvant treatment in painful diabetic peripheral neuropathy (DPN). In this randomized controlled trial, 30 subjects with painful DPN received daily Sativex or placebo. The primary outcome measure was change in mean daily pain scores, and secondary outcome measures included quality-of-life assessments. There was significant improvement in pain scores in both groups, but mean change between groups was not significant. There were no significant differences in secondary outcome measures. Patients with depression had significantly greater baseline pain scores that improved regardless of intervention. This first-ever trial assessing the efficacy of cannabis has shown it to be no more efficacious than placebo in painful DPN. Depression was a major confounder and may have important implications for future trials on painful DPN.

Metabolites of cannabidiol identified in human urine

Article

Full-text available

Apr 1990

1. Urine from a dystonic patient treated with cannabidiol (CBD) was examined by g.l.c.-mass spectrometry for CBD metabolites. Metabolites were identified as their trimethylsilyl (TMS), [2H9]TMS, and methyl ester/TMS derivatives and as the TMS derivatives of the product of lithium aluminium deuteride reduction. 2. Thirty-three metabolites were identified in addition to unmetabolized CBD, and a further four metabolites were partially characterized. 3. The major metabolic route was hydroxylation and oxidation at C-7 followed by further hydroxylation in the pentyl and propenyl groups to give 1"-, 2"-, 3"-, 4"- and 10-hydroxy derivatives of CBD-7-oic acid. Other metabolites, mainly acids, were formed by beta-oxidation and related biotransformations from the pentyl side-chain and these were also hydroxylated at C-6 or C-7. The major oxidized metabolite was CBD-7-oic acid containing a hydroxyethyl side-chain. 4. Two 8,9-dihydroxy compounds, presumably derived from the corresponding epoxide were identified. 5. Also present were several cyclized cannabinoids including delta-6- and delta-1-tetrahydrocannabinol and cannabinol. 6. This is the first metabolic study of CBD in humans; most observed metabolic routes were typical of those found for CBD and related cannabinoids in other species.

Pharmacokinetics and Metabolism of the Plant Cannabinoids, Δ 9-Tetrahydrocannibinol, Cannabidiol and Cannabinol

Article

Full-text available

Feb 2005
Handbook Exp Pharmacol

Marilyn A Huestis

Increasing interest in the biology, chemistry, pharmacology, and toxicology of cannabinoids and in the development of cannabinoid medications necessitates an understanding of cannabinoid pharmacokinetics and disposition into biological fluids and tissues. A drug’s pharmacokinetics determines the onset, magnitude, and duration of its pharmacodynamic effects. This review of cannabinoid pharmacokinetics encompasses absorption following diverse routes of administration and from different drug formulations, distribution of analytes throughout the body, metabolism by different tissues and organs, elimination from the body in the feces, urine, sweat, oral fluid, and hair, and how these processes change over time. Cannabinoid pharmacokinetic research has been especially challenging due to low analyte concentrations, rapid and extensive metabolism, and physicochemical characteristics that hinder the separation of drugs of interest from biological matrices—and from each other—and lower drug recovery due to adsorption of compounds of interest to multiple surfaces. Δ 9-Tetrahydrocannabinol, the primary psychoactive component of Cannabis sativa, and its metabolites 11-hydroxy-Δ 9-tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol are the focus of this chapter, although cannabidiol and cannabinol, two other cannabinoids with an interesting array of activities, will also be reviewed. Additional material will be presented on the interpretation of cannabinoid concentrations in human biological tissues and fluids following controlled drug administration.

In vitro metabolism of cannabidiol in seven common laboratory mammals

Article

Jan 1990

The metabolism of cannabidiol was studied in rat, mouse, rabbit, guinea pig, cat, gerbil and hamster. Metabolites were extracted from hepatic microsomal preparations with ethyl acetate, concentrated by chromatography on Sephadex LH-20 and examined as trimethylsilyl (TMS) and [2H9]TMS derivatives by GC/MS. The identified metabolites were mainly mono- and di-hydroxy compounds and their relative concentrations were found to differ considerably between the seven species. 10-Hydroxy-CBD was newly characterised by mass spectrometry; this compound was the major metabolite in the hamster. 7-Hydroxy-CBD was the major metabolite in the mouse, rat and rabbit whereas the gerbil and guinea-pig favoured hydroxylation at C-4''. The cat, on the other hand gave 6-hydroxy-CBD as the major metabolite. Low concentrations of new metabolites, dihydroxylated in the isopropenyl group were also identified in hamster and in the female rabbit: these appeared to have arisen from an intermediate epoxide.

Total syntheses of cannabidiol and Δ1-tetrahydrocannabinol metabolites

Article

Mar 1976
Perkin Trans 1

10-Hydroxycannabidiol [2-(10-hydroxy-p-mentha-1,8-dien-3-yl)-5-pentylresorcinol](Va), which has tentatively been identified as a cannabidiol metabolite, as well as 6α- and 6β-hydroxy-cannabidiol [(VIa) and (VIIa)], which are now reported to be metabolites, have been prepared from cannabidiol. Total syntheses of 7-hydroxycannabidiol triacetate (IIIb) and 7-acetoxy-Δ1-tetrahydrocannabinol (9-acetoxymethyl-6a,7,8,10a-tetrahydro-6,6-dimethyl-3-pentyl-6H-dibenzo[b,d]pyran-1-ol)(IIc) from p-mentha-1,8-dien-7-ol are described.

Zur Identifikation potentieller Metabolite von Cannabis‐Inhaltstoffen: Kernresonanz‐ und massenspektroskopische Untersuchungen an seitenkettenhydroxylierten Cannabinoiden

Article

Dec 1974
HELV CHIM ACTA

The 100-MHz-NMR-spectra of 11 side chain hydroxylated derivatives of cannabidiol (1), Δ6-tetrahydrocannabinol (2) and cannabinol (3) were analysed for signals specific for the position of hydroxyl groups. The mass spectra of these compounds and their trimethylsilyl ethers were investigated at ionisation voltages between 70 and 10 eV. The mass spectra of the non-silylated compounds showed no similarities independent on the basic type of cannabinoid but in the case of their trimethylsilyl ethers it was possible to derive fragmentations specific for the site of hydroxylation. These data are presented as a general method for the identification of small quantities of side chain hydroxylated in vitro and in vivo metabolites of cannabinoids.

8-Hydroxycannabinol: A new metabolite of cannabinol formed by human hepatic microsomes

Article

Dec 2006

Metabolism of cannabinol (CBN) was studied in vitro using hepatic microsomes from human livers. The metabolites formed were analyzed by thinlayer chromatography (TLC) and identified by gas chromatography-mass spectrometry as their trimethylsilyl derivatives. 11-Hydroxy-CBN, the major metabolite, was detected together with a smaller amount of another mono-hydroxylated metabolite. The minor metabolite was identified as 8-hydroxy-CBN, after comparing its Rf value by TLC, retention time by GC, and the mass spectrum with those of the authentic compound. 8-Hydroxy-CBN was confirmed to be a new metabolite of CBN formed by human hepatic microsomes.

Randomized controlled trial of Sativex to treat detrusor overactivity in multiple sclerosis

Article

Nov 2010
MULT SCLER

Bladder dysfunction is a common feature of multiple sclerosis (MS). Objective: In this study we aimed to assess the efficacy, tolerability and safety of Sativex(®) (nabiximols) as an add-on therapy in alleviating bladder symptoms in patients with MS. We undertook a 10-week, double-blind, randomized, placebo-controlled, parallel-group trial in 135 randomized subjects with MS and overactive bladder (OAB). The primary endpoint was the reduction in daily number of urinary incontinence episodes from baseline to end of treatment (8 weeks). Other endpoints included incidence of nocturia and urgency, overall bladder condition (OBC), daytime frequency, Incontinence Quality of Life (I-QOL), Patient's Global Impression of Change (PGIC) and volume voided. The primary endpoint showed little difference between Sativex and placebo. Four out of seven secondary endpoints were significantly in favour of Sativex: number of episodes of nocturia (adjusted mean difference -0.28, p = 0.010), OBC (-1.16, p = 0.001), number of voids/day (-0.85, p = 0.001) and PGIC (p = 0.005). Of the other endpoints, number of daytime voids was statistically significantly in favour of Sativex (-0.57, p = 0.044). The improvement in I-QOL was in favour of Sativex but did not reach statistical significance. Although the primary endpoint did not reach statistical significance, we conclude that Sativex did have some impact on the symptoms of overactive bladder in patients with MS, providing evidence of some improvement in symptoms associated with bladder dysfunction in these subjects.

A double-blind, randomized, placebo-controlled, parallel-group study of Sativex, in subjects with symptoms of spasticity due to multiple sclerosis

Article

Mar 2010
NEUROL RES

Muscle spasticity is common in multiple sclerosis (MS), occurring in more than 60% of patients. To compare Sativex with placebo in relieving symptoms of spasticity due to MS. A 15-week, multicenter, double-blind, randomized, placebo-controlled, parallel-group study in 337 subjects with MS spasticity not fully relieved with current anti-spasticity therapy. The primary endpoint was a spasticity 0-10 numeric rating scale (NRS). Intention-to-treat (ITT) analysis showed a non-significant improvement in NRS score, in favor of Sativex. The per protocol (PP) population (79% of subjects) change in NRS score and responder analyses (> or =30% improvement from baseline) were both significantly superior for Sativex, compared with placebo: -1.3 versus -0.8 points (change from baseline, p=0.035); and 36% versus 24% (responders, p=0.040). These were supported by the time to response (ITT: p=0.068; PP: p=0.025) analyses, carer global impression of change assessment (p=0.013) and timed 10-meter walk (p=0.042). Among the subjects who achieved a > or =30% response in spasticity with Sativex, 98, 94 and 73% reported improvements of 10, 20 and 30%, respectively, at least once during the first 4 weeks of treatment. Sativex was generally well tolerated, with most adverse events reported being mild-to-moderate in severity. The 0-10 NRS and responder PP analyses demonstrated that Sativex treatment resulted in a significant reduction in treatment-resistant spasticity, in subjects with advanced MS and severe spasticity. The response observed within the first 4 weeks of treatment appears to be a useful aid to prediction of responder/non-responder status.

Identification of monohydroxylated metabolites of cannabidiol formed by rat liver

Article

May 1976

Cannabidiol (CBD) was metabolized in vitro by rat liver enzymes. Unchanged CBD and eight monohydroxylated metabolites were isolated and positively identified. As previously reported, 7-hydroxy-CBD was the major metabolite. The second most abundant metabolite was 6alpha-hydroxy-CBD; whereas only a trace amount of 6beta-hydroxy-CBD was found. In addition hydroxylation occurred in all positions of the pentyl side chain, 4 inches-hydroxy-CBD being most abundant. 3 inches-Hydroxy-CBD was formed in half of the yield of 4 inches-hydroxy-CBD, while 1 inches-, 2 inches-, 5 inches-hydroxy-CBD were each formed in approximately one fourth of the yield of 4 inches-hydroxy-CBD.

Dioxygenated metabolites of cannabidiol formed by rat liver

Article

Sep 1976

The metabolism of cannabidiol (CBD) was studied in vitro using a 10 000 g supernatant from rat liver. After removal of unchanged CBD and its monohydroxylated metabolites, a polar fraction remained from which ten dioxygenated metabolites were isolated. Mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify the following metabolites: 6,7-dihydroxy-CBD, 1 inch,7-dihydroxy-CBD, 3 inch,7-dihydroxy-CBD, 4 inch,7-dihydroxy-CBD, 5 inch,7-dihydroxy-CBD, 2 inch,6-dihydroxy-CBD, 3 inch,6beta-dihydroxy-CBD, 4 inch, 6beta-dihydroxy-CBD (tentative), 3 inch-hydroxy-6-oxo-CBD, and 4 inch-hydroxy-6-oxo-CBD. The abundance of isolated dihydroxy metabolites reflected the quantity of monohydroxy metabolites that was previously found. In both series, 7-hydroxylation occurred to the greatest extent. Side chain hydroxylation occurred predominantly at C-4 inch and to a lesser degree at C-3 inch. Trace amounts of metabolites were hydroxylated at C-1 inch,-2 inch, or 5 inch.

Biotransformation of cannabidiol in mice. Identification of new acid metabolites

Article

May 1977

The in vivo metabolism of cannabidiol (CBD) was investigated in mice. Following the ip administration of CBD to mice, livers were removed and metabolites were extracted with ethyl acetate prior to partial purification on Sephadex LH-20 columns. Fractions from the columns were converted into trimethylsilyl, d9-trimethylsilyl, and methylester-trimethylsilyl derivatives for analysis by gas-liquid chromatography-mass spectrometry. In addition, metabolites containing carboxylic acid and ketone functional groups were reduced to alcohols with lithium aluminum deuteride before trimethylsilation. A total of 22 metabolites were characterized, 14 of which had not been reported previously. The metabolites could be categorized as follows: monohydroxylated (N=2), dihydroxylated (N=3), CBD-7-oic acid, side chain hydroxy-GBD-7-oic acids (N=3), side-chain acids (N=3), 7-hydroxy-side-chain acids (N=4), 6-oxo-side-chain acids (N=3) and glucuronide conjugates (N=3). The most significant biotransformations were glucuronide conjugation and, to a lesser extent, formation of CBD-7-oic acid.

Synthesis and psychotropic activity of side-chain hydroxylated Δ 6-tetrahydrocannabinol metabolites

Article

Feb 1979

Syntheses of the five side chain mono-hydroxylated Δ 6-tetrahydrocannabinol derivatives are described. On the basis of behavioural tests with these compounds in rhesus monkeys, it was concluded that hydroxylation at the benzylic C-1' position sharply reduces 'Cannabis tup' activity annabis ttypactivity as compared to Δ 6-THC; that on C-2' causes some reduction in activity, whereas hydroxylations at the other positions cause no changes.

Total synthesis of cannabidiol and delta1-tetrahydrocannabinol metabolites

Article

Feb 1976
Perkin Trans 1

10-Hydroxycannabidiol [2-(10-hydroxy-p-mentha-1,8-dien-3-yl)-5- pentylresorcinol] (Va), which has tentatively been identified as a cannabidiol metabolite, as well as 6α- and 6β-hydroxy-cannabidiol [(VIa) and (VIIa)], which are now reported to be metabolites, have been prepared from cannabidiol. Total syntheses of 7-hydroxycannabidiol triacetate (IIIb) and 7-acetoxy-Δ1-tetrahydrocannabinol (9-acetoxymethyl-6a,7,8,10a- tetrahydro-6,6-dimethyl-3-pentyl-6H-dibenzo[b,d]pyran-1-ol) (IIc) from p-mentha-1,8-dien-7-ol are described.

Anticonvulsant activity of four oxygenated cannabidiol derivatives

Article

Oct 1975
Res Comm Chem Pathol Pharmacol

A pharmacological comparison between cannabidiol (CBD) and four CBD derivatives, namely CBD-aldehyde-diacetate (I), 6-oxo-CBD-diacetate (II), 6-hydroxy-CBD-tri-acetate (III), and 9-hydroxy-CBD-triacetate (IV) was carried out in mice. Protection against maximal electroshock convulsions, potentiation of pentobarbital sleeping-time and reduction of spontaneous motor activity were the effects measured. All 5 compounds were equally potent in potentiating barbiturate sleeping time at doses ranging from 6.25 to 100 mg/kg. At 12.5 and 25 mg/kg only CBD and IV were able to decrease significantly the spontaneous motor activity. CBD, II, III and IV were also active in protecting mice against electroconvulsive shock at doses of 100-200 mg/kg, although at the larger dose CBD and compound II were the most efficient. Compound I was toxic, killing about half of the animals within 24 h after injection.

Catalytic activity of cytochrome P450 isozymes purified from rat liver in converting 11-oxo-Δ8-tetrahydrocannabinol to Δ8-tetrahydrocannabinol-11-oic acid

Article

Sep 1991
BIOCHEM PHARMACOL

Cytochrome P450 isozymes purified from rat hepatic microsomes were able to catalyse the oxidation of 11-oxo-delta 8-tetrahydrocannabinol (11-oxo-delta 8-THC) to delta 8-THC-11-oic acid in the presence of NADPH, cytochrome P450 reductase and dilauroylphosphatidylcholine. The catalytic activities (nmol/min/nmol P450) of cytochrome P450s, UT-2 (IIC11), UT-4 (IIA2), UT-5 (IIC13), PB-1, PB-2 (IIC6), PB-4 (IIB1), MC-1 (IA2), MC-5 (IA1) and IF-3 (IIA1), were 0.69, 0.08, 0.07, 0.23, 0.46, 0.02, 0.06, 0.07 and 0.34, respectively, whereas the activities of cytochrome P450s, PB-5 (IIB2) and DM (IIE1), were less than 0.02 nmol/min/nmol P450. Cytochrome P450 IIC11 showed the highest catalytic activity of the cytochromes examined. The mechanism for the oxidation of 11-oxo-delta 8-THC to delta 8-THC-11-oic acid by cytochrome P450 IIC11 was established as being an oxygenation since one atom of oxygen-18 was exclusively incorporated into the carboxylic acid formed under 18O2. The antibody raised to cytochrome P450 IIC11 inhibited by 60% the hepatic microsomal oxidation of 11-oxo-delta 8-THC to delta 8-THC-11-oic acid in male rats. These results indicate that cytochrome P450 IIC11 is a major form of the cytochrome to catalyse the oxidation of 11-oxo-delta 8-THC to delta 8-THC-11-oic acid in the hepatic microsomes of male rats and that the oxidation of aldehyde to carboxylic acid is a catalytic activity common to most isozymes of P450.

Purification and characterization of the major hepatic cannabinoid hydroxylase in the mouse: A possible member of the cytochrome P-450IIC subfamily

Article

Sep 1991

Acute cannabidiol treatment of mice inactivated hepatic microsomal cytochrome P-450IIIA (P-450IIIA) and markedly inhibited in vitro cannabinoid metabolism. Antibodies raised against purified P-450IIIA inhibited the microsomal formation of quantitatively minor cannabinoid metabolites but had no effect on the major metabolites. Cannabinoid hydroxylation to the major metabolites was used as a functional probe to isolate and purify a P-450 (termed P-450THC) from hepatic microsomes of untreated mice. The purified protein had an apparent molecular weight of 47,000 and a specific content of 15.4 nmol/mg and exhibited an absorbance maximum at 452 nm for the reduced carbon monoxide complex. NH2-terminal sequence analysis of the first 16 residues of P-450THC suggests that it is a member of the P-450IIC subfamily, because its sequence is 85 and 69% identical to published sequences of rat hepatic P-450IIC7 and P-450IIC6, respectively. P-450THC exhibited high activity for cannabinoid hydroxylation and specifically produced 6 alpha- and 7-hydroxy-delta 1-tetrahydrocannabinol, as well as 6 alpha-, 7-, and 4"-hydroxycannabidiol. Unlike anti-P-450IIIA antibody, antibody raised against purified P-450THC markedly inhibited the microsomal formation of all major cannabinoid metabolites. Similar immunoinhibition studies also revealed the existence of orthologs of mouse P-450THC and P-450IIIA in human liver microsomes. Thus, cannabidiol treatment of mice resulted in the inactivation of at least two constitutive P-450 isozymes, which together account for the majority of the detected cannabinoid metabolites.

Structure-Activity Relationships of the Cannabinoids

Article

Jul 1986

R K Razdan

Despite the extensive knowledge about the pharmacological actions of cannabinoids, the two most promising therapeutic areas of Δ9-THC, i.e., antiemetic and antiglaucoma activities, were discovered serendipitously without any preclinical pharmacology. This emphasizes the importance of early studies in humans and the difficulties encountered in correlating animal activity with activity in man for this class of compounds. The role of cannabinoids as antinauseants to patients undergoing cancer chemotherapy is now well established. Δ9-THC has recently been approved by the Food and Drug Administration (FDA) for marketing in the USA, and a synthetic analog, Nabilone, is already marketed in Europe. In the antiglaucoma field, the utility of Δ9-THC as a novel agent has been established, and several synthetic analogs are presently in the developmental stage. From pharmacological screening of cannabinoids, a separation of several specific pharmacological actions has been noted in different derivatives, but the relevance of these to humans is not presently clear. Hopefully, with the introduction of more sophisticated pharmacological screens and with the extended clinical usage of Δ9-THC and Nabilone, there will be a resurgence of interest in this field. Other areas of therapeutic use will become evident, and the potential of this class of novel drugs will begin to emerge. A parallel can be drawn between the opioid and the cannabinoids, since morphine and Δ9-THC both are drugs of abuse. To use the opioid work as a guide, the cannabinoids are at present in their early stages of development, comparable to morphine before the discovery of nalorphine. However, it should be emphasized that the concept of drug development from THCs and cannabinoids is based on very sound foundations, since, unlike morphine, Δ9-THC has a remarkably low toxicity in animals and humans. In addition, it has practically no respiratory-depressant activity, none or very low physical dependence liability, and, finally, a unique pharmacological profile compared to other psychoactive drugs.

Forensic Chemical Study on Marihuana. I. A Detection Method of the Principal Constituents by Thin-layer and Gas Chromatographies

Article

Jun 1968

A new solvent system benzene-n-hexane-diethylamine (25 : 10 : 1), was found to show a good separation of cannabidiol, tetrahydrocannabinol and cannabinol in hemp resin by thin-layer chromatography, in which Rf-values of three constituents were 0.45, 0.35 and 0.25, respectively. Furthermore, the same solvent system was successfully applied to silica gel column chromatography for isolation of three constituents of hemp resin. Using cocaine hydrochloride as an internal standard of gas chromatography, relative retention times of cannabidiol, tetrahydrocannabinol and cannabinol were calculated to be 1.76, 2.34 and 2.88, respectively. Six kinds of hemps grown in India, U.S.A. and Japan, were quantitatively analyzed using gas chromatography, and against a common opinion, Japanese hemps were found to contain considerable amounts of tetrahydrocannabinol, a physiologically active constituent.

Involvement of CYP2C in the Metabolism of Cannabinoids by Human Hepatic Microsomes from an Old Woman.

Article

Sep 1995

The hepatic microsomal metabolism of cannabinoids was studied using the liver from an old woman. delta 8-Tetrahydrocannabinol, delta 9-tetrahydrocannabinol and cannabinol were biotransformed to their respective 11-hydroxy metabolites by a microsomal fraction with specific activities (pmol/min/mg protein) of 29.1, 47.1 and 27.9, respectively. In addition, both 11-oxo-delta 8-tetrahydrocannabinol and 11-oxo-delta 9-tetrahydrocannabinol were metabolized to the corresponding carboxylic acids with the microsomes. An antibody against mouse CYP2C29 almost completely inhibited 11-hydroxylation of the cannabinoids and microsomal aldehyde oxygenase (MALDO) activity for 11-oxo-delta 8-tetrahydrocannabinol and 11-oxo-delta 9-tetrahydrocannabinol, used as substrates, whereas an antibody against rat CYP3A2 conversely stimulated the 11-hydroxylation of delta 8-tetrahydrocannabinol and MALDO activity for 11-oxo-delta 8-tetrahydrocannabinol. The results indicate that a member of CYP2C is primarily responsible for the metabolism of the above cannabinoids in the human hepatic microsomes.

Effects of Freezing, Thawing, and Storing Human Liver Microsomes on Cytochrome P450 Activity

Article

Aug 1996

The stability of cytochrome P450 enzymes, cytochrome b5, and NADPH-cytochrome c reductase was examined in (A) human liver samples frozen in liquid nitrogen and stored at -80 degrees C, (B) human liver microsomes suspended in 250 mM sucrose and stored at -80 degrees C, and (C) human liver microsomes subjected to as many as 10 cycles of thawing and freezing. In study A, microsomes from five human livers were prepared from fresh (unfrozen) tissue and from tissue that was stored frozen at -80 degrees C for 1, 2, 4, or 6 months. The apparent concentration of cytochromes P450 and b5 and the activity of NADPH-cytochrome c reductase decreased 20-40% as a result of freezing the liver, regardless of whether the liver was stored for 1 or 6 months. Similar decreases were observed in the activities of cytochrome P450 enzymes belonging to several gene families, namely CYP1A2 (7-ethoxyresorufin O-dealkylation and caffeine N3-demethylation), CYP2A6 (coumarin 7-hydroxylation), CYP2C9 (tolbutamide methylhydroxylation), CYP2C19 (S-mephenytoin 4'- hydroxylation), CYP2D6 (dextromethorphan O-de-methylation), CYP2E1 (chlorzoxazone 6-hydroxylation), CYP3A4solidus5 (testosterone 6beta-hydroxylation), and CYP4A9solidus11 (lauric acid 12-hydroxylation). Freezing human liver did not convert cytochrome P450 to its inactive form, cytochrome P420, but it increased the contamination of liver microsomes with hemoglobin or other heme-containing proteins, which resulted in a uniform decrease in the specific activity of cytochromes P450 and b5 and in the specific activity of all P450 enzymes. In study B, the concentration of cytochromes P450 and b5, the activity of NADPH-cytochrome c reductase, and the activity of individual cytochrome P450 enzymes were determined in 10 samples of human liver microsomes stored at -80 degrees C for approximately 0, 1, or 2 years. The sample-to-sample variation in the concentration and activity of cytochrome P450, cytochrome b5, and NADPH-cytochrome c reductase was nominally affected by long-term storage of human liver microsomes at -80 degrees C, indicating there was no differential loss of cytochrome P450 activity, cytochrome b5 concentration, or NADPH-cytochrome c reductase activity. In study C, microsomes from a pool of human livers were subjected to 1, 2, 3, 5, 7, or 10 cycles of freezing at -80 degrees C followed by thawing at room temperature. Freezing/thawing liver microsomes for up to 10 cycles did not convert cytochrome P450 to P420, nor did it cause significant loss of CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4/5, or CYP4A9/11 activity. Overall, these results suggest that our current methods for storing and processing human liver are well suited to preserving microsomal P450 enzyme activity.

In vitro inhibition and induction of human hepatic cytochrome P450 enzymes by modafinil

Article

Jun 2000

The ability of modafinil to affect human hepatic cytochrome P450 (CYP) activities was examined in vitro. The potential for inhibition of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4/5, and CYP4A9/11 by modafinil (5-250 microM) was evaluated with pooled human liver microsomes. Modafinil exhibited minimal capacity to inhibit any CYP enzyme, except CYP2C19. Modafinil inhibited the 4'-hydroxylation of S-mephenytoin, a marker substrate for CYP2C19, reversibly and competitively with a K(i) value of 39 microM, which approximates the steady-state C(max) value of modafinil in human plasma at a dosage of 400 mg/day. No irreversible inhibition of any CYP enzyme was observed, and there was no evidence of metabolism-dependent inhibition. The potential for induction of CYP activity was evaluated by exposing primary cultures of human hepatocytes to modafinil (10-300 microM). Microsomes were then prepared and assayed for CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5 activities. The mean activities of microsomal CYP1A2, CYP2B6, and CYP3A4/5 from modafinil-treated hepatocytes were higher (up to 2-fold) than those in the solvent-treated controls but were less than those produced by reference inducers of these enzymes. At high concentrations of modafinil (>/=100 microM), the mean activity of CYP2C9 was decreased (up to 60%) relative to that in the solvent controls. Overall, modafinil was shown to have effects on human hepatic CYP1A2, CYP2B6, CYP2C9, CYP2C19, and CYP3A4/5 activities in vitro. Although effects obtained in vitro are not always predictive of effects in vivo, such results provide a rational basis for understanding drug-drug interactions that are observed clinically and for planning subsequent investigations.

Metabolism of (+)- and (-)-Limonenes to Respective Carveols and Perillyl Alcohols by CYP2C9 and CYP2C19 in Human Liver Microsomes

Article

Jun 2002

Limonene, a monocyclic monoterpene, is present in orange peel and other plants and has been shown to have chemopreventive activities. (+)- and (-)-Limonene enantiomers were incubated with human liver microsomes and the oxidative metabolites thus formed were analyzed using gas chromatography-mass spectrometry. Two kinds of metabolites, (+)- and (-)-trans-carveol (a product by 6-hydroxylation) and (+)- and (-)-perillyl alcohol (a product by 7-hydroxylation), were identified, and the latter metabolites were found to be formed more extensively, the former ones with liver microsomes prepared from different human samples. Sulfaphenazole, flavoxamine, and antibodies raised against purified liver cytochrome P450 (P450) 2C9 that inhibit both CYP2C9- and 2C19-dependent activities, significantly inhibited microsomal oxidations of (+)- and (-)-limonene enantiomers. The limonene oxidation activities correlated well with contents of CYP2C9 and activities of tolbutamide methyl hydroxylation in liver microsomes of 62 human samples, whereas these activities did not correlate with contents of CYP2C19 and activities of S-mephenytoin 4-hydroxylation. Of 11 recombinant human P450 enzymes (expressed in Trichoplusia ni cells) tested, CYP2C8, 2C9, 2C18, 2C19, and CYP3A4 catalyzed oxidations of (+)- and (-)-limonenes to respective carveols and perillyl alcohol. Interestingly, human CYP2B6 did not catalyze limonene oxidations, whereas rat CYP2B1 had high activities in catalyzing limonene oxidations. These results suggest that both (+)- and (-)-limonene enantiomers are oxidized at 6- and 7-positions by CYP2C9 and CYP2C19 in human liver microsomes. CYP2C9 may be more important than CYP2C19 in catalyzing limonene oxidations in human liver microsomes, since levels of the former protein are more abundant than CYP2C19 in these human samples. Species-related differences exist in the oxidations of limonenes in CYP2B subfamily in rats and humans.

Cannabidiol: An Overview of Some Pharmacological Aspects

Article

Nov 2002

Over the past few years, considerable attention has focused on cannabidiol (CBD), a major nonpsychotropic constituent of cannabis. The authors present a review on the chemistry of CBD and discuss the anticonvulsive, antianxiety, antipsychotic, antinausea, and antirheumatoid arthritic properties of CBD. CBD does not bind to the known cannabinoid receptors, and its mechanism of action is yet unknown. It is possible that, in part at least, its effects are due to its recently discovered inhibition of anandamide uptake and hydrolysis and to its antioxidative effect.

Conversion of the HIV protease inhibitor nelfinavir to a bioactive metabolite by human liver CYP2C19

Article

Jan 2005

Antiretroviral therapy for human immunodeficiency virus (HIV) infection includes treatment with both reverse transcriptase inhibitors and protease inhibitors, which markedly suppress viral replication and circulating HIV RNA levels. Cytochrome P450 (P450) enzymes in human liver, chiefly CYP3A4, play a pivotal role in protease inhibitor biotransformation, converting these agents to largely inactive metabolites. However, the protease inhibitor nelfinavir (Viracept) is metabolized mainly to nelfinavir hydroxy-t-butylamide (M8), which exhibits potent antiviral activity, and to other minor products (termed M1 and M3) that are inactive. Since indirect evidence suggests that CYP2C19 underlies M8 formation, we examined the role of this inducible, polymorphic P450 enzyme in nelfinavir t-butylamide hydroxylation by human liver. Rates of microsomal M8 formation were 50.6 +/- 28.3 pmol of product formed/min/nmol P450 (n = 5 subjects), whereas kinetic analysis of the reaction revealed a KM of 21.6 microM and a Vmax of 24.6 pmol/min/nmol P450. In reconstituted systems, CYP2C19 catalyzed nelfinavir t-butylamide hydroxylation at a turnover rate of 2.2 min(-1), whereas CYP2C9, CYP2C8, and CYP3A4 were inactive toward nelfinavir. Polyclonal anti-CYP2C9 (cross-reactive with CYP2C19) and monoclonal anti-CYP2C19 completely inhibited microsomal M8 production, whereas monoclonal CYP2C9 and polyclonal CYP3A4 antibodies were without effect. Similarly, the CYP2C19 substrate omeprazole strongly inhibited (75%) hepatic nelfinavir t-butylamide hydroxylation at a concentration of only 12.5 microM. Our study shows that CYP2C19 underlies formation in human liver of M8, a bioactive nelfinavir metabolite. The inducibility of CYP2C19 by agents (e.g., rifampicin) often taken concurrently with nelfinavir, together with this P450's known polymorphic nature, may thus be important determinants of nelfinavir's antiviral potency.

Cytochrome P450 enzymes involved in the metabolism of tetrahydrocannabinols and cannabinol by human hepatic microsomes

Article

Apr 2007
LIFE SCI

In this study, tetrahydrocannabinols (THCs) were mainly oxidized at the 11-position and allylic sites at the 7alpha-position for Delta(8)-THC and the 8beta-position for Delta(9)-THC by human hepatic microsomes. Cannabinol (CBN) was also mainly metabolized to 11-hydroxy-CBN and 8-hydroxy-CBN by the microsomes. The 11-hydroxylation of three cannabinoids by the microsomes was markedly inhibited by sulfaphenazole, a selective inhibitor of CYP2C enzymes, while the hydroxylations at the 7alpha-(Delta(8)-THC), 8beta-(Delta(9)-THC) and 8-positions (CBN) of the corresponding cannabinoids were highly inhibited by ketoconazole, a selective inhibitor of CYP3A enzymes. Human CYP2C9-Arg expressed in the microsomes of human B lymphoblastoid cells efficiently catalyzed the 11-hydroxylation of Delta(8)-THC (7.60 nmol/min/nmol CYP), Delta(9)-THC (19.2 nmol/min/nmol CYP) and CBN (6.62 nmol/min/nmol CYP). Human CYP3A4 expressed in the cells catalyzed the 7alpha-(5.34 nmol/min/nmol CYP) and 7beta-hydroxylation (1.39 nmol/min/nmol CYP) of Delta(8)-THC, the 8beta-hydroxylation (6.10 nmol/min/nmol CYP) and 9alpha,10alpha-epoxidation (1.71 nmol/min/nmol CYP) of Delta(9)-THC, and the 8-hydroxylation of CBN (1.45 nmol/min/nmol CYP). These results indicate that CYP2C9 and CYP3A4 are major enzymes involved in the 11-hydroxylation and the 8-(or the 7-) hydroxylation, respectively, of the cannabinoids by human hepatic microsomes. In addition, CYP3A4 is a major enzyme responsible for the 7alpha- and 7beta-hydroxylation of Delta(8)-THC, and the 9alpha,10alpha-epoxidation of Delta(9)-THC.

The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: Δ9-tetrahydrocannabinol, cannabidiol and Δ9-tetrahydrocannabivarin

Article

Feb 2008

Roger G Pertwee

Cannabis sativa is the source of a unique set of compounds known collectively as plant cannabinoids or phytocannabinoids. This review focuses on the manner with which three of these compounds, (−)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), (−)-cannabidiol (CBD) and (−)-trans-Δ9-tetrahydrocannabivarin (Δ9-THCV), interact with cannabinoid CB1 and CB2 receptors. Δ9-THC, the main psychotropic constituent of cannabis, is a CB1 and CB2 receptor partial agonist and in line with classical pharmacology, the responses it elicits appear to be strongly influenced both by the expression level and signalling efficiency of cannabinoid receptors and by ongoing endogenous cannabinoid release. CBD displays unexpectedly high potency as an antagonist of CB1/CB2 receptor agonists in CB1- and CB2-expressing cells or tissues, the manner with which it interacts with CB2 receptors providing a possible explanation for its ability to inhibit evoked immune cell migration. Δ9-THCV behaves as a potent CB2 receptor partial agonist in vitro. In contrast, it antagonizes cannabinoid receptor agonists in CB1-expressing tissues. This it does with relatively high potency and in a manner that is both tissue and ligand dependent. Δ9-THCV also interacts with CB1 receptors when administered in vivo, behaving either as a CB1 antagonist or, at higher doses, as a CB1 receptor agonist. Brief mention is also made in this review, first of the production by Δ9-THC of pharmacodynamic tolerance, second of current knowledge about the extent to which Δ9-THC, CBD and Δ9-THCV interact with pharmacological targets other than CB1 or CB2 receptors, and third of actual and potential therapeutic applications for each of these cannabinoids. British Journal of Pharmacology (2008) 153, 199–215; doi:10.1038/sj.bjp.0707442; published online 10 September 2007

Identification of cytochrome P450 enzymes responsible for metabolism of cannabidiol by human liver microsomes

Abstract

No full-text available

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