A novel phytocannabinoid isolated from Cannabis sativa L. with an in vivo cannabimimetic activity higher than Δ9-tetrahydrocannabinol: Δ9-Tetrahydrocannabiphorol

Development of an accelerated ageing protocol for the study of phytocannabinoid stability in Cannabis sativa L

Cannabis sativa L. is a plant belonging to the Cannabaceae family known primarily for its recreational use due to the psychoactive properties of Δ9-tetrahydrocannabinol (THC). Despite this, several compounds belonging to the category of phytocannabinoids have shown in recent years a number of potentially promising therapeutic effects that have increased the interest in the pharmaceutical field towards this plant. However, the content of these compounds is very variable and influenced by different factors, such as growing conditions and time of the year. An indication of the status and age of Cannabis samples is provided by the content of CBN, a minor phytocannabinoid and degradation product of other phytocannabinoids, including THC. In this research work an innovative, solid state analytical approach has been developed to observe and evaluate the variations in the content of two phytocannabinoids (CBN and CBD) in Cannabis-derived products over time. In order to simulate the ageing of the Cannabis samples, an artificially accelerated ageing procedure has been developed and optimised by using high temperatures. The analyses were carried out using an innovative ATR-FTIR method for solid state analysis, enabling direct analysis of a solid sample without any pretreatment phase. This study has allowed the development of an innovative analytical approach for the evaluation of the age and state of conservation of Cannabis samples and may be a useful tool both in the industrial, pharmaceutical and forensic fields.

Thermally induced changes in the profiles of phytocannabinoids and other bioactive compounds in Cannabis sativa L. inflorescences

Phytocannabinoids occurring in Cannabis Sativa L. are unique secondary metabolites possessing interesting pharmacological activities. In this study, the dynamics of thermally induced (60 and 120 °C) phytocannabinoid reactions in four cannabis varieties were investigated. Using UHPLC-HRMS/MS, 40 phytocannabinoids were involved in target analysis, and an additional 281 compounds with cannabinoid-like structures and 258 non-cannabinoid bioactive compounds were subjected to suspect screening. As expected, the key reaction was the decarboxylation of acidic phytocannabinoids. Nevertheless, the rate constants differed among cannabis varieties, documenting the matrix-dependence of this process. Besides neutral counterparts of acidic species, ́neẃ bioactive compounds such as hydroxyquinones were found in heated samples. In addition, changes in other bioactive compounds with both cannabinoid-like and non-cannabinoid structures were documented during cannabis heating at 120 °C. The data document the complexity of heat-induced processes and provide a further understanding of changes in bioactivities occurring under such conditions.

Investigation of the intrinsic cannabinoid activity of hemp-derived and semisynthetic cannabinoids with β-arrestin2 recruitment assays-and how this matters for the harm potential of seized drugs

Cultivation of industrial low-Δ9-tetrahydrocannabinol (Δ9-THC) hemp has created an oversupply of cannabidiol (CBD)-rich products. The fact that phytocannabinoids, including CBD, can be used as precursors to synthetically produce a range of THC variants-potentially located in a legal loophole-has led to a diversification of cannabis recreational drug markets. 'Hemp-compliant', 'hemp-derived' and 'semisynthetic' cannabinoid products are emerging and being advertised as (legal) alternatives for Δ9-THC. This study included a large panel (n = 30) of THC isomers, homologs, and analogs that might be derived via semisynthetic procedures. As a proxy for the abuse potential of these compounds, we assessed their potential to activate the CB1 cannabinoid receptor with a β-arrestin2 recruitment bioassay (picomolar-micromolar concentrations). Multiple THC homologs (tetrahydrocannabihexol, THCH; tetrahydrocannabiphorol, THCP; tetrahydrocannabinol-C8, THC-C8) and THC analogs (hexahydrocannabinol, HHC; hexahydrocannabiphorol, HHCP) were identified that showed higher potential for CB1 activation than Δ9-THC, based on either higher efficacy (Emax) or higher potency (EC50). Structure-activity relationships were assessed for Δ9-THC and Δ8-THC homologs encompassing elongated alkyl chains. Additionally, stereoisomer-specific differences in CB1 activity were established for various THC isomers (Δ7-THC, Δ10-THC) and analogs (HHC, HHCP). Evaluation of the relative abundance of 9(S)-HHC and 9(R)-HHC epimers in seized drug material revealed varying epimeric compositions between batches. Increased abundance of the less active 9(S)-HHC epimer empirically resulted in decreased potency, but sustained efficacy for the resulting diastereomeric mixture. In conclusion, monitoring of semisynthetic cannabinoids is encouraged as the dosing and the relative composition of stereoisomers can impact the harm potential of these drugs, relative to Δ9-THC products.

Analysis of phytocannabinoids in hemp seeds, sprouts and microgreens

Hemp-sprouts are emerging as a new class of attractive functional food due to their numerous health benefits when compared to other sprout species. Indeed, the high content of beneficial components including polyphenols and flavonoids makes this type of food a promising and successful market. However, the available literature on this topic is limited and often conflicting as regards to the content of phytocannabinoids. High-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC-HRMS) was applied in an untargeted metabolomics fashion to extracts of hemp seeds, sprouts and microgreens of nine different genotypes. Both unsupervised and supervised multivariate statistical analysis was performed to reveal variety-specific profiles of phytocannabinoids with surprisingly remarkable levels of phytocannabinoids even in chemotype V samples. Furthermore, a targeted HPLC-HRMS analysis was carried out for the quantitative determination of the major phytocannabinoids including CBDA, CBD, CBGA, CBG, CBCA, CBC, THCA, and trans-Δ9-THC. The last part of the study was focused on the evaluation of the enantiomeric composition of CBCA in hemp seeds, sprouts and microgreens in the different varieties by HPLC-CD (HPLC with online circular dichroism). Chiral analysis of CBCA showed a wide variability of its enantiomeric composition in the different varieties, thus contributing to the understanding of the intriguing stereochemical behavior of this compound in an early growth stage. However, further investigation is needed to determine the genetic factors responsible for the low enantiopurity of this compound.

A new HPLC method with multiple detection systems for impurity analysis and discrimination of natural versus synthetic cannabidiol

Cannabidiol (CBD) is the main non-psychoactive phytocannabinoid derived from Cannabis sativa L. It is now an active pharmaceutical ingredient (API), given its usage in treating some types of pediatric epilepsy. For this reason, this compound requires a deep characterization in terms of purity and origin. Previous research work has shown two impurities in CBD samples from hemp inflorescences, namely, cannabidivarin (CBDV) and cannabidibutol (CBDB), while abnormal-cannabidiol (abn-CBD) has been described as the primary by-product that is generated from CBD synthesis. Both natural and synthetic CBD samples exhibit the presence of Δ9-tetrahydrocannabinol (Δ9-THC) and Δ8-THC. This study aimed to develop a new analytical method based on high-performance liquid chromatography (HPLC) with different detection systems to study the purity of CBD and to define its origin based on the impurity profile. In addition to the above-mentioned cannabinoids, other compounds, such as cannabigerovarin (CBGV), cannabigerol (CBG), cannabichromevarin (CBCV), and cannabichromene (CBC), were examined as potential discriminating impurities. Qualitative and quantitative analyses were carried out by UHPLC-HRMS and HPLC-UV/Vis, respectively. Principal component analysis was applied for statistical exploration. Natural CBD samples exhibited purities ranging between 97.5 and 99.7%, while synthetic samples were generally pure, except for three initially labeled as synthetic, revealing natural-derived impurities. To further confirm the origin of CBD samples, the presence of other two minor impurities, namely cannabidihexol (CBDH) and cannabidiphorol (CBDP), was assessed as unequivocal for a natural origin. Finally, an enantioselective HPLC analysis was carried out and the results confirmed the presence of the (-)-trans enantiomer in all CBD samples. In conclusion, the HPLC method developed represents a reliable tool for detecting CBD impurities, thus providing a clear discrimination of the compound origin.

Effects of Biomaterials Derived from Germinated Hemp Seeds on Stressed Hair Stem Cells and Immune Cells

Androgenetic alopecia is a genetic disorder that commonly causes progressive hair loss in men, leading to diminished self-esteem. Although cannabinoids extracted from Cannabis sativa are used in hair loss treatments, no study has evaluated the effects of germinated hemp seed extract (GHSE) and exosomes derived from the calli of germinated hemp seeds on alopecia. Therefore, this study aimed to demonstrate their preventive effects against alopecia using various methodologies, including quantitative PCR, flow cytometry, ELISA, and immunocytochemistry. Our research highlights the preventive functions of GHSE (GE2000: 2000 µg/mL) and exosomes from the calli of germinated hemp seeds (E40: 40 μg/mL) in three biochemical categories: genetic modulation in hair follicle dermal papilla stem cells (HFDPSCs), cellular differentiation, and immune system modulation. Upon exposure to dihydrotestosterone (DT), both biomaterials upregulated genes preventing alopecia (Wnt, β-catenin, and TCF) in HFDPSCs and suppressed genes activating alopecia (STAT1, 5α-reductase type 1, IL-15R). Additionally, they suppressed alopecia-related genes (NKG2DL, IL2-Rβ, JAK1, STAT1) in CD8+ T cells. Notably, E40 exhibited more pronounced effects compared to GE2000. Consequently, both E40 and GE2000 effectively mitigated DT-induced stress, activating mechanisms promoting hair formation. Given the limited research on alopecia using these materials, their pharmaceutical development promises significant economic and health benefits.

CBD Versus CBDP: Comparing In Vitro Receptor-Binding Activities

Phytocannabinoids with seven-carbon alkyl chains (phorols) have gained a lot of attention, as they are commonly believed to be more potent versions of typical cannabinoids with shorter alkyl chains. At the time of this article, cannabidiphorol (CBDP) and tetrahydrocannabiphorol (THCP) can both be purchased in the North American market, even though their biological activities are nearly unknown. To investigate their relative potency, we conducted in vitro receptor-binding experiments with CBDP (cannabinoid CB1/CB2 receptor antagonism, serotonin 5HT-1A agonism, dopamine D2S (short form) agonism, and mu-opioid negative allosteric modulation) and compared the observed activity with that of CBD. To our knowledge, this is the first publication to investigate CBDP's receptor activity in vitro. A similar activity profile was observed for both CBD and CBDP, with the only notable difference at the CB2 receptor. Contrary to common expectations, CBD was found to be a slightly more potent CB2 antagonist than CBDP (p < 0.05). At the highest tested concentration, CBD demonstrated antagonist activity with a 33% maximum response of SR144528 (selective CB2 antagonist/inverse agonist). CBDP at the same concentration produced a weaker antagonist activity. A radioligand binding assay revealed that among cannabinoid and serotonin receptors, CB2 is likely the main biological target of CBDP. However, both CBD and CBDP were found to be significantly less potent than SR144528. The interaction of CBDP with the mu-opioid receptor (MOR) produced unexpected results. Although the cannabidiol family is considered to be a set of negative allosteric modulators (NAMs) of opioid receptors, we observed a significant increase in met-enkephalin-induced mu-opioid internalization when cells were incubated with 3 µM of CBDP and 1 µM met-enkephalin, a type of activity expected from positive allosteric modulators (PAMs). To provide a structural explanation for the observed PAM effect, we conducted molecular docking simulations. These simulations revealed the co-binding potential of CBDP (or CBD) and met-enkephalin to the MOR.

Cross-reactivity of 24 cannabinoids and metabolites in blood using the Immunalysis Cannabinoids Direct enzyme-linked immunosorbent assay

With wider availability of synthetic and semi-synthetic cannabinoids in the consumer space, there is a growing impact on public health and safety. Forensic toxicology laboratories should keep these compounds in mind as they attempt to remain effective in screening for potential sources of human performance impairment. Enzyme-linked immunosorbent assay (ELISA) is a commonly utilized tool in forensic toxicology, as its efficiency and sensitivity make it useful for rapid and easy screening for a large number of drugs. This screening technique has lower specificity, which allows for broad cross-reactivity among structurally similar compounds. In this study, the Cannabinoids Direct ELISA kit from Immunalysis was utilized to assess the cross-reactivities of 24 cannabinoids and metabolites in whole blood. The assay was calibrated with 5 ng/mL of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol and the analytes of interest were evaluated at concentrations ranging from 5 to 500 ng/mL. Most parent compounds demonstrated cross-reactivity ≥20 ng/mL, with increasing alkyl side-chain length relative to Δ9-tetrahydrocannabinol resulting in decreased cross-reactivity. Of the 24 analytes, only the carboxylic acid metabolites, 11-nor-9-carboxy-Δ8-tetrahydrocannabinol, 11-nor-9(R)-carboxy-hexahydrocannabinol and 11-nor-9(S)-carboxy-hexahydrocannabinol, were cross-reactive at levels ≤10 ng/mL. Interestingly, 11-nor-9(R)-carboxy-hexahydrocannabinol demonstrated cross-reactivity at 5 ng/mL, where its stereoisomer 11-nor-9(S)-carboxy-hexahydrocannabinol, did not. As more information emerges about the prevalence of these analytes in blood specimens, it is important to understand and characterize their impact on current testing paradigms.

Using In Silico Molecular Docking to Explain Differences in Receptor Binding Behavior of HHC and THCV Isomers: Revealing New Binding Modes

Even slight structural differences between phytocannabinoid isomers are usually enough to cause a change in their biological properties. In this study, we used in vitro CB1 agonism/antagonism assays to compare the receptor binding functionality of THCV (tetrahydrocannabivarin) and HHC (hexahydrocannabinol) isomers and applied molecular docking to provide an explanation for the difference in the activities. No CB1 agonism was observed for ∆9- and ∆8-THCV. Instead, both isomers antagonized CP 55940, with ∆9-THCV being approximately two times more potent than the ∆8 counterpart (IC50 = 52.4 nM and 119.6 nM for ∆9- and ∆8-THCV, respectively). Docking simulations found two binding poses for THCV isomers, one very similar to ∆9-THC and one newly discovered pose involving the occupation of side pocket 1 of the CB1 receptor by the alkyl chain of the ligand. We suggested the latter as a potential antagonist pose. In addition, our results established 9R-HHC and 9S-HHC among partial agonists of the CB1 receptor. The 9R-HHC (EC50 = 53.4 nM) isomer was a significantly more potent agonist than 9S (EC50 = 624.3 nM). ∆9-THC and 9R-HHC showed comparable binding poses inside the receptor pocket, whereas 9S-HHC adopted a new and different binding posture that can explain its weak agonist activity.

An emerging trend in Novel Psychoactive Substances (NPSs): designer THC

Since its discovery as one of the main components of cannabis and its affinity towards the cannabinoid receptor CB1, serving as a means to exert its psychoactivity, Δ9-tetrahydrocannabinol (Δ9-THC) has inspired medicinal chemists throughout history to create more potent derivatives. Initially, the goal was to synthesize chemical probes for investigating the molecular mechanisms behind the pharmacology of Δ9-THC and finding potential medical applications. The unintended consequence of this noble intent has been the proliferation of these compounds for recreational use. This review comprehensively covers the most exhaustive number of THC-like cannabinoids circulating on the recreational market. It provides information on the chemistry, synthesis, pharmacology, analytical assessment, and experiences related to the psychoactive effects reported by recreational users on online forums. Some of these compounds can be found in natural cannabis, albeit in trace amounts, while others are entirely artificial. Moreover, to circumvent legal issues, many manufacturers resort to semi-synthetic processes starting from legal products extracted from hemp, such as cannabidiol (CBD). Despite the aim to encompass all known THC-like molecules, new species emerge on the drug users' pipeline each month. Beyond posing a significantly high public health risk due to unpredictable and unknown side effects, scientific research consistently lags behind the rapidly evolving recreational market.

The Developmental Trajectory to Cannabis Use Disorder

The increase of cannabis use, particularly with the evolution of high potency products, and of cannabis use disorder (CUD) are a growing healthcare concern. While the harms of adult use and potential medicinal properties of cannabis continue to be debated, it is becoming evident that adolescent cannabis use is a critical window for CUD risk with potential lifelong mental health implications. Herein, we discuss mental health consequences of adolescent cannabis use, factors that contribute to the risk of developing CUD, and what remains unclear in the changing legal landscape of cannabis use. We also discuss the importance of preclinical models to provide translational insight about the causal relationship of cannabis to CUD-related phenotypes and conclude with highlighting opportunities for clinicians and allied professionals to engage in addressing adolescent cannabis use.

Phytochemical Characterization and TRPA1/TRPM8 Modulation Profile of the Cannabigerol-Rich Cannabis sativa L. Chemotype IV

The first detailed phytochemical analysis of the cannabigerol (CBG)-rich chemotype IV of Cannabis sativa L. resulted in the isolation of the expected cannabigerolic acid/cannabigerol (CBGA/CBG) and cannabidiolic acid/cannabidiol (CBDA/CBD) and of nine new phytocannabinoids (5-13), which were fully characterized by HR-ESIMS and 1D and 2D NMR. These included mono- or dihydroxylated CBGA/CBG analogues, a congener with a truncated side chain (10), cyclocannabigerol B (11), and the CBD derivatives named cannabifuranols (12 and 13). Cyclocannabigerol B and cannabifuranols are characterized by a novel phytocannabinoid structural architecture. The isolated phytocannabinoids were assayed on the receptor channels TRPA1 and TRPM8, unveiling a potent dual TRPA1 agonist/TRPM8 antagonist profile for compounds 6, 7, and 14. Chiral separation of the two enantiomers of 5 resulted in the discovery of a synergistic effect of the two enantiomers on TRPA1.

Toll-like receptor signalling as a cannabinoid target

Toll-like receptors (TLRs) have become a focus in biomedicine and biomedical research given the roles of this unique family of innate immune proteins in immune activation, infection, and autoimmunity. It is evident that TLR dysregulation, and subsequent alterations in TLR-mediated inflammatory signalling, can contribute to disease pathogenesis, and TLR targeted therapies are in development. This review highlights evidence that cannabinoids are key regulators of TLR signalling. Cannabinoids include component of the plant Cannabis sativa L. (C. sativa), synthetic and endogenous ligands, and overall represent a class of compounds whose therapeutic potential and mechanism of action continues to be elucidated. Cannabinoid-based medicines are in the clinic, and are furthermore under intense investigation for broad clinical development to manage symptoms of a range of disorders. In this review, we present an overview of research evidence that signalling linked to a range of TLRs is targeted by cannabinoids, and such cannabinoid mediated effects represent therapeutic avenues for further investigation. First, we provide an overview of TLRs, adaptors and key signalling events, alongside a summary of evidence that TLRs are linked to disease pathologies. Next, we discuss the cannabinoids system and the development of cannabinoid-based therapeutics. Finally, for the bulk of this review, we systematically outline the evidence that cannabinoids (plant-derived cannabinoids, synthetic cannabinoids, and endogenous cannabinoid ligands) can cross-talk with innate immune signalling governed by TLRs, focusing specifically on each member of the TLR family. Cannabinoids should be considered as key regulators of signalling controlled by TLRs, and such regulation should be a major focus in terms of the anti-inflammatory propensity of the cannabinoid system.

Cannabinoid-Induced Stereoselective Inhibition of R-S-Oxazepam Glucuronidation: Cannabinoid-Oxazepam Drug Interactions

Benzodiazepines (BZDs) such as oxazepam are commonly prescribed depressant drugs known for their anxiolytic, hypnotic, muscle relaxant, and anticonvulsant effects and are frequently used in conjunction with other illicit drugs including cannabis. Oxazepam is metabolized in an enantiomeric-specific manner by glucuronidation, with S-oxazepam metabolized primarily by UGT2B15 and R-oxazepam glucuronidation mediated by both UGT 1A9 and 2B7. The goal of the present study was to evaluate the potential inhibitory effects of major cannabinoids, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), and major THC metabolites, 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (11-COOH-THC), on the UGT-mediated metabolism of R- and S-oxazepam. The cannabinoids and metabolites were screened as inhibitors of R- and S-oxazepam glucuronidation in microsomes isolated from HEK293 cells overexpressing individual UGT enzymes (rUGTs). The IC50 values were determined in human liver microsomes (HLM), human kidney microsomes (HKM), and rUGTs and utilized to estimate the nonspecific, binding-corrected Ki (Ki,u) values and predict the area under the concentration-time curve ratio (AUCR). The estimated Ki,u values observed in HLM for S- and R-oxazepam glucuronidation by CBD, 11-OH-THC, and THC were in the micromolar range (0.82 to 3.7 µM), with the Ki,u values observed for R-oxazepam glucuronidation approximately 2- to 5-fold lower as compared to those observed for S-oxazepam glucuronidation. The mechanistic static modeling predicted a potential clinically significant interaction between oral THC and CBD with oxazepam, with the AUCR values ranging from 1.25 to 3.45. These data suggest a pharmacokinetic drug-drug interaction when major cannabinoids like CBD or THC and oxazepam are concurrently administered.

Bidimensional heart-cut achiral-chiral liquid chromatography coupled to high-resolution mass spectrometry for the separation of the main chiral phytocannabinoids and enantiomerization studies of cannabichromene and cannabichromenic acid

In this work, a heart-cut bidimensional achiral-chiral liquid chromatography method coupled to high-resolution mass spectrometry was developed for the separation of the main carboxylated phytocannabinoids, namely cannabidiolic acid (CBDA), tetrahydrocannabinolic acid (THCA), cannabichromenic acid (CBCA), and cannabicyclolic acid (CBLA), and decarboxylated derivatives, namely cannabidiol (CBD), Δ9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC), and cannabicyclol (CBL), and the evaluation of their enantiomeric composition in extracts of different Cannabis sativa L. varieties. Optimal conditions for the chiral analysis of CBC- and CBL-type compounds were found with methanol and water (95:5, v/v, with 0.1% formic acid, 1.5 mL/min) on an amylose-based chiral stationary phase. These settings also allowed to evaluate the parameters responsible for CBC and CBCA racemization.

Identification of hexahydrocannabinol (HHC), dihydro-iso-tetrahydrocannabinol (dihydro-iso-THC) and hexahydrocannabiphorol (HHCP) in electronic cigarette cartridge products

PURPOSE

Since 2021, products claiming to contain hexahydrocannabinol (HHC) and hexahydrocannabiphorol (HHCP), which are tetrahydrocannabinol (THC) analogs, have been distributed via the Internet. Owing to the presence of three asymmetric carbons in their structure, HHC and HHCP have multiple stereoisomers. This study aimed to identify the actual stereoisomers of HHC and HHCP isolated from electronic cigarette cartridge products using nuclear magnetic resonance (NMR) spectroscopy.

METHODS

Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-photodiode array-mass spectrometry (LC-PDA-MS) were used for the analyses of two major peaks and one minor peak in product A and two major peaks in product B. These five compounds were isolated by silica gel column chromatography, and their structures were analyzed by 1H, 13C-NMR and various two-dimensional NMR techniques, i.e., H-H correlation spectroscopy, heteronuclear multiple quantum coherence, heteronuclear multiple-bond correlation, and nuclear Overhauser effect spectroscopy.

RESULTS

Three compounds isolated from product A were identified as rel-(6aR,9R,10aR)-hexahydrocannabinol (11β-hexahydrocannabinol; 11β-HHC), rel-(6aR,9S,10aR)-hexahydrocannabinol (11α-hexahydrocannabinol, 11α-HHC), and a minor compound (2R,5S,6R)-dihydro-iso-tetrahydrocannabinol (dihydro-iso-THC). Meanwhile, the structural isomers of the major compound isolated from product B were identified as rel-(6aR, 9R, 10aR)-hexahydrocannabiphorol (11β-hexahydrocannabiphorol; 11β-HHCP) and rel-(6aR, 9S, 10aR)-hexahydrocannabiphorol (11α-hexahydrocannabiphorol; 11α-HHCP).

CONCLUSIONS

The presence of both 11β-HHC and 11α-HHC in the HHC products analyzed in this study suggests that they were most likely synthesized via the reduction reaction of Δ8-THC or Δ9-THC. Dihydro-iso-THC was probably obtained as a byproduct of the synthesis of Δ8-THC or Δ9-THC from cannabidiol. Similarly, 11β-HHCP and 11α-HHCP in the HHCP product could stem from Δ9-tetrahydrocannabiphorol.

Cannabidiol-Derived Cannabinoids: The Unregulated Designer Drug Market Following the 2018 Farm Bill

Background

In this review, we summarize current scientific knowledge on psychoactive cannabinoids synthesized from cannabidiol (CBD) and sold in the semi-legal market established in response to the passage of the US Agriculture Improvement Act of 2018, commonly known as the 2018 Farm Bill. The discussion focuses on recent developments that suggest this unregulated market may be fertile ground for a potential health crisis.

Summary

Current research into CBD-derived cannabinoids is mainly limited to Δ8-tetrahydrocannabinol (Δ8-THC) products, with some recent publications beginning to explore O-acetyl-THC, a term describing the acetate ester of Δ8-THC or Δ9-THC, and its potential pulmonary toxicity. We advance the discussion on the CBD-derived cannabinoid market, shedding light on the introduction and associated dangers of novel cannabinoids, likely produced via fully synthetic routes using sidechain variants of CBD, with purportedly greater agonist activity at the human cannabinoid receptor 1 (as a source of euphorigenic activity) than Δ9-THC. We discuss the expanded incorporation of the acetate ester motif into other THC analogues. We also discuss the lack of regulatory oversight for the production of CBD-derived cannabinoids and the unlabeled presence of under-researched cannabinoids formed as reaction side products in the CBD-derived cannabinoid products being sold. Accordingly, we suggest approaches to monitoring the CBD-derived cannabinoid market and investigating the pharmacology of the cannabinoids being consumed. Finally, important epidemiological findings are discussed and future directions for research are suggested to call investigators to this critically understudied field.

Key Messages

The CBD-derived cannabinoid market is growing internationally, and the market has diversified to include potent synthetic cannabinoids. The products sold on this unregulated market are under-researched despite growing availability and consumer interest. Ernest investigation of the pharmacology of these novel cannabinoids and the contents of CBD-derived cannabinoid products is critical for monitoring this potential source of another vaping-related epidemic.

The endocannabinoid system as a putative target for the development of novel drugs for the treatment of psychiatric illnesses

Cannabis is well established to impact affective states, emotion and perceptual processing, primarily through its interactions with the endocannabinoid system. While cannabis use is quite prevalent in many individuals afflicted with psychiatric illnesses, there is considerable controversy as to whether cannabis may worsen these conditions or provide some form of therapeutic benefit. The development of pharmacological agents which interact with components of the endocannabinoid system in more localized and discrete ways then via phytocannabinoids found in cannabis, has allowed the investigation if direct targeting of the endocannabinoid system itself may represent a novel approach to treat psychiatric illness without the potential untoward side effects associated with cannabis. Herein we review the current body of literature regarding the various pharmacological tools that have been developed to target the endocannabinoid system, their impact in preclinical models of psychiatric illness and the recent data emerging of their utilization in clinical trials for psychiatric illnesses, with a specific focus on substance use disorders, trauma-related disorders, and autism. We highlight several candidate drugs which target endocannabinoid function, particularly inhibitors of endocannabinoid metabolism or modulators of cannabinoid receptor signaling, which have emerged as potential candidates for the treatment of psychiatric conditions, particularly substance use disorder, anxiety and trauma-related disorders and autism spectrum disorders. Although there needs to be ongoing clinical work to establish the potential utility of endocannabinoid-based drugs for the treatment of psychiatric illnesses, the current data available is quite promising and shows indications of several potential candidate diseases which may benefit from this approach.

An overview on synthetic and biological activities of cannabidiol (CBD) and its derivatives

(-)-Cannabidiol is a class of non-psychoactive plant cannabinoids derived from cannabis plants. Currently, Epidiolex (Cannabidiol) has been approved by the FDA for the treatment of two rare and severe forms of epilepsy related diseases, namely Lennox-Gastaut syndrome (LGS) and Dravet (DS). In addition, Cannabidiol and its structural analogues have received increasing attention due to their potential therapeutic effects such as neuroprotection, anti-epilepsy, anti-inflammation, anti-anxiety, and anti-cancer. Based on literature review, no comprehensive reviews on the synthesis of Cannabidiol and its derivatives have been found in recent years. Therefore, this article summarizes the published synthesis methods of Cannabidiol and the synthesis routes of Cannabidiol derivatives, and introduces the biological activities of some Cannabidiol analogues that have been studied extensively and have significant activities.

Predicting Maternal and Infant Tetrahydrocannabinol Exposure in Lactating Cannabis Users: A Physiologically Based Pharmacokinetic Modeling Approach

A knowledge gap exists in infant tetrahydrocannabinol (THC) data to guide breastfeeding recommendations for mothers who use cannabis. In the present study, a paired lactation and infant physiologically based pharmacokinetic (PBPK) model was developed and verified. The verified model was used to simulate one hundred virtual lactating mothers (mean age: 28 years, body weight: 78 kg) who smoked 0.32 g of cannabis containing 14.14% THC, either once or multiple times. The simulated breastfeeding conditions included one-hour post smoking and subsequently every three hours. The mean peak concentration (Cmax) and area under the concentration-time curve (AUC(0-24 h)) for breastmilk were higher than in plasma (Cmax: 155 vs. 69.9 ng/mL; AUC(0-24 h): 924.9 vs. 273.4 ng·hr/mL) with a milk-to-plasma AUC ratio of 3.3. The predicted relative infant dose ranged from 0.34% to 0.88% for infants consuming THC-containing breastmilk between birth and 12 months. However, the mother-to-infant plasma AUC(0-24 h) ratio increased up to three-fold (3.4-3.6) with increased maternal cannabis smoking up to six times. Our study demonstrated the successful development and application of a lactation and infant PBPK model for exploring THC exposure in infants, and the results can potentially inform breastfeeding recommendations.

Predicting binding between 55 cannabinoids and 4,799 biological targets by in silico methods

Recently, there has been an increase in cannabis-derived products being marketed as foods, dietary supplements, and other consumer products. Cannabis contains over a hundred cannabinoids, many of which have unknown physiological effects. Since there are large numbers of cannabinoids, and many are not commercially available for in vitro testing, an in silico tool (Chemotargets Clarity software) was used to predict binding between 55 cannabinoids and 4,799 biological targets (enzymes, ion channels, receptors, and transporters). This tool relied on quantitative structure activity relationships (QSAR), structural similarity, and other approaches to predict binding. From this screening, 827 cannabinoid-target binding pairs were predicted, which included 143 unique targets. Many cannabinoids sharing core structures (cannabinoid "types") had similar binding profiles, whereas most cannabinoids containing carboxylic acid groups were similar without regards to their core structure. For some of the binding predictions (43), in vitro binding data were available, and they agreed well with in silico binding data (median fourfold difference in binding concentrations). Finally, clinical adverse effects associated with 22 predicted targets were identified from an online database (Clarivate Off-X), providing important insights on potential human health hazards. Overall, in silico biological target predictions are a rapid means to identify potential hazards due to cannabinoid-target interactions, and the data can be used to prioritize subsequent in vitro and in vivo testing.

Synthesis and pharmacological activity of the epimers of hexahydrocannabinol (HHC)

Cannabis is a multifaceted plant with numerous therapeutic properties on one hand, and controversial psychotropic activities on the other hand, which are modulated by CB1 endocannabinoid receptors. Δ9-Tetrahydrocannabinol (Δ9-THC) has been identified as the main component responsible for the psychotropic effects, while its constitutional isomer cannabidiol (CBD) has shown completely different pharmacological properties. Due to its reported beneficial effects, Cannabis has gained global popularity and is openly sold in shops and online. To circumvent legal restrictions, semi-synthetic derivatives of CBD are now frequently added to cannabis products, producing "high" effects similar to those induced by Δ9-THC. The first semi-synthetic cannabinoid to appear in the EU was obtained through cyclization and hydrogenation of CBD, and is known as hexahydrocannabinol (HHC). Currently, there is limited knowledge regarding HHC, its pharmacological properties, and its prevalence, as it is not commonly investigated in routine toxicological assays. In this study, synthetic strategies were explored to obtain an excess of the active epimer of HHC. Furthermore, the two epimers were purified and individually tested for their cannabinomimetic activity. Lastly, a simple and rapid chromatographic method employing a UV detector and a high-resolution mass spectrometer was applied to identify and quantify up to ten major phytocannabinoids, as well as the HHC epimers, in commercial cannabis samples.

Cannabinoids as multifaceted compounds

Since ancient times, Cannabis and its preparations have found various applications such as for medical, recreational and industrial purposes. Subsequently the 1930s, legislation in many countries has restricted its use due to its psychotropic properties. More recently, the discovery of endocannabinoid system, including new receptors, ligands, and mediators, its role in maintaining the homeostasis of the human body and the possible implication in various physiological and pathophysiological processes has also been understood. Based on this evidence, researchers were able to develop new therapeutic targets for the treatment of various pathological disorders. For this purpose, Cannabis and cannabinoids were subjected for the evaluation of their pharmacological activities. The renewed interest in the medical use of cannabis for its potential therapeutic application has prompted legislators to take action to regulate the safe use of cannabis and products containing cannabinoids. However, each country has an enormous heterogeneity in the regulation of laws. Here, we are pleased to show a general and prevailing overview of the findings regarding cannabinoids and the multiple research fields such as chemistry, phytochemistry, pharmacology and analytics in which they are involved.

Recent Research on Cannabis sativa L.: Phytochemistry, New Matrices, Cultivation Techniques, and Recent Updates on Its Brain-Related Effects (2018-2023)

Cannabis sativa L. is a plant that humankind has been using for millennia. The basis of its widespread utilization is its adaptability to so many different climatic conditions, with easy cultivability in numerous diverse environments. Because of its variegate phytochemistry, C. sativa has been used in many sectors, although the discovery of the presence in the plant of several psychotropic substances (e.g., Δ⁹-tetrahydrocannabinol, THC) caused a drastic reduction of its cultivation and use together with its official ban from pharmacopeias. Fortunately, the discovery of Cannabis varieties with low content of THC as well as the biotechnological development of new clones rich in many phytochemical components endorsed with peculiar and many important bioactivities has demanded the reassessment of these species, the study and use of which are currently experiencing new and important developments. In this review we focus our attention on the phytochemistry, new matrices, suitable agronomic techniques, and new biological activities developed in the five last years.

Enantioseparation of chiral phytocannabinoids in medicinal cannabis

The evaluation of the chiral composition of phytocannabinoids in the cannabis plant is particularly important as the pharmacological effects of the (+) and (-) enantiomers of these compounds are completely different. Chromatographic attempts to assess the presence of the minor (+) enantiomers of the main phytocannabinoids, cannabidiolic acid (CBDA) and trans-Δ⁹-tetrahydrocannabinolic acid (trans-Δ⁹-THCA), were carried out on heated plant extracts for the determination of the corresponding decarboxylated species, cannabidiol (CBD) and trans-Δ⁹-tetrahydrocannabinol (trans-Δ⁹-THC), respectively. This process produces an altered phytocannabinoid composition with several new and unknown decomposition products. The present work reports for the first time the stereoselective synthesis of the pure (+) enantiomers of the main phytocannabinoids, trans-CBDA, trans-Δ⁹-THCA, trans-CBD and trans-Δ⁹-THC, and the development and optimization of an achiral-chiral liquid chromatography method coupled to UV and high-resolution mass spectrometry detection in reversed phase conditions (RP-HPLC-UV-HRMS) for the isolation of the single compounds and evaluation of their actual enantiomeric composition in plant. The isolation of the peaks with the achiral stationary phase ensured the absence of interferences that could potentially co-elute with the analytes of interest in the chiral analysis. The method applied to the Italian medicinal cannabis variety FM2 revealed no trace of the (+) enantiomers for all phytocannabinoids under investigation before and after decarboxylation, thus suggesting that the extraction procedure does not lead to an inversion of configuration.

Cannabinoids and the placenta: Receptors, signaling and outcomes

Cannabis use during pregnancy is increasing. The improvement of pregnancy-related symptoms including morning sickness and management of mood and stress are among the most reported reasons for its use. Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) are the most abundant cannabinoids found within the cannabis flower. The concentration of these components has drastically increased in the past 20 years. Additionally, many edibles contain only one cannabinoid and are marketed to achieve a specific goal, meaning there are an increasing number of pregnancies that are exposed to isolated cannabinoids. Both Δ9-THC and CBD cross the placenta and can impact the fetus directly, but the receptors through which cannabinoids act are also expressed throughout the placenta, suggesting that the effects of in-utero cannabinoid exposure may include indirect effects from the placenta. In-utero cannabis research focuses on short and long-term fetal health and development; however, these studies include little to no placenta analysis. Prenatal cannabinoid exposure is linked to small for gestational age and fetal growth-restricted babies. Compromised placental development is also associated with fetal growth restriction and the few studies (clinical and animal models) that included placental analysis, identify changes in placental vasculature and function in these cannabinoid-exposed pregnancies. In vitro studies further support cannabinoid impact on cell function in the different populations that comprise the placenta. In this article, we aim to summarize how phytocannabinoids can impact placental development and function. Specifically, the cannabinoids and their actions at the different receptors are described, with receptor localization throughout the human and murine placenta discussed. Findings from studies that included placental analysis and how cannabinoid signaling may modulate critical developmental processing including cell proliferation, angiogenesis and migration are described. Considering the current research, prenatal cannabinoid exposure may significantly impact placental development, and, as such, identifying windows of placental vulnerability for each cannabinoid will be critical to elucidate the etiology of fetal outcome studies.

Investigation of Cannabis sativa Phytochemicals as Anti-Alzheimer's Agents: An In Silico Study

Cannabis sativa is a medicinal plant that has been known for years and is used as an Ayurvedic medicine. This plant has great potential in treating various types of brain diseases. Phytochemicals present in this plant act as antioxidants by maintaining synaptic plasticity and preventing neuronal loss. Cannabidiol (CBD) and Tetrahydrocannabinol (THC) are both beneficial in treating Alzheimer's disease by increasing the solubility of Aβ42 amyloid and Tau aggregation. Apart from these therapeutic effects, there are certain unknown functions of these phytochemicals in Alzheimer's disease that we want to elucidate through this study. In this research, our approach is to analyze the effect of phytochemicals in Cannabis sativa on multiple culprit enzymes in Alzheimer's disease, such as AChE (Acetylcholinesterase), BChE (Butyrylcholinesterase), γ-secretase, and BACE-1. In this study, the compounds were selected by Lipinski's rule, ADMET, and ProTox based on toxicity. Molecular docking between the selected compounds (THCV, Cannabinol C2, and Cannabidiorcol) and enzymes mentioned above was obtained by various software programs including AutoDock Vina 4.2, AutoDock, and iGEMDOCK. In comparison to Donepezil (BA = -8.4 kcal/mol, Ki = 1.46 mM), Rivastigmine (BA = -7.0 kcal/mol, Ki = 0.02 mM), and Galantamine (BA = -7.1, Ki = 2.1 mM), Cannabidiorcol (BA = -9.4 kcal/mol, Ki = 4.61 mM) shows significant inhibition of AChE. On the other hand, Cannabinol C2 (BA = -9.2 kcal/mol, Ki = 4.32 mM) significantly inhibits Butyrylcholinesterase (BuChE) in comparison to Memantine (BA = -6.8 kcal/mol, Ki = 0.54 mM). This study sheds new light and opens new avenues for elucidating the role of bioactive compounds present in Cannabis sativa in treating Alzheimer's disease.

Current status and future prospects in cannabinoid production through in vitro culture and synthetic biology

For centuries, cannabis has been a rich source of fibrous, pharmaceutical, and recreational ingredients. Phytocannabinoids are the most important and well-known class of cannabis-derived secondary metabolites and display a broad range of health-promoting and psychoactive effects. The unique characteristics of phytocannabinoids (e.g., metabolite likeness, multi-target spectrum, and safety profile) have resulted in the development and approval of several cannabis-derived drugs. While most work has focused on the two main cannabinoids produced in the plant, over 150 unique cannabinoids have been identified. To meet the rapidly growing phytocannabinoid demand, particularly many of the minor cannabinoids found in low amounts in planta, biotechnology offers promising alternatives for biosynthesis through in vitro culture and heterologous systems. In recent years, the engineered production of phytocannabinoids has been obtained through synthetic biology both in vitro (cell suspension culture and hairy root culture) and heterologous systems. However, there are still several bottlenecks (e.g., the complexity of the cannabinoid biosynthetic pathway and optimizing the bioprocess), hampering biosynthesis and scaling up the biotechnological process. The current study reviews recent advances related to in vitro culture-mediated cannabinoid production. Additionally, an integrated overview of promising conventional approaches to cannabinoid production is presented. Progress toward cannabinoid production in heterologous systems and possible avenues for avoiding autotoxicity are also reviewed and highlighted. Machine learning is then introduced as a powerful tool to model, and optimize bioprocesses related to cannabinoid production. Finally, regulation and manipulation of the cannabinoid biosynthetic pathway using CRISPR- mediated metabolic engineering is discussed.

Efficient Synthesis for Altering Side Chain Length on Cannabinoid Molecules and Their Effects in Chemotherapy and Chemotherapeutic Induced Neuropathic Pain

(1) Background: Recently, a number of side chain length variants for tetrahydrocannabinol and cannabidiol have been identified in cannabis; however, the precursor to these molecules would be based upon cannabigerol (CBG). Because CBG, and its side chain variants, are rapidly converted to other cannabinoids in the plant, there are typically only small amounts in plant extracts, thus prohibiting investigations related to CBG and CBG variant therapeutic effects. (2) Methods: To overcome this, we developed an efficient synthesis of corresponding resorcinol fragments using the Wittig reaction which, under acid catalyzed coupling with geraniol, produced the desired side chain variants of CBG. These compounds were then tested in an animal model of chemotherapeutic-induced neuropathic pain and to reduce colorectal cancer cell viability. (3) Results: We found that all side-chain variants were similarly capable of reducing neuropathic pain in mice at a dose of 10 mg/kg. However, the molecules with shorter side chains (i.e., CBGV and CBGB) were better at reducing colorectal cancer cell viability. (4) Conclusions: The novel synthesis method developed here will be of utility for studying other side chain derivatives of minor cannabinoids such as cannabichromene, cannabinol, and cannabielsoin.

Characterizing the degradation of cannabidiol in an e-liquid formulation

The reported characteristics of cannabidiol (CBD) have encouraged significant growth in commercial CBD products. There is limited information on the stability of CBD and some researchers have noted significant reductions of CBD in products. In this study, the chemical profiles of plant-based and chemically synthesized CBD in a prototype e-liquid formulation were assessed during 4 weeks of storage under varying conditions. Samples were analysed on days 1, 8, 15, 22, and 29 by untargeted analysis using ultra-high performance liquid chromatography-trapped ion mobility-time-of-flight mass spectrometry (UHPLC-TIMS-TOF-MS). On day 1, analysis of plant-based and synthetic CBD formulations showed small differences in their composition, with plant-based CBD e-liquid containing trace levels of a higher number of phytocannabinoid-related impurities. Storage for 4 weeks under stress (40 °C, 75% relative humidity, dark) and ambient (25 °C, 60% relative humidity, daylight) conditions led to increases in the number and abundance of cannabinoid-related degradation products, including cannabielsoin (CBE) and CBD-hydroxyquinone (HU-331), which are products of the oxidation of CBD, and other unidentified cannabinoid-related compounds. The unidentified cannabinoid-related compounds were probed by accurate mass measurement and MS² fragmentation but could not be matched using a mass spectral library derived from 39 commercially available cannabinoid reference standards. Based on elemental composition and MS² fragmentation patterns, the unidentified cannabinoid-related compounds were classified as hydroxy-CBE, hydroxy-CBD, and dihydroxy-CBD. The analysis of e-liquid formulations protected from light and stored at 4 °C for 4 weeks indicated only very small increases in CBD oxidation products. The results indicate that CBD degrades in e-liquid solution at ambient temperature in dark and light to form potentially undesirable products, including cannabielsoin and cannabidiol hydroxyquinone.

Heterologous production of Cannabis sativa-derived specialised metabolites of medicinal significance - Insights into engineering strategies

Cannabis sativa L. has been known for at least 2000 years as a source of important, medically significant specialised metabolites and several bio-active molecules have been enriched from multiple chemotypes. However, due to the many levels of complexity in both the commercial cultivation of cannabis and extraction of its specialised metabolites, several heterologous production approaches are being pursued in parallel. In this review, we outline the recent achievements in engineering strategies used for heterologous production of cannabinoids, terpenes and flavonoids along with their strength and weakness. We provide an overview of the specialised metabolism pathway in C. sativa and a comprehensive list of the specialised metabolites produced along with their medicinal significance. We highlight cannabinoid-like molecules produced by other species. We discuss the key biosynthetic enzymes and their heterologous production using various hosts such as microbial and eukaryotic systems. A brief discussion on complementary production strategies using co-culturing and cell-free systems is described. Various approaches to optimise specialised metabolite production through co-expression, enzyme engineering and pathway engineering are discussed. We derive insights from recent advances in metabolic engineering of hosts with improved precursor supply and suggest their application for the production of C. sativa speciality metabolites. We present a collation of non-conventional hosts with speciality traits that can improve the feasibility of commercial heterologous production of cannabis-based specialised metabolites. We provide a perspective of emerging research in synthetic biology, allied analytical techniques and plant heterologous platforms as focus areas for heterologous production of cannabis specialised metabolites in the future.

Genetic Evaluation of In Vitro Micropropagated and Regenerated Plants of Cannabis sativa L. Using SSR Molecular Markers

Simple sequence repeat (SSR) markers were used to evaluate the genetic stability of the acclimatized micropropagated and regenerated plants of a high cannabidiol (H-CBD) and a high cannabigerol (H-CBG) variety of Cannabis sativa L. Shoot regeneration and proliferation were achieved by culturing calli in Murashige and Skoog basal medium (MS) supplemented with several concentrations of 6-benzyladenine (BA) or thidiazuron (TDZ). Calli derived mostly from stem explants, rather than leaves, cultured on MS supplemented with 2,4-Dichlorophenoxyacetic acid (2,4-D) or combination of kinetin (KIN) with 1-Naphthaleneacetic acid (NAA) or 2,4-D. Rooting of the regenerated plantlets accomplished on half-strength MS medium supplemented with indole-3-butyric acid (IBA). Previous studies performed have developed an efficient in vitro micropropagation protocol for mass production. Both in vitro methodologies can be employed in genetic breeding via molecular techniques. The genetic stability of micropropagated and regenerated plants was accomplished using twelve SSR primer pairs that produced reproducible and clear bands, ranging from 90 to 330 bp in size, and resulted in amplification of one or two alleles, corresponding to homozygous or heterozygous individuals. The SSR amplification products were monomorphic across all the micropropagated and regenerated plants and comparable to mother plants. The monomorphic banding pattern confirmed the genetic homogeneity of the in vitro cultured acclimatized and mother plants as no somaclonal variation was detected in clones for these specific SSRs. Our results evidently suggest that the developed culture protocols for in vitro multiplication is appropriate and applicable for clonal mass propagation of the C. sativa varieties and demonstrate the reliability of this in vitro propagation system.

Semi-quantitative analysis of cannabinoids in hemp (Cannabis sativa L.) using gas chromatography coupled to mass spectrometry

Background

Hemp (Cannabis sativa L.) is a producer of cannabinoids. These organic compounds are of increasing interest due to their potential applications in the medicinal field. Advances in analytical methods of identifying and quantifying these molecules are needed.

Method

This study describes a new method of cannabinoid separation from plant material using gas chromatography-mass spectrometry (GC-MS) as the analytical tool to detect low abundance cannabinoids that will likely have implications for future therapeutical treatments. A novel approach was adopted to separate trichomes from plant material to analyse cannabinoids of low abundance not observed in raw plant extract. Required plant sample used for analysis was greatly reduced compared to other methods. Derivatisation method was simplified and deconvolution software was utilised to recognise unknown cannabinoid compounds of low abundance.

Results

The method produces well-separated spectra and allows the detection of major and minor cannabinoids. Ten cannabinoids that had available standards could be identified and quantified and numerous unidentified cannabinoids or pathway intermediates based on GC-MS spectra similarities could be extracted and analysed simultaneously with this method.

Conclusions

This is a rapid novel extraction and analytical method from plant material that can identify major and minor cannabinoids using a simple technique. The method will be of use to future researchers seeking to study the multitude of cannabinoids whose values are currently not understood.

Biosynthetic origins of unusual cannabimimetic phytocannabinoids in Cannabis sativa L: A review

Plants of Cannabis sativa L. (Cannabaceae) produce an array of more than 160 isoprenylated resorcinyl polyketides, commonly referred to as phytocannabinoids. These compounds represent molecules of therapeutic importance due to their modulation of the human endocannabinoid system (ECS). While understanding of the biosynthesis of the major phytocannabinoids Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and cannabidiol (CBD) has grown rapidly in recent years, the biosynthetic origin and genetic regulation of many potentially therapeutically relevant minor phytocannabinoids remain unknown, which limits the development of chemotypically elite varieties of C. sativa. This review provides an up-to-date inventory of unusual phytocannabinoids which exhibit cannabimimetic-like activities and proposes putative metabolic origins. Metabolic branch points exploitable for combinatorial biosynthesis and engineering of phytocannabinoids with augmented therapeutic activities are also described, as is the role of phytocannabinoid remodelling to accelerate the therapeutic portfolio expansion in C. sativa.

Cannabinoids in movement disorders

INTRODUCTION

On the basis of both scientific progress and popular lore, there is growing optimism in the therapeutic potential of cannabis (marijuana) and cannabinoid-based chemicals for movement disorders. There is also notable skepticism regarding the scientific basis for this therapeutic optimism and significant concerns regarding the safety and regulation of cannabinoid products, particularly those available without prescription.

METHODS

In recognition of the high interest and controversial nature of this subject, the meeting committee of the International Parkinson and Movement Disorders Society arranged for a talk on cannabis at the 2019 annual meeting's Controversies in Movement Disorders plenary session. This paper summarizes the highlights of this session.

RESULTS

The endocannabinoid system is strongly tied to motor function and dysfunction, with basic research suggesting several promising therapeutic targets related to cannabinoids for movement disorders. Clinical research on cannabinoids for motor and nonmotor symptoms in Parkinson's disease, Huntington's disease, Tourette's syndrome, dystonia, and other movement disorders to date are promising at best and inconclusive or negative at worst. Research in other populations suggest efficacy for common symptoms like pain. While social campaigns against recreational cannabinoid use focus on cognitive changes in adolescents, the long-term sequelae of regulated medical use in older adults with movement disorders is unknown. The overall risks of cannabinoids may be similar to other commonly used medications and include falls and apathy.

CONCLUSION

Further research is greatly needed to better understand the actual clinical benefits and long-term side effects of medical cannabis products for movement disorders indications and populations.

Development of an Indole-Amide-Based Photoswitchable Cannabinoid Receptor Subtype 1 (CB1R) "Cis-On" Agonist

Activation of the human cannabinoid receptor type 1 (hCB₁R) with high spatiotemporal control is useful to study processes involved in different pathologies related to nociception, metabolic alterations, and neurological disorders. To synthesize new agonist ligands for hCB₁R, we have designed different classes of photoswitchable molecules based on an indole core. The modifications made to the central core have allowed us to understand the molecular characteristics necessary to design an agonist with optimal pharmacological properties. Compound 27a shows high affinity for CB₁R (K_i (cis-form) = 0.18 μM), with a marked difference in affinity with respect to its inactive "trans-off" form (CB₁R K_i trans/cis ratio = 5.4). The novel compounds were evaluated by radioligand binding studies, receptor internalization, sensor receptor activation (GRABeCB2.0), Western blots for analysis of ERK1/2 activation, NanoBiT βarr2 recruitment, and calcium mobilization assays, respectively. The data show that the novel agonist 27a is a candidate for studying the optical modulation of cannabinoid receptors (CBRs), serving as a new molecular tool for investigating the involvement of hCB₁R in disorders associated with the endocannabinoid system.

Prenatal exposure to Cannabis smoke induces early and lasting damage to the brain

Cannabis is the most widely used illegal drug during pregnancy, however, the effects of gestational exposure to Cannabis smoke (CS) on the central nervous system development remain uncharacterised. This study investigates the effects of maternal CS inhalation on brain function in the offspring. Pregnant mice were exposed daily to 5 min of CS during gestational days (GD) 5.5-17.5. On GD 18.5 half of the dams were euthanized for foetus removal. The offspring from the remaining dams were euthanized on postnatal days (PND) 20 and 60 for evaluation. Brain volume, cortex cell number, SOX2, histone-H3, parvalbumin, NeuN, and BDNF immunoreactivity were assessed in all groups. In addition, levels of NeuN, CB1 receptor, and BDNF expression were assessed and cortical primary neurons from rats were treated with Cannabis smoke extract (CSE) for assessment of cell viability. We found that male foetuses from the CS exposed group had decreased brain volume, whereas mice at PND 60 from the exposed group presented with increased brain volume. Olfactory bulb and diencephalon volume were found lower in foetuses exposed to CS. Mice at PND 60 from the exposed group had a smaller volume in the thalamus and hypothalamus while the cerebellum presented with a greater volume. Also, there was an increase in cortical BDNF immunoreactivity in CS exposed mice at PND 60. Protein expression analysis showed an increase in pro-BDNF in foetus brains exposed to CS. Mice at PND 60 presented an increase in mature BDNF in the prefrontal cortex (PFC) in the exposed group and a higher CB1 receptor expression in the PFC. Moreover, hippocampal NeuN expression was higher in adult animals from the exposed group. Lastly, treatment of cortical primary neurons with doses of CSE resulted in decreased cell viability. These findings highlight the potential negative neurodevelopmental outcomes induced by gestational CS exposure.

Minor Phytocannabinoids: A Misleading Name but a Promising Opportunity for Biomedical Research

Despite the very large number of phytocannabinoids isolated from Cannabis (Cannabis sativa L.), bioactivity studies have long remained focused on the so called “Big Four” [Δ⁹-THC (1), CBD (2), CBG (3) and CBC (4)] because of their earlier characterization and relatively easy availability via isolation and/or synthesis. Bioactivity information on the chemical space associated with the remaining part of the cannabinome, a set of ca 150 compounds traditionally referred to as “minor phytocannabinoids”, is scarce and patchy, yet promising in terms of pharmacological potential. According to their advancement stage, we sorted the bioactivity data available on these compounds, better referred to as the “dark cannabinome”, into categories: discovery (in vitro phenotypical and biochemical assays), preclinical (animal models), and clinical. Strategies to overcome the availability issues associated with minor phytocannabinoids are discussed, as well as the still unmet challenges facing their development as mainstream drugs.

A Review on the Bioactivity of Cannabinoids on Zebrafish Models: Emphasis on Neurodevelopment

For centuries, the cannabis plant has been used as a source of food, fiber, and medicine. Recently, scientific interest in cannabis has increased considerably, as its bioactive compounds have shown promising potential in the treatment of numerous musculoskeletal and neurological diseases in humans. However, the mechanisms that underlie its possible effects on neurodevelopment and nervous-system functioning remain poorly understood and need to be further investigated. Although the bulk of research on cannabis and cannabinoids is based on in vitro or rodent models, the zebrafish has now emerged as a powerful in vivo model for drug-screening studies and translational research. We here review the available literature on the use of cannabis/cannabinoids in zebrafish, and particularly in zebrafish models of neurological disorders. A critical analysis suggests that zebrafish could serve as an experimental tool for testing the bioactivity of cannabinoids, and they could thus provide important insights into the safety and efficacy of different cannabis-extract-based products. The review showed that zebrafish exhibit similar behaviors to rodents following cannabinoid exposure. The authors stress the importance of analyzing the full spectrum of naturally occurring cannabinoids, rather than just the main ones, THC and CBD, and they offer some pointers on performing behavioral analysis in zebrafish.

Determination of Cross-Reactivity of Contemporary Cannabinoids with THC Direct Immunoassay (ELISA) in Whole Blood

Immunoassay procedures, such as enzyme-linked immunosorbent assay (ELISA), are widely used for screening samples in both driving under the influence of drugs (DUID) and postmortem (PM) investigations. While these are sensitive and widely used techniques, they lack specificity compared to more novel instrumental screening platforms. In this study, the cross-reactivities of several cannabinoid isomers and related compounds were evaluated in whole blood using the Cannabinoids Direct ELISA kit from Immunalysis. The compounds of interest were supplemented individually at three different concentrations, ranging from 10-100 ng/mL or 10-1,000 ng/mL depending on analyte, to determine initial feasibility. Compounds exhibiting cross-reactivity were then tested to create dose-response curves to calculate the percent cross-reactivity. The cross-reactivity was determined to be 200% for delta-8-carboxy-tetrahydrocannabinol (THC) (delta-8-carboxy-THC), 25% for delta-9,11-THC, 13% for delta-10-THC, 7% for delta-6a(10a)-THC, 3% for THC-O-acetate and 0.5% for tetrahydrocannabiphorol (THCP). To determine potential impacts to forensic laboratory casework, a review of DUID and PM casework was also performed. From November 2020 to June 2021, a random sampling of DUID and PM cases was selected monthly and evaluated for the presence of cannabinoid isomer(s) in the absence of a reportable delta-9-carboxy-THC result. While validated techniques for the identification and confirmation of these isomer(s) did not exist at the time of routine testing, delta-8-carboxy-THC was believed to the be the most common isomer finding based on current testing capability. This study demonstrated a noticeable increase in the presence of isomeric cannabinoid compounds in both forensic DUID and PM casework sampled during this period and suggests potential impacts for clinical casework as well.

The Phytochemical Potential for Brain Disease Therapy and the Possible Nanodelivery Solutions for Brain Access

Plant-derived phytochemicals have gifted humans with vast therapeutic potentials. Yet, the unique features of the blood-brain barrier significantly limit their accession to the target tissue and thus clinical translation in brain disease treatment. Herein, we explore the medicinal outcomes of both the rare examples of phytochemicals that can easily translocate across the blood-brain barrier and most of the phytochemicals that were reported with brain therapeutic effects, but a bizarre amount of dosage is required due to their chemical nature. Lastly, we offer the nanodelivery platform that is capable of optimizing the targeted delivery and application of the non-permeable phytochemicals as well as utilizing the permeable phytochemicals for boosting novel applications of nanodelivery toward brain therapies.

Use of cannabis in the treatment of animals: a systematic review of randomized clinical trials

Cannabis is used in the treatment of several human conditions; however, its use is still less explored in veterinary medicine. This systematic review aims to summarize the evidence of efficacy and safety of the use of cannabis for the treatment of animal disease. A literature search was performed for studies published until 16 March 2021 in five databases. Randomized clinical trials (RCTs) that reported the efficacy or safety of cannabis in the treatment of animal disease were included. The RoB 2 Tool was used to assess the risk of bias. A total of 2427 records were identified, of which six studies fully met the eligibility criteria. RCTs were conducted in dogs with osteoarthritis (n = 4), with epilepsy (n = 1), and with behavioral disorders (n = 1). All studies used cannabidiol (CBD) oil in monotherapy or in combination with other drugs. Studies used CBD at 2 or 2.5 mg kg^-1 twice daily (n = 4), orally (n = 5), during 4 or 6 weeks (n = 3), and compared CBD with placebo (n = 5). CBD significantly reduced pain and increased activity in dogs with osteoarthritis (n = 3). Moreover, CBD significantly reduced the frequency of seizures in dogs with epilepsy (n = 1) and the aggressive behavior of dogs (n = 1). Although promising results were identified, studies were heterogeneous and presented risks of bias that required caution in the interpretation of findings. Therefore, there was some evidence to support the use of CBD in dogs with osteoarthritis to reduce pain and increased activity, but limited evidence against epilepsy and behavioral problems. In addition, CBD was well tolerated with mild adverse effects. More RCTs with high quality of evidence are needed, including greater numbers of animal subjects, additional species, and clear readout measures to confirm these findings.

Cannabidiol (CBD) From Non-Cannabis Plants: Myth or Reality?

Reports on the occurrence of cannabidiol (CBD, 1) in non-cannabis plants are critically reviewed. The isolation of 1 from Humulus Kriya (sic) was fraudulent and from Trema orientalis and stevia dubious, while the occurrence of traces of 1 in flax needs additional confirmation. The presence of high concentration of cannabigerol (CBG, 3a) and its corresponding acidic precursor (GBGA, 3b) in Helichrysum umbraculigerum could not be confirmed, but this plant deserves additional attention due to the possible phytocannabinoids accumulation in selected chemotypes.

The Efficacy of Cannabis on Multiple Sclerosis-Related Symptoms

Multiple sclerosis (MS) is known as an autoimmune disease that damages the neurons in the central nervous system. MS is characterized by its most common symptoms of spasticity, muscle spasms, neuropathic pain, tremors, bladder dysfunction, dysarthria, and some intellectual problems, including memory disturbances. Several clinical studies have been conducted to investigate the effects of cannabis on the relief of these symptoms in MS patients. The efficacy of Cannabis sativa (C. Sativa) in the management of MS outcomes such as spasticity, pain, tremors, ataxia, bladder functions, sleep, quality of life, and adverse effects were assessed in this review. Most clinical studies showed the positive effects of cannabinoids with their different routes of administration, such as oromucosal spray and oral form, in reducing most MS symptoms. The oromucosal spray Nabiximols demonstrated an improvement in reducing MS spasticity, pain, and quality of life with a tolerated adverse effect. Oral cannabinoids are significantly effective for treating MS pain and spasticity, while the other symptoms indicate slight improvement and the evidence is quite inconsistent. Oromucosal spray and oral cannabis are mainly used for treating patients with MS and have positive effects on treating the most common symptoms of MS, such as pain and spasticity, whereas the other MS symptoms indicated slight improvement, for which further studies are needed.

Beyond Δ9-tetrahydrocannabinol and cannabidiol: chemical differentiation of cannabis varieties applying targeted and untargeted analysis

Cannabis sativa (C. sativa) is commonly chemically classified based on its Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) content ratios. However, the plant contains nearly 150 additional cannabinoids, referred to as minor cannabinoids. Minor cannabinoids are gaining interest for improved plant and product characterization, e.g., for medical use, and bioanalytical questions in the medico-legal field. This study describes the development and validation of an analytical method for the elucidation of minor cannabinoid fingerprints, employing liquid chromatography coupled to high-resolution mass spectrometry. The method was used to characterize inflorescences from 18 different varieties of C. sativa, which were cultivated under the same standardized conditions. Complementing the targeted detection of 15 cannabinoids, untargeted metabolomics employing in silico assisted data analysis was used to detect additional plant ingredients with focus on cannabinoids. Principal component analysis (PCA) was used to evaluate differences between varieties. The overall purpose of this study was to examine the ability of targeted and non-targeted metabolomics using the mentioned techniques to distinguish cannabis varieties from each other by their minor cannabinoid fingerprint. Quantitative determination of targeted cannabinoids already gave valuable information on cannabinoid fingerprints as well as inter- and intra-variety variability of cannabinoid contents. The untargeted workflow led to the detection of 19 additional compounds. PCA of the targeted and untargeted datasets revealed further subgroups extending commonly applied phenotype classification systems of cannabis. This study presents an analytical method for the comprehensive characterization of C. sativa varieties.

Cannabis for Medical Use: Versatile Plant Rather Than a Single Drug

Medical Cannabis and its major cannabinoids (−)-trans-Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD) are gaining momentum for various medical purposes as their therapeutic qualities are becoming better established. However, studies regarding their efficacy are oftentimes inconclusive. This is chiefly because Cannabis is a versatile plant rather than a single drug and its effects do not depend only on the amount of THC and CBD. Hundreds of Cannabis cultivars and hybrids exist worldwide, each with a unique and distinct chemical profile. Most studies focus on THC and CBD, but these are just two of over 140 phytocannabinoids found in the plant in addition to a milieu of terpenoids, flavonoids and other compounds with potential therapeutic activities. Different plants contain a very different array of these metabolites in varying relative ratios, and it is the interplay between these molecules from the plant and the endocannabinoid system in the body that determines the ultimate therapeutic response and associated adverse effects. Here, we discuss how phytocannabinoid profiles differ between plants depending on the chemovar types, review the major factors that affect secondary metabolite accumulation in the plant including the genotype, growth conditions, processing, storage and the delivery route; and highlight how these factors make Cannabis treatment highly complex.