Pharmacokinetics and pharmacodynamics of the synthetic cannabinoid, 5F-MDMB-PICA, in male rats

Log D7.4 and plasma protein binding of synthetic cannabinoid receptor agonists and a comparison of experimental and predicted lipophilicity

The emergence of new synthetic cannabinoid receptor agonists (SCRAs) onto the illicit drugs market continues to cause harm, and the overall availability of physicochemical and pharmacokinetic data for new psychoactive substances is lacking. The lipophilicity of 23 SCRAs and the plasma protein binding (PPB) of 11 SCRAs was determined. Lipophilicity was determined using a validated chromatographic hydrophobicity index (CHI) log D method; tested SCRAs showed moderate to high lipophilicity, with experimental log D7.4 ranging from 2.48 (AB-FUBINACA) to 4.95 (4F-ABUTINACA). These results were also compared to in silico predictions generated using seven commercially available software packages and online tools (Canvas; ChemDraw; Gastroplus; MoKa; PreADMET; SwissADME; and XlogP). Licenced, dedicated software packages provided more accurate lipophilicity predictions than those which were free or had prediction as a secondary function; however, the latter still provided competitive estimates in most cases. PPB of tested SCRAs, as determined by equilibrium dialysis, was in the upper range of the lipophilicity scale, ranging from 90.8% (ADB-BUTINACA) to 99.9% (BZO-HEXOXIZID). The high PPB of these drugs may contribute to reduced rate of clearance and extended durations of pharmacological effects compared to lesser-bound SCRAs. The presented data improve understanding of the behaviour of these drugs in the body. Ultimately, similar data and predictions may be used in the prediction of the structure and properties of drugs yet to emerge on the illicit market.

Differential cannabinoid-like effects and pharmacokinetics of ADB-BICA, ADB-BINACA, ADB-4en-PINACA and MDMB-4en-PINACA in mice: A comparative study

Despite synthetic cannabinoids' (SCs) prevalent use among humans, these substances often lack comprehensive pharmacological data, primarily due to their rapid emergence in the market. This study aimed to discern differences and causal factors among four SCs (ADB-BICA, ADB-BINACA, ADB-4en-PINACA and MDMB-4en-PINACA), with respect to locomotor activity, body temperature and nociception threshold. Adult male C57BL/6 mice received intraperitoneal injections of varying doses (0.5, 0.1 and 0.02 mg/kg) of these compounds. Three substances (including ADB-BINACA, ADB-4en-PINACA and MDMB-4en-PINACA) demonstrated dose- and time-dependent hypolocomotive and hypothermic effects. Notably, 0.1 mg/kg MDMB-4en-PINACA exhibited analgesic properties. However, ADB-BICA did not cause any effects. MDMB-4en-PINACA manifested the most potent and sustained effects, followed by ADB-4en-PINACA, ADB-BINACA and ADB-BICA. Additionally, the cannabinoid receptor 1 (CB1R) antagonist AM251 suppressed the effects induced by acute administration of the substances. Analysis of molecular binding configurations revealed that the four SCs adopted a congruent C-shaped geometry, with shared linker binding pockets conducive to robust steric interaction with CB1R. Essential residues PHE268 , PHE200 and SER173 within CB1R were identified as pivotal contributors to enhancing receptor-ligand associations. During LC-MS/MS analysis, 0.5 mg/kg MDMB-4en-PINACA exhibited the highest plasma concentration and most prolonged detection window post-administration. The study of SCs' pharmacological and pharmacokinetic profiles is crucial for better understanding the main mechanisms of cannabinoid-like effects induced by SCs, interpreting clinical findings related to SC uses and enhancing SCs risk awareness.

Cannabinoids in Medicine: A Multifaceted Exploration of Types, Therapeutic Applications, and Emerging Opportunities in Neurodegenerative Diseases and Cancer Therapy

In this review article, we embark on a thorough exploration of cannabinoids, compounds that have garnered considerable attention for their potential therapeutic applications. Initially, this article delves into the fundamental background of cannabinoids, emphasizing the role of endogenous cannabinoids in the human body and outlining their significance in studying neurodegenerative diseases and cancer. Building on this foundation, this article categorizes cannabinoids into three main types: phytocannabinoids (plant-derived cannabinoids), endocannabinoids (naturally occurring in the body), and synthetic cannabinoids (laboratory-produced cannabinoids). The intricate mechanisms through which these compounds interact with cannabinoid receptors and signaling pathways are elucidated. A comprehensive overview of cannabinoid pharmacology follows, highlighting their absorption, distribution, metabolism, and excretion, as well as their pharmacokinetic and pharmacodynamic properties. Special emphasis is placed on the role of cannabinoids in neurodegenerative diseases, showcasing their potential benefits in conditions such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. The potential antitumor properties of cannabinoids are also investigated, exploring their potential therapeutic applications in cancer treatment and the mechanisms underlying their anticancer effects. Clinical aspects are thoroughly discussed, from the viability of cannabinoids as therapeutic agents to current clinical trials, safety considerations, and the adverse effects observed. This review culminates in a discussion of promising future research avenues and the broader implications for cannabinoid-based therapies, concluding with a reflection on the immense potential of cannabinoids in modern medicine.

Focusing on the 5F-MDMB-PICA, 4F-MDMB-BICA synthetic cannabinoids and their primary metabolites in analytical and pharmacological aspects

Nowadays, more and more new synthetic cannabinoids (SCs) appearing on the illicit market present challenges to analytical, forensic, and toxicology experts. For a better understanding of the physiological effect of SCs, the key issue is studying their metabolomic and psychoactive properties. In this study, our validated targeted reversed phase UHPLC-MS/MS method was used for determination of urinary concentration of 5F-MDMB-PICA, 4F-MDMB-BICA, and their primary metabolites. The liquid-liquid extraction procedure was applied for the enrichment of SCs.The pharmacological characterization of investigated SCs were studied by radioligand competition binding and ligand stimulated [³⁵S]GTPγS binding assays. For 5F-MDMB-PICA and 4F-MDMB-BICA, the median urinary concentrations were 0.076 and 0.312 ng/mL. For primary metabolites, the concentration range was 0.029-881.02* ng/mL for 5F-MDMB-PICA-COOH, and 0.396-4579* ng/mL for 4F-MDMB-BICA-COOH. In the polydrug aspect, the 22 urine samples were verified to be abused with 6 illicit drugs. The affinity of the metabolites to CB1R significantly decreased compared to the parent ligands. In the GTPγS functional assay, both 5F-MDMB-PICA and 4F-MDMB-BICA were acting as full agonists, while the metabolites were found as weak inverse agonists. Additionally, the G-protein stimulatory effects of the full agonist 5F-MDMB-PICA and 4F-MDMB-BICA were reduced by metabolites. These results strongly indicate the dose-dependent CB1R-mediated weak inverse agonist effects of the two butanoic acid metabolites. The obtained high concentration of main urinary metabolites of 5F-MDMB-PICA and 4F-MDMB-BICA confirmed the relevance of their routine analysis in forensic and toxicological practices. Based on in vitro binding assays, the metabolites presumably might cause a lower psychoactive effect than parent compounds.

In vitro and in vivo pharmacology of nine novel synthetic cannabinoid receptor agonists

Synthetic cannabinoid receptor agonists (SCRAs) are novel psychoactive substances that bind to and activate CB1 receptors in the brain. The structural manipulations observed in newer SCRAs suggest that manufacturers have incorporated modern drug development techniques into their repertoire, often producing higher CB1 receptor affinity than Δ9-tetrahydrocannabinol (Δ9-THC). This study examined nine SCRAs recently detected by forensic surveillance, some of which caused fatalities: 5F-MDMB-PICA, FUB-144, 5F-MMB-PICA, MMB-4en-PICA, MMB-FUBICA, 5F-EDMB-PINACA, APP-BINACA, MDMB-4en-PINACA, and FUB-AKB48. Compounds were evaluated for CB1 and CB2 receptor binding affinity and functional activation and for their effects on body temperature, time course, and pharmacological equivalence with Δ9-THC in Δ9-THC drug discrimination in mice. All SCRAs bound to and activated CB1 and CB2 receptors with high affinity, with similar or greater affinity for CB2 than CB1 receptors and stimulated [35S]GTPγS binding in CB1 and CB2 expressing cell membranes. All compounds produced hypothermia, with shorter latency to peak effects for SCRAs than Δ9-THC. All SCRAs fully substituted for Δ9-THC in drug discrimination at one or more doses. Rank order potency in producing in vivo effects mostly aligned with rank order CB1 receptor affinities. Potencies for Δ9-THC-like discriminative stimulus effects were similar across sex except Δ9-THC was more potent in females and 5F-MMB-PICA was more potent in males. In summary, 5F-EMDB-PINACA, 5F-MDMB-PICA, MDMB-4en-PINACA, FUB-144, FUB-AKB48, 5F-MMB-PICA, MMB-4en-PICA, and MMB-FUBICA are potent and efficacious SCRAs with pharmacology like that of past SCRAs that have been abused in humans. In contrast, APP-BINACA was efficacious, but had lower potency than most past SCRAs.

Linking in vitro and ex vivo CB1 activity with serum concentrations and clinical features in 5F-MDMB-PICA users to better understand SCRAs and their metabolites

Synthetic cannabinoid receptor agonists (SCRAs) pose a danger to public health. This study focused on individuals experiencing recreational drug toxicity who had used 5F-MDMB-PICA.Patient records were evaluated regarding vital signs, Glasgow Coma Scale (GCS) and clinical features. Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) confirmed and quantified the presence of 5F-MDMB-PICA (and/or metabolites) as the only SCRA present in the serum of 71 patients. Cannabinoid activity was evaluated by a cannabinoid receptor (CB₁) bioassay, to assess the relationship between serum concentrations and ex vivo human CB₁ activation potential. Furthermore, a link with the clinical presentation was appraised.5F-MDMB-PICA and five metabolites were pharmacologically profiled in vitro, revealing theoretically possible contributions of two active in vivo metabolites to overall cannabinoid activity. Serum concentrations of 5F-MDMB-PICA were correlated to the ex vivo cannabinoid activity, revealing a sigmoidal relationship. The latter could also be predicted based on pharmacological characterization of 5F-MDMB-PICA and its metabolites and an in-depth investigation of the bioassay outcome. Clinically, the GCS showed a significant trend (decrease) with increasing ex vivo cannabinoid activity.This is the first study to evaluate possible toxic effects of 5F-MDMB-PICA in a unique large patient cohort. It allows a better understanding of 5F-MDMB-PICA and metabolites in humans, suggesting a negligible contribution by 5F-MDMB-PICA metabolites to the overall cannabinoid activity in serum. Additionally, this work shows that in vitro pharmacological characterization allows close prediction of an individual's ex vivo CB₁ activity, the latter showing a relationship with the level of consciousness.

Structure-activity relationships for 5F-MDMB-PICA and its 5F-pentylindole analogs to induce cannabinoid-like effects in mice

Synthetic cannabinoid receptor agonists (SCRAs) are an evolving class of new psychoactive substances found on recreational drug markets worldwide. The indole-containing compound, 5F-MDMB-PICA, is a popular SCRA associated with serious medical consequences, including overdose and hospitalizations. In vitro studies reveal that 5F-MDMB-PICA is a potent agonist at cannabinoid type 1 receptors (CB₁), but little information exists regarding in vivo pharmacology of the drug. To this end, we examined the in vitro and in vivo cannabinoid-like effects produced by 5F-MDMB-PICA and related 5F-pentylindole analogs with differing composition of the head group moiety (i.e., 5F-NNEI, 5F-SDB-006, 5F-CUMYL-PICA, 5F-MMB-PICA). In mouse brain membranes, 5F-MDMB-PICA and its analogs inhibited binding to [³H]rimonabant-labeled CB₁ and displayed agonist actions in [³⁵S]GTPγS functional assays. 5F-MDMB-PICA exhibited the highest CB₁ affinity (K_i = 1.24 nM) and functional potency (EC₅₀ = 1.46 nM), but head group composition markedly influenced activity in both assays. For example, the 3,3-dimethylbutanoate (5F-MDMB-PICA) and cumyl (5F-CUMYL-PICA) head groups engendered high CB₁ affinity and potency, whereas a benzyl (5F-SDB-006) head group did not. In C57BL/6J mice, all 5F-pentylindole SCRAs produced dose- and time-dependent hypothermia, catalepsy, and analgesia that were reversed by rimonabant, indicating CB₁ involvement. In vitro K_i and EC₅₀ values were positively correlated with in vivo ED₅₀ potency estimates. Our findings demonstrate that 5F-MDMB-PICA is a potent SCRA, and subtle alterations to head group composition can have profound influence on pharmacological effects at CB₁. Importantly, measures of CB₁ binding and efficacy in mouse brain tissue seem to accurately predict in vivo drug potency in this species.