Synthetic Cathinone Derivatives Research Articles

Structural and functional perspectives on interactions between synthetic cathinones and monoamine transporters.

Synthetic cathinone derivatives comprise a family of psychoactive compounds structurally related to amphetamine. Over the last decade, clandestine chemists have synthesized a consistent stream of innovative cathinone derivatives to outpace governmental regulatory restrictions. Many of these unregulated substances are produced and distributed as designer drugs. Two of the principal chemical scaffolds exploited to expand the synthetic cathinone family are methcathinone and α-pyrrolidinopentiophenone (or α-pyrrolidinovalerophenone, α-PVP). These compounds' main physiological targets are monoamine transporters, where they promote addiction by potentiating dopaminergic neurotransmission. This chapter describes techniques used to study the pharmacodynamic properties of cathinones at monoamine transporters in vitro. Biochemical techniques described include uptake inhibition and release assays in rat brain synaptosomes and in mammalian expression systems. Electrophysiological techniques include current measurements using the voltage clamp technique. We describe a Ca2+ mobilization assay wherein voltage-gated Ca2+ channels function as reporters to study the action of synthetic cathinones at monoamine transporters. We discuss results from systematic structure-activity relationship studies on simple and complex cathinones at monoamine transporters with an emphasis on identifying structural moieties that modulate potency and selectivity at these transporters. Moreover, different profiles of selectivity at monoamine transporters directly predict compounds associated with behavioral and subjective effects within animals and humans. In conclusion, clarification of the structural aspects of compounds which modulate potency and selectivity at monoamine transporters is critical to identify and predict potential addictive drugs. This knowledge may allow prompt allocation of resources toward drugs that represent the greatest threats after drugs are identified by forensic laboratories.

Effects of repeated binge intake of the pyrovalerone cathinone derivative 3,4-methylenedioxypyrovalerone on prefrontal cytokine levels in rats - a preliminary study.

Drugs of abuse activate neuroimmune signaling in addiction-related regions of the brain, including the prefrontal cortex (PFC) which mediates executive control, attention, and behavioral inhibition. Traditional psychostimulants including methamphetamine and cocaine are known to induce PFC inflammation, yet the effects of synthetic cathinone derivatives are largely unexplored. In this study, we examined the ability of repeated binge-like intake of the pyrovalerone cathinone derivative 3,4-methylenedioxypyrovalerone (MDPV) to alter cytokine profiles in the PFC. Male and female rats were allowed to intravenously self-administer MDPV (0.05 mg/kg/infusion) or saline as a control under conditions of prolonged binge-like access, consisting of three 96 h periods of drug access interspersed with 72 h of forced abstinence. Three weeks following cessation of drug availability, PFC cytokine levels were assessed using antibody arrays. Employing the unsupervised clustering and regression analysis tool CytoMod, a single module of co-signaling cytokines associated with MDPV intake regardless of sex was identified. With regards to specific cytokines, MDPV intake was positively associated with PFC levels of VCAM-1/CD106 and negatively associated with levels of Flt-3 ligand. These findings indicate that prolonged MDPV intake causes changes in PFC cytokine levels that persist into abstinence; however, the functional ramifications of these changes remain to be fully elucidated.

Mephedrone – a synthetic derivative of cathinone

Abstract Novel psychoactive substances (NPS) are a very diverse group of recreational drugs that mimic effects of classic drugs of abuse and, at least at the beginning, are not usually prohibited. Representative of this group is mephedrone – a cathinone derivative. It is widely used as a recreational drug, particularly among club guests. Mephedrone`s effects are compared to effects of cocaine and MDMA but are more short-lived and include: psychostimulation, enhanced empathy, reduced feeling of tiredness, euphoria, hallucinations. This drug also exerts adverse effects, such as: anxiety, delusions, paranoia, psychosis, increased body temperature, elevated blood pressure, sleep disturbances. According to surveys performed on mephedrone users, it may be addictive. Those findings confirms a growing number of behavioural and molecular studies on animals. Mephedrone acts mainly via increasing monoamine transmission through increasing release of dopamine, serotonin and noradrenaline into synaptic cleft, inhibiting their re-uptake and reducing their metabolism. However, participation of other transmitters, modulators and pathways are investigated, including glutamate and nitric oxide. Favorable routes of administering mephedrone is intranasal and per os. Moreover, most often drug users use it in a binge way, e.g. taking repeated doses of a drug in a short period of time. According to animal studies, this pattern of mephedrone use leaves more neural injuries than taking it regularly, but in smaller doses. Our aim was to present a short, but essential, overview of the current knowledge on mephedrone, focusing on its effects, mechanism of action, animal studies evaluating its influence on the brain structures, toxicity and pharmacokinetics.

Mephedrone induced apoptosis and impaired neurogenesis in embryonic neural stem/progenitor cells.

Mephedrone, a synthetic derivative of cathinone, is a commonly used psychoactive substance. Our previous study showed that exposure to mephedrone during pegnancy induced antiproliferative and pro-apoptotic effects in hippocampus of mice delivered pups. However, its effects on neural stem/progenitor cells (NS/PC) remain unexplored. The aim of this study is to investigate the effects of mephedrone exposure on the proliferation, differentiation, and apoptosis of rat embryonic NS/PC. NS/PC were isolated from rat fetal ganglionic eminence region at embryonic day 14.5. The effects of mephedrone on cell proliferation, neurosphere formation (colonies of NS/PC), neuronal differentiation, and apoptosis of NS/PC were assessed using MTT, immunocytochemistry, and flow cytometry. Mephedrone at concentrations of 20-640 µM significantly decreased the proliferation of NS/PC, induced cell cycle arrest, and enhanced the percent of apoptotic and necrotic cells. Neurosphere assays revealed a significant reduction in the number and diameter of neurosphere-forming cells. In addition, mephedrone significantly decreased the expressions of DCX and NeuN neuronal markers. Taken together, our results suggeste that exposure to mephedrone decreases the viability and neuronal differentiation of embryonic NS/PC. This study showed that mephedrone exposure during fetal or neonatal life may impair neurogenesis and subsequent brain development.

Binge-like mephedrone treatment induces memory impairment concomitant with brain kynurenic acid reduction in mice

While mephedrone (4-methylmethcathinone), a synthetic cathinone derivative, is widely abused by adolescents and young adults, the knowledge about its long-term effects on memory processes is limited. Kynurenic acid (KYNA) is a neuroactive metabolite of the kynurenine pathway of tryptophan degradation. KYNA is considered an important endogenous modulator influencing physiological and pathological processes, including learning and memory processes. The aim of this study was to determine whether (A) binge-like mephedrone administration (10.0 and 30.0 mg/kg, intraperitoneally, in 4 doses separated by 2 h) induces memory impairments, assessed 2, 8 and 15 days after mephedrone cessation in the passive avoidance test in mice, and whether (B) KYNA is involved in these memory processes. To clarify the role of KYNA in the mephedrone effects, its production in the murine brain in vivo, and in cortical slices in vitro, as well as the activities of kynurenine aminotransferases (KATs) I and II were assessed. Furthermore, cell line experiments were conducted to investigate the effects of mephedrone on normal human brain cells. Our results showed memory impairments 8 and 15 days after binge-like mephedrone administration. At the same time, reduction in the KYNA level in the murine brain was noted. In vitro studies showed no effect of mephedrone on the production of KYNA in cortical slices or on the activity of the KAT I and II enzymes. Finally, exposure of normal cells to mephedrone in vitro resulted in a modest reduction of cell viability and proliferation.

Repeated administration of N-ethyl-pentedrone induces increased aggression and impairs social exploration after withdrawal in mice

N-ethyl-pentedrone (NEPD, 2-(ethylamino)-1-phenyl-1-pentanone) is one of the latest synthetic cathinone derivatives that emerged into the illicit drug market. This drug has psychostimulant properties and has been related with several intoxications and even fatalities. However, information about the consequences of its acute and repeated consumption is lacking. Thus, the aim of our study was to investigate the behavioral effects after both acute and repeated NEPD exposure as well as the neurochemical changes. Male OF1 mice were treated with an acute dose (1, 3 or 10 mg/kg, i.p.) or received repeated injections of these doses (twice/day, 5 days) of NEPD. Shortly after drug-exposure or during drug-withdrawal, anxiety-like behavior, aggressiveness, social interaction, depressive-like symptoms, body weight and temperature were assessed. Also, monoamine synthesis enzymes, levels of neurotransmitters and their precursors and main metabolites, as well as ΔFosB, were determined in striatum and prefrontal cortex from post-mortem tissue. Acute administration of NEPD induced anxiolytic effects and reduced social exploration whereas during withdrawal after repeated administration the anxiolytic effect had vanished, and the reduced social exploration was still present and accompanied with increased aggressive behavior. Moreover, NEPD (10 mg/kg) induced slight hyperthermia and reduced weight gain during the repeated administration, whereas increased locomotor activity and lack of depressive symptoms were found during withdrawal. This was accompanied by increased plasma corticosterone and decrease in striatal dopamine. Finally, the long-lasting and robust increase in ΔFosB levels found in striatum after NEPD chronic exposure suggests a high risk of dependence. The increased aggressivity and locomotor activity, together with this potential of inducing dependence justify a warning about the risks of consumption of NEPD if translated to humans.

Determination of 19 Psychoactive Substances in Premortem and Postmortem Whole Blood Samples Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

An ever-increasing need exists within the forensic laboratories to develop analytical processes for the qualitative and quantitative determination of a broad spectrum of new psychoactive substances. Phenylethylamine derivatives are among the major classes of psychoactive substances available on the global market and include both amphetamine analogues and synthetic cathinones. In this work, an ultra-high-performance liquid chromatography-positive ion electrospray ionization tandem mass spectrometric method (UHPLC-ESI-MS/MS) has been developed and fully validated for the determination of 19 psychoactive substances, including nine amphetamine-type stimulants and 10 synthetic cathinone derivatives, in premortem and postmortem whole blood. The assay was based on the use of 1 mL premortem or postmortem whole blood, following solid phase extraction prior to the analysis. The separation was achieved on a Poroshell 120 EC-C18 analytical column with a gradient mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water in 9 min. The dynamic multiple reaction monitoring used in this work allowed for limit of detection (LOD) and lower limit of quantitation (LOQ) values of 0.5 and 2 ng mL−1, respectively, for all analytes both in premortem and postmortem whole blood samples. A quadratic calibration model was used for the 12 quantitative analytes over the concentration range of 20–2000 ng mL−1, and the method was shown to be precise and accurate both in premortem and postmortem whole blood. The method was applied to the analysis of real cases and proved to be a valuable tool in forensic and clinical toxicology.

Reinforcing and discriminative-stimulus effects of two pyrrolidine-containing synthetic cathinone derivatives in rats

The molecular and behavioral aspects of α-pyrrolidinopentiophenone (α-PVP) have been characterized; however, how the structural modification of α-PVP affects its abuse potential is still unknown. In this study, we investigated the abuse potential of two pyrrolidinylated second-generation cathinones:4-chloro-α-pyrrolidinopentiophenone (4cl-α-PVP) and 4-chloro-α-pyrrolidinopropiophenone (4cl-α-PPP). Male Sprague-Dawley rats were trained to self-administer methamphetamine (METH, 0.05 mg·kg−1·infusion−1), α-PVP (0.05 mg·kg−1·infusion−1), 4cl-α-PVP (0.05 mg·kg−1·infusion−1), and 4cl-α-PPP (0.5 mg·kg−1·infusion−1) under a fixed ratio (FR) 1 reinforcement schedule for 10 sessions. The discriminative-stimulus effect of METH (0.8 mg/kg) from saline was tested under an FR10 schedule of food delivery. α-PVP, 4cl-α-PVP and 4cl-α-PPP produced reinforcement behaviors and presented an inverted U-shaped dose effect. The reinforcing potency was displayed with a rank order of α-PVP (0.029 mg·kg−1·infusion−1) > METH (0.040 mg·kg−1·infusion−1) > 4cl-α-PVP (0.094 mg·kg−1·infusion−1) > 4cl-α-PPP (0.51 mg·kg−1·infusion−1). All three drugs were fully substituted for the discriminative-stimulus effects of METH in rats. The substitution potency for discriminative-stimulus effects of α-PVP (ED50 = 0.4 mg/kg) was approximately equal to that of METH (ED50 = 0.3 mg/kg), while the discriminative potency of 4cl-α-PVP (ED50 = 1.0 mg/kg) and 4cl-α-PPP (ED50 = 5 mg/kg) was approximately 3 and 16-fold less than that of METH. The rank order of potency was α-PVP ≈ METH >4cl-α-PVP > 4cl-α-PPP. The present data demonstrated that 4cl-α-PVP and 4cl-α-PPP produced reinforcing effects and fully and dose-dependently substituted for the subjective effects of METH, suggesting that both 4cl-α-PVP and 4cl-α-PPP have abuse potential that may be similar to METH.

Development and validation of GC–MS method for determination of methcathinone and its main metabolite in mice plasma and brain tissue after SPE: Pharmacokinetic and distribution study

Only focusing on the plasma levels is inadequate for the full consideration of the physiological disposition of illicit drugs in vivo. Therefore, we conducted the inclusive study on the in vivo dynamic process of intraperitoneal administration of methcathinone (MET), a well-known member of the synthetic cathinone derivatives, which is structurally similar to amphetamine analogs. This study described a validated, selective and sensitive GC–MS method for the simultaneous quantification of MET and its main metabolite, ephedrine (EPD), in the plasma and brain tissue of mice, after solid phase extraction (SPE). Ephedrine-d3 was used as an internal standard (IS). The developed method was validated following US-FDA guidelines within a concentration range of 5–1000 ng/mL for both drugs (r2 > 0.998) in the mice plasma and brain. The recoveries of MET and EPD from the mice plasma and brain ranged from 108.5 to 112.1%. The intra- and inter-day RSDs were ≤ 11.0 %. The proposed method was applied, for the first time, to investigate the pharmacokinetic (PK) and distribution study of MET and EPD following intraperitoneal administration of MET (1.4 mg/kg) to Swiss albino mice. The results exhibited that the Cmax and Tmax of MET in mice plasma was 517.1 ng/mL and 15 min as compared to 3.6 ng/mL and 2 h of EPD. Moreover, MET rapidly passed the blood brain barrier with Cmax of 1444.5 ng/mL achieved at 15 min, whereas, EPD monitored Cmax of 43.6 ng/mL at 4 h in mice brain. The highest concentration of MET in the mice brain followed by plasma was reported, with a necessity to perform more detailed clinical investigations.

Methylenedioxymethamphetamine-like discriminative stimulus effects of seven cathinones in rats.

Synthetic cathinone derivatives are commonly considered quasi-legal alternatives for stimulant drugs, such as cocaine and methamphetamine, but some derivatives are increasingly being detected in club drug formulations of Ecstasy or 'Molly' as substitutes for methylenedioxymethamphetamine (±-MDMA). Although several studies have evaluated the psychostimulant-like effects of synthetic cathinones, few cathinone compounds have been assessed for MDMA-like activity. In order to determine their likelihood of interchangeability with entactogenic club drugs, the discriminative stimulus effects of methcathinone, 4-fluoromethcathinone, 4-methylmethcathinone, 4-methylethcathinone, 3-fluoromethcathinone, pentedrone, and ethylone were assessed in Sprague-Dawley rats trained to discriminate 1.5 mg/kg racemic methylenedioxymethamphetamine (±-MDMA) from vehicle. Methamphetamine and the cathinones 4-fluoromethcathinone, 4-methylmethcathinone, 4-methylethcathinone, 3-fluoromethcathinone, pentedrone, and ethylone fully substituted for the discriminative stimulus effects of ±-MDMA. In contrast, methcathinone produced a maximum of only 43% ±-MDMA-appropriate responding and higher doses suppressed responding. Most, but not all of the cathinone compounds tested have discriminative stimulus effects similar to those of MDMA as well as psychostimulant-like effects; however, the potency of MDMA versus psychostimulant substitution varies substantially among the compounds, suggesting that a subset of synthetic cathinones are more MDMA-like than psychostimulant-like. These findings further highlight the highly-variable pharmacology of this class of compounds and suggest that those cathinones with MDMA-like effects may also have increased use as club drugs.

Combined effects of mephedrone and cocaine on locomotor activity and conditioned place preference in male Sprague-Dawley rats.

Mephedrone (MEPH) is one of several synthetic cathinone derivatives and a common constituent of illicit 'bath salts'. Concomitant use of MEPH with other psychostimulants is common among recreational users, but their combined effects have not been evaluated rigorously. In experiment 1, 56 male Sprague-Dawley rats were administered saline, MEPH (1 or 5 mg/kg), COC (5 mg/kg), or a mixture of MEPH (1 or 5 mg/kg) + COC (5 mg/kg) for seven consecutive days. Following a 10-day drug washout, rats were given a challenge injection of COC (5 mg/kg). Locomotor activity was recorded for 60 minutes immediately before and for 60 minutes immediately after injections on days 1, 7, and 17. In experiment 2, an unbiased conditioned place preference procedure was implemented over a 10-day period with a separate group of 66 male Sprague-Dawley rats randomly assigned to similar drug treatments used in experiment. Results of experiment 1 indicated significant increases in horizontal activity after repeated treatment with MEPH+COC mixtures, but not with either drug alone. Additionally, rats pretreated with MEPH + COC mixtures exhibited an augmented response to cocaine following drug abstinence. Evidence for CPP was established in rats treated with 5 mg/kg MEPH, 5 mg/kg COC and the 5 mg/kg MEPH + 5 mg/kg COC mixture. In conclusion, cocaine and mephedrone may have additive locomotor stimulant effects, although further assessment with a wider range of dose combinations must be evaluated. As a precautionary note, concurrent use of these substances may pose an enhanced risk for abuse.

Fragmentation pathways of odd- and even-electron N-alkylated synthetic cathinones

Three ionization techniques, isotopic labeling, high-resolution mass spectrometry (HRMS) and multi-stage mass spectrometry (MSn) were used to analyze a series of N-alkylated synthetic cathinone derivatives and gain a deeper understanding of their fragmentation behavior during mass spectrometric analysis. The compounds analyzed represent 15 unique structures with common substitutions to the core synthetic cathinone structure, including substitutions to the aromatic ring and the number and types of N-alkyl functionalities. The analytical techniques employed include gas chromatography-electron ionization-mass spectrometry (GC-EI-MS), electrospray ionization-tandem mass spectrometry (ESI-MS/MS) with HRMS and direct analysis in real time tandem mass spectrometry (DART-MS/MS) with HRMS. These techniques cover a variety of forensic applications, including seized drug analysis, toxicological analysis and screening analysis, in local, state and federal laboratories. For collision-induced dissociation (CID) of protonated precursors, the spectra of 2° and 3° amines showed evidence for charge-remote and charge-directed fragmentation mechanisms. The 2° amines lost H2O as a dominant pathway whereas the 3° amines favored the formation of alkylphenones. As reported by others, CID of protonated N-alkylated cathinones containing 2° and 3°amines also provided an abundance of odd-electron product ions from the even-electron precursors. In contrast to the rearrangements observed in CID of protonated cathinones, EI fragmentation patterns were dominated by radical-directed cleavages to form iminium ions and charge-directed cleavages to form acylium ions. A comparison between the fragmentation behaviors of N-alkylated synthetic cathinones under all three ionization techniques enables a deeper understanding of N-alkylated synthetic cathinone fragmentation under varying instrumental setups.

Fragmentation pathways of α-pyrrolidinophenone synthetic cathinones and their application to the identification of emerging synthetic cathinone derivatives

The expanding use of emerging synthetic drugs is creating a growing problem for both seized drug analysts and toxicologists because the clandestine suppliers continually tweak the chemical structures to keep one step ahead of the law. Synthetic cathinones, commonly referred to as bath salts, are a specific class of emerging synthetic drugs. These substances are derivatives of cathinone, which is the psychoactive component of the Catha edulis plant, commonly referred to as khat. Of the synthetic cathinone class of compounds, the α-pyrrolidinophenone synthetic cathinone derivatives stand out as one of the most abused designer drugs.The fragmentation behavior of a series of α-pyrrolidinophenone synthetic cathinones was studied with three different ionization and fragmentation techniques to enhance the current understanding of α-pyrrolidinophenone synthetic cathinones in mass spectrometers. Gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) fragmentation is commonly used by seized drug analysts, whereas liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) is more commonly used in toxicological analyses. Direct analysis in real time mass spectrometry (DART-MS) is becoming more popular as a screening technique, especially in national laboratories. Each ionization and activation method encourage particular pathways of fragmentation, and whereas some pathways are conserved across all platforms, other pathways are unique to a particular instrument. This study combines isotope-labeling, multi-stage mass spectrometry (MSn) and accurate mass measurements with high-resolution mass spectrometry (HRMS) to enhance the current understanding about α-pyrrolidinophenone synthetic cathinones. This manuscript provides characteristic protonated tandem mass spectrometry fragmentation pathways and the mechanistic origins of the EI-MS fragmentation observed for this class of synthetic cathinones and provides examples of how this knowledge can be applied to the identification of novel synthetic cathinones.

Discrimination of synthetic cannabinoids in herbal matrices and of cathinone derivatives by portable and laboratory-based Raman spectroscopy

One of the greatest challenges for European drug police and customs forces is how to effectively respond to the dynamically changing market for new psychoactive substances (NPS). Due to the NPS phenomenon, there is an increasing demand by customs or drug enforcement organisations for rapid and portable analytical techniques to characterise unknown samples, such as Raman spectroscopy, which are frequently used as first indicative techniques to detect controlled substances like illicit drugs. In this study, the effective discrimination of 28 synthetic cannabinoids and 15 cathinone derivatives using three different Raman spectrometers with different excitation wavelengths (532, 785 and 1064 nm) was investigated. The results show a high comparability of the Raman spectra from different spectrometers using spectral pre-processing methods. A PCA model allows assigning a substance to a specific substance class and additionally provides information on the nature of structural building blocks of the cathinone derivatives or synthetic cannabinoids being in the focus of this study. Characteristic group frequencies for synthetic cannabinoids and cathinone derivatives are summarised in tables to support future identification in other studies and in police and customs forensic case work. Combining both the use of chemometrics and Raman frequency tables has been shown as a successful tool to improve the characterisation of 60 seized herbal mixtures containing synthetic cannabinoids as active ingredients.

Development, validation and evaluation of a quantitative method for the analysis of twenty-four new psychoactive substances in oral fluid by LC–MS/MS

The use of new psychoactive substances (NPS) has been recognized worldwide at an alarming rate. Oral fluid collection is becoming more prevalent as a matrix for evaluating drug consumption. In this study, a specific, quick and non-invasive method for detection and quantitation of twenty-four synthetic cannabinoids and cathinone derivatives, including ten not previously reported NPS in oral fluid was performed. A quantitative method was developed on a liquid chromatography coupled to a triple quadrupole mass spectrometer system operated in dynamic multiple reaction monitoring (dMRM) mode using solid phase extraction (SPE) as pre-concentration step. Analytical separation of the target drugs was reached in a total elution time of 10 min. The developed method was validated according to the ASB standard 036. Overall bias and precision of the method were within ±20% for twenty-three compounds. All drugs showed acceptable linearity with R2 values greater than 0.98, and LLOQ values of 0.25 ng/mL and 1.0 ng/mL for selected NPS. The overall bias for a performed blind verification study was 7%. Our results demonstrate the method is suitable for quantifying NPS in oral fluid through solid phase extraction and analysis using LC–MS/MS.

The psychoactive cathinone derivative pyrovalerone alters locomotor activity and decreases dopamine receptor expression in zebrafish (Danio rerio).

IntroductionPyrovalerone (4‐methyl‐β‐keto‐prolintane) is a synthetic cathinone (beta‐keto‐amphetamine) derivative. Cathinones are a concern as drugs of abuse, as related street drugs such as methylenedioxypyrovalerone have garnered significant attention. The primary mechanism of action of cathinones is to inhibit reuptake transporters (dopamine and norepinephrine) in reward centers of the central nervous system.MethodsWe measured bioenergetic, behavioral, and molecular responses to pyrovalerone (nM‐µM) in zebrafish to evaluate its potential for neurotoxicity and neurological impairment.ResultsPyrovalerone did not induce any mortality in zebrafish larvae over a 3‐ and 24‐hr period; however, seizures were prevalent at the highest dose tested (100 µM). Oxidative phosphorylation was not affected in the embryos, and there was no change in superoxide dismutase 1 expression. Following a 3‐hr treatment to pyrovalerone (1–100 µM), larval zebrafish (6d) showed a dose‐dependent decrease (70%–90%) in total distance moved in a visual motor response (VMR) test. We interrogated potential mechanisms related to the hypoactivity, focusing on the expression of dopamine‐related transcripts as cathinones can modulate the dopamine system. Pyrovalerone decreased the expression levels of dopamine receptor D1 (~60%) in larval zebrafish but did not affect the expression of tyrosine hydroxylase, dopamine active transporter, or any other dopamine receptor subunit examined, suggesting that pyrovalerone may regulate the expression of dopamine receptors in a specific manner.DiscussionFurther studies using zebrafish are expected to reveal new insight into molecular mechanisms and behavioral responses to cathinone derivates, and zebrafish may be a useful model for understanding the relationship between the dopamine system and bath salts.

Sacharomyces cerevisiae as a screening tool to assess cathinones’ toxicity

Introduction: Novel psychoactive substances (NPS) are sold on Internet under the appearance of herbal blends or bath salts as an alternative to cannabis, khat and ephedra. Synthetic cathinones are artificial mimetics of khat and like methamphetamine are indirect agonists of dopamine, serotonin and noradrenaline receptors [1]. Ninety-seven fatal cases of intoxication by ingestion of mephedrone (4-methylmethcathinone), one of the types of synthetic cathinone derivatives, were reported on literature since 2010 [2]. New synthetic cathinones emerges in the street market and internet on a regular base and the properties of this substances change regularly, due to modification on the molecules, to avoid legislation. This makes almost impossible to characterize synthetic cathinones toxicological profiles on a short time scale, mostly due to the typical time-consuming experimental assays. In here we propose the use of Saccharomyces cerevisiae, which has been proven an invaluable model to study the fundamental molecular mechanisms involved in several human diseases [3], growth curves in the presence of synthetic cathinones to get an indicative measure of its toxicity. Materials and methods: BY4741 yeast cells were diluted to a standardized OD600 nm =2×10−3 (∼1.67×10-5 cells/mL) in YNB medium (Yeast Nitrogen Base w/o Amino Acids 0.67%, glucose 2%, required amino acids) and grown at 30 °C. Buphedrone was acquired from the best source available. The cytotoxic potential of synthetic cathinones was assessed by monitoring the growth of Saccharomyces cerevisiae BY4741 in the presence and absence of substances. Yeast growth curves (O.D.600nm versus growth time) were compared. Results: Figure 1 shows that yeast growth in the presence of 75 mM cat is lower when compared to the growth curve in the absence of the substance. These preliminary results points that cathinones inhibits yeast growth. Figure 1. Growth curves results in Saccharomyces cerevisiae BY4741 in the presence of 75 mM of buphedrone. Discussion and conclusions: Saccharomyces cerevisiae has been used previously to test the toxicity of pharmacological drugs. Our results show that yeast is sensitive to cathinones suggesting that this system has potential to assess the possible toxicity of these legal highs. This rapid and inexpensive methodology may allow high throughput screening of cathinones’ toxicity, which might help the legislators to schedule NPS avoiding expected public health problems.

Identification and structural characterization of synthetic cathinones: N-propylcathinone, 2,4-dimethylmethcathinone, 2,4-dimethylethcathinone, 2,4-dimethyl-\u03b1-pyrrolidinopropiophenone, 4-bromo-\u03b1-pyrrolidinopropiophenone, 1-(2,3-dihydro-1H-inden-5-yl)-2-(pyrrolidin-1-yl)hexan-1-one and 2,4-dimethylisocathinone

PurposeSeven synthetic cathinone derivatives detected in samples seized in Poland from clandestine laboratories: N-propylcathinone, 2,4-dimethylmethcathinone (2,4-DMMC), 2,4-dimethylethcathinone (2,4-DMEC), 2,4-dimethyl-α-pyrrolidinopropiophenone (2,4-DMPPP) and 2,4-dimethylisocathinone (4-iso-DMC), collected from smartshops: 4-bromo-α-pyrrolidinopropiophenone (4-Br-PPP) or received from an attorney 1-(2,3-dihydro-1H-inden-5-yl)-2-(pyrrolidin-1-yl)hexan-1-one (5-BPDi) were identified and analytically characterized.MethodsUnequivocal identification of seven cathinones was performed using liquid chromatography–high-resolution tandem mass spectrometry with a quadrupole time-of-flight analyzer, gas chromatography with mass spectrometry and nuclear magnetic resonance spectroscopy.ResultsIn this study, we reported the detection and structure elucidation of seven substituted cathinones: N-propylcathinone, 2,4-DMMC, 2,4-DMEC, 2,4-DMPPP, 4-Br-PPP, 5-BPDi and 2,4-iso-DMC.ConclusionsNew derivatives of cathinone still appear on the market, mainly due to their legal status. This situation clearly indicates and alarms that permanent recognition of the designer drug market should be conducted. To the best of our knowledge, this is the first comprehensive report to fully characterize these cathinones; however, some analytical data have been published recently.

Designer drugs – still a threat?

In Poland, an increasing number of psychoactive substances are becoming prohibited by law as psychotropic or narcotic substances, or as new psychoactive substances (NPSs). Owing to the enormous technological possibilities offered by today’s science, synthesis of new derivatives of prohibited compounds is no longer a problem. The moment a dangerous substance is outlawed, new designer drugs (in Poland known as ‘dopalacze’) appear on the market. An amendment to the Act on Counteracting Drug Addiction issued in July 2018 made it possible for the NPS to be considered drugs by law. Synthetic cannabinoids and cathinone derivatives make up the majority of NPSs identified by the authorities in Poland. Synthetic cannabinoids which can, unlike cannabinoid receptor agonists of plant origin, cause death by somatic toxicity, are particularly dangerous. The ability to quickly recognize poisoning with synthetic opioids is crucial, since an antidote reversing the depressive effect of opioids on the respiratory center can be administered. This work collects the most important and up-to-date information on designer drugs, based on reports and articles published between 2015 and 2019. The covered aspects include: the current definition of designer drugs in relation to the Polish law, their exact division due to the clinical effects they cause and the description of the threats they pose. Emphasis was given to the current situation of the designer drug market in Poland.

Methcathinone and 3-Fluoromethcathinone Stimulate Spontaneous Horizontal Locomotor Activity in Mice and Elevate Extracellular Dopamine and Serotonin Levels in the Mouse Striatum

Methcathinone (MC) and 3-fluoromethcathinone (3-FMC) are well-known members of the synthetic cathinone derivatives, the second most abused group of novel psychoactive substances (NPS). They are considered as methamphetamine-like cathinones, as they elicit their psychostimulatory effects via inhibition of monoamine uptake and enhanced release. The present study examines the effects of MC and 3-FMC on the spontaneous locomotor activity of mice and extracellular levels of dopamine and serotonin in the mouse striatum. Both MC and 3-FMC produced a dose-dependent increase of horizontal locomotor activity, but no significant changes in rearing behavior were observed. The locomotor stimulation induced by MC and 3-FMC is mediated by activation of dopaminergic neurotransmission, as selective D1-dopamine receptor antagonist, SCH 23390, abolished the effects of both drugs. In line with pharmacological data obtained by previous in vitro studies, MC and 3-FMC produced potent increases of extracellular dopamine and serotonin levels in the mouse striatum. Taken together, results presented within this study confirm previous findings and expand our knowledge on the pharmacology of MC and 3-FMC along with their behavioral effects.