An In Vitro Study of the Neurotoxic Effects of N-Benzylpiperazine: A Designer Drug of Abuse

Metabolism of m-CPP, trazodone, nefazodone, and etoperidone: clinical and forensic aspects

Trazodone, nefazodone, and etoperidone are classified as atypical antidepressants belonging to the phenylpiperazine class. These antidepressants are primarily metabolized by CYP3A4 into m-chlorophenylpiperazine (mCPP), which was initially employed in veterinary medicine but has gained widespread use as a recreational drug globally despite legal restrictions in numerous countries. The active metabolite, mCPP, exerts various neuropsychiatric effects by interacting with serotonin receptors. It primarily exhibits nonselective agonistic properties with some antagonistic effects and influences temperature, behavior, and hormone release via central 5-HT receptors. The surge in mCPP popularity can be attributed to its MDMA-like effects, and its initial misidentification as an MDMA substitute facilitated its unregulated distribution worldwide. This review aims to comprehensively explore the pharmacokinetics and pharmacodynamics of these compounds, with a specific focus on the forensic challenges posed by mCPP as a metabolite of antidepressants. The primary objective is to delineate the consumption patterns of these compounds in laboratory settings, making this review crucial for understanding the intricate nuances of these drugs in forensic contexts.

Chemical composition of Ecstasy tablets seized in Poland between 2005 and 2020

PURPOSE

The most commonly associated substance found in Ecstasy tablets is MDMA (3,4-methylenedioxymethamphetamine). In our study, we showed how the composition of psychoactive ingredients in Ecstasy tablets seized on the drug market in Poland has changed in the years 2005-2020.

METHODS

The study material consisted of nearly 20,000 single Ecstasy tablets seized by representatives of law enforcement (the police, prosecutors) from 2005 to 2020 and analysed by the Institute of Forensic Research, Krakow, Poland. The analysis of the tablets was carried out by gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography with diode array detection (HPLC-DAD) and ultra-high-performance liquid chromatography with photodiode array detection (UHPLC-PDA).

RESULTS

Currently, new types of MDMA tablets are introduced onto the market, available in various colours and shapes. Our study showed that tablets sold on the street as Ecstasy have variable purity and sometimes contain little or no MDMA. The mean content of MDMA in one tablet seized in 2005-2011 decreased from 90 to 50 mg. In 2013, Ecstasy tablets with a very high MDMA content (average 195 mg per tablet) appeared on the market, but in the next 2 years, the MDMA content decreased again. From 2016, the average MDMA content began to rise again, ranging from 60 to 280 mg.

CONCLUSION

Tablets sold as Ecstasy also contained completely different psychoactive substances, including new psychoactive substances (NPS) (found in almost 20% of all examined tablets sold as Ecstasy) belonging to different chemical groups or their dangerous combinations (i.e. phenylethylamines, piperazines, tryptamines, cathinones, arylalkylamines, arylcyclohexylamines and piperidines). Such a large variety of psychoactive substances in Ecstasy tablets is associated with a high risk for users unaware of their composition.

An Update on the Implications of New Psychoactive Substances in Public Health

The emergence of new psychoactive substances has earned a great deal of attention, and several reports of acute poisoning and deaths have been issued involving, for instance, synthetic opiates. In recent years, there have been profound alterations in the legislation concerning consumption, marketing, and synthesis of these compounds; rapid alert systems have also been subject to changes, and new substances and new markets, mainly through the internet, have appeared. Their effects and how they originate in consumers are still mostly unknown, primarily in what concerns chronic toxicity. This review intends to provide a detailed description of these substances from the point of view of consumption, toxicokinetics, and health consequences, including case reports on intoxications in order to help researchers and public health agents working daily in this area.

Comparison of LC-MS and LC-DAD Methods of Detecting Abused Piperazine Designer Drugs

Recreational use of piperazine designer drugs is a serious threat to human health. These compounds act on the body in a similar fashion to illegal drugs. They induce psychostimulatory effects as well as visual and auditory hallucinations to varying degrees. In many cases of poisoning and deaths, the presence of two or even several psychoactive substances have been demonstrated. Piperazine derivatives are often found in such mixtures and pose a great analytical problem during their identification. Additionally, some piperazine derivatives can be detected in biological material as a result of metabolic changes to related drugs. Therefore, it is necessary to correctly identify these compounds and ensure repeatability of determinations. This article presents a comparison of the methods used to detect abused piperazine designer drugs using liquid chromatography in combination with a diode-array detector (LC-DAD) or mass spectrometer (LC-MS). Each of methods can be used independently for determinations, obtaining reliable results in a short time of analysis. These methods can also complement each other, providing qualitative and quantitative confirmation of results. The proposed methods provide analytical confirmation of poisoning and may be helpful in toxicological diagnostics.

Rapid Targeted Method of Detecting Abused Piperazine Designer Drugs

Piperazine derivatives belong to the popular psychostimulating compounds from the group of designer drugs. They are an alternative to illegal drugs such as ecstasy and amphetamines. They are being searched by consumers for recreational use due to their stimulating and hallucinogenic effects. Many NPS-related poisonings and deaths have been reported where piperazines have been found. However, a major problem is the potential lack of laboratory confirmation of the involvement of piperazine derivatives in the occurrence of poisoning. Although many methods have been published, piperazine derivatives are not always included in a routine analytical approach or targeted toxicological analysis. There is an increasing need to provide qualitative evidence for the presence of piperazine derivatives and to ensure reproducible quantification. This article describes a new rapid method of detecting piperazine derivatives in biological material, using LC-MS. All target analytes were separated in a 15 min run time and identified based on the precursor ion, at least two product ions, and the retention time. Stable isotopically labeled (SIL) internal standards: BZP-D7, mCPP-D8 and TFMPP-D4 were used for analysis, obtaining the highest level of confidence in the results. The proposed detection method provides the analytical confirmation of poisoning with piperazine designer drugs.

Molecular and clinical aspects of potential neurotoxicity induced by new psychoactive stimulants and psychedelics

New psychoactive stimulants and psychedelics continue to play an important role on the illicit new psychoactive substance (NPS) market. Designer stimulants and psychedelics both affect monoaminergic systems, although by different mechanisms. Stimulant NPS primarily interact with monoamine transporters, either as inhibitors or as substrates. Psychedelic NPS most potently interact with serotonergic receptors and mediate their mind-altering effects mainly through agonism at serotonin 5-hydroxytryptamine-2A (5-HT_2A) receptors. Rarely, designer stimulants and psychedelics are associated with potentially severe adverse effects. However, due to the high number of emerging NPS, it is not possible to investigate the toxicity of each individual substance in detail. The brain is an organ particularly sensitive to substance-induced toxicity due to its high metabolic activity. In fact, stimulant and psychedelic NPS have been linked to neurological and cognitive impairments. Furthermore, studies using in vitro cell models or rodents indicate a variety of mechanisms that could potentially lead to neurotoxic damage in NPS users. Cytotoxicity, mitochondrial dysfunction, and oxidative stress may potentially contribute to neurotoxicity of stimulant NPS in addition to altered neurochemistry. Serotonin 5-HT_2A receptor-mediated toxicity, oxidative stress, and activation of mitochondrial apoptosis pathways could contribute to neurotoxicity of some psychedelic NPS. However, it remains unclear how well the current preclinical data of NPS-induced neurotoxicity translate to humans.

Piperazine derivatives as dangerous abused compounds

Piperazine derivatives are a group of compounds with a psychostimulant effect. They are an alternative to illegal drugs. They are being searched for recreational use due to their psychoactive and hallucinogenic effects. The high popularity of these compounds can be noticed all over the world due to easy purchase, lack of legal regulations and incorrect assessment of the safety of use. The recreational use of piperazine derivatives can often result in chronic and acute health problems and additionally with unpredictable remote effects. It is also common to take mixtures of psychoactive compounds. This hinders the correct diagnosis and treatment of patients with poisoning. The presented work is an illustration of the wide problem of piperazine derivatives abuse. The health effects and the possibility of identifying these compounds in preparations and biological material are described.

Dopaminergic neurotoxic effects of 3-TFMPP derivatives

Designer drugs are synthetically formulated to mimic the psychostimulatory effects of an original controlled/illegal drug of abuse. Designer drugs have similar chemical structure or functional analog as compared to existing controlled psychostimulatory drugs. There is a substantial rise in the production and use of designer drugs globally. Piperazine designer drugs were synthesized as an alternative to MDMA and have shown to induce numerous toxic effects leading to huge health, safety, law enforcement & monetary problems, and lethality. Currently, there are very few studies on the dopaminergic neurotoxicity of 1-(3-trifluoromethylphenyl) piperazine (3-TFMPP) and its derivatives (structural congeners). N27 rat dopaminergic neurons are valid cells to investigate the neurotoxic effects and establish the neurotoxic mechanisms of various substances. In the current study, we studied the time and dose-dependent neurotoxicity mechanisms of dopaminergic neurotoxicity of 3-TFMPP (parent compound) and its derivatives (2-TFMPP, 4-TFMPP). TFMPP derivatives-induced significant neurotoxicity (induced dopaminergic neuronal death. TFMPP derivatives-induced oxidative stress, mitochondrial dysfunction, apoptosis and decreased tyrosine hydroxylase expression. If the use of designer drugs are not strictly regulated and restricted around the world, this can lead to numerous central and peripheral disorders leading to a liability to the current and future society.

The Designer Drug 3-Fluoromethcathinone Induces Oxidative Stress and Activates Autophagy in HT22 Neuronal Cells

Synthetic cathinones are psychoactive substances, derivatives of a natural psychostimulant cathinone. Although many synthetic cathinones have lost their legal status in many countries, their abuse still continues worldwide. Recently, they have been reported to exert neurotoxic effects in vitro and in vivo. The molecular mechanisms of their action have not been fully elucidated. Recently, they have been linked to the induction of oxidative stress, autophagy, and apoptosis. The aim of this study was to investigate whether 3-fluoromethcathinone (3-FMC), a synthetic cathinone, is able to induce oxidative stress, autophagy, and apoptosis in HT22 immortalized mouse hippocampal cells. We found that treatment of HT22 cells with this compound results in a concentration-dependent increase in the intracellular production of reactive oxygen species. Moreover, 3-FMC induced concentration-dependent conversion of cytosolic LC3-I to membrane-bound LC3-II and formation of autophagic vacuoles. Additionally, the level of p62/SQSTM1 protein decreased after 3-FMC treatment, suggesting that accumulation of autophagic vacuoles resulted from activation rather than inhibition of autophagy. Our results also showed that 3-FMC at millimolar concentration is able to induce caspase-dependent apoptotic cell death in HT22 cells. Our findings suggest that abuse of 3-FMC may disturb neuronal homeostasis and impair functioning of the central nervous system.

In vitro hepatotoxicity of 'Legal X': the combination of 1-benzylpiperazine (BZP) and 1-(m-trifluoromethylphenyl)piperazine (TFMPP) triggers oxidative stress, mitochondrial impairment and apoptosis

N-Benzylpiperazine (BZP) and 1-(3-trifluoromethylphenyl)piperazine (TFMPP) are two synthetic phenylpiperazine analogues that have been frequently commercialized in combination as an alternative to ecstasy ('Legal X'). Despite reports of several clinical complications following the use of these drugs in association, few studies have been conducted so far to elucidate their combined toxicity. The present study was aimed at clarifying the cytotoxic effects of mixtures of BZP and TFMPP in vitro. Human-derived HepaRG cells and primary rat hepatocytes were exposed to the drugs, individually or combined at different mixture ratios, and cytotoxicity was assessed by the MTT assay. Mixture additivity expectations were calculated by the independent action and the concentration addition (CA) models and compared with the experimental outcomes. To delineate the mechanisms underlying the elicited effects, a range of stress endpoints was evaluated, including oxidative stress, energetic imbalance, and metabolic interactions. It was observed that primary rat hepatocytes are more sensitive than HepaRG cells to the toxicity of BZP (EC50 2.20 and 6.60 mM, respectively) and TFMPP (EC50 0.14 and 0.45 mM, respectively). For all BZP-TFMPP combinations tested, CA was the most appropriate model to predict the mixture effects. TFMPP proved to act additively with BZP to produce significant hepatotoxicity (p < 0.01). Remarkably, substantial mixture effects were observed even when each drug was present at concentrations that were harmless individually. In primary hepatocytes, a small deviation from additivity (antagonism) was observed toward the upper range of the concentration-response curve. GC/MS data suggest that a metabolic interaction may be at a play, as the mixture favors the metabolism of both substances, to a significant extent in the case of BZP (p < 0.05). Also, our results demonstrate the influence of oxidative stress and energetic imbalance on these effects (increase in RNS and ROS production, decrease in intracellular GSH/GSSG, ATP depletion and mitochondrial Δψm disruption). The present work clearly demonstrates that potentially harmful interactions among BZP and TFMPP are expected when these drugs are taken concomitantly.