Neurotoxicological profile of the hallucinogenic compound 25I-NBOMe.

4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is a new psychoactive substance with strong hallucinogenic properties. Our previous data reported increased release of dopamine, serotonin, and glutamate after acute injections and a tolerance development in the neurotransmitters release and rats' behavior after chronic treatment with 25I-NBOMe. The recreational use of 25I-NBOMe is associated with severe intoxication and deaths in humans. There is no data about 25I-NBOMe in vivo toxicity towards the brain tissue. In this article 25I-NBOMe-crossing through the blood-brain barrier (BBB), the impact on DNA damage, apoptosis induction, and changes in the number of cortical and hippocampal cells were studied. The presence of 25I-NBOMe in several brain regions shortly after the drug administration and its accumulation after multiple injections was found. The DNA damage was detected 72 h after the chronic treatment. On the contrary, at the same time point apoptotic signal was not identified. A decrease in the number of glial but not in neural cells in the frontal (FC) and medial prefrontal cortex (mPFC) was observed. The obtained data indicate that 25I-NBOMe passes easily across the BBB and accumulates in the brain tissue. Observed oxidative DNA damage may lead to the glial cells' death.

A retrospective analysis of the "Neverending Trip" after administration of a potent full agonist of 5-HT2A receptor - 25I-NBOMe.

BACKGROUND: 5-HT2A receptor (e.g. 25I-NBOMe) agonists not only pose risks of acute intoxication but also long-term effects and significant adverse reactions, e.g. hallucinogen persisting perception disorder (HPPD), derealization, and depersonalization. AIMS: We evaluated the risk associated with single and repeated use of 25I-NBOMe. We aimed to identify factors that may increase the risk of HPPD, increase its severity and determine the time when the first symptoms appear. Herein, we report the first extensive evaluation of 25I-NBOMe-induced HPPD. METHOD: We assessed all reports (58) collected by The Pomeranian Pharmacovigilance Centre (PPC) from 2013 to 2020. RESULTS: The study included a total of 58 reports of adverse reactions caused by 25I-NBOMe. In the case of 15 reports (in patients aged 19-26 years), symptoms persisted many months after the discontinuation of 25I-NBOMe. The most common were: pseudohallucinations, bizarre delusions, derealizations and in some cases development or worsening of depression has been diagnosed. HPPD-like symptoms were most common in patients who took the drug regularly (i.e., several times a month). The risk of HPPD-like symptoms is higher in patients who have severe visual pseudohallucinations, severe bizarre delusions, derealization and/or depersonalization onset immediately after taking the drug. Recurrence of HPPD symptoms may be provoked by many factors, however, there is some cases there is no apparent reason. HPPD after 25I-NBOMe use can last from 2 months up to 2 years. In some patients, pharmacological treatment was necessary due to 25I-NBOMe-induced HPPD and depression. CONCLUSIONS: The study showed long-lasting effects after 25I-NBOMe administration and allowed for the determination of HPPD risk factors.

25I-NBOMe, a phenethylamine derivative, induces adverse cardiovascular effects in rodents: possible involvement of p21 (CDC42/RAC)-activated kinase 1.

Abuse of new psychoactive substances is an emerging social problem. Several phenethylamines are internationally controlled substances as they are likely to be abused and have adverse effects. Phenethylamine analog 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25I-NBOMe) has been reported as one of the most commonly abused psychoactive substance. However, the cardiotoxicity of this compound has not been extensively evaluated. Thus, in this study, we investigated the adverse cardiovascular effects of 25I-NBOMe, related to p21 (CDC42/RAC)-activated kinase 1 (PAK1). The cardiotoxicity of 25I-NBOMe was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, live/dead cytotoxicity assay, PAK1/CDC42 kinase assay, and in vivo electrocardiography (ECG). Also, we analyzed the expression level of PAK1, which is known to play key roles in the cardiovascular system. In the MTT assay, cell viability of 25I-NBOMe-treated H9c2 cells or primary cardiomyocytes of ICR mice decreased in a concentration-dependent manner. Results from the in vitro cytotoxicity assay in cardiomyocytes showed that 25I-NBOMe decreased the viability of H9c2 rat cardiomyocytes, and TC50 of 25I-NBOMe was found to be 70.4 µM. We also observed that 25I-NBOMe reduced PAK1 activity in vitro. Surface ECG measurement revealed that intravenous injection of 25I-NBOMe (doses of 1.0 and 3.0 mg/kg, corresponding to serum concentrations of 18.1 and 28.6 ng/mL, respectively) prolonged the QTc interval in SD rats. Furthermore, treatment with 25I-NBOMe downregulated the expression of PAK1 in the hearts of SD rats and H9c2 cells. In summary, our findings indicate that PAK1-related adverse effects of 25I-NBOMe can cause toxicity to cardiomyocytes and induce an abnormal ECG pattern in animals.

Tolerance to neurochemical and behavioral effects of the hallucinogen 25I-NBOMe.

RATIONALE: 4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is a potent serotonin 5-HT2A/2C receptor agonist with hallucinogenic activity. There is no data on the 25I-NBOMe effect on brain neurotransmission and animal performance after chronic administration. OBJECTIVES: We examined the effect of a 7-day treatment with 25I-NBOMe (0.3 mg/kg/day) on neurotransmitters' release and rats' behavior in comparison to acute dose. METHODS: Changes in dopamine (DA), serotonin (5-HT), acetylcholine (ACh), and glutamate release were studied using microdialysis in freely moving rats. The hallucinogenic activity was measured in the wet dog shake (WDS) test. The animal locomotion was examined in the open field (OF) test, short-term memory in the novel object recognition (NOR) test. The anxiogenic/anxiolytic properties of the drug were tested using the light/dark box (LDB) test. RESULTS: Repeated administration of 25I-NBOMe decreased the response to a challenge dose of DA, 5-HT, and glutamatergic neurons in the frontal cortex as well as weakened the hallucinogenic activity in comparison to acute dose. In contrast, striatal and accumbal DA and 5-HT release and accumbal but not striatal glutamate release in response to the challenge dose of 25I-NBOMe was increased in comparison to acute treatment. The ACh release was increased in all brain regions. Behavioral tests showed a motor activity reduction and memory deficiency in comparison to a single dose and induction of anxiety after the drug's chronic and acute administration. CONCLUSIONS: Our findings suggest that multiple injections of 25I-NBOMe induce tolerance to hallucinogenic activity and produce alterations in neurotransmission. 25I-NBOMe effect on short-term memory, locomotor function, and anxiety seems to be the result of complex interactions between neurotransmitter pathways.

The use of multiple keratinous matrices (head hair, axillary hair, and toenail clippings) can help narrowing a period of drug exposure: experience with a criminal case involving 25I-NBOMe and 4-MMC.

The objective of this publication is to present the interest of collecting several keratinous specimens in order to document possible drug impairment at the time of the assault, when knowledge solely occurred 7 months after. A subject committed a murder and within minutes after the crime self-inflicted serious wounds. He was charged to the hospital where he slowly recovered. After several weeks, he was sent to prison. During this period, intelligence indicated possible drug impairment at the time of the assault after using 25I-NBOMe and 4-MMC. Head hair (4 cm), axillary hair, and toenails were collected 7 months after the crime. New psychoactive substances were tested in each specimen using LC-MS/MS, which revealed the presence of 25I-NBOMe and 4-MMC in axillary hair (2 and 6 pg/mg) and toenails (1 and 5 pg/mg). However, the perpetrator claimed that the positive findings were due to contamination in prison. Therefore, the head hair was also tested and results returned negative (LOQ at 1 pg/mg), demonstrating absence of contamination during the last 4 months before collection. Combining the window of drug detection in axillary hair (about 4 to 8 months) and the one of toenail clippings (up to 8 months), and excluding drug exposure during the previous 4 months as well as external contamination as the head hair results were negative, allowed us to conclude that the positive findings in axillary hair and toenails are more likely than not consistent with consumption of both 25I-NBOMe and 4-MMC at the time of the crime.

2-(4-Iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25I-NBOME): A Harmful Hallucinogen Review.

NBOMes are N-benzylmethoxy derivatives of the 2C family compounds with N-2-methoxybenzyl moiety substituted by the methoxy group at the 2- and 5-position and the halogen group at the 4-position of the phenyl ring. These substances are a new class of potent serotonin 5-HT2A receptor agonist hallucinogens with potential harmful effects. The substitution with halogen of the already psychoactive phenethylamine produces a derivative (2C-I) with increased hallucinogenic effects. This class of hallucinogens has chemical structures very similar to natural hallucinogenic alkaloid mescaline and these are sold mainly via internet as a 'legal' alternative to other hallucinogenic drug-lysergic acid diethylamide (LSD). 25I-NBOMe is the first synthesized and one of the most common compound from NBOMes. Knowledge of pharmacological properties of 25I-NBOMe is very limited so far. There are only a few in vivo and in vitro so far published studies. The behavioral experiments are mainly related with the hallucinogenic effect of 25I-NBOMe while the in vitro studies concerning mainly the affinity for 5-HT2A receptors. The 25I-NBOMe Critical Review 2016 reported 51 non-fatal intoxications and 21 deaths associated with 25I-NBOMe across Europe. Case reports describe various toxic effects of 25I-NBOMe usage including tachycardia, hypertension, hallucinations, rhabdomyolysis, acute kidney injury and death. The growing number of fatal and non-fatal intoxication cases indicates that 25I-NBOMe should be considered as a serious danger to public health. This review aims to present the current state of knowledge on pharmacological effects and chemical properties of 25I-NBOMe and to describe reported clinical cases and analytical methods available for identification of this agent in biological material.

Novel Psychoactive Phenethylamines: Impact on Genetic Material.

Psychedelic and stimulating phenethylamines belong to the family of new psychoactive substances (NPS). The acute toxicity framework has begun to be investigated, while studies showing genotoxic potential are very limited or not available. Therefore, in order to fill this gap, the aim of the present work was to evaluate the genotoxicity by treating TK6 cells with 2C-H, 2C-I, 2C-B, 25B-NBOMe, and the popular 3,4-Methylenedioxymethylamphetamine (MDMA). On the basis of cytotoxicity and cytostasis results, we selected the concentrations (6.25-35 µM) to be used in genotoxicity analysis. We used the micronucleus (MN) as indicator of genetic damage and analyzed the MNi frequency fold increase by an automated flow cytometric protocol. All substances, except MDMA, resulted genotoxic; therefore, we evaluated reactive oxygen species (ROS) induction as a possible mechanism at the basis of the demonstrated genotoxicity. The obtained results showed a statistically significant increase in ROS levels for all genotoxic phenethylamines confirming this hypothesis. Our results highlight the importance of genotoxicity evaluation for a complete assessment of the risk associated also with NPS exposure. Indeed, the subjects who do not have hazardous behaviors or require hospitalization by using active but still "safe" doses could run into genotoxicity and in the well-known long-term effects associated.

Contribution of serotonin receptor subtypes to hallucinogenic activity of 25I-NBOMe and to its effect on neurotransmission.

BACKGROUND: 4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is a potent serotonin (5-HT) receptor agonist with hallucinogenic properties. The aim of our research was to examine the role of the 5-HT2A, 5-HT2C and 5-HT1A serotonin receptor subtypes in 25I-NBOMe hallucinogenic activity and its effect on dopamine (DA), 5-HT and glutamate release in the rat frontal cortex. METHODS: Hallucinogenic activity was investigated using the wet dog shake (WDS) test. The release of DA, 5-HT and glutamate in the rat frontal cortex was studied using a microdialysis in freely moving rats. Neurotransmitter levels were analyzed by HPLC with electrochemical detection. The selective antagonists of the 5-HT2A, 5-HT2C and 5-HT1A serotonin receptor subtypes: M100907, SB242084 and WAY100635, respectively were applied through a microdialysis probe. RESULTS: The WDS response to 25I-NBOMe (1 and 3 mg/kg) was significantly reduced by local administration of M100907 and SB242084 (100 nM). The 25I-NBOMe-induced increase in glutamate, DA and 5-HT release was inhibited by M100907 and SB242084. WAY100635 had no effect on 25I-NBOMe-induced WDS and glutamate release, while it decreased DA and 5-HT release from cortical neuronal terminals. CONCLUSION: The obtained results suggest that 5-HT2A and 5-HT2C receptors play a role in 25I-NBOMe-induced hallucinogenic activity and in glutamate, DA and 5-HT release in the rat frontal cortex as their respective antagonists attenuated the effect of this hallucinogen. The disinhibition of GABA cells by the 5-HT1A receptor antagonist seems to underlie the mechanism of decreased DA and 5-HT release from neuronal terminals in the frontal cortex.

The Clinical Toxicology of 4-Bromo-2,5-dimethoxyphenethylamine (2C-B): The Severity of Poisoning After Exposure to Low to Moderate and High Doses.

STUDY OBJECTIVE: We studied the severity of poisoning after exposure to low to moderate and high doses of 4-bromo-2,5-dimethoxyphenethylamine (2C-B). METHODS: Patients for whom the Dutch Poisons Information Centre was consulted for 2C-B exposure from 2016 to 2018 were included in a prospective cohort study. Data were collected through telephone interviews with the physician or patient. Patients were categorized according to the reported 2C-B dose: low to moderate (up to 20 mg), high (greater than 20 mg), or unknown. Presence of 2C-B was analyzed in leftover drug and biological samples with liquid/gas chromatography-mass spectrometry. The severity of poisoning was graded with the Poisoning Severity Score. RESULTS: We included 59 patients, of whom 32 could be followed up. Low to moderate 2C-B doses were reported by 9 patients (28%), high doses by 17 (53%), and unknown doses by 6 (19%). Poisoning was moderate in the majority of patients in both the low- to moderate-dose and high-dose groups. Frequently reported symptoms included mydriasis, agitation or aggression, hallucinations, confusion, anxiety, hypertension, and tachycardia. The presence of 2C-B was confirmed in 5 patients in urine (n=3) or drug samples (n=4). CONCLUSION: In this study, most 2C-B poisonings resulted in moderate toxicity even at high reported doses up to 192 mg. No severe cases were observed. The clinical course was usually short-lived (up to 24 hours) and typically involved hallucinations in addition to mild somatic effects.

Novel Phenethylamines and Their Potential Interactions With Prescription Drugs: A Systematic Critical Review.

BACKGROUND: The novel phenethylamines 4-fluoroamphetamine (4-FA) and 2,5-dimethoxy-4-bromophenethylamine (2C-B) fall in the top 10 most used new psychoactive substances (NPSs) among high-risk substance users. Various phenethylamines and NPS are also highly used in populations with mental disorders, depression, or attention deficit hyperactivity disorder (ADHD). Moreover, NPS use is highly prevalent among men and women with risky sexual behavior. Considering these specific populations and their frequent concurrent use of drugs, such as antidepressants, ADHD medication, and antiretrovirals, reports on potential interactions between these drugs, and phenethylamines 4-FA and 2C-B, were reviewed. METHODS: The authors performed a systematic literature review on 4-FA and 2C-B interactions with antidepressants (citalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, duloxetine, bupropion, venlafaxine, phenelzine, moclobemide, and tranylcypromine), ADHD medications (atomoxetine, dexamphetamine, methylphenidate, and modafinil), and antiretrovirals. RESULTS: Limited literature exists on the pharmacokinetics and drug-drug interactions of 2C-B and 4-FA. Only one case report indicated a possible interaction between 4-FA and ADHD medication. Although pharmacokinetic interactions between 4-FA and prescription drugs remain speculative, their pharmacodynamic points toward interactions between 4-FA and ADHD medication and antidepressants. The pharmacokinetic and pharmacodynamic profile of 2C-B also points toward such interactions, between 2C-B and prescription drugs such as antidepressants and ADHD medication. CONCLUSIONS: A drug-drug (phenethylamine-prescription drug) interaction potential is anticipated, mainly involving monoamine oxidases for 2C-B and 4-FA, with monoamine transporters being more specific to 4-FA.

Nanosensor for Sensitive Detection of the New Psychedelic Drug 25I-NBOMe.

This work reports the synthesis, characterization, and sensing behavior of a hybrid nanodevice for the detection of the potent abuse drug 25I-NBOMe. The system is based on mesoporous silica nanoparticles, loaded with a fluorescent dye, functionalized with a serotonin derivative and capped with the 5-HT2A receptor antibody. In the presence of 25I-NBOMe the capping antibody is displaced, leading to pore opening and rhodamine B release. This delivery was ascribed to 5-HT2A receptor antibody detachment from the surface due to its stronger coordination with 25I-NBOMe present in the solution. The prepared nanodevice allowed the sensitive (limit of detection of 0.6 µm) and selective recognition of the 25I-NBOMe drug (cocaine, heroin, mescaline, lysergic acid diethylamide, MDMA, and morphine were unable to induce pore opening and rhodamine B release). This nanodevice acts as a highly sensitive and selective fluorometric probe for the 25I-NBOMe illicit drug in artificial saliva and in sweets.

Multimodal imaging of hallucinogens 25C- and 25I-NBOMe on blotter papers.

Due to the much lower production costs but similar effects to lysergic acid diethylamide (LSD), phenethylamine derivatives are sold as a cheaper replacement or deceptively as LSD itself. These potent hallucinogenic substances can lead to severe intoxication, thus a more profound understanding of their use is required. This includes the elucidation of the manufacturing processes for the commonly used blotter papers and the assessment of the risk of overdosing because of a heterogeneous distribution on the blotter papers. Besides the rapid detection of the analytes, the manufacturing process was elucidated by three different imaging techniques and liquid chromatography-mass spectrometry (LC-MS). A blotter paper sample, containing the two hallucinogenic phenethylamine derivatives 25I-NBOMe and 25C-NBOMe, was analyzed by complementary techniques such as micro x-ray fluorescence (µXRF), laser ablation (LA)-inductively coupled plasma-optical emission spectroscopy (ICP-OES), matrix assisted laser desorption ionization (MALDI)-MS, and with LC-MS after extraction. Using the signal from chlorine and iodine within the compounds, µXRF proved to be the fastest, cheapest and easiest method for identification, requiring no sample preparation at all. LA-ICP-OES provided three-dimensional information of the elements in the blotter paper. These results helped to confirm the assumption that manufacturers spray the compounds onto the paper. Whereas µXRF and LA-ICP-OES detected signals for chlorine and iodine, MALDI-MS-imaging showed the molecular distribution of both analytes. LC-MS analyses as a complementary method support the imaging results. Quantitative results for different drug hotspots revealed a heterogeneous distribution of the drugs on the blotter paper implying an inherent risk of overdosing for consumers.

Acute Limb Ischemia after Intake of the Phenylethylamine Derivate NBOMe.

Objective: N-(2-methoxy) benzyl-phenethylamine (NBOMe) derivatives have a high affinity to the serotonin receptor 2A and emerged as new psychedelic agents. We report the case of a 30-year-old man admitted to the hospital because of acute ischemia of the left arm with clinical symptoms of pallor, pulselessness, paresthesia, and a motoric deficit. The patient had a history of schizophrenia and drug abuse and disclosed during the hospital stay the sublingual intake of a substance bought as 25I-NBOMe the night before the ischemic event. Methods: Routine clinical diagnostics including among others color-coded duplex sonography and computed tomography angiography (CTA) were performed. The remainder of the drugs was analyzed using high performance liquid chromatography. Results: Initial color-coded duplex sonography of the upper left limb showed pathological flow profiles of the axillary, brachial, ulnar, and radial artery with a reduced diameter of the ulnar (0.9 mm) and radial (1.1 mm) artery. In consequence, peripheral vasospasm, distal arterial thrombosis, or arterial embolization was anticipated. As therapeutic measures, the patient immediately received intravenous systemic vasodilators (alprostadil) and therapeutic anticoagulation with low molecular weight heparin. Instant symptom improvement was observed within the first day after therapy initiation. The subsequently performed CTA of the heart and left arm showed no signs of thrombotic material. Treatment was continued for five days and the patient was released thereafter having completely normalized perfusion in his left arm. Outpatient treatment was continued with calcium-channel blockers, as the patient had also displayed arterial hypertension. Drug analysis retrieved a composition of the isomers 25I-NBOMe, 25C-NBOMe, and 25H-NBOMe as well as traces of pentylon. Conclusion: NBOMe ingestion implicates the risk of peripheral vasospasms with severe, limb-threatening ischemia.

Mix of new substances psychoactive, NPS, found in blotters sold in two Colombian cities.

The new psychoactive substances (NPS) in Colombia are detected by national authorities, in blotters strip, in different circumstances and places: airports, music concerts, discos and parks. Blotters are marketed as LSD and cause several cases of intoxication and death in some consumers: due to acute intoxication or when mixed with other drugs and may have different effects on the central nervous system (CNS). This study was conducted to research into and identify the chemical composition of the drugs impregnated in the blotters sold in two Colombian cities. This research provides the analysis of 70 doses coming from forensic cases of the Colombian Attorney General's Office in Bogota and from the Laboratory of Narcotics of the Colombian National Institute of Legal Medicine and Forensic Sciences (North Headquarter) in Barranquilla. Mixtures of drugs, such as DOB, 25I-NBOMe, MDMA and 25I-NBOMe imine were found within the blotters through gas chromatography coupled to mass spectrometry (CGMS); these drugs are classified by international authorities as NPS belonging to the phenylethylamines group. The results clearly warn about a growing public health problem in the country.

Unexpected Serotonin Syndrome, Epileptic Seizures, and Cerebral Edema Following 2,5-dimethoxy-4-bromophenethylamine Ingestion.

4-bromo-2,5-dimethoxyphenethylamine (2C-B) is a designer drug. In Europe, 2C-B is easily obtained and used for recreational purposes. It is known for its stimulating effects similar to those of 3,4-methylenedioxymethamphetamine, although in higher doses it has more hallucinogenic effects. Here, we report a case of 2C-B ingestion, confirmed by liquid chromatography-tandem mass spectrometry, in an 18-year-old man. The neurological consequences were severe, including the development of serotonin syndrome and severe brain edema. Supportive therapy resulted in a stable condition, although, after several months, the patient still suffered from severe neurological impairment due to the drug-induced toxicity. This case showed that 2C-B could not be identified with the drugs of abuse screening routinely used in Dutch hospitals. The use of 2C-B carries many risks, with potentially profound neurological damage, that both consumers and healthcare physicians are unaware of.

In vivo PET Imaging of [11C]CIMBI-5, a 5-HT2AR Agonist Radiotracer in Nonhuman Primates.

PURPOSE: 5-HT2AR exists in high and low affinity states. Agonist PET tracers measure binding to the active high affinity site and thus provide a functionally relevant measure of the receptor. Limited in vivo data have been reported so far for a comparison of agonist versus antagonist tracers for 5-HT2AR used as a proof of principle for measurement of high and low affinity states of this receptor. We compared the in vivo binding of [11C]CIMBI-5, a 5-HT2AR agonist, and of the antagonist [11C]M100907, in monkeys and baboons. METHODS: [11C]CIMBI-5 and [11C]M100907 baseline PET scans were performed in anesthetized male baboons (n=2) and male vervet monkeys (n=2) with an ECAT EXACT HR+ and GE 64-slice PET/CT Discovery VCT scanners. Blocking studies were performed in vervet monkeys by pretreatment with MDL100907 (0.5 mg/kg, i.v.) 60 minutes prior to the scan. Regional distribution volumes and binding potentials were calculated for each ROI using the likelihood estimation in graphical analysis and Logan plot, with either plasma input function or reference region as input, and simplified reference tissue model approaches. RESULTS: PET imaging of [11C]CIMBI-5 in baboons and monkeys showed the highest binding in 5-HT2AR-rich cortical regions, while the lowest binding was observed in cerebellum, consistent with the expected distribution of 5-HT2AR. Very low free fractions and rapid metabolism were observed for [11C]CIMBI-5 in baboon plasma. Binding potential values for [11C]CIMBI-5 were 25-33% lower than those for [11C]MDL100907 in the considered brain regions. CONCLUSION: The lower binding potential of [11C]CIMBI-5 in comparison to [11C]MDL100907 is likely due to the preferential binding of the former to the high affinity site in vivo in contrast to the antagonist,  [11C]MDL100907, which binds to both high and low affinity sites.

Hallucinogen-Like Action of the Novel Designer Drug 25I-NBOMe and Its Effect on Cortical Neurotransmitters in Rats.

NBOMes are N-benzylmethoxy derivatives of the 2C family hallucinogens. 4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is one of the commonly used illicit drugs. It exhibits high binding affinity for 5-HT2A/C and 5-HT1A serotonin receptors. Activation of 5-HT2A receptor induces head-twitch response (HTR) in rodents, a behavioral marker of hallucinogen effect in humans. There is not much data on neurochemical properties of NBOMes. Therefore, we aimed to investigate the effect of 25I-NBOMe on extracellular level of dopamine (DA), serotonin (5-HT), and glutamate (GLU) in the rat frontal cortex, tissue contents of monoamines, and hallucinogenic activity in rats. The extracellular levels of DA, 5-HT, and GLU were studied using microdialysis in freely moving animals. The tissue contents of DA, 5-HT and their metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were determined in the rat frontal cortex. We also tested a drug-elicited HTR. 25I-NBOMe at doses 1, 3, and 10 mg/kg (sc) increased extracellular DA, 5-HT, and GLU levels, enhanced tissue content of 5-HT and 5-HIAA, but did not affect tissue level of DA and its metabolites. The compound exhibited an inverted U-shaped dose-response curve with respect to the effect on extracellular DA and 5-HT levels, but a U-shaped dose-response curve was observed for its effect on GLU release and HTR. The data from our study suggest that hallucinogenic activity of 25I-NBOMe seems to be related with the increase in extracellular GLU level-mediated via cortical 5-HT2A receptors. The influence of 25I-NBOMe on 5-HT2C and 5-HT1A receptors may modulate its effect on neurotransmitters and HTR.

Abuse potential of 2-(4-iodo-2, 5-dimethoxyphenyl)N-(2-methoxybenzyl)ethanamine (25INBOMe); in vivo and ex vivo approaches.

25INBOMe ("25-I", "N-Bomb"), one of new psychoactive substances (NPSs), is being abused for recreational purpose. However, the liability for abuse or dependence has not been systematically studied yet. The objective of the present study was to evaluate rewarding and reinforcing effects of 25INBOMe using conditioned place preference (CPP) and self-administration (SA) paradigms. In addition, ultrasonic vocalizations (USVs) were measured to investigate relationships between USVs and emotional state regarding dependence on psychoactive substances. To understand molecular mechanism involved in its action, dopamine (DA) level changes were analyzed using synaptosomes extracted from the striatal region of the brain. Expression level changes of SGK1 (serum/glucocorticoid regulated kinase 1) and PER2 (period circadian protein homolog 2), two putative biomarkers for drug dependence, were also analyzed. Results showed that 25INBOMe increased both CPP (0.3 mg/kg) and SA (0.03 mg/kg/infusion) and produced higher frequencies in USVs analysis. It also increased DA levels in the striatal region and changed expression levels of SGK1 and PER2. Results of the present study suggest that 25INBOMe might produce rewarding and reinforcing effects, indicating its dependence liability. In addition, frequencies of USV might be associated with emotional state of mice induced by psychoactive substances regarding substance dependence. This is the first systemic preclinical report on the dependence liability of 25INBOMe and the first attempt to introduce a possible relationship between USVs and emotional state of mice regarding substance dependency. Further studies are needed to clarify the mechanism involved in 25INBOMe dependency and determine the usefulness of USV measurement as a method for evaluating dependence liability.

Two immunoassays for the detection of 2C-B and related hallucinogenic phenethylamines.

INTRODUCTION: The use of new psychoactive substances as drugs of abuse has dramatically increased over the last years. Hallucinogenic phenethylamines gained particular popularity as they have both stimulating and psychedelic effects. Although generally perceived as safe, these illicit drugs pose a serious health risk; they have been linked to cases of severe poisoning or even deaths. Therefore, simple, cost-effective and reliable methods are needed for rapid determination of abused hallucinogens. METHODS: For this purpose, two haptens derived from 2C-H were designed, synthesized and subsequently attached to a carrier protein. Polyclonal antibodies obtained from a rabbit immunized with one of the prepared immunogens were used for the development of two immunoassays. RESULTS: In this study, a lateral flow immunoassay (LFIA) and an enzyme linked immunosorbent assay (ELISA) for the detection of 2C-B and related hallucinogenic phenethylamines in urine were developed. The presented LFIA is primarily suitable for on-site monitoring as it is simple and can provide a visual evidence of 2C-B presence within a few minutes. Its reasonable sensitivity (LODLFIA = 15 ±â€¯7 ng mL-1) allows detection of the drug presence in urine after acute exposure. For greater accuracy, highly sensitive ELISA (LODELISA = 6 ±â€¯3 pg mL-1) is proposed for toxicological quantitative analyses of positive samples captured by the LFIA. DISCUSSION: The comparison of the ELISA with the well-established UHPLC-MS-MS method shows excellent agreement of results, which confirms good potential of the ELISA to be used for routine analyses of 2C-B and related hallucinogenic phenethylamines of both main sub-families.