2-(2,5-Dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine (25C-NBOMe) induce adverse cardiac effects in vitro and in vivo

Designer Drug, 25D-NBOMe, Has Reinforcing and Rewarding Effects through Change of a Dopaminergic Neurochemical System

2-(2,5-Dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)_ethanamine (25D-NBOMe), an analogue of the 2C family, is a newly synthesized psychoactive substance. It acts as an agonist at the 5-HT2A receptor and has a similar mechanism to that of NBOMe compounds. However, the pharmacological mechanism for its rewarding and reinforcing effects has not been revealed. In the present study, intravenous self-administration (IVSA) test and conditioned place preference (CPP) test were performed to investigate whether 25D-NBOMe has abuse potential. We also evaluated the effects of 25D-NBOMe on neurochemical changes using western blot analysis and microdialysis. The IVSA test revealed increased self-administration in 25D-NBOMe (0.03 mg/kg)-treated rats. In addition, the CPP test revealed rewarding effects in 25D-NBOMe (1 mg/kg)-treated mice. In the neurochemical studies, 25D-NBOMe treatment affected the expression of dopamine (DA) receptor D1 (DRD1), DA receptor D2 (DRD2), tyrosine hydroxylase, DA transporter (DAT), and phospho-DAT (p-DAT) in the nucleus accumbens (NAc). In addition, microdialysis revealed that treatment with progressively increasing doses (1, 3, and 10 mg/kg) of 25D-NBOMe increased the extracellular levels of DA, 3,4-dihydroxyphenylacetic acid, and homovanillic acid in the rat NAc. Taken together, our results show the abuse potential and neurochemical changes related to addictive behavior after administration of 25D-NBOMe.

Neurotoxic and cardiotoxic effects of N-methyl-1-(naphthalen-2-yl)propan-2-amine (methamnetamine) and 1-phenyl-2-pyrrolidinylpentane (prolintane)

Two synthetic phenylethylamines, N-methyl-1-(naphthalen-2-yl)propan-2-amine (MNA) and 1-phenyl-2-pyrrolidinylpentane (prolintane), are being abused by people seeking hallucinogens for pleasure. These new psychotropic substances may provoke problems because there is no existing information about their toxicity and pharmacological behaviors. Therefore, we evaluated the safety of nerves and cardiovascular systems by determining toxicity after MNA and prolintane drugs administrations to mice and rat. Consequently, side effects such as increased spontaneous motion and body temperature were observed in oral administration of MNA. In addition, both substances reduced motor coordination levels. The IHC tests were conducted to see whether the immune response also shows abnormalities in brain tissue compared to the control group. It has been confirmed that the length of allograft inflammatory factor 1(IBA-1), an immune antibody known as microglia marker, has been shortened. We identified that a problem with the contact between synapses and neurons might be possibly produced. In the assessment of the cardiac toxicity harmfulness, no substances have been confirmed to be toxic to myocardial cells, but at certain concentrations, they have caused the QT prolongation, an indicator of ventricular arrhythmia. In addition, the hERG potassium channel, the biomarker of the QT prolongation, has been checked for inhibition. The results revealed that the possibility of QT prolongation through the hERG channel could not be excluded, and the two substances can be considered toxic that may cause ventricular arrhythmia. In sum, this study demonstrated that the possibility of toxicity in MNA and prolintane compounds might bring many harmful effects on nerves and hearts.

25X-NBOMe compounds - chemistry, pharmacology and toxicology. A comprehensive review

Recently, a growing number of reports have indicated a positive effect of hallucinogenic-based therapies in different neuropsychiatric disorders. However, hallucinogens belonging to the group of new psychoactive substances (NPS) may produce high toxicity. NPS, due to their multi-receptors affinity, are extremely dangerous for the human body and mental health. An example of hallucinogens that have been lately responsible for many severe intoxications and deaths are 25X-NBOMes - N-(2-methoxybenzyl)-2,5-dimethoxy-4-substituted phenethylamines, synthetic compounds with strong hallucinogenic properties. 25X-NBOMes exhibit a high binding affinity to serotonin receptors but also to dopamine, adrenergic and histamine receptors. Apart from their influence on perception, many case reports point out systemic and neurological poisoning with these compounds. In humans, the most frequent side effects are tachycardia, anxiety, hypertension and seizures. Moreover, preclinical studies confirm that 25X-NBOMes cause developmental impairments, cytotoxicity, cardiovascular toxicity and changes in behavior of animals. Metabolism of NBOMes seems to be very complex and involves many metabolic pathways. This fact may explain the observed high toxicity. In addition, many analytical methods have been applied in order to identify these compounds and their metabolites. The presented review summarized the current knowledge about 25X-NBOMes, especially in the context of toxicity.

The designer benzodiazepine, flubromazepam, induces reward-enhancing and cardiotoxic effects in rodents

The use of many benzodiazepines is controlled worldwide due to their high likelihood of abuse and potential adverse effects. Flubromazepam—a designer benzodiazepine—is a long-acting gamma-aminobutyric acid subtype A receptor agonist. There is currently a lack of scientific evidence regarding the potential for flubromazepam dependence or other adverse effects. This study aimed to evaluate the dependence potential, and cardiotoxicity via confirmation of the QT and RR intervals which are the factors on the electrical properties of the heart of flubromazepam in rodents. Using a conditioned place preference test, we discovered that mice treated intraperitoneally with flubromazepam (0.1 mg/kg) exhibited a significant preference for the flubromazepam-paired compartment, suggesting a potential for flubromazepam dependence. In addition, we observed several cardiotoxic effects of flubromazepam; 100-μM flubromazepam reduced cell viability, increased RR intervals but not QT intervals in the electrocardiography measurements, and considerably inhibited potassium channels in a human ether-à-go-go-related gene assay. Collectively, these findings suggest that flubromazepam may have adverse effects on psychological and cardiovascular health, laying the foundation for further efforts to list flubromazepam as a controlled substance at both national and international levels.

2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH) induce adverse effects on the cardiovascular system

Two new psychoactive substances (NPSs) classified as phenethylamines, namely 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH), are being abused by people seeking recreational hallucinogens. These NPSs may cause serious health problems as their adverse effects are not known in most cases. Therefore, in the present study, we evaluated the cardiotoxicity of 25I-NBOH and 25C-NBOH using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), Langendorff test, and human ether-a-go-go-related gene (hERG) assay. Furthermore, we analyzed the expression levels of p21 CDC42/RAC1-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, treatment with 25I-NBOH or 25C-NBOH dramatically decreased viability of H9c2 cardiomyocytes. Meanwhile, these two compounds significantly increased QT intervals and RR intervals in the rat ECG measurement. 25I-NBOH down-regulated the PAK1 protein expression in rat primary cardiomyocytes as well as H9c2 cells. However, 25C-NBOH had no effect on the PAK1 expression in H9c2 cells. In an in-depth study, 25I-NBOH inhibited potassium channels in the hERG assay, but in ex vivo test, the substance did not affect the left ventricular developed pressure (LVDP) and heart rate of the isolated rat hearts. Taken together, these results suggest that both 25I-NBOH and 25C-NBOH may have adverse cardiovascular effect. Further investigation would be needed to determine which factors mainly influence the relationship between PAK1 expression and cardiotoxicity.

2C-B-Fly-NBOMe Metabolites in Rat Urine, Human Liver Microsomes and C. elegans: Confirmation with Synthesized Analytical Standards

Compounds from the N-benzylphenethylamine (NBPEA) class of novel psychoactive substances are being increasingly utilized in neurobiological and clinical research, as diagnostic tools, or for recreational purposes. To understand the pharmacology, safety, or potential toxicity of these substances, elucidating their metabolic fate is therefore of the utmost interest. Several studies on NBPEA metabolism have emerged, but scarce information about substances with a tetrahydrobenzodifuran ("Fly") moiety is available. Here, we investigated the metabolism of 2-(8-bromo-2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran-4-yl)-N-(2-methoxybenzyl)ethan-1-amine (2C-B-Fly-NBOMe) in three different systems: isolated human liver microsomes, Cunninghamella elegans mycelium, and in rats in vivo. Phase I and II metabolites of 2C-B-Fly-NBOMe were first detected in an untargeted screening and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Several hypothesized metabolites were then synthesized as reference standards; knowledge of their fragmentation patterns was utilized for confirmation or tentative identification of isomers. Altogether, thirty-five phase I and nine phase II 2C-B-Fly-NBOMe metabolites were detected. Major detected metabolic pathways were mono- and poly-hydroxylation, O-demethylation, oxidative debromination, and to a lesser extent also N-demethoxybenzylation, followed by glucuronidation and/or N-acetylation. Differences were observed for the three used media. The highest number of metabolites and at highest concentration were found in human liver microsomes. In vivo metabolites detected from rat urine included two poly-hydroxylated metabolites found only in this media. Mycelium matrix contained several dehydrogenated, N-oxygenated, and dibrominated metabolites.

In vitro and in vivo estrogenic activity of triclosan

Triclosan (TCS) is an antibacterial and antifungal agent used in many consumer products and exhibits a chemical structure similar to non-steroidal estrogen, which is known to induce endocrine disruption. Triclosan has been found in human plasma, urine, and breast milk, and the safety of TCS-containing products has been disputed. Although studies attempted to determine the estrogenic activity of TCS, no clear results have emerged. The aim of the present study was to examine estrogenic activity of TCS using an in vitro E-screen assay and an in vivo uterotrophic assay. The in vitro E-screen assay demonstrated that TCS significantly enhanced proliferation of MCF-7 breast cancer cells, although not in a concentration-dependent manner. The in vivo uterotrophic results showed no significant change in the weight of uteri obtained from TCS-administered Sprague-Dawley rats. Further, to understand the estrogenic activity attributed to TCS at the molecular level, gene-expression profiling of uterus samples was performed from both TCS- or estrogen-treated rats and the genes and cellular processes affected by TCS or estrogen were compared. Data demonstrated that both the genes and cellular processes affected by TCS or estrogen were significantly similar, indicating the possibility that TCS-mediated estrogenic activity occurred at the global transcriptome level. In conclusion, in vitro and gene-profiling results suggested that TCS exhibited estrogenic activity.

Pharmacology and adverse effects of new psychoactive substances: synthetic cannabinoid receptor agonists

Over the last decade, new psychoactive substances (NPS) have continuously been the focus of the international society since their emergence on the illicit drug market. NPS can be classified into six groups including; synthetic cannabinoid receptor agonists (SCRAs), stimulants, opioids, dissociatives, sedatives/hypnotics, and classic hallucinogens with psychoactive effects. These are sold as "herbal incense," "bath salts," "legal highs," and "research chemicals". They can be synthesized easily with slight changes in the chemical moieties of known psychoactive substances. NPS are sold worldwide via on- and off-line markets without proper scientific evaluation regarding their safety or harmfulness. Abuse of NPS poses a serious public health issue, and systematic studies on their adverse effects are lacking. Therefore, it would be meaningful to collect currently available data in order to understand NPS and to establish viable solutions to cope with the various health issues related to them. In this article, we reviewed the general pharmacological characteristics, recent findings, and adverse effects of representative NPS; SCRAs. SCRAs are known as the most commonly abused NPS. Most SCRAs, cannabinoid receptor 1 and cannabinoid receptor 2 agonists, are often associated with severe toxicities, including cardiotoxicity, immunotoxicity, and even death, unlike natural cannabinoid Δ⁹-Tetrahydrocannabinol.

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.

Zebrafish and Artemia salina in vivo evaluation of the recreational 25C-NBOMe drug demonstrates its high toxicity

The NBOMe (N-2-methoxybenzyl-phenethylamines) family of compounds are synthetic hallucinogens derived from the 2C series. Although this family of compounds has been responsible for multiple cases of acute toxicity and several deaths around the world, to date there are few studies. These compounds act as potent 5-HT2A receptor agonists, including the hallucinogen 25C-NBOMe (2-(4-chloro-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine). In this study, we first evaluated the toxicity of 25C-NBOMe in two animal models: Artemia salina and zebrafish using the lethality test of Meyer et al. (1982) modified for Artemia salina and the Fish Embryo Toxicity test (FET) for zebrafish (Danio rerio). Subsequently, we determined the behavioral and morphological effects using different concentrations of the 25C-NBOMe. As a result, we found that this substance is highly toxic according to lethality tests in both animal models. We also observe that this hallucinogen induces alterations in swimming and motility patterns in Artemia salina. Similarly, there were alterations in the motor response to a stimulus, as well as abnormal development in the zebrafish. The developmental effects of zebrafish suggest a teratogenic potential for 25C-NBOMe. Therefore, these findings are correlated with side effects, such as motor response abnormalities and muscle deterioration, clinically reported for consumers of this recreational drug. Finally, although recent studies are addressing the neurotoxicity and cardiotoxicity of 25C-NBOMe in cell cultures, to the best of our knowledge, this is the first in vivo report for 25C-NBOMe related to toxicological parameters and their global effects on development. Therefore, it could represent an advance in the study of the substance that contributes to the understanding of the effects on behavior and development in humans.

NBOMes-Highly Potent and Toxic Alternatives of LSD

Recently, a new class of psychedelic compounds named NBOMe (or 25X-NBOMe) has appeared on the illegal drug market. NBOMes are analogs of the 2C family of phenethylamine drugs, originally synthesized by Alexander Shulgin, that contain a N-(2-methoxy)benzyl substituent. The most frequently reported drugs from this group are 25I-NBOMe, 25B-NBOMe, and 25C-NBOMe. NBOMe compounds are ultrapotent and highly efficacious agonists of serotonin 5-HT_2A and 5-HT_2C receptors (Ki values in low nanomolar range) with more than 1000-fold selectivity for 5-HT_2A compared with 5-HT_1A. They display higher affinity for 5-HT_2A receptors than their 2C counterparts and have markedly lower affinity, potency, and efficacy at the 5-HT_2B receptor compared to 5-HT_2A or 5-HT_2C. The drugs are sold as blotter papers, or in powder, liquid, or tablet form, and they are administered sublingually/buccally, intravenously, via nasal insufflations, or by smoking. Since their introduction in the early 2010s, numerous reports have been published on clinical intoxications and fatalities resulting from the consumption of NBOMe compounds. Commonly observed adverse effects include visual and auditory hallucinations, confusion, anxiety, panic and fear, agitation, uncontrollable violent behavior, seizures, excited delirium, and sympathomimetic signs such mydriasis, tachycardia, hypertension, hyperthermia, and diaphoresis. Rhabdomyolysis, disseminated intravascular coagulation, hypoglycemia, metabolic acidosis, and multiorgan failure were also reported. This survey provides an updated overview of the pharmacological properties, pattern of use, metabolism, and desired effects associated with NBOMe use. Special emphasis is given to cases of non-fatal and lethal intoxication involving these compounds. As the analysis of NBOMes in biological materials can be challenging even for laboratories applying modern sensitive techniques, this paper also presents the analytical methods most commonly used for detection and identification of NBOMes and their metabolites.

DARK Classics in Chemical Neuroscience: NBOMes

N-Benzylphenethylamines, commonly known as NBOMes, are synthetic psychedelic compounds derived from the phenethylamine class of psychedelics (2C-X compounds), which originally have been derived from the naturally occurring alkaloid mescaline. Analogously to their parent compounds and other classical psychedelics, such as psilocybin and lysergic acid diethylamide (LSD), NBOMes are believed to exert their main pharmacological effects through activation of serotonin 2A (5-HT_2A) receptors. Since their introduction as New Psychoactive Substances (NPSs) in 2010, NBOMes have been widely used for recreational purposes; this has resulted in numerous cases of acute toxicity, sometimes with lethal outcomes, leading to the classification of several NBOMes as Schedule I substances in 2013. However, in addition to their recreational use, the NBOMe class has yielded several important biochemical tools, including [¹¹C]Cimbi-36, which is now being used in positron emission tomography (PET) studies of the 5-HT_2A and 5-HT_2C receptors in the mammalian brain, and 25CN-NBOH, one of the most selective 5-HT_2A receptor agonists developed to date. In this Review, the history, chemistry, structure-activity relationships, ADME (absorption, distribution, metabolism, and excretion) properties, and safety profiles of NBOMes will be outlined and discussed.

Cardiotoxic effects of [3-[2-(diethylamino)ethyl]-1H-indol-4-yl] acetate and 3-[2-[ethyl(methyl)amino]ethyl]-1H-indol-4-ol

Two synthetic tryptamines, namely [3-[2-(diethylamino)ethyl]-1H-indol-4-yl] acetate (4-AcO-DET) and 3-[2-[ethyl(methyl)amino]ethyl]-1H-indol-4-ol (4-HO-MET), are abused by individuals seeking recreational hallucinogens. These new psychoactive substances (NPSs) can cause serious health problems because their adverse effects are mostly unknown. In the present study, we evaluated the cardiotoxicity of 4-AcO-DET and 4-HO-MET using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, electrocardiography (ECG), and the human ether-a-go-go-related gene (hERG) assay. In addition, we analyzed the expression level of p21 (CDC42/RAC)-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, 4-AcO-DET- and 4-HO-MET-treated H9c2 cells proliferated in a concentration-dependent manner. Moreover, both substances increased QT intervals (as determined using ECG) in Sprague-Dawley rats and inhibited potassium channels (as verified by the hERG assay) in Chinese hamster ovary cells. However, there was no change in PAK1 expression. Collectively, the results indicated that 4-AcO-DET and 4-HO-MET might cause adverse effects on the cardiovascular system. Further studies are required to confirm the relationship between PAK1 expression and cardiotoxicity. The findings of the present study would provide science-based evidence for scheduling the two NPSs.