The role of oxidative stress, metabolic compromise, and inflammation in neuronal injury produced by amphetamine-related drugs of abuse

Valerenic acid ameliorates amphetamine-related neurotoxicity by improving hypothalamus tyrosine hydroxylase and histamine-N-methyl transferase enzymes

Background

Narcolepsy, obesity, and attention deficit hyperactivity disorder are all treated with amphetamine (a central nervous system stimulant) while valerenic acid (VA) has a pharmacological effect in the central nervous system.

Objectives

The purpose of this study was to ascertain whether VA is able to make amends for neurotoxicity by modifying hypothalamus expressions of the enzymes tyrosine hydroxylase and histamine-N-methyl transferase in rats orally administered with methamphetamine (METH).

Methods

There were thirty-six male albino rats split up into six equal groups, Control, VA (5 mg/kg)-treated, and VA (10 mg/kg)-treated groups: For four weeks, normal rats received oral administration of 1 ml of distilled water, 5 mg/kg of VA, and 10 ml/kg of VA once daily. METH-treated, VA (5 mg/kg) prior to METH-treated, and VA (10 mg/kg) before METH-treated groups: normal rats were oral administrated with METH (2.5 mg/kg), 3 days/week for 3 weeks, where the last two groups were oral administrated daily during four weeks at 5 mg/kg and 10 mg/kg VA, starting one week prior to METH administration.

Results

METH decreased superoxide dismutase, glutathione peroxidase, catalase, NADPH oxidase, interleukin-10, sucrose preference test, distance traveled test, and center square entries test, ATPase activity and the enzymes tyrosine hydroxylase and histamine-N-methyl transferase but increased malondialdehyde, conjugated dienes, oxidative index, serotonin, dopamine, norepinephrine, γ-aminobutyric acid, tumor necrosis factor-α, interleukin-1β, interleukin-6, nuclear factor kappa B levels, the center square duration test, tail suspension test, and forced swimming test. in the METH-treated animals' brain in contrast to the control group. After four weeks of oral administration of VA to METH-treated rats, all of these parameters returned to levels that were nearly control, indicating that a higher dose was more effective than a lower one.

Conclusion

VA ameliorated METH-related neurotoxicity by improving hypothamalus expressions of the enzymes tyrosine hydroxylase and histamine-N-methyl transferase.

Excessive iron accumulation in the striatum associated with addictive behaviors of medication-overuse headache: a prospective study

BACKGROUND

Abnormal iron deposition may be a biomarker for a disrupted central antinociceptive neuronal network, and the relationship between iron deposition and the pathophysiological mechanisms of chronic migraine (CM) with medication overuse (MOH) remains unclear. We investigated iron deposition in the deep gray matter (DGM) of the brain in CM patients with and without MOH using quantitative susceptibility mapping (QSM).

METHODS

Forty-eight healthy controls (HCs) and 69 CM patients (36 with MOH; 33 without MOH) were recruited. QSM data were acquired using a 3.0 T Magnetic resonance imaging (MRI). Regions of interest (ROI) in the DGM, including the bilateral caudate, putamen, globus pallidus (GP), hippocampus, nucleus accumbens, and amygdala, were segmented from the T1-weighted images (T1WI) of the whole brain of each individual patient using FreeSurfer. QSM images were registered to T1WI. QSM values within each ROI were extracted and compared between CM and HCs, as well as between CM with MOH and CM without MOH. Correlations between QSM values and clinical assessment scale scores were calculated. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic performance of QSM values in these DGM for detecting CM and CM with MOH.

RESULTS

Compared to HCs, CM patients exhibited increased iron deposition in the caudate (p = 0.013) and putamen (p < 0.001). In the CM without MOH group, headache duration correlated positively with iron deposition in the caudate (r = 0.502, p = 0.010) and putamen (r = 0.514, p = 0.009). CM with MOH patients showed greater iron deposition in the caudate (p < 0.001), putamen (p < 0.001), and GP (p = 0.049) than those without MOH, with medication use frequency correlating positively with iron deposition in the caudate (r = 0.427, p = 0.023) and putamen (r = 0.445, p = 0.018). ROC curve analysis indicated that the caudate (AUC = 0.736) and putamen (AUC = 0.729) exhibited high sensitivity and specificity in diagnosing CM with MOH.

CONCLUSIONS

CM patients with MOH had excessive iron deposition in basal ganglia regions, including the caudate, putamen, and GP, which may be related to the medication overuse behavior. Iron deposition in the caudate and putamen may be a potential biomarker for CM with MOH. These findings provide insight into the common pathophysiological mechanisms underlying MOH and potential addiction.

Emerging risk factors for heart failure in younger populations: A growing public health concern

Heart failure (HF) is a growing public health concern, with an increasing incidence among younger populations. Traditionally, HF was considered a condition primarily affecting the elderly, but of late, emerging evidence hints at a rapidly rising HF incidence in youth in the past 2 decades. HF in youth has been linked to a complex interaction between emerging risk factors, such as metabolic syndrome, environmental exposures, genetic predispositions, and lifestyle behaviors. This review examines these evolving determinants, including substance abuse, autoimmune diseases, and the long-term cardiovascular effects of coronavirus disease 2019, which disproportionately affect younger individuals. Through a comprehensive analysis, the study highlights the importance of early detection, targeted prevention strategies, and multidisciplinary management approaches to address this alarming trend. Promoting awareness and integrating age-specific interventions could significantly reduce the burden of HF and improve long-term outcomes among younger populations.

Transdiagnostic features of inflammatory markers and executive function across psychiatric disorders

Executive dysfunction and dysregulated inflammation are found in patients with different psychiatric disorders. However, whether there are different associations between inflammatory markers and executive performance in patients with different psychiatric diagnoses is unknown. Our study aims were (1) to compare peripheral cytokine expression and executive function in patients with bipolar disorder (BD), substance use disorder (SUD), and schizophrenia (SCZ), and in healthy controls (HC) and (2) to explore the potential association between inflammatory cytokines and executive function in different patient groups and HC. Participants with BD (n = 816), SUD (opioid use disorder and/or methamphetamine use disorder, n = 518), SCZ (n = 146), and HC (n = 186) were recruited. Plasma cytokine levels [tumor necrosis factor (TNF)-α, interleukin (IL)-8 (only measured in 8 SCZ patients), transforming growth factor (TGF)-β1 (not measured in SCZ patients)], C-reactive protein (CRP), brain-derived neurotrophic factor (BDNF) levels, and executive function [Wisconsin Card Sorting Test (WCST) and Continuous Performance Test (CPT)] were assessed. We found that all patient groups had worse executive performance and higher inflammatory cytokine levels than the HC group. SCZ patients had the worst executive performance, while SUD patients had the highest inflammatory cytokine levels. Increased plasma IL-8, CRP, and TNF-α levels were specifically associated with worse executive function in BD, SUD, and SCZ patients (P = 0.009, 0.04, and 0.03, respectively). We concluded that dysregulated inflammation might be a transdiagnostic feature among different psychiatric disorders and associated with executive dysfunction. Further studies to investigate the causal relationship and mechanisms between inflammation and executive dysfunction may be needed.

Glutamate-Mediated Excitotoxicity in the Pathogenesis and Treatment of Neurodevelopmental and Adult Mental Disorders

Glutamate is the main excitatory neurotransmitter in the brain wherein it controls cognitive functional domains and mood. Indeed, brain areas involved in memory formation and consolidation as well as in fear and emotional processing, such as the hippocampus, prefrontal cortex, and amygdala, are predominantly glutamatergic. To ensure the physiological activity of the brain, glutamatergic transmission is finely tuned at synaptic sites. Disruption of the mechanisms responsible for glutamate homeostasis may result in the accumulation of excessive glutamate levels, which in turn leads to increased calcium levels, mitochondrial abnormalities, oxidative stress, and eventually cell atrophy and death. This condition is known as glutamate-induced excitotoxicity and is considered as a pathogenic mechanism in several diseases of the central nervous system, including neurodevelopmental, substance abuse, and psychiatric disorders. On the other hand, these disorders share neuroplasticity impairments in glutamatergic brain areas, which are accompanied by structural remodeling of glutamatergic neurons. In the current narrative review, we will summarize the role of glutamate-induced excitotoxicity in both the pathophysiology and therapeutic interventions of neurodevelopmental and adult mental diseases with a focus on autism spectrum disorders, substance abuse, and psychiatric disorders. Indeed, glutamatergic drugs are under preclinical and clinical development for the treatment of different mental diseases that share glutamatergic neuroplasticity dysfunctions. Although clinical evidence is still limited and more studies are required, the regulation of glutamate homeostasis is attracting attention as a potential crucial target for the control of brain diseases.

Dextromethorphan moderates reward deficiency associated with central serotonin transporter availability in 3,4-methylenedioxy-methamphetamine-treated animals

BACKGROUND

The neurotoxicity of 3,4-methylenedioxy-methamphetamine (MDMA) to the serotonergic system is well-documented. Dextromethorphan (DM), an antitussive drug, decreased morphine- or methamphetamine (MA)-induced reward in rats and may prevent MDMA-induced serotonergic deficiency in primates, as indicated by increased serotonin transporter (SERT) availability. We aimed to investigate the effects of DM on reward, behavioral sensitization, and neurotoxicity associated with loss of SERT induced by chronic MDMA administration in rats.

METHODS

Conditioned place preference (CPP) and locomotor activity tests were used to evaluate drug-induced reward and behavioral sensitization; 4-[ 18 F]-ADAM/animal-PET and immunohistochemistry were used to explore the effects of DM on MDMA-induced loss of SERT.

RESULTS

MDMA significantly reduced SERT binding in the rat brain; however, co-administration of DM significantly restored SERT, enhancing the recovery rate at day 14 by an average of ~23% compared to the MDMA group. In confirmation of the PET findings, immunochemistry revealed MDMA reduced SERT immunoactivity in all brain regions, whereas DM markedly increased the serotonergic fiber density after MDMA induction.

CONCLUSION

Behavioral tests and in vivo longitudinal PET imaging demonstrated the CPP indexes and locomotor activities of the reward system correlate negatively with PET 4-[ 18 F]ADAM SERT activity in the reward system. Our findings suggest MDMA induces functional abnormalities in a network of brain regions important to decision-making processes and the motivation circuit. DM may exert neuroprotective effects to reverse MDMA-induced neurotoxicity.

Luteolin amends neural neurotransmitters, antioxidants, and inflammatory markers in the cerebral cortex of Adderall exposed rats

BACKGROUND

Adderall is a central nervous system stimulant while luteolin has neuroprotective activity. This study aimed to determine whether luteolin can amend neural neurotransmitters, antioxidants, and inflammatory markers in the cerebral cortex of Adderall exposed rats.

METHODS

Thirty-six male albino rats were divided into 6 equal groups, Control, Luteolin (1 g/kg)-treated, and Luteolin (2 g/kg)-treated groups: normal rats were orally administrated once a day with 2 ml distilled water, luteolin (1 g/kg), and luteolin (2 g/kg), respectively for 4 weeks. Adderall rats, Adderall rats + luteolin (1 g/kg)-treated, and Adderall rats + luteolin (2 g/kg)-treated groups: normal rats were orally administrated once a day with 10 mg/kg of Adderall, 3 days/week for 4 weeks, then these rats orally administrated daily once a day with 2 ml of distilled water, luteolin (1 g/kg), and luteolin (2 g/kg), respectively for another 4 weeks.

RESULTS AND CONCLUSION

Adderall decreased superoxide dismutase, glutathione peroxidase, catalase, NADPH oxidase, interleukin-10, serotonin, dopamine, norepinephrine, γ-aminobutyric acid, and acetylcoline estrase but increased malondialdehyde, conjugated dienes, oxidative index, tumour necrosis factor-α, interleukin-1β, and interleukin-6 levels in the cerebral cortex. Adderall increased the expression of glial fibrillary acidic protein, ionized calcium binding adaptor molecule 1, and anti-calbindin in the cerebral cortex of Adderall-treated rats. In Adderall-treated rats, daily oral administration of luteolin for 4 weeks brought all these parameters back to values that were close to control where higher dose was more effective than lower dose. The importance of this research is to provide natural compound that amends Adderall-related neural disturbances and this natural compound is cheap, avaliable without any side effect and it does not interfer with Adderall efficiency.

Linalool attenuates hypothalamus proteome disturbance facilitated by methamphetamine induced neurotoxicity in rats

BACKGROUND

One of the most powerful stimulants of the central nervous system is methamphetamine (METH). Linalool has a neuroprotective effect against ischemia injury by reducing oxidative stress and apoptosis. The present study investigated whether linalool can reverse the hypothalamus neurotoxicity and proteome disturbance in METH-treated rats.

BRIEF METHOD

A total of 36 male albino rats were split into two equal groups (normal and METH-treated). Three equal subgroups of normal rats were created; Control, Linalool (25 mg/kg), and Linalool (50 mg/kg); Normal rats were given daily oral doses of 1 ml of distilled water, 25 mg/kg linalool, and 50 mg/kg of linalool, respectively. METH groups were divided into 3 equal subgroups; METH-treated rats, Linalool (25 mg/kg)+METH-treated, and Linalool (50 mg/kg)+METH-treated subgroups; METH-treated rats received daily and oral doses of 1 ml distilled water, 25 mg/kg linalool, and 50 mg/kg of linalool, respectively.

RESULTS

According to the data obtained, METH caused a decrease of the sucrose preference test, travel distance test, and center square entries test, superoxide dismutase, glutathione peroxidase, catalase, NADPH oxidase, interleukin-10 but a rise in the center square duration test, tail suspension test, and forced swimming test, malondialdehyde, conjugated dienes, oxidative index, serotonin, dopamine, norepinephrine, γ-aminobutyric acid, tumour necrosis factor-α, interleukin-1β, interleukin-6 levels. When compared to the control group, rats treated with METH had lower sodium/potassium ATPase activity and missing of prothrombin, fibrinogen, and ceruloplasmin protein bands in the hypothalamus. In METH-treated rats, daily and oral co-administration with linalool brought all these parameters back to values that were close to control.

SIGNIFICANCE

According to obtained data, linalool could protect the hypothalamus against METH-induced neurotoxicity and proteome disturbance probably by modifying oxidative stress, neurotransmitters, inflammation, sodium/potassium-ATPase activity, proteome disturbance, and tissue histology in METH-treated rats where higher dose of linalool was more efficient than lower dose.

Tracing Superoxide Anion in Serotonergic Neurons of Living Mouse Brains with Depression by Small-Molecule Fluorescence Probes

In brains, the serotonergic neurons are the unique resource of the neurotransmitter serotonin, which plays a pivotal role in the physiology of the brain. The dysfunction of serotonergic neurons caused by oxidative stress in the brain is closely related to the occurrence and development of various mental diseases, such as depression. As the biomarker of oxidative stress, the superoxide anion radical (O2•-) can cause oxidative damage to proteins, nucleic acids and lipids, disturbing the function of neurons and brains. A serotonin transporter (SERT) specifically expresses in serotonergic neurons, which is the biomarker of serotonergic neurons. Thus, we created two novel small molecular fluorescent probes (PA-CA and HT-CA) for imaging O2•- in serotonergic neurons of living brains of mice based on specific targeting groups of SERT. Both PA-CA and HT-CA exert excellent SERT-targetable and glorious selectivity for O2•-. Those two probes could monitor the boost of O2•- in living hsert-HEK293 cells that specifically express SERT under oxidative stress. With two-photon fluorescence imaging, we revealed for the first time that O2•- is significantly increased in serotonergic neurons in living brains of mice with depression. More importantly, proteomic analyses suggested that O2•- could oxidize cysteine and histidine in the active site of SERT, which is involved in the development of depression. This work provides new materials for living brain imaging and offers new strategy for unraveling the pathophysiology of depression.

Striatal Iron Deposition in Recreational MDMA (Ecstasy) Users

BACKGROUND

The common club drug MDMA (also known as ecstasy) enhances mood, sensory perception, energy, sociability, and euphoria. While MDMA has been shown to produce neurotoxicity in animal models, research on its potential neurotoxic effects in humans is inconclusive and has focused primarily on the serotonin system.

METHODS

We investigated 34 regular, largely pure MDMA users for signs of premature neurodegenerative processes in the form of increased iron load in comparison to a group of 36 age-, sex-, and education-matched MDMA-naïve control subjects. We used quantitative susceptibility mapping, a novel tool able to detect even small tissue (nonheme) iron accumulations. Cortical and relevant subcortical gray matter structures were grouped into 8 regions of interest and analyzed.

RESULTS

Significantly increased iron deposition in the striatum was evident in the MDMA user group. The effect survived correction for multiple comparisons and remained after controlling for relevant confounding factors, including age, smoking, and stimulant co-use. Although no significant linear relationship between measurements of the amounts of MDMA intake (hair analysis and self-reports) and quantitative susceptibility mapping values was observed, increased striatal iron deposition might nevertheless point to MDMA-induced neurotoxic processes. Additional factors (hyperthermia and simultaneous co-use of other substances) that possibly amplify neurotoxic effects of MDMA during the state of acute intoxication are discussed.

CONCLUSIONS

The demonstrated increased striatal iron accumulation may indicate that regular MDMA users have an increased risk potential for neurodegenerative diseases with progressing age.

In silico clinical trial evaluating lisdexamfetamine's and methylphenidate's mechanism of action computational models in an attention-deficit/hyperactivity disorder virtual patients' population

Introduction

Attention-deficit/hyperactivity disorder (ADHD) is an impairing psychiatric condition with the stimulants, lisdexamfetamine (LDX), and methylphenidate (MPH), as the first lines pharmacological treatment.

Methods

Herein, we applied a novel in silico method to evaluate virtual LDX (vLDX) and vMPH as treatments for ADHD applying quantitative systems pharmacology (QSP) models. The objectives were to evaluate the model's output, considering the model characteristics and the information used to build them, to compare both virtual drugs' efficacy mechanisms, and to assess how demographic (age, body mass index, and sex) and clinical characteristics may affect vLDX's and vMPH's relative efficacies.

Results and Discussion

We molecularly characterized the drugs and pathologies based on a bibliographic search, and generated virtual populations of adults and children-adolescents totaling 2,600 individuals. For each virtual patient and virtual drug, we created physiologically based pharmacokinetic and QSP models applying the systems biology-based Therapeutic Performance Mapping System technology. The resulting models' predicted protein activity indicated that both virtual drugs modulated ADHD through similar mechanisms, albeit with some differences. vMPH induced several general synaptic, neurotransmitter, and nerve impulse-related processes, whereas vLDX seemed to modulate neural processes more specific to ADHD, such as GABAergic inhibitory synapses and regulation of the reward system. While both drugs' models were linked to an effect over neuroinflammation and altered neural viability, vLDX had a significant impact on neurotransmitter imbalance and vMPH on circadian system deregulation. Among demographic characteristics, age and body mass index affected the efficacy of both virtual treatments, although the effect was more marked for vLDX. Regarding comorbidities, only depression negatively impacted both virtual drugs' efficacy mechanisms and, while that of vLDX were more affected by the co-treatment of tic disorders, the efficacy mechanisms of vMPH were disturbed by wide-spectrum psychiatric drugs. Our in silico results suggested that both drugs could have similar efficacy mechanisms as ADHD treatment in adult and pediatric populations and allowed raising hypotheses for their differential impact in specific patient groups, although these results require prospective validation for clinical translatability.

Withania somnifera influences MDMA-induced hyperthermic, cognitive, neurotoxic and neuroinflammatory effects in mice

Withania somnifera (WS) is utilized in Ayurvedic medicine owing to its central and peripheral beneficial properties. Several studies have accrued indicating that the recreational amphetamine-related drug (+/-)- 3,4-methylenedioxymethamphetamine (MDMA; Ecstasy) targets the nigrostriatal dopaminergic system in mice, inducing neurodegeneration and gliosis, causing acute hyperthermia and cognitive impairment. This study aimed to investigate the effect of a standardized extract of W. somnifera (WSE) on MDMA-induced neurotoxicity, neuroinflammation, memory impairment and hyperthermia. Mice received a 3-day pretreatment with vehicle or WSE. Thereafter, vehicle- and WSE-pretreated mice were randomly divided into four groups: saline, WSE, MDMA alone, WSE plus MDMA. Body temperature was recorded throughout treatment, and memory performance was assessed by a novel object recognition (NOR) task at the end of treatment. Thereafter, immunohistochemistry was performed to evaluate in the substantia nigra pars compacta (SNc) and striatum the levels of tyrosine hydroxylase (TH), as marker of dopaminergic degeneration, and of glial fibrillary acidic protein (GFAP) and TMEM119, as markers of astrogliosis or microgliosis, respectively. MDMA-treated mice showed a decrease in TH-positive neurons and fibers in the SNc and striatum respectively, an increase in gliosis and body temperature, and a decrease in NOR performance, irrespective of vehicle or WSE pretreatment. Acute WSE plus MDMA counteracted the modifications in TH-positive cells in SNc, GFAP-positive cells in striatum, TMEM in both areas and NOR performance, as compared to MDMA alone, while no differences were observed as compared to saline. Results indicate that WSE acutely administered in combination with MDMA, but not as pretreatment, protects mice against the noxious central effects of MDMA.

The Inflammatory Signals Associated with Psychosis: Impact of Comorbid Drug Abuse

Psychosis and substance use disorders are two diagnostic categories whose association has been studied for decades. In addition, both psychosis spectrum disorders and drug abuse have recently been linked to multiple pro-inflammatory changes in the central nervous system. We have carried out a narrative review of the literature through a holistic approach. We used PubMed as our search engine. We included in the review all relevant studies looking at pro-inflammatory changes in psychotic disorders and substance use disorders. We found that there are multiple studies that relate various pro-inflammatory lipids and proteins with psychosis and substance use disorders, with an overlap between the two. The main findings involve inflammatory mediators such as cytokines, chemokines, endocannabinoids, eicosanoids, lysophospholipds and/or bacterial products. Many of these findings are present in different phases of psychosis and in substance use disorders such as cannabis, cocaine, methamphetamines, alcohol and nicotine. Psychosis and substance use disorders may have a common origin in an abnormal neurodevelopment caused, among other factors, by a neuroinflammatory process. A possible convergent pathway is that which interrelates the transcriptional factors NFκB and PPARγ. This may have future clinical implications.

Psychostimulants influence oxidative stress and redox signatures: the role of DNA methylation

Objective: Psychostimulant use induces oxidative stress and alters redox imbalance, influencing epigenetic signatures in the central nervous system (CNS). Among the various epigenetic changes, DNA methylation is directly linked to oxidative stress metabolism via critical redox intermediates such as NAD+, S-adenosylmethionine (SAM), and 2-oxoglutarate. Fluctuations in these intermediates directly influence epigenetic signatures, which leads to detectable alterations in gene expression and protein modification. This review focuses on recent advances in the impact of psychostimulant use on redox-imbalance-induced DNA methylation to develop novel epigenetics-based early interventions. Methods: This review is based on collective research data obtained from the PubMed, Science Direct, and Medline databases. The keywords used in the electronic search in these databases were redox, substance use disorder, psychostimulants, DNA methylation, and neurological diseases. Results: Instability in DNA methylation levels and redox expression effects are reported in various behavioral models stimulated by psychostimulants and opioids, indicating the widespread involvement of epigenetic changes in DNA methylation signatures in neurological disorders. Discussion: This review summarizes the need for more studies and experimental evaluations of DNA-methylation-based strategies that may help to understand the association between psychostimulant use and oxidative stress or redox-linked metabolic recalibration influencing neuronal impairments.

Stress- and drug-induced neuroimmune signaling as a therapeutic target for comorbid anxiety and substance use disorders

Stress and substance use disorders remain two of the most highly prevalent psychiatric conditions and are often comorbid. While individually these conditions have a debilitating impact on the patient and a high cost to society, the symptomology and treatment outcomes are further exacerbated when they occur together. As such, there are few effective treatment options for these patients, and recent investigation has sought to determine the neural processes underlying the co-occurrence of these disorders to identify novel treatment targets. One such mechanism that has been linked to stress- and addiction-related conditions is neuroimmune signaling. Increases in inflammatory factors across the brain have been heavily implicated in the etiology of these disorders, and this review seeks to determine the nature of this relationship. According to the "dual-hit" hypothesis, also referred to as neuroimmune priming, prior exposure to either stress or drugs of abuse can sensitize the neuroimmune system to be hyperresponsive when exposed to these insults in the future. This review completes an examination of the literature surrounding stress-induced increases in inflammation across clinical and preclinical studies along with a summarization of the evidence regarding drug-induced alterations in inflammatory factors. These changes in neuroimmune profiles are also discussed within the context of their impact on the neural circuitry responsible for stress responsiveness and addictive behaviors. Further, this review explores the connection between neuroimmune signaling and susceptibility to these conditions and highlights the anti-inflammatory pharmacotherapies that may be used for the treatment of stress and substance use disorders.

Molecular Characterisation of the Mechanism of Action of Stimulant Drugs Lisdexamfetamine and Methylphenidate on ADHD Neurobiology: A Review

Attention-deficit/hyperactivity disorder (ADHD) is a common childhood-onset neurodevelopmental disorder characterised by persistent inattention, hyperactivity and impulsivity. Moreover, ADHD is commonly associated with other comorbid diseases (depression, anxiety, bipolar disorder, etc.). The ADHD symptomatology interferes with subject function and development. The treatment of ADHD requires a multidisciplinary approach based on a combination of non-pharmacological and pharmacological treatments with the aim of ameliorating the symptomatology; among first-line pharmacological treatments are stimulants [such as methylphenidate (MPH) and lisdexamfetamine dimesylate (LDX)]. In this review we explored recent ADHD- and stimulants-related literature, with the aim of compiling available descriptions of molecular pathways altered in ADHD, and molecular mechanisms of current first-line stimulants MPH and LDX. While conducting the narrative review, we applied structured search strategies covering PubMed/MEDLINE database and performed handsearching of reference lists on the results of those searches. The aetiology and pathophysiology of ADHD are incompletely understood; both genetic and environmental factors have been associated with the disorder and its grade of burden, and also the relationship between the molecular mechanisms of pharmacological treatments and their clinical implications. The lack of comprehensive understanding of the underlying molecular pathology makes both the diagnosis and treatment difficult. Few published studies evaluating molecular data on the mechanism of action (MoA) of MPH and LDX on ADHD are available and most of them are based on animal models. Further studies are necessary to improve the knowledge of ADHD pathophysiology and how the MoAs of MPH and LDX differentially modulate ADHD pathophysiology and control ADHD symptomatology.

Sex differences in neurobehavioral consequences of methamphetamine exposure in adult mice

RATIONALE

Recreational and medical use of stimulants is increasing, and their use may increase susceptibility to aging and promote neurobehavioral impairments. The long-term consequences of these psychostimulants and how they interact with age have not been fully studied.

OBJECTIVES

Our study investigated whether chronic exposure to the prototypical psychostimulant, methamphetamine (METH), at doses designed to emulate human therapeutic dosing, would confer a pro-oxidizing redox shift promoting long-lasting neurobehavioral impairments.

METHODS

Groups of 4-month-old male and female C57BL/6 J mice were administered non-contingent intraperitoneal injections of either saline or METH (1.4 mg/kg) twice a day for 4 weeks. Mice were randomly assigned to one experimental group: (i) short-term cognitive assessments (at 5 months), (ii) long-term cognitive assessments (at 9.5 months), and (ii) longitudinal motor assessments (at 5, 7, and 9 months). Brain regions were assessed for oxidative stress and markers of neurotoxicity after behavior testing.

RESULTS

Chronic METH exposure induced short-term effects on associative memory, gait speed, dopamine (DA) signaling, astrogliosis in females, and spatial learning and memory, balance, DA signaling, and excitotoxicity in males. There were no long-term effects of chronic METH on cognition; however, it decreased markers of excitotoxicity in the striatum and exacerbated age-associated motor impairments in males.

CONCLUSION

In conclusion, cognitive and motor functions were differentially and sex-dependently affected by METH exposure, and oxidative stress did not seem to play a role in the observed behavioral outcomes. Future studies are necessary to continue exploring the long-term neurobehavioral consequences of drug use in both sexes and the relationship between aging and drugs.

Brain-derived neurotrophic factor protects serotonergic neurons against 3,4-methylenedioxymethamphetamine ("Ecstasy") induced cytoskeletal damage

3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy") use has been linked to persistent alterations of the brain serotonergic (5-HT) system in animal and human studies, but the molecular underpinnings are still unclear. Cytoskeletal structures such as neurofilament light chain (NfL) are promising markers of drug-induced brain toxicity and may be involved in MDMA neurotoxicity. The brain-derived neurotrophic factor (BDNF) promotes the growth and sprouting of 5-HT neurons and its differential response to MDMA administration was suggested to mediate dose- and region-dependent 5-HT damage by MDMA. However, the role of BDNF pre-treatment in preventing MDMA neurotoxicity and the potential effects of MDMA on NfL are still elusive. Therefore, a differentiated 5-HT neuronal cell line obtained from rat raphe nucleus (RN46A) was treated in vitro with either MDMA, BDNF, MDMA + BDNF, or vehicle. Cell viability (measured by MTT) and intracellular NfL levels (immunocytochemistry assay) were reduced by MDMA, but partially rescued by BDNF co-treatment. Our findings confirmed that BDNF levels can influence MDMA-induced 5-HT damage, and support BDNF to be a crucial target for neuroprotective interventions of the 5-HT system. We also provide evidence on the sensitivity of NfL to MDMA neurotoxicity, with potential implications for in-vivo monitoring of drug-induced neurotoxicity.

Potential Treat-to-Target Approach for Methamphetamine Use Disorder: A Pilot Study of Adenosine 2A Receptor Antagonist With Positron Emission Tomography

Introduction: The misuse of stimulant drugs such as methamphetamine is a global public health issue. One important neurochemical mechanism of methamphetamine use disorder may be altered dopaminergic neurotransmission. For instance, previous studies using positron emission tomography (PET) have consistently shown that striatal dopamine D2-type receptor availability (quantified as binding potential; BPND) is lower in methamphetamine use disorder. Further, methamphetamine use is known to induce chronic neuroinflammation through multiple physiological pathways. Upregulation of D2-type receptor and/or attenuation of neuroinflammation may therefore provide a therapeutic effect for this disorder. In vitro studies have shown that blockage of adenosine 2A (A2A) receptors may prevent D2-receptor downregulation and neuroinflammation-related brain damage. However, no study has examined this hypothesis yet.

Methods and Analysis: Using a within-subject design, this trial will assess the effect of the selective A2A receptor antagonist, istradefylline, primarily on D2-type BPND in the striatum, and secondarily on neuroinflammation in the whole brain in individuals with methamphetamine use disorder. The research hypotheses are that istradefylline will increase striatal D2-type BPND and attenuate neuroinflammation. Twenty participants with methamphetamine use disorder, aged 20–65, will be recruited to undergo [11C]raclopride PET (for every participant) and [11C]DAA1106 PET (if applicable) once before and once after administration of 40 mg/day istradefylline for 2 weeks. Neuropsychological measurements will be performed on the same days of the PET scans.

Selective Inhibition of PDE4B Reduces Methamphetamine Reinforcement in Two C57BL/6 Substrains

Methamphetamine (MA) is a highly addictive psychostimulant drug, and the number of MA-related overdose deaths has reached epidemic proportions. Repeated MA exposure induces a robust and persistent neuroinflammatory response, and the evidence supports the potential utility of targeting neuroimmune function using non-selective phosphodiesterase 4 (PDE4) inhibitors as a therapeutic strategy for attenuating addiction-related behavior. Off-target, emetic effects associated with non-selective PDE4 blockade led to the development of isozyme-selective inhibitors, of which the PDE4B-selective inhibitor A33 was demonstrated recently to reduce binge drinking in two genetically related C57BL/6 (B6) substrains (C57BL/6NJ (B6NJ) and C57BL/6J (B6J)) that differ in their innate neuroimmune response. Herein, we determined the efficacy of A33 for reducing MA self-administration and MA-seeking behavior in these two B6 substrains. Female and male mice of both substrains were first trained to nose poke for a 100 mg/L MA solution followed by a characterization of the dose-response function for oral MA reinforcement (20 mg/L-3.2 g/L), the demand-response function for 400 mg/L MA, and cue-elicited MA seeking following a period of forced abstinence. During this substrain comparison of MA self-administration, we also determined the dose-response function for A33 pretreatment (0-1 mg/kg) on the maintenance of MA self-administration and cue-elicited MA seeking. Relative to B6NJ mice, B6J mice earned fewer reinforcers, consumed less MA, and took longer to reach acquisition criterion with males of both substrains exhibiting some signs of lower MA reinforcement than their female counterparts during the acquisition phase of the study. A33 pretreatment reduced MA reinforcement at all doses tested. These findings provide the first evidence that pretreatment with a selective PDE4B inhibitor effectively reduces MA self-administration in both male and female mice of two genetically distinct substrains but does not impact cue-elicited MA seeking following abstinence. If relevant to humans, these results posit the potential clinical utility of A33 or other selective PDE4B inhibitors for curbing active drug-taking in MA use disorder.

Potential Effects of Nrf2 in Exercise Intervention of Neurotoxicity Caused by Methamphetamine Oxidative Stress

Methamphetamine can cause oxidative stress-centered lipid peroxidation, endoplasmic reticulum stress, mitochondrial dysfunction, excitatory neurotoxicity, and neuroinflammation and ultimately lead to nerve cell apoptosis, abnormal glial cell activation, and dysfunction of blood-brain barrier. Protecting nerve cells from oxidative destroy is a hopeful strategy for treating METH use disorder. Nrf2 is a major transcriptional regulator that activates the antioxidant, anti-inflammatory, and cell-protective gene expression through endogenous pathways that maintains cell REDOX homeostasis and is conducive to the survival of neurons. The Nrf2-mediated endogenous antioxidant pathway can also prevent neurodegenerative effects and functional defects caused by METH oxidative stress. Moderate exercise activates this endogenous antioxidant system, which involves in many diseases, including neurodegenerative diseases. Based on evidence from existing literature, we argue that appropriate exercise can play an endogenous antioxidant regulatory role in the Nrf2 signaling pathway to reduce a number of issues caused by METH-induced oxidative stress. However, more experimental evidence is needed to support this idea. In addition, further exploration is necessary about the different effects of various parameters of exercise intervention (such as exercise mode, time, and intensity) on the Nrf2 signaling pathway intervention. Whether there are synergistic effects between exercise and plant-derived Nrf2 activators is worth further investigation.

Effectiveness of Traditional Chinese Health-Promoting Exercise as an Adjunct Therapy for Drug Use Disorders: A Systematic Review and Meta-Analysis

Objective: Meta-analysis was used to quantitatively examine the effectiveness of Traditional Chinese Health-Promoting Exercise (TCE) as an adjuvant therapy for drug use disorders and rehabilitation based on previously published studies. Methods: Potential literature was retrieved by searching eight electronic databases (China National Knowledge Infrastructure [CNKI], Wanfang, Chinese Scientific Journal Database, China Biology Medicine [CBM], PubMed, Embase, Cochrane Library, and EBSCOhost) from January 2000 to May 2021, as well as through manual searches, including email. These literature reports comprised randomized, controlled trial studies and nonrandomized, controlled trial studies assessing the effects of TCE intervention on the physical and psychological (mental) health of drug addicts. The quality and bias risk of each study were assessed using the Cochrane bias risk assessment tool. The RevMan5.3 statistical software was employed to evaluate the methodological quality of the included studies, and sensitivity and subgroup analyses using the Stata16.0 MP software were performed to explore the sources of heterogeneity among the data. This study is registered on PROSPERO (CRD42021254124). Results: Data from 14 studies (1094 individuals with drug abuse) meeting the inclusion criteria were extracted for meta-analysis. Compared to the control group, TCE intervention induced significant improvements in the systolic blood pressure (standardized mean difference [SMD] = -0.42, p < 0.05), diastolic blood pressure (SMD = -0.34, p < 0.05), one-leg stand with eyes closed (SMD = 0.74, p < 0.05), Symptom Check List (SMD = -0.42, p < 0.05), anxiety scale (self-rating anxiety scale/STI) (SMD = -0.49, p < 0.05), and depression scale (self-rating depression scale/Beck Depression Inventory/Hamilton Depression Rating Scale for Depression) (SMD = -0.37, p < 0.05). Sensitivity and subgroup analyses of the individual outcome indicators with high heterogeneity (I2 ≥ 50%, p < 0.10) were performed to further explore the source of heterogeneity. The results of the sensitivity analysis showed that, after removing studies one by one, the heterogeneity of the data remained high (I2 > 50), and the difference of synthetic overall effect did not change (p < 0.05), indicating that the sensitivity was low and that the results were robust and reliable. The results of the subgroup analysis results indicated that the gender of the participants and the drug type were the sources of heterogeneity. Conclusion: As an effective mind-body movement intervention, long-term TCE is beneficial to improving the physical and mental health of drug addicts. The specific intervention methods are dependent on the gender of the addict and the drug type, and longer intervention times yielded greater impacts on their physical health.

Evaluation of the health status outcome among inpatients treated for Amphetamine Addiction

Amphetamine is one of the most abuser drugs in Saudi Arabia. The aim of this study was to evaluate health status outcome at baseline and after detoxification in amphetamine users through the evaluation of the body mass index, renal function tests, cardiac biomarkers, gonadal hormonal levels, and oxidative stress markers. A cross-sectional study was conducted on 90 participants. Sixty participants were hospitalized patients for treatment of addiction and 30 participants were healthy volunteers. This study was performed at a psychiatric and rehabilitation center, in Qassim region, in the Kingdom of Saudi Arabia. Participants were divided into: group I = control; group II = amphetamine users and group III = amphetamine plus cannabis users. Socio-demographic data was collected. The urinary amphetamine level, Severity Dependence Scale (SDS), body mass index (BMI), vital signs; serum levels of troponin T (TnT), immunoglobulin M (IgM), immunoglobulin G (IgG), luteinizing Hormone (LH), testosterone Hormone (TSTS), urea, creatinine, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured on admission and after detoxification. The results showed that the BMI was significantly decreased while, vital signs such as heart rate, blood pressure and respiratory rate were significantly increased in all abusers and returned to normal values after the detoxification period. The cardiac biomarker troponin T was significantly increased and reversed after detoxification. The immune system was evaluated through assessing serum levels of immunoglobulin (Ig) M and IgG. The immune system remained immunocompromised in drug users, and IgM and IgG levels did not reach the level of control group after treatment. Luteinizing and testosterone hormones were evaluated. Both hormones were increased on admission and improved after the detoxification period. Renal function showed no significant differences between drug users and the control group. In the evaluation of the antioxidant system, there was a significant increase in serum MDA, SOD, GPx, and CAT levels compared to healthy controls. After the detoxification phase, these oxidative stress biomarkers still remained elevated. The current results have shown the addiction of amphetamine and cannabis exert detrimental effects on different body organs and the exert major consequences on the health status of drug users. The present study showed that, there was no improvement in the levels of oxidative stress biomarkers, although an improvement was observed in the other parameters after the detoxification phase.

Apocynin-Tandospirone Derivatives Suppress Methamphetamine-Induced Hyperlocomotion in Rats with Neonatal Exposure to Dizocilpine

Accumulating evidence implicates oxidative stress as a potential pathophysiological mechanism of schizophrenia. Accordingly, we synthesized new chemicals using apocynin and tandospirone as lead compounds (A-2, A-3 and A-4). These novel compounds decreased reactive oxygen species (ROS) concentrations in vitro and reversed decreases in glutathione levels in the medial prefrontal cortex of rats transiently exposed to MK-801, an N-methyl-d-aspartate receptor antagonist, in the neonatal period. To determine whether A-2, A-3 and A-4 show behavioral effects associated with antipsychotic properties, the effects of these compounds on methamphetamine (MAP)-induced locomotor and vertical activity were examined in the model rats. A-2 and A-3, administered for 14 days around the puberty period, ameliorated MAP-induced hyperlocomotion in MK-801-treated rats in the post-puberty period, while A-4 suppressed MAP-induced vertical activity. These findings indicate that apocynin-tandospirone derivatives present anti-dopaminergic effects and may alleviate psychotic symptoms of schizophrenia.

Schizophrenia-like endurable behavioral and neuroadaptive changes induced by ketamine administration involve Angiotensin II AT1 receptor

Schizophrenia is a chronic disease affecting 1% worldwide population, of which 30% are refractory to the available treatments: thus, searching for new pharmacological targets is imperative. The acute and repeated ketamine administration are validated preclinical models that recreate the behavioral and neurochemical features of this pathology, including the parvalbumin-expressing interneurons dysfunction. Angiotensin II, through AT₁ receptors (AT₁-R), modulates the dopaminergic and GABAergic neurotransmission. We evaluated the AT₁-R role in the long-term neuronal activation and behavioral alterations induced by repeated ketamine administration. Adult male Wistar rats received AT₁-R antagonist candesartan/vehicle (days 1-10) and ketamine/saline (days 6-10). After 14 days of drug-free, neuronal activation and behavioral analysis were performed. Locomotor activity, social interaction and novel object recognition tests were assessed at basal conditions or after ketamine challenge. Immunostaining for c-Fos, GAD67 and parvalbumin were assessed after ketamine challenge in cingulate, insular, piriform, perirhinal, and entorhinal cortices, striatum, and hippocampus. Additionally, to evaluate the AT₁-R involvement in acute ketamine psychotomimetic effects, the same behavioral tests were performed after 6 days of daily-candesartan and a single-ketamine administration. We found that ketamine-induced long-lasting schizophrenia-like behavioral alterations, and regional-dependent neuronal activation changes, involving the GABAergic neurotransmission system and the parvalbumin-expressing interneurons, were AT₁-R-dependent. The AT₁-R were not involved in the acute ketamine psychotomimetic effects. These results add new evidence to the wide spectrum of action of ketamine and strengthen the AT₁-R involvement in endurable alterations induced by psychostimulants administration, previously proposed by our group, as well as their preponderant role in the development of psychiatric pathologies.

Methamphetamine Downregulates the Sperm-Specific Calcium Channels Involved in Sperm Motility in Rats

Calcium channels play essential roles in sperm motility. A family of sperm-specific cation channels including CatSper1-4 has been identified as voltage-dependent ion channels that act as sperm motility regulators. Methamphetamine is known to cause apoptosis in seminiferous tubules and affect sperm quality. This research was conducted to investigate the effects of methamphetamine on expression of the CatSper family and Mvh genes. Thirty-six adult Wistar rats were divided into four groups of nine rats each: the control and experimental groups 1, 2, and 3. The control group received no solvents or drugs, but experimental groups 1, 2, and 3 were daily given 0.2 mL of a solution by gavage that contained 0.5, 1, and 2 mg of methamphetamine, respectively, for 45 days. The rats were then anesthetized, and one testis removed from each rat was used in a reverse transcription-polymerase chain reaction (RT-PCR). Analysis of variance (ANOVA) and Tukey's posthoc test were used to analyze the data at the P < 0.05 significance level. Treatment with methamphetamine resulted in decreased testis and epididymis weights compared to the control rats. The results showed that the mRNA fold expression level of the CatSper family and Mvh genes decreased significantly in experimental groups compared to that in the control (P < 0.05). Methamphetamine decreased the expression levels of the CatSper and Mvh genes, and thus, it seemed that it can increase the probability of infertility through sperm motility reduction by lowering the expression levels of these genes.

Mental Disorders Are Associated With Leukocytes Telomere Shortening Among People Who Inject Drugs

Premature biological aging, assessed by shorter telomere length (TL) and mitochondrial DNA (mtDNA) alterations, has been reported among people with major depressive disorders or psychotic disorders. However, these markers have never been assessed together among people who inject drugs (PWIDs), although mental disorders are highly prevalent in this population, which, in addition, is subject to other aggravating exposures. Diagnosis of mental disorders was performed by a psychiatrist using the Mini International Neuropsychiatric Interview test among active PWIDs in Haiphong, Vietnam. mtDNA copy number (MCN), mtDNA deletion, and TL were assessed by quantitative PCR and compared to those without any mental disorder. We next performed a multivariate analysis to identify risk factors associated with being diagnosed with a major depressive episode (MDE) or a psychotic syndrome (PS). In total, 130 and 136 PWIDs with and without psychiatric conditions were analyzed. Among PWIDs with mental disorders, 110 and 74 were diagnosed with MDE and PS, respectively. TL attrition was significantly associated with hepatitis C virus-infected PWIDs with MDE or PS (adjusted odds ratio [OR]: 0.53 [0.36; 0.80] and 0.59 [0.39; 0.88], respectively). TL attrition was even stronger when PWIDs cumulated at least two episodes of major depressive disorders. On the other hand, no difference was observed in mtDNA alterations between groups. The telomeric age difference with drug users without a diagnosis of psychiatric condition was estimated during 4.2-12.8 years according to the number of MDEs, making this group more prone to age-related diseases.

Astrocyte-derived TNF and glutamate critically modulate microglia activation by methamphetamine

Methamphetamine (Meth) is a powerful illicit psychostimulant, widely used for recreational purposes. Besides disrupting the monoaminergic system and promoting oxidative brain damage, Meth also causes neuroinflammation, contributing to synaptic dysfunction and behavioral deficits. Aberrant activation of microglia, the largest myeloid cell population in the brain, is a common feature in neurological disorders triggered by neuroinflammation. In this study, we investigated the mechanisms underlying the aberrant activation of microglia elicited by Meth in the adult mouse brain. We found that binge Meth exposure caused microgliosis and disrupted risk assessment behavior (a feature that usually occurs in individuals who abuse Meth), both of which required astrocyte-to-microglia crosstalk. Mechanistically, Meth triggered a detrimental increase of glutamate exocytosis from astrocytes (in a process dependent on TNF production and calcium mobilization), promoting microglial expansion and reactivity. Ablating TNF production, or suppressing astrocytic calcium mobilization, prevented Meth-elicited microglia reactivity and re-established risk assessment behavior as tested by elevated plus maze (EPM). Overall, our data indicate that glial crosstalk is critical to relay alterations caused by acute Meth exposure.

Parkin regulates drug-taking behavior in rat model of methamphetamine use disorder

There is no FDA-approved medication for methamphetamine (METH) use disorder. New therapeutic approaches are needed, especially for people who use METH heavily and are at high risk for overdose. This study used genetically engineered rats to evaluate PARKIN as a potential target for METH use disorder. PARKIN knockout, PARKIN-overexpressing, and wild-type young adult male Long Evans rats were trained to self-administer high doses of METH using an extended-access METH self-administration paradigm. Reinforcing/rewarding properties of METH were assessed by quantifying drug-taking behavior and time spent in a METH-paired environment. PARKIN knockout rats self-administered more METH and spent more time in the METH-paired environment than wild-type rats. Wild-type rats overexpressing PARKIN self-administered less METH and spent less time in the METH-paired environment. PARKIN knockout rats overexpressing PARKIN self-administered less METH during the first half of drug self-administration days than PARKIN-deficient rats. The results indicate that rats with PARKIN excess or PARKIN deficit are useful models for studying neural substrates underlying "resilience" or vulnerability to METH use disorder and identify PARKIN as a novel potential drug target to treat heavy use of METH.

Pharmacological and Molecular Evidence of Neuroprotective Curcumin Effects Against Biochemical and Behavioral Sequels Caused by Methamphetamine: Possible Function of CREB-BDNF Signaling Pathway

INTRODUCTION

The neuroprotective impact of curcumin and the role of CREB (Cyclic AMP Response Element Binding protein)-BDNF (Brain-Derived Neurotrophic Factor) signaling pathway was evaluated in Methamphetamine (METH)-induced neurodegeneration in rats.

METHODS

Sixty adult male rats were randomly divided into 6 groups. While normal saline and 10 mg/kg METH were administered intraperitoneally in groups 1 and 2, groups 3, 4, 5, and 6 received METH (10 mg/kg) and curcumin (10, 20, 40, and 80 mg/kg, respectively) simultaneously. Morris water maze test was administered, and oxidative hippocampal, antioxidant, inflammatory, apoptotic, and CREB and BDNF were assessed.

RESULTS

We found that METH disturbs learning and memory. Concurrent curcumin therapy (40 and 80 mg/kg) decreased cognitive disturbance caused by METH. Multiple parameters, such as lipid peroxidation, the oxidized form of glutathione, interleukin 1 beta, tumor necrosis factor-alpha, and Bax were increased by METH therapy, while the reduced type of glutathione, Bcl-2, P-CREB, and BDNF concentrations in the hippocampus were decreased.

CONCLUSION

Different doses of curcumin adversely attenuated METH-induced apoptosis, oxidative stress, and inflammation but enhanced the concentrations of P-CREB and BDNF. The neuroprotection caused by curcumin against METH-induced neurodegeneration is mediated through P-CREB-BDNF signaling pathway activation.

Beyond ecstasy: Alternative entactogens to 3,4-methylenedioxymethamphetamine with potential applications in psychotherapy

The last two decades have seen a revival of interest in the entactogen 3,4-methylenedioxy-N-methylamphetamine (MDMA) as an adjunct to psychotherapy, particularly for the treatment of post-traumatic stress disorder. While clinical results are highly promising, and MDMA is expected to be approved as a treatment in the near future, it is currently the only compound in its class of action that is being actively investigated as a medicine. This lack of alternatives to MDMA may prove detrimental to patients who do not respond well to the particular mechanism of action of MDMA or whose treatment calls for a modification of MDMA's effects. For instance, patients with existing cardiovascular conditions or with a prolonged history of stimulant drug use may not fit into the current model of MDMA-assisted psychotherapy, and could benefit from alternative drugs. This review examines the existing literature on a host of entactogenic drugs, which may prove to be useful alternatives in the future, paying particularly close attention to any neurotoxic risks, neuropharmacological mechanism of action and entactogenic commonalities with MDMA. The substances examined derive from the 1,3-benzodioxole, cathinone, benzofuran, aminoindane, indole and amphetamine classes. Several compounds from these classes are identified as potential alternatives to MDMA.

Telomere length is associated with HIV infection, methamphetamine use, inflammation, and comorbid disease risk

BACKGROUND

HIV infection and methamphetamine dependence (METH) are each associated with inflammation and premature aging, but their impact on biological aging is difficult to measure. Here we examined the impact of HIV and METH on leukocyte telomere lengths (LTL), and the correlations between LTL and other aging biomarkers.

METHODS

The study was a cross-sectional analysis of 161 individuals categorized by HIV and methamphetamine (METH) dependence status into four groups: HIV-METH- (n = 50), HIV-METH+ (n = 29), HIV + METH- (n = 40), and HIV + METH+ (n = 42). We analyzed the relationships of leukocyte telomere length (telomere to single copy gene [T/S] ratio) with demographic and clinical data as well as a panel of biomarkers of inflammation and endothelial activation measured in blood and cerebrospinal fluid (CSF).

RESULTS

HIV and METH were independently associated with shorter T/S ratio, even after adjusting for demographics and leukocyte count (R2 = 0·59, p < 0·0001). Higher plasma C-reactive protein (p = 0·0036) and CSF VCAM-1 (p = 0·0080) were also associated with shorter T/S ratio. A shorter T/S ratio was associated with higher risk for cardiovascular disease (p < 0·0001) and stroke (p < 0·0001), worse motor functioning (p = 0·037) and processing speed (p = 0·023), more depressive symptoms (p = 0·013), and higher CSF neurofilament-light (p = 0·003).

CONCLUSIONS

HIV and METH dependence were each associated with shorter telomeres. After adjusting for demographics, HIV, and METH, T/S ratio remained associated with aging-related outcomes including neurocognitive impairment, neurodegeneration, risks of cardiovascular disease and stroke. While not establishing causality, this study supports using the T/S ratio as a biomarker for estimating the impact of HIV and comorbidities on long-term health.

Psychoactive Drugs-From Chemical Structure to Oxidative Stress Related to Dopaminergic Neurotransmission. A Review

Nowadays, more and more young people want to experience illegal, psychoactive substances, without knowing the risks of exposure. Besides affecting social life, psychoactive substances also have an important effect on consumer health. We summarized and analyzed the published literature data with reference to the mechanism of free radical generation and the link between chemical structure and oxidative stress related to dopaminergic neurotransmission. This review presents data on the physicochemical properties, on the ability to cross the blood brain barrier, the chemical structure activity relationship (SAR), and possible mechanisms by which neuronal injuries occur due to oxidative stress as a result of drug abuse such as "bath salts", amphetamines, or cocaine. The mechanisms of action of ingested compounds or their metabolites involve intermediate steps in which free radicals are generated. The brain is strongly affected by the consumption of such substances, facilitating the induction of neurodegenerative diseases. It can be concluded that neurotoxicity is associated with drug abuse. Dependence and oxidative stress are linked to inhibition of neurogenesis and the onset of neuronal death. Understanding the pathological mechanisms following oxidative attack can be a starting point in the development of new therapeutic targets.

The psychoactive drug of abuse mephedrone differentially disrupts blood-brain barrier properties

Background

Synthetic cathinones are a category of psychostimulants belonging to the growing number of designer drugs also known as “Novel Psychoactive Substances” (NPS). In recent years, NPS have gained popularity in the recreational drug market due to their amphetamine-like stimulant effects, low cost, ease of availability, and lack of detection by conventional toxicology screening. All these factors have led to an increase in NPS substance abuse among the young adults, followed by spike of overdose-related fatalities and adverse effects, severe neurotoxicity, and cerebral vascular complications. Much remains unknown about how synthetic cathinones negatively affect the CNS and the status of the blood-brain barrier (BBB).

Methods

We used in vitro models of the BBB and primary human brain microvascular endothelial cells (hBMVEC) to investigate the effects of the synthetic cathinone, 4-methyl methcathinone (mephedrone), on BBB properties.

Results

We showed that mephedrone exposure resulted in the loss of barrier properties and endothelial dysfunction of primary hBMVEC. Increased permeability and decreased transendothelial electrical resistance of the endothelial barrier were attributed to changes in key proteins involved in the tight junction formation. Elevated expression of matrix metalloproteinases, angiogenic growth factors, and inflammatory cytokines can be explained by TLR-4-dependent activation of NF-κB signaling.

Conclusions

In this first characterization of the effects of a synthetic cathinone on human brain endothelial cells, it appears clear that mephedrone-induced damage of the BBB is not limited by the disruption of the barrier properties but also include endothelial activation and inflammation. This may especially be important in comorbid situations of mephedrone abuse and HIV-1 infections. In this context, mephedrone could negatively affect HIV-1 neuroinvasion and NeuroAIDS progression.

Chemokines, cytokines and substance use disorders

Efficacious pharmacotherapies for the treatment of substance use disorders need to be expanded and improved. Non-neuronal cells, particularly astrocytes and microglia, have emerged as therapeutic targets for the development of pharmacotherapies to treat dependence and relapse that accompanies chronic drug use. Cytokines and chemokines are neuroimmune factors expressed in neurons, astrocytes, and microglia that demonstrate promising clinical utility as therapeutic targets for substance use disorders. In this review, we describe a role for cytokines and chemokines in the rewarding and reinforcing effects of alcohol, opioids, and psychostimulants. We also discuss emerging cytokine- and chemokine-based therapeutic strategies that differ from conventional strategies directed toward transporters and receptors within the dopamine, glutamate, GABA, serotonin, and GABA systems.

DNA Damage and Repair in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a complex multifactorial disease with both genetic and environmental dynamics contributing to disease progression. Over the last decade, several studies have demonstrated the presence of genomic instability and increased levels of DNA damage in PAH lung vascular cells, which contribute to their pathogenic apoptosis-resistant and proliferating characteristics. In addition, the dysregulated DNA damage response pathways have been indicated as causal factors for the presence of persistent DNA damage. To understand the significant implications of DNA damage and repair in PAH pathogenesis, the current review summarizes the recent advances made in this field. This includes an overview of the observed DNA damage in the nuclear and mitochondrial genome of PAH patients. Next, the irregularities observed in various DNA damage response pathways and their role in accumulating DNA damage, escaping apoptosis, and proliferation under a DNA damaging environment are discussed. Although the current literature establishes the pertinence of DNA damage in PAH, additional studies are required to understand the temporal sequence of the above-mentioned events. Further, an exploration of different types of DNA damage in conjunction with associated impaired DNA damage response in PAH will potentially stimulate early diagnosis of the disease and development of novel therapeutic strategies.

Substances of abuse and the blood brain barrier: Interactions with physical exercise

Substance use disorders pose a common medical, social and financial problem. Among the pathomechanisms of substance use disorders, the disruption and increased permeability of the blood-brain barrier has been recently revealed. Physical exercise appears to be a relatively inexpensive and feasible way to implement behavioral therapy counteracting the blood-brain barrier impairment. Concomitantly, there are also studies supporting a potential protective role of selected substances of abuse in maintaining the blood-brain barrier integrity. In this review, we aim to provide a summary on the modulatory influence of physical exercise, a non-pharmacological intervention, on the blood-brain barrier alterations caused by substances of abuse. Further studies are needed to understand the precise mechanisms that underlie various effects of physical exercise in substance use disorders.

Poria cocos water extract ameliorates the behavioral deficits induced by unpredictable chronic mild stress in rats by down-regulating inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos is a medicinal mushroom of the Polyporaceae family with antioxidant and anti-inflammatory activities, which has been used for its sedative, diuretic and tonic effects in traditional medicine for several hundred years.

AIM OF STUDY

Considering that depression is an inflammatory related mental disease, this study investigated the antidepressant-like effects of water extract of P. cocos in a rodent animal model.

MATERIALS AND METHODS

Rats that were exposed to a forced swimming test (FST) for 28 consecutive days, and unpredictable chronic mild stress (UCMS) for five weeks underwent treatment with P. cocos water extract (PCW) (doses: 100, 300 and 900 mg/kg body weight [bw]; administered by gavage). Dopamine (DA), serotonin (5-HT) and their metabolites in the frontal cortex of rats were measured.

RESULTS

Our results firstly showed that sucrose preference during the UCMS paradigm was increased and immobility time in the FST was reduced with administration of PCW. In addition, PCW significantly attenuated UCMS-induced turnover rate of DA and 5-HT in the frontal cortex. Moreover, PCW inhibited UCMS-induced activated inflammatory response, reflected by reduced expression in the frontal cortex of p38, NF-κB and TNF-α.

CONCLUSIONS

Our results strongly suggest that PCW exhibits a potent antidepressant-like effect via regulation of monoaminergic neurotransmission and inactivation of inflammation, and that P. cocos may be considered as a traditional herbal potential medicine for the treatment of depression.

The OATH Syndemic: opioids and other substances, aging, alcohol, tobacco, and HIV

PURPOSE OF REVIEW

Persons living with HIV (PLWH) are aging, continue to use alcohol and other substances, and experience age-associated adverse effects. We explore a new syndemic: OATH (opioids and other substances, aging, alcohol, tobacco, and HIV).

RECENT FINDINGS

Frailty and falls are important problems that affect the health status of PLWH who continue to use alcohol and other substances. HIV, alcohol and other substance use, and aging each contributes to inflammaging. Multimorbidity and polypharmacy are also important pathways as alcohol and other substances interact with prescribed medications resulting in adverse-drug interactions leading to potentially serious consequences. Social conditions including racism, poverty, sex bias, stress, and stigma contribute to the existence and persistence of this syndemic.

SUMMARY

Substance use, HIV, and aging are linked in a new syndemic (OATH) that drives age-related outcomes such as frailty and falls. We need to expand our understanding of the 'healthcare team' so that we include social and political advocates who can support necessary structural change. Treatment of substance use should be better incorporated into the management of HIV, including a focus on potential medication/substance interactions. Finally, we need to explore treatment of frailty rather than individual manifestations of frailty (e.g., atherosclerosis, neurodegeneration).

Methamphetamine exposure modulated oxidative status and altered the reproductive output in Daphnia magna

Methamphetamine (METH) is a central nervous system stimulant drug whose use has increased in the last few years worldwide. After the ingestion of even a single dose, METH is excreted by the organism and enters the aquatic ecosystems, whereby concentrations up to hundreds of ng/L were measured in both sewage and surface waters. Although the environmental concentrations are currently quite low, the high biological activity of METH might cause adverse effects towards non-target organisms. However, to date the information on METH toxicity towards aquatic organisms is limited. Thus, the present study aimed at investigating biochemical and behavioral effects induced by METH exposure towards the Cladoceran Daphnia magna. A 21-days exposure to two environmental concentrations of METH (50 ng/L and 500 ng/L) was performed. At selected time points (7, 14 and 21 days) the amount of pro-oxidant molecules, the activity of antioxidant enzymes (SOD, CAT, GPx) and levels of lipid peroxidation (LPO) were measured as oxidative stress-related endpoints. Changes in swimming activity and reproductive output were assessed as behavioral endpoints. METH exposure affected the oxidative status of D. magna specimens at both tested concentrations, although no oxidative damage occurred. Although METH did not modulate the swimming activity of D. magna, a significant, positive effect on reproductive output, in terms of number of offspring was found. Our results showed that low concentrations of METH might represent a threat for D. magna, affecting the health status of this aquatic species at different level of biological organization.

The Relationship Between Serum Cytokine Levels and the Degree of Psychosis and Cognitive Impairment in Patients With Methamphetamine-Associated Psychosis in Chinese Patients

Background: Cytokine levels can be changed in methamphetamine (METH) use disorders (MUDs) and primary psychosis. The present study assessed serum levels of some kinds of interleukins (ILs) in METH-associated psychosis (MAP) and their relationships with psychotic symptoms and cognitive dysfunction. Methods: Serum IL-2R, IL-6, IL-8, and IL-10 levels were examined by chemiluminescence assays in MAP patients (n = 119) and healthy controls (n = 108). The Positive and Negative Syndrome Scale (PANSS) and Montreal Cognitive Assessment (MOCA) were administered. Results: Serum levels of IL-6 and IL-8 were significantly increased in MAP patients (all p < 0.05). There was a negative relationship between IL-2R levels and PANSS positive (P) subscale scores (r = -0.193, p = 0.035). IL-6, IL-8 and IL-10 levels were all negatively correlated with the naming, delayed recall and orientation subscores on the MOCA (r = -0.209, p = 0.022; r = -0.245, p = 0.007; r = -0.505, p < 0.001, respectively). Conclusions: Our results indicate that immune disturbances are related to MAP and that IL-2R, IL-6, IL-8, and IL-10 are associated with the severity of psychotic symptoms and cognitive function impairment.

Evaluation of Microglia/Macrophage Cells from Rat Striatum and Prefrontal Cortex Reveals Differential Expression of Inflammatory-Related mRNA after Methamphetamine

RNA sequencing (RNAseq) can be a powerful tool in the identification of transcriptional changes after drug treatment. RNAseq was utilized to determine expression changes in Fluorescence-activated cell sorted (FACS) CD11b/c+ cells from the striatum (STR) and prefrontal cortex (PFC) of male Sprague-Dawley rats after a methamphetamine (METH) binge dosing regimen. Resident microglia and infiltrating macrophages were collected 2 h or 3 days after drug administration. Gene expression changes indicated there was an increase toward an overall pro-inflammatory state, or M1 polarization, along with what appears to be a subset of cells that differentiated toward the anti-inflammatory M2 polarization. In general, there were significantly more mRNA expression changes in the STR than the PFC and more at 2 h post-binge METH than at 3 days post-binge METH. Additionally, Ingenuity^® Pathway Analysis along with details of RNA expression changes revealed cyclo-oxygenase 2 (COX2)-driven prostaglandin (PG) E2 synthesis, glutamine uptake, and the Nuclear factor erythroid2-related factor 2 (NRF2) canonical pathway in microglia were associated with the binge administration regimen of METH.

Function of complement factor H and imaging of small molecules by MALDI-MSI in a methamphetamine behavioral sensitization model

BACKGROUND

At present, the harm of new-type drug, methamphetamine (METH), has gradually exceeded that of the traditional opioid drugs, and METH abuse has become a serious public health and social problem. In our previous study, complement factor H (CFH) was found to be upregulated in the sera of METH-addicted patients and rats and in certain brain regions in the rats.

METHODS

We used ELISA and immunofluorescence to confirm the changes in CFH in the serum and hippocampus of a METH behavioral sensitization mouse model, and C1q expression was also detected by immunofluorescence in the hippocampus. We aimed to elucidate the involvement of CFH and C1q in the mechanism of METH addiction. We also detected the distribution of various small molecules by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) in select brain regions: the nucleus accumbens, the hippocampus and the ventral tegmental area.

RESULTS

The expression of CFH was upregulated in the serum and hippocampus of METH behavioral sensitization model mice, consistent with our previous research on conditioned place preference rats. In contrast, C1q decreased dramatically in the mossy fibers of the hippocampus. The results of small-molecule imaging by MALDI-MSI showed that the levels of K⁺, antioxidants, neurotransmitters, and ATP metabolism-related molecules were altered in different regions.

CONCLUSIONS

These results indicate the involvement of the complement system in the mechanism of METH addiction and validate the presence of oxidative stress, energy metabolism changes during addiction. This suggests the utility of further investigation into the above aspects.

The cellular basis of fetal endoplasmic reticulum stress and oxidative stress in drug-induced neurodevelopmental deficits

Prenatal substance exposure is a growing public health concern worldwide. Although the opioid crisis remains one of the most prevalent addiction problems in our society, abuse of cocaine, methamphetamines, and other illicit drugs, particularly amongst pregnant women, are nonetheless significant and widespread. Evidence demonstrates prenatal drug exposure can affect fetal brain development and thus can have long-lasting impact on neurobehavioral and cognitive performance later in life. In this review, we highlight research examining the most prevalent drugs of abuse and their effects on brain development with a focus on endoplasmic reticulum stress and oxidative stress signaling pathways. A thorough exploration of drug-induced cellular stress mechanisms during prenatal brain development may provide insight into therapeutic interventions to combat effects of prenatal drug exposure.

Methamphetamine reduces expressions of tight junction proteins, rearranges F-actin cytoskeleton and increases the blood brain barrier permeability via the RhoA/ROCK-dependent pathway

Methamphetamine (METH) is a psychostimulant with severe neurotoxicity, which is related to an increase of blood-brain barrier (BBB) permeability. However, the exact mechanisms have not been fully illuminated. In the present study, male Sprague Dawley rats were treated with METH or saline with 8 injections (i.p.) at 12-h intervals and sacrificed 24 h after the last METH injection. To evaluate BBB permeability, 6 rats were administered with Evans blue (EB) by tail vein injection 1 h prior to sacrifice. EB levels significantly increased in both left and right frontal lobes in METH-treated rats, suggesting increase of BBB permeability, which was proved by the rearrangement of F-actin cytoskeleton and decreased expressions of tight junction (TJ) proteins in hippocampus. Over-expressions of RhoA, ROCK, myosin light chain (MLC), cofilin, phosphorylation (p)-MLC, p-cofilin and matrix metalloproteinase (MMP)-9 were observed, indicating activated RhoA/ROCK pathway. Rat brain microvascular endothelial cells (RBMECs) were isolated and treated with inhibitors of RhoA and ROCK followed by METH. Pretreatments of the inhibitors significantly decreased expressions of RhoA, ROCK, MLC, cofilin, p-MLC and p-cofilin, increased expressions of TJ proteins, suppressed F-actin cytoskeleton rearrangement and reduced the permeability of RBMECs. These results suggested that METH increased BBB permeability through activating the RhoA/ROCK pathway, which resulted in F-actin cytoskeleton rearrangement and down-regulation of TJ proteins.

Altered serum levels of glial cell line-derived neurotrophic factor in male chronic schizophrenia patients with tardive dyskinesia

OBJECTIVES

Many research indicate that the tardive dyskinesia (TD) is generally linked with long-term antipsychotic therapy for schizophrenia. Glial cell line-derived neurotrophic factor (GDNF) is a critical role in the protection of catecholaminergic, dopaminergic, and cholinergic neurons. Thus, we examined the serum GDNF levels in schizophrenia patients with TD (WTD) and without TD (NTD) and compared with healthy controls (HC), respectively.

METHODS

Totally 75 males with schizophrenia were recruited into this study. All were measured by the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, the Positive and Negative Syndrome Scale, and the Abnormal Involuntary Movement Scale (AIMS). The patient group was divided into two subgroups: WTD (n = 32) and NTD (n = 43) according to the AIMS score. Fifty-three healthy controls matching in age and gender were also enlisted from the region. GDNF levels were examined with sandwich enzyme-linked immunosorbent assay.

RESULTS

Analysis of variance indicated significant differences between the three groups (P = 0.012); GDNF levels in the WTD group were significantly different from those in the NTD (P = 0.030) and HC (P = 0.003) groups.

CONCLUSION

Decreased GDNF levels in TD patients indicated that alterations in neurotrophic factors may be involved in the pathophysiology of TD, but the exact mechanisms need further investigation.

Differential effect of the DRD3 genotype on inflammatory cytokine responses during abstinence in amphetamine-dependent women

Amphetamine exposure impacts on innate and adaptive immunity and DRD3 may modulate the effect of amphetamine on the immune response. We assessed the immune-cytokine markers in 72 female patients with amphetamine dependence (AD) at baseline and after 4-week drug abstinence and in 51 healthy women. Multiplex magnetic bead assay was used to measure the plasma cytokine expression level simultaneously in all participants and DRD3 rs6280 polymorphism was genotyped in patients. We demonstrated an increase of the T helper 1 (Th1) cytokines (IL-2), Th2 cytokines (IL-4, IL-5, IL-6 and IL-10) and other cytokines (IL-1β) in the entire AD cohort. A similar cytokine pattern, along with a significantly decreased IL-8 and IL-10 levels was observed after 4-week abstinence. Among AD patients with DRD3 rs6280 TT genotype, the cytokine expression profile was consistent with total AD cohort at baseline and revealed a significant down-regulated plasma level of the Th1, Th2, and other cytokines except for IL-6 after 4-week abstinence. In AD group with DRD3 rs6280 C allele carrier, we found IL-2 level was significantly higher than healthy controls at baseline and remained higher, accompanied with a borderline increase in IL-4, IL-6 and IL-1β levels after 4-week abstinence. Our results suggest that chronic use of amphetamine increased both pro- and anti-inflammatory cytokines in AD patients, indicating the immune imbalance that may persist for 4 weeks or more. Besides, DRD3 rs6280 TT genotype may be associated with favorable recovery in general inflammatory cytokines during period of abstinence.

Epigenetic Effects Induced by Methamphetamine and Methamphetamine-Dependent Oxidative Stress

Methamphetamine is a widely abused drug, which possesses neurotoxic activity and powerful addictive effects. Understanding methamphetamine toxicity is key beyond the field of drug abuse since it allows getting an insight into the molecular mechanisms which operate in a variety of neuropsychiatric disorders. In fact, key alterations produced by methamphetamine involve dopamine neurotransmission in a way, which is reminiscent of spontaneous neurodegeneration and psychiatric schizophrenia. Thus, understanding the molecular mechanisms operated by methamphetamine represents a wide window to understand both the addicted brain and a variety of neuropsychiatric disorders. This overlapping, which is already present when looking at the molecular and cellular events promoted immediately after methamphetamine intake, becomes impressive when plastic changes induced in the brain of methamphetamine-addicted patients are considered. Thus, the present manuscript is an attempt to encompass all the molecular events starting at the presynaptic dopamine terminals to reach the nucleus of postsynaptic neurons to explain how specific neurotransmitters and signaling cascades produce persistent genetic modifications, which shift neuronal phenotype and induce behavioral alterations. A special emphasis is posed on disclosing those early and delayed molecular events, which translate an altered neurotransmitter function into epigenetic events, which are derived from the translation of postsynaptic noncanonical signaling into altered gene regulation. All epigenetic effects are considered in light of their persistent changes induced in the postsynaptic neurons including sensitization and desensitization, priming, and shift of neuronal phenotype.