Concentrations Of Methamphetamine Research Articles

The impact of methamphetamine on psychosocial variables in patients from Iraq.

The current work reviews the psychosocial factors associated with different urinary methamphetamine concentration levels. From April to November 2023, 243 participants from Baghdad's Al-Ataa Hospital were the subjects of a cross-sectional descriptive analysis study. We included 73 patients in this study. The urinary methamphetamine concentration levels were from 3 to 92,274 ng/ml, with a mean ± SD of 10,873.6 ± 18,641. Patients diagnosed with major depression disorder exhibited higher scores on GHQ-30, UCLA, MOAS, and BDI-II with a significant P-value of 0.0001, 0.001, 0.0001, and 0.0001, consequently with an effect size of 0.015, 0.001, 1.05, and 3.24, respectively. The multi-screening test can produce a false positive. It frequently interferes with other drugs, especially antidepressants. This will result in patients being stigmatized and accused. On the other hand, those who accidentally come into contact with crystal smoke will experience the same withdrawal symptoms as the addicted patients. Their urinary methamphetamine level (titer) could have negative results. Urinary methamphetamine levels should be zero in healthy patients. In this situation, screening tests, expert opinion, and urine methamphetamine testing are strongly recommended.

Preliminary Analysis of Methamphetamine Detection in Lucilia sericata (Diptera: Calliphoridae) Reared in Methamphetamine-Treated Meat at Various Developmental Stages

Background: It is possible to identify drugs and poisons present in cadavers by analyzing blowfly larvae and pupae col­lected during forensic autopsies. The main purpose of this study was to use Lucilia sericata’s larvae and pupae to iden­tify drugs and poisons present in human cadavers.
 Methods: In an investigation, immature L. sericata fed meat treated with methamphetamine (MA) at various concentra­tions (45, 90, and 180 ng/mg) were analyzed to detect MA. Acetylation derivatization and liquid-liquid extraction (LLE) were used as sample preparation methods prior to gas chromatography-mass spectrometry (GC-MS) analytical instru­men­tation to find MA.
 Results: According to this study, L. sericata can be used in toxicological testing to identify MA in a host body. All L. seri­cata larval stages, particularly the third stage larva, pupa and empty pupa tested were positive for MA. Larvae in their first instar produced weak peaks. The L. sericata post-feeding instar following the 45 ng/mg treatment showed the highest MA concentration. For the first time, derivatization using the acetylation approach was used to prepare samples, and successfully, excellent results were obtained.
 Conclusion: Low quantities of MA can be easily found in immature fly samples using GC-MS. It is important to ana­lyze all samples including human tissues and insect samples, for postmortem drug testing. They can be utilized to find entire MA before they are excreted in excretory samples such as urine. Also, third instar larvae are a great and reliable sample for toxicological study.

Aptamer-based fluorescent sensor for highly sensitive detection of methamphetamine.

The construction of a fluorescence aptamer sensor was achieved by employing the fundamental principle of fluorescence resonance energy transfer. By employing molecular modeling technologies to identify the binding site, the high-affinity aptamer APT-40nt was derived from the whole sequence and utilized on the graphene oxide (GO) fluorescent platform for the purpose of achieving a highly sensitive detection of methamphetamine (METH). The aptamer tagged with fluorescein (FAM) dye undergoes quenching in the presence of GO due to π-stacking interaction. With the addition of the target, the aptamer that has been tagged was detached from the GO surface, forming a stable complex with METH. This process resulted in fluorescence restoration of the system, and the degree of fluorescence restoration was proportional to METH concentration in the linear range of 1-50 and 50-200 nM. Notably, under optimized conditions, the detection limit of this aptasensor was as low as 0.78 nM, which meets the detection limit requirements of METH detection in saliva and urine in some countries and regions. Moreover, other common illicit drugs and metabolites had minimizing interference with the determination. The established aptasensor, therefore, has been successfully applied to detect METH in saliva and urine samples and exhibited satisfactory recoveries (87%-111%). This aptasensor has the advantages of low detection limit, excellent selectivity, ease of operation, and low cost, providing a promising strategy for on-site detection of METH in saliva and urine.

Kidney Biopsy Proven Thrombotic Microangiopathy Induced by Methamphetamine: A Case Report.

A 47-year-old man was admitted to our hospital with acute kidney injury, severe hypertension, heart failure, thrombocytopenia, and elevated lactate dehydrogenase. Renal biopsy revealed fibrin thrombi within the glomerular capillaries and moderate fibrotic intimal thickening in the interlobular arteries. The histological diagnosis was thrombotic microangiopathy (TMA). Regarding cardiac involvement, we found marked stenosis in the left anterior descending artery on coronary angiography and cardiomyopathy on myocardial biopsy. Blood concentrations of amphetamine and methamphetamine were high (14.1 ng/mL and 333 ng/mL, respectively). It is important to consider methamphetamine as a cause of renal TMA and multi-organ dysfunction.

Shedding light on the hidden methamphetamine abuse: a nation-wide 7-year post-mortem study in Taiwan.

The number of methamphetamine-related deaths has been increasing in recent decades. However, current data primarily rely on a few large-scale national surveys, highlighting the need for diverse data sources. Post-mortem studies offer advantages that compensate for the limitations of cohort studies. In this study, we aimed to (1) examine mortality rates and years of potential life lost, (2) compare proportionate mortality with previous cohort studies, and (3) quantitatively investigate causes of death as potential risk factors associated with each manner of death. We analyzed 740 cases from 2013 to 2019 in Taiwan. The mean age of cases was 38.4 years, with a notable loss of 30s years of potential life, and 79.6% were male. The crude mortality rate was 0.45 per 100,000 person-years. The proportionate mortality indicated that autopsy dataset, compared to cohort studies, provided more accurate estimations for accidental deaths, equivalent suicides, underestimated natural deaths, and overestimated homicides. Accidental deaths were evident in 67% of cases with 80% attributed to drug intoxication. Multiple substances were detected in 61% of cases, with psychiatric medications detected in 43% of cases. Higher methamphetamine concentrations and a greater proportion of multiple substances and benzodiazepines were detected in suicidal deaths. Among accidental deaths, traffic accidents (7.9%) were the second most common cause, particularly motorcycle riders. Using autopsy dataset as a secondary source, we identified that over half of the cases involved accidental drug intoxication. The significant proportion of cases involving multiple substances, psychiatric medications, and drug-impaired driving raises concerning.

Development of Liquid Chromatography-Tandem Mass Spectrometry Analytical Methods for the Study of Whole-Body, Head, and Trunk Uptake and Elimination of Methamphetamine in 5-Day Postfertilization Zebrafish Larvae Using the Quick, Easy, Cheap, Effective, Rugged, and Safe Technique.

Synthetic cathinones are drugs of abuse substituted for amphetamine-like stimulant drugs such as methamphetamine. In this study, methamphetamine was studied as a prototypical amphetamine-like drug as a first step toward establishing methods to study this entire drug class. The internal concentration of methamphetamine in zebrafish larvae was determined using matrix-matched calibration along with extraction and purification of samples using the quick, easy, cheap, effective, rugged, and safe technique in liquid chromatography-tandem mass spectrometry. Whole-body and head/trunk uptake and elimination in 5-day postfertilization zebrafish larvae were determined. A gradient method was developed using 5 mM ammonium formate with 0.1% formic acid and methanol with 0.1% formic acid as mobile phases, 10 min of total run time, and a 0.3 mL/min flow rate. The limit of quantification was 60 ng/mL, linearity with r2 = 0.9991, and recovery values from 92% to 120%. The internal concentration of methamphetamine was quantifiable in whole-body homogenates within 15 min of uptake analysis. The internal concentration increased with time, whereas a biphasic elimination pattern was shown. With increasing length of exposure, a higher accumulation of drugs was found in the head than in the trunk.

Increased AGE-RAGE axis stress in methamphetamine abuse and methamphetamine-induced psychosis: Associations with oxidative stress and increased atherogenicity.

Methamphetamine (MA)-induced psychosis (MIP) is associated with increased oxidative toxicity (especially lipid peroxidation) and lowered antioxidant defences. Advanced glycation end products (AGEs) cause oxidative stress upon ligand binding to AGE receptors (RAGEs). There is no data on whether MA use may cause AGE-RAGE stress or whether the latter is associated with MIP. This case-control study recruited 60 patients with MA use disorder and 30 normal controls and measured serum levels of oxidative stress toxicity (OSTOX, lipid peroxidation), antioxidant defences (ANTIOX), magnesium, copper, atherogenicity, AGE and soluble RAGE (sRAGE) and computed a composite reflecting AGE-RAGE axis activity. MA dependence and use were associated with elevated levels of AGE, sRAGE, OSTOX/ANTIOX, Castelli Risk Index 1 and atherogenic index of plasma. Increased sRAGE concentrations were strongly correlated with dependence severity and MA dose. Increased AGE-RAGE stress was correlated with OSTOX, OSTOX/ANTIOX and MA-induced intoxication symptoms, psychosis, hostility, excitement and formal thought disorders. The regression on AGE-RAGE, the OSTOX/ANTIOX ratio, decreased magnesium and increased copper explained 54.8% of the variance in MIP symptoms, and these biomarkers mediated the effects of increasing MA concentrations on MIP symptoms. OSTOX/ANTIOX, AGE-RAGE and insufficient magnesium were found to explain 36.0% of the variance in the atherogenicity indices. MA causes intertwined increases in AGE-RAGE axis stress and oxidative damage, which together predict the severity of MIP symptoms and increased atherogenicity.

Classical stimulants in Dallas County: A retrospective review of toxicological, seized drug, and demographical data from 2017 to 2022.

Cocaine and methamphetamine remain highly abused drugs in the United States due to their euphoric effects. This study examines classical stimulant casework, defined as cases positive for methamphetamine and/or cocaine, received by the Toxicology Laboratory and the Drug Analysis Laboratory at the Dallas County Southwestern Institute of Forensic Sciences from local law enforcement agencies and/or the Office of the Medical Examiner (OME) between January 1, 2017, and December 31, 2022. Methamphetamine positivity increased from 10.4% to 20.3% in the Toxicology Laboratory over the 6 years, whereas cocaine positivity remained relatively stable at approximately 17%. Similarly, in the Drug Analysis Laboratory, the methamphetamine positivity rate changed from 24.8% to 33.2%, whereas cocaine identification remained stable at approximately 20%. Blood concentrations of methamphetamine in OME cases ranged from 10.1-42,740.0 ng/mL while they were lower in DWI casework ranging from 10.2-2385.0 ng/mL. The blood concentration trends of cocaine were similar to methamphetamine, with OME casework ranging higher (10.0-24,501.0 ng/mL) than DWI casework (10.2-371.6 ng/mL). Polydrug use was evident for both methamphetamine and cocaine in postmortem cases, and the top three most frequently co-occurring drug/drug class were opioids/opiates, cannabinoids, and ethanol. The results from this study aid in the understanding of historical usage trends of cocaine and methamphetamine in Dallas County and how those trends have changed over time as newer stimulant drugs have emerged.

Evaluation of commercially available methamphetamine presumptive tests for site contamination

Presumptive tests or lateral flow immunoassay testing kits are increasingly being utilised as a fast, portable, cost-effective method to detect an array of analytes, particularly illicit drugs. In Australia, the methamphetamine and decontamination industry regularly use presumptive testing kits to determine whether a property is contaminated. These presumptive test kits advertise a detection limit of 0.5 µg/100 cm2 and above for methamphetamine. The performance of seven methamphetamine presumptive test brands and their kit components were analysed in this study. Following the kit instructions, each kit was analysed using a ceramic tile that was spiked with a known concentration of methamphetamine. These presumptive test kits were highly sensitive, with positive results also found below the limit of detection. Therefore, if there is a negative result it is likely that there is no methamphetamine present. Those that return a positive result require further quantitative assessment. Thus, the presumptive test kits may detect the presence of methamphetamine that is below the Australian Clandestine Drug Laboratory Remediation Guideline of 0.5 µg/100 cm2. This indicates these tests might be useful as a screening assessment but should not be relied upon to develop a remediation action plan.

From metabolism to behaviour – Multilevel effects of environmental methamphetamine concentrations on fish

Methamphetamine (METH) is a concerning drug of abuse that produces strong psychostimulant effects. The use of this substance, along with the insufficient removal in the sewage treatment plants, leads to its occurrence in the environment at low concentrations. In this study, brown trout (Salmo trutta fario) were exposed to 1 μg/L of METH as environmental relevant concentration for 28 days in order to elucidate the complex effects resulting from the drug, including behaviour, energetics, brain and gonad histology, brain metabolomics, and their relations. Trout exposed to METH displayed lowered activity as well as metabolic rate (MR), an altered morphology of brain and gonads as well as changes in brain metabolome when compared to controls. Increased activity and MR were correlated to an increased incidence of histopathology in gonads (females - vascular fluid and gonad staging; males - apoptotic spermatozoa and peritubular cells) in exposed trout compared to controls. Higher amounts of melatonin in brain were detected in exposed fish compared to controls. Tyrosine hydroxylase expression in locus coeruleus was related to the MR in exposed fish, but not in the control. Brain metabolomics indicated significant differences in 115 brain signals between control and METH exposed individuals, described by the coordinates within the principal component analyses (PCA) axes. These coordinates were subsequently used as indicators of a direct link between brain metabolomics, physiology, and behaviour - as activity and MR varied according to their values. Exposed fish showed an increased MR correlated with the metabolite position in PC1 axes, whereas the control had proportionately lower MR and PC1 coordinates. Our findings emphasize the possible complex disturbances in aquatic fauna on multiple interconnected levels (metabolism, physiology, behaviour) as a result of the presence of METH in aquatic environments. Thus, these outcomes can be useful in the development of AOP's (Adverse Outcome Pathways).

Bioconcentrations, depuration, shift in metabolome and a behavioural response in the nymphs of the dragonfly Aeshna cyanea (Müller, 1764) to environmentally relevant concentrations of methamphetamine

Methamphetamine (MEA) is commonly detected in municipal wastewater. It causes imbalances in the system of neurotransmitters as well as several other adverse effects on human health. The aim of this study was to investigate bioconcentration and depuration rates at an environmentally relevant concentration of 1 µg·L−1 in Aeshna cyanea nymphs exposed to MEA for six days followed by three days of depuration. The metabolomes of nymphs sampled during exposure and depuration were compared using non-targeted screening. Concurrently, a behavioural experiment was run to evaluate the effect of MEA on movement. Since most samples were below the limits of quantification (LOQs) – MEA was quantified in only four out of the 87 samples and only during the first 24 h of exposure at concentrations at LOQ level – we estimated maximal possible bioconcentration factor (BCF) on 0.63 using the LOQ. An MEA metabolite – amphetamine – was not detected in any sample at levels above their LOQs. From 247 up to 1458 significant down- and up-regulated metabolite signals (p ≤ 0.05) were detected by non-targeted screening during initial times of exposure and depuration. Numbers of significant down- and/or up-regulated signals in metabolomes (p ≤ 0.05) calculated for particular sampling times possibly correlated with the size of the effect on movement recorded at the same times. In the MEA treatment, movement was not significantly greater during exposure (p > 0.05) but was significantly lower during depuration (p < 0.05). This study shows how MEA acts on dragonfly nymphs, an ecologically important group of aquatic insects with a high trophic level.

Convolutional Neural Network for Accurate Analysis of Methamphetamine with Upconversion Lateral Flow Biosensor.

Methamphetamine is a powerful stimulant drug, the abuse of which threatens human health and social stability. Rapid and accurate quantification of methamphetamine is essential to inhibit the abuse and prevalence of methamphetamine effectively. In this paper, we present a portable fluorescence reader with upconverting nanoparticle-labeled lateral flow immunoassay (LFIA) for rapid and accurate quantification of methamphetamine. Based on specific binding of a methamphetamine antigen to an antibody in the LFIA, the fluorescence reader is designed to capture and record the fluorescence intensities T and C of the test and control lines, respectively, and the T/C ratio is calculated to determine the concentration of methamphetamine. The linear range for methamphetamine is 0.1-100 ng/mL. Because the sensor is often susceptible to noise interference, using only the T/C ratio to distinguish weakly positive and negative samples of methamphetamine renders the results inaccurate. To solve this problem, we applied a convolutional neural network (CNN) to learn image features of different methamphetamine concentrations (0, 0.01, 0.05, 0.1, and 0.5 ng/mL) for accurate detection of weakly positive and negative samples. The results show that the proposed method can effectively detect weakly positive and negative samples of methamphetamine with an accuracy of up to 92%. The CNN provides a novel scheme for accurate analysis of weakly positive and negative samples in upconverting nanoparticle-labeled LFIA.

Influence of fecal microbial transplant (FMT) between male and female rats on methamphetamine-induced hyperthermia

Objective To investigate the effect of bidirectional fecal microbial transplant (FMT) between male and female rats on methamphetamine (MA)-induced hyperthermia. Methods FMT was performed between male and female rats prior to MA (10 mg/kg, sc) treatment. Core body temperature, plasma drug and norepinephrine (NE) levels were measured and compared between treatment groups. 16S rRNA gene sequencing of bacterial communities between male and female rats was performed. Results MA treatment resulted in significantly higher core body temperatures in male groups (control and FMT-treated) compared to MA-treated female groups (control and FMT-treated). Plasma concentrations of MA and amphetamine were higher in females than males. Whereas, plasma norepinephrine (NE) levels were not different between male and female rats 90 minutes after MA treatment. At the phyla level, the microbiome of male and female control rats were dominated by Firmicutes and Bacteroidetes. Males had a higher relative abundance of Firmicutes and lower relative abundances of Bacteroidetes than females. The FMT procedure changed the recipient group towards their donor with males getting closer to their donors than females. In the control groups following MA treatment, Firmicutes increased and Bacteroides decreased in females and males. Conversely, in the FMT treatment groups following MA treatment, Firmicutes decreased while Bacteroidetes increased in females and males. Conclusions Although definite differences in the structure and diversity of the gut microbiome were observed using 16S rRNA gene sequencing of bacterial communities between male and female rats, these differences do not seem to contribute to the sex-based differences in MA-induced hyperthermia.

Neuroprotective effect of thyroid hormones on methamphetamine-induced neurotoxicity via cell surface receptors

Thyroid hormones (THs) have an essential role in normal brain development and function. Methamphetamine (MA) is a widely abused psychostimulant that induces irreversible damages to neuronal cells. In the current study, we used rat primary hippocampal neurons (PHNs) to investigate the neuroprotective effect of THs against MA neurotoxicity. PHNs were prepared from 18-day rat embryos and cell viability was assessed using MTT assay, following treatment with various concentrations of MA, T3, T4 or tetrac, an integrin αvβ3 cell surface receptor antagonist. Our results showed that 7 mM MA induced an approximately 50 % reduction in the PHNs viability. Treatment with 800 nM T3 or 8 μM T4 protected PHNs against MA toxicity, an effect which was blocked in the presence of tetrac. These findings suggest that THs protect PHNs against MA-induced cell death by the activation of integrin αvβ3 cell surface receptors. So, targeting integrin αvβ3 receptors or using THs can be considered as promising therapeutic strategies to overcome MA neurotoxicity.

A Case of Amphetamine and Methamphetamine Intoxication in Cat.

Stimulants belonging to the amphetamine group nowadays pose an undeniable worldwide threat to the life and health of users. Intoxications of domestic animals also occur, which can either be accidental or related to intentional human action. This study presents the first ever reported case of a simultaneous amphetamine and methamphetamine intoxication of a cat, along with the results of toxicological studies. Blood, urine, vitreous humor and liver were collected during the cat's autopsy and analyzed by UHPLC─QqQ─MS/MS. The sample preparation technique was based on one-step precipitation of proteins with cold acetonitrile. The determined amphetamine concentrations in the collected biological materials were 93.4 ng/mL in blood, 496.6 ng/mL in urine, 589.2 ng/mL in the vitreous humor and 291.2 ng/g in liver, respectively. Methamphetamine concentrations were 45.5 ng/mL in blood, 263.1 ng/mL in urine, 351.2 ng/mL in vitreous humor, and 97.7 ng/g in liver. Other substances were also found in the biological material, i.e., diazepam, oxazepam and nordiazepam. Cases of intentional or accidental poisoning of pets with psychoactive substances are a serious problem, carrying the risk to the health and life of the animal. Therefore, it is important to increase awareness of the high risk of poisoning of domestic animals, as well as to learn about the incompletely understood mechanisms of pharmacokinetics of various drugs in animals, including cats.

Methamphetamine-related forensic autopsy cases in a Japanese prefecture over a 7-year period: Characteristics of deaths and blood concentrations

Understanding the actual conditions of methamphetamine (MA)-related death is important from the perspectives of criminal justice and public health. In this report, we review 104 cases of MA-related death handled by our departments between January 2014 and December 2020. Based on information from police and autopsy examinations, we classified the cases into the following categories: “accidental intoxication” (“MA only” and “multiple drugs or alcohol”), “fatal disease” (“definitively MA-related,” “possibly MA-related,” and “unlikely MA-related”), “accident,” “suicide,” “homicide,” and “undetermined.” The total number and annual trends for each category and their respective femoral blood concentrations were investigated. “Fatal disease” was the most common category (48 cases), followed by “suicide” (25 cases), “accidental intoxication” (14 cases), and “accident” (11 cases). “Definitively MA-related” in which MA may have played a role in their onset or exacerbation accounted for the majority of “fatal disease”: 12 cases of heart disease, 4 cases of aortic dissection, 12 cases of cerebral hemorrhage, and 4 cases of subarachnoid hemorrhage. Cases classified as “definitively MA-related” died with lower femoral blood concentrations of MA compared with “MA only.” Cases with “fatal disease” might have been misdiagnosed as “death by natural causes” if a proper autopsy and toxicology examinations were not performed. In death investigations, it is necessary to keep in mind that there are some MA-related deaths, and efforts should be made to increase awareness about the risk of death in using this drug.

Smartphone enabled upconversion nanoparticle-based lateral flow strip for ultra-low concentration of methamphetamine detection

The combination of upconversion nanoparticles (UCNPs) and Lateral Flow Assays (LFAs) is becoming one of the most desirable quantitative assays for point-of-care testing (POCT) due to their excellent chemical and optical properties, which make them commercially viable as fast, sensitive and portable. We propose upconversion nanoparticle-based lateral flow assays (UCNP-LFAs) combined with computer vision for the instantaneous detection of small molecule targets in a commercial medical device. The device overcomes the traditional lengthy pre-processing and ambiguous qualitative results, where computer vision algorithms improve the sensitivity and robustness of quantitative results. Compared with the standard quantitative testing process, the accuracy of its quantitative test results was improved by 17.4%. The device detected and reported the quantitative results of Methamphetamine (MET) concentration with the lower limit of detection (LOD) of 0.1 ng/ml in 20 s in field tests. Its success demonstrated good sensitivity, repeatability, and robustness. Most importantly, the entire device measures only 100 mm * 120 mm* 74 mm and weighs 351.2 g, combining portability and immediacy and providing quantitative data for small molecule targets at a lower concentration. This makes our system an extraordinarily creative and attractive approach, especially for applications in complex field environments with chaotic personnel and special emergencies.

Investigation on consumption of psychoactive substances and their ecological risks using wastewater-based epidemiology: a case study on Qinghai-Tibet Plateau.

The Qinghai-Tibet Plateau is the third pole of the world, and information on the consumption of psychoactive substances (PSs) in this area is scarce. In this study, we selected Qinghai Province as the research area, and the per capita consumption and prevalence of PSs were investigated using wastewater-based epidemiology. Samples from 17 wastewater treatment plants (WWTPs) in 5 major cities in Qinghai Province were monitored, and 11 PSs were detected by ultra-high performance liquid chromatography-tandem mass spectrometry. Results showed that the target compounds were detected in all samples, with relatively high concentrations of ephedrine (2.1-4825.3ng/L) and methamphetamine (1.5-295.7ng/L). The consumption of methamphetamine in Xining City, Haidong City, and Haixi City was up to 78.4, 16.8, and 21.2mg/1000 inh/d (the PS consumption per 1000 inhabitants in 1day), respectively, higher than that in the other two cities, which was the result of the different consumption patterns and its relationship with the economic levels of each city. High consumption of methadone (47.9mg/1000 inh/day) was found in Xining City, which might be related to the methadone maintenance therapy sites in the city. Methamphetamine was the most prevalent drug, with the prevalence ranging from 0.003 (Guoluo) to 0.197% (Xining), and the prevalence of other PSs was low. The ecological risk assessment of PSs in the effluent of WWTPs showed that methadone exerted a low risk to aquatic organisms in three sites, while other substances posed potential risk or no risk. However, the long-term effect of PSs cannot be ignored.

Methamphetamine-induced lethal toxicity in zebrafish larvae.

The use of novel psychoactive substances has been steadily increasing in recent years. Given the rapid emergence of new substances and their constantly changing chemical structure, it is necessary to develop an efficient and expeditious approach to examine the mechanisms underlying their pharmacological and toxicological effects. Zebrafish (Danio rerio) have become a popular experimental subject for drug screening due to their amenability to high-throughput approaches. In this study, we used methamphetamine (METH) as an exemplary psychoactive substance to investigate its acute toxicity and possible underlying mechanisms in 5-day post-fertilization (5 dpf) zebrafish larvae. Lethality and toxicity of different concentrations of METH were examined in 5-dpf zebrafish larvae using a 96-well plate format. METH induced lethality in zebrafish larvae in a dose-dependent manner, which was associated with initial sympathomimetic activation, followed by cardiotoxicity. This was evidenced by significant heart rate increases at low doses, followed by decreased cardiac function at high doses and later time points. Levels of ammonia in the excreted water were increased but decreased internally. There was also evidence of seizures. Co-administration of the glutamate AMPA receptor antagonist GYKI-52466 and the dopamine D2 receptor antagonist raclopride significantly attenuated METH-induced lethality, suggesting that this lethality may be mediated synergistically or independently by glutamatergic and dopaminergic systems. These experiments provide a baseline for the study of the toxicity of related amphetamine compounds in 5-dpf zebrafish as well as a new high-throughput approach for investigating the toxicities of rapidly emerging new psychoactive substances.

Effect of the Sargassum angustifolium Extract on Methamphetamine-Induced Cytotoxicity in SH-SY5Y Cells.

This study aimed to assess the effect of the Sargassum angustifolium extract in methamphetamine-induced SH-SY5Y cells death. The brown algae S. angustifolium was extracted with 80% ethanol. The SH-SY5Y cells were treated with different concentrations of methamphetamine to measure IC50.. The MTT test was used to assess the toxic effect of the S. angustifolium extract in SH-SY5Y cells. SH-SY5Y cells' survival was measured while cells were treated with different concentrations of methamphetamine and S. angustifolium extract simultaneously. A specific kit measured intracellular ROS levels. Western blot analysis evaluated the expression of cytochrome C and Bax/Bcl2 ratio. The results showed that 5 mM methamphetamine approximately killed 50% of the cells, so it is considered IC50. The MTT test showed no toxicity effect for the S. angustifolium extract. 80, 160, 320, and 640 μg/ml of S. angustifolium extract prevented the occurrence of methamphetamine toxic effects in SH-SY5Y cells after 24 hours. Moreover, the S. angustifolium extract decreased ROS levels and cytochrome C release and reduced BaX/Bcl2 ratio in cells treated by methamphetamine. On the whole, it seems that the S. angustifolium hydroalcoholic extract has the potential to increase cell survival through in vitro antioxidant and antiapoptotic activities.