Oxidative stress in methamphetamine-induced self-injurious behavior in mice

Gender Differences of Antioxidant System and Thyroid Function in Depressed Adolescents with Non-Suicidal Self-Injury

Purpose

The aim of our study was to explore the relation between serum levels of non-enzymatic antioxidants, thyroid function with the risk of non-suicidal self-injury (NSSI) in depressed adolescents.

Patients and Methods

We retrospected the electronic records of 454 hospitalized patients aged 13-17 years old with a diagnosis of major depressive disorder (239 patients with NSSI and 215 subjects without NSSI), and collected their demographic and clinical information, including serum levels of total bilirubin (Tbil), uric acid (UA), free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH).

Results

The incidence of NSSI was 52.6% among depressed adolescents aged 13-17, 57.1% in female and 38.5% in male. After using the propensity scoring method to exclude the influence of age between the two groups, it was found that patients with NSSI showed lower levels of Tbil (P=0.046) and UA (P=0.015) compared with those without NSSI. Logistic regression results showed that serum UA was associated with NSSI behavior in female patients (OR=0.995, 95% CI: 0.991-0.999, P=0.014), and TSH was associated with NSSI in male participants (OR=0.499, 95% CI: 0.267-0.932, P=0.029).

Conclusion

Female and male may have different pathological mechanisms of NSSI. NSSI is more likely to be related to antioxidant reaction in female adolescent patients, while more likely to be related to thyroid function in male depressed adolescent patients.

[Underlying Mechanisms of Methamphetamine-Induced Self-Injurious Behavior and Lethal Effects in Mice]

Relatively high doses of psychostimulants induce neurotoxicity on the dopaminergic system and self-injurious behavior (SIB) in rodents. However the underlying neuronal mechanisms of SIB remains unclear. Dopamine receptor antagonists, N-methyl-D-aspartic acid (NMDA) receptor antagonists, Nitric Oxide Synthase (NOS) inhibitors and free radical scavengers significantly attenuate methamphetamine-induced SIB. These findings indicate that activation of dopamine as well as NMDA receptors followed by radical formation and oxidative stress, especially when mediated by NOS activation, is associated with methamphetamine-induced SIB. On the other hand, an increase in the incidence of polydrug abuse is a major problem worldwide. Coadministered methamphetamine and morphine induced lethality in more than 80% in mice, accompanied by an increase in the number of poly (ADP-ribose) polymerase (PARP)-immunoreactive cells in the heart, kidney and liver. The lethal effect and the increase in the incidence of rupture or PARP-immunoreactive cells induced by the coadministration of methamphetamine and morphine were significantly attenuated by pretreatment with a phospholipase A2 inhibitor or a radical scavenger, or by cooling of body from 30 to 90 min after drug administration. These results suggest that free radicals play an important role in the increased lethality induced by the coadministration of methamphetamine and morphine. Therefore, free radical scavengers and cooling are beneficial for preventing death that is induced by the coadministration of methamphetamine and morphine. These findings may help us better understand for masochistic behavior, which is a clinical phenomenon on SIB, as well as polydrug-abuse-induced acute toxicity.

The Role of Oxidative Stress in Methamphetamine-induced Toxicity and Sources of Variation in the Design of Animal Studies

BACKGROUND

The prevalence of methamphetamine (MA) use has increased in recent years. In order to assess how this drug produces its effects, both clinical and preclinical studies have recently begun to focus on oxidative stress as an important biochemical mechanism in mediating these effects.

OBJECTIVE

The purpose of this review is to illustrate the variation in the design of preclinical studies investigating MA exposure on oxidative stress parameters in animal models.

METHOD

The experimental variables investigated and summarised include MA drug treatment, measurements of oxidative stress and antioxidant treatments that ameliorate the harmful effects of MA.

RESULTS

These preclinical studies differ greatly in their experimental design with respect to the dose of MA (ranging between 0.25 and 20 mg/kg), the dosing regime (acute, binge or chronic), the time of measurement of oxidative stress (0.5 h to 2 wks after last MA administration), the antioxidant system targeted and finally the use of antioxidants including the route of administration (i.p. or p.o.), the frequency of exposure and the time of exposure (preventative or therapeutic).

CONCLUSION

The findings in this paper suggest that there is a large diversity among these studies and so the interpretation of these results is challenging. For this reason, the development of guidelines and how best to assess oxidative stress in animal models may be beneficial. The use of these simple recommendations mean that results will be more comparable between laboratories and that future results generated will give us a greater understanding of the contribution of this important biochemical mechanism and its implications for the clinical scenario.

Multidisciplinary assessment and treatment of self-injurious behavior in autism spectrum disorder and intellectual disability: integration of psychological and biological theory and approach

The objective of this review is to consider the psychological (largely behavioral) and biological [neurochemical, medical (including genetic), and pharmacological] theories and approaches that contribute to current thinking about the etiology and treatment of self-injurious behavior (SIB) in individuals with autism spectrum disorder and/or intellectual disability. Algorithms for the assessment and treatment of SIB in this context, respectively, from a multidisciplinary, integrative perspective are proposed and challenges and opportunities that exist in clinical and research settings are discussed.

Histopathology of fathead minnow (Pimephales promelas) exposed to hydroxylated fullerenes

Hydroxylated fullerenes are reported to be very strong antioxidants, acting to quench reactive oxygen species, thus having strong potential for important and widespread applications in innovative therapies for a variety of disease processes. However, their potential for toxicological side effects is still largely controversial and unknown. Effects of hydroxylated fullerenes C60(OH)24 on the fathead minnow (Pimephales promelas) were investigated microscopically after a 72-hour (acute) exposure by intraperitoneal injection of 20 ppm of hydroxylated fullerenes per gram of body mass. Cumulative, semi-quantitative histopathologic evaluation of brain, liver, anterior kidney, posterior kidney, skin, coelom, gills and the vestibuloauditory system revealed significant differences between control and hydroxylated fullerene-treated fish. Fullerene-treated fish had much higher cumulative histopathology scores. Histopathologic changes included loss of cellularity in the interstitium of the kidney, a primary site of haematopoiesis in fish, and loss of intracytoplasmic glycogen in liver. In the coelom, variable numbers of leukocytes, including many macrophages and fewer heterophils and rodlet cells, were admixed with the nanomaterial. These findings raise concern about in vivo administration of hydroxylated fullerenes in experimental drugs and procedures in human medicine, and should be investigated in more detail.

Concentration-dependent effects of fullerenol on cultured hippocampal neuron viability

Background

Recent studies have shown that the biological actions and toxicity of the water-soluble compound, polyhydroxyfullerene (fullerenol), are related to the concentrations present at a particular site of action. This study investigated the effects of different concentrations of fullerenol on cultured rat hippocampal neurons.

Methods and results

Fullerenol at low concentrations significantly enhanced hippocampal neuron viability as tested by MTT assay and Hoechst 33342/propidium iodide double stain detection. At high concentrations, fullerenol induced apoptosis confirmed by Comet assay and assessment of caspase proteins.

Conclusion

These findings suggest that fullerenol promotes cell death and protects against cell damage, depending on the concentration present. The concentration-dependent effects of fullerenol were mainly due to its influence on the reduction-oxidation pathway.

Acute inhalation exposure to vaporized methamphetamine causes lung injury in mice

Methamphetamine (MA) is currently the most widespread illegally used stimulant in the United States. Use of MA by smoking is the fastest growing mode of administration, which increases concerns about potential pulmonary and other medical complications. A murine exposure system was developed to study the pulmonary affects of inhaled MA. Mice were exposed to 25-100 mg vaporized MA and assessments were made 3 h following initiation of exposure to model acute lung injury. Inhalation of MA vapor resulted in dose-dependent increases in MA plasma levels that were in the range of those experienced by MA users. At the highest MA dose, histological changes were observed in the lung and small but significant increases in lung wet weight to body weight ratios (5.656 +/- 0.176 mg/g for the controls vs. 6.706+/- 0.135 mg/g for the 100 mg MA-exposed mice) were found. In addition, there was 53% increase in total protein in bronchoalveolar lavage (BAL) fluid, greater than 20% increase in albumin levels in the BAL fluid, greater than 2.5-fold increase in lactate dehydrogenase levels in the BAL fluid, and reduced total BAL cell numbers (approximately 77% of controls). Levels of the early response cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were dose-dependently increased in BAL fluid of MA-exposed mice. Exposure to 100 mg MA significantly increased free radical generation in the BAL cells to 107-146% of controls and to approximately 135% of the controls in lung tissue in situ. Together, these data show that acute inhalation exposure to relevant doses of volatilized MA is associated with elevated free radical formation and significant lung injury.

In vivo biology and toxicology of fullerenes and their derivatives

Fullerenes represent a group of nanoparticles discovered in 1985. They are spherical molecules consisting entirely of carbon atoms (C(x)) to which side chains can be added, furnishing compounds with widely different properties. Fullerenes interact with biological systems, for example, by enzyme inhibition, causing phototoxic reactions, being scavengers of reactive oxygen species and free radicals, in addition to being able to initiate free radical reactions. Absorption, distribution and excretion strongly depend on the properties of the side chains. The pristine C(60) has a very long biological half-life, whereas the most water-soluble derivatives are eliminated from the exposed animals within weeks. A long biological half-life raises concern about bioaccumulation and long-term effects. In general, the acute oral, dermal and airway toxicity is low. However, few relevant experimental studies of repeated dose toxicity, reproductive toxicity and carcinogenic effect are available. The data suggest that direct DNA damaging effects are low, but formation of reactive oxygen species may cause inflammation and genetic damage. Apparently, it is dose-dependent whether a beneficial or an adverse effect occurs.

Complicated interaction between psychostimulants and morphine in expression of phenotype of behavior in the dopaminergic system of BALB/c mice

It is believed that BALB/c mice appear to be less sensitive to the locomotor effects of abused drugs compared to other strains, and several behaviors induced by abused drugs depend on genetic factors. The present study was designed to investigate the effects of the interaction between psychostimulants and morphine on behavior in BALB/c mice. Morphine and cocaine induced hyperlocomotion and hypolocomotion, respectively, while methamphetamine did not affect locomotor activity and high doses of methamphetamine significantly increased self-injurious behavior. Cocaine or methamphetamine increased the effects of morphine on locomotor behavior. Haloperidol (a dopamine-receptor antagonist) attenuated the hyperlocomotion induced by the combination of cocaine or methamphetamine plus morphine. These results indicate that the synergistic effects of methamphetamine or cocaine and morphine on locomotor activity are mediated through enhancement of the dopaminergic system and that combinations of psychostimulants and morphine enhance the locomotor activity in BALB/c mice. On the other hand, morphine completely attenuated methamphetamine-induced self-injurious behavior. Furthermore, a low dose (0.01 mg/kg) of haloperidol significantly increased the effects of methamphetamine and morphine on the locomotor activity. Hyperlocomotion induced by psychostimulants is mediated by the mesolimbic dopaminergic system, whereas stereotyped behaviors is mediated by the nigrostriatal dopaminergic system. Our findings suggest that balances of the activation of dopaminergic neurons (between mesolimbic and nigrostriatal systems) may play an important role to engender corresponding behavioral outcomes in BALB/c mice.

Differential effects of the ascorbyl and tocopheryl derivative on the methamphetamine-induced toxic behavior and toxicity

A previous study showed that high doses of methamphetamine induce self-injurious behavior (SIB) in rodents. Furthermore, the combination of methamphetamine and morphine increased lethality in mice. We recently surmised that the rise in SIB and mortality induced by methamphetamine and/or morphine may be related to oxidative stress. The present study was designed to determine whether an antioxidant could inhibit SIB or mortality directly induced by methamphetamine and/or morphine. The SIB induced by 20mg/kg of methamphetamine was abolished by the administration of Na L-ascorbyl-2-phosphate (APS: 300 mg/kg), but not Na DL-alpha-tocopheryl phosphate (TPNa: 200mg/kg). In contrast, APS (300 mg/kg) and TPNa (200mg/kg) each significantly attenuated the lethality induced by methamphetamine and morphine. The present study showed that the signal intensity of superoxide adduct was increased by 20mg/kg of methamphetamine in the heart and lungs, and methamphetamine plus morphine tended to increase superoxide adduct in all of the tissues measured by ESR spin trap methods. Adduct signal induced in brain by methamphetamine administration increased in significance, but in mouse administrated methamphetamine plus morphine. There are differential effects of administration of methamphetamine and coadministration of methamphetamine plus morphine on adduct signal. These results suggest that APS and TPNa are effective for reducing methamphetamine-induced toxicity and/or toxicological behavior. While APS and TPNa each affected methamphetamine- and/or morphine-induced toxicology and/or toxicological behavior, indicating that both drugs have antioxidative effects, their effects differed.