Oxidative pathways as a drug target for the treatment of autism

Sleep Problems and 6-Sulfatoxymelatonin as Possible Predictors of Symptom Severity, Adaptive and Maladaptive Behavior in Children with Autism Spectrum Disorder

In children with autism spectrum disorder (ASD), sleep disturbances are a frequent comorbidity with an adverse effect on their behavior and functioning. It was suggested that melatonin deficit is at least partly responsible for the sleep problems. The study aimed to investigate, in a sample of 56 children with ASD aged 2.8–13.3 years, if the sleep problems and melatonin secretion can serve as predictors of adaptive functioning and severity of the ASD core symptoms. We demonstrated that, after adjustment for age, the Sleep score assessed by the Children’s Sleep Habits Questionnaire predicts the Adaptive behavior composite score only in children younger than 6 years, and the preferred predictive model is for the domain Socialization. The age-adjusted Sleep score predicted Externalizing and Internalizing maladaptive behavior, with a near-zero contribution of age to the relationship between the Internalizing maladaptive behavior and Sleep score. After adjustment for age, the reduced night-time melatonin secretion predicted a higher severity of ASD symptoms in the domain Social affect and the Calibrated Severity Score, but not the sleep problems. Our results emphasize the importance of assessing sleep problems as a modifiable predictor of behavior in children with ASD and support the hypothesis about the role of melatonin in pathophysiology of ASD.

Improvement of the Clinical and Psychological Profile of Patients with Autism after Methylcobalamin Syrup Administration

(1) Background: Autism, also known as autism-spectrum disorder, is a pervasive developmental disorder affecting social skills and psychological status in particular. The complex etiopathogenesis of autism limits efficient therapy, which leads to problems with the normal social integration of the individual and causes severe family distress. Injectable methylcobalamin was shown to improve the clinical status of patients via enhanced cell oxidative status and/or methylation capacity. Here we tested the efficiency of a syrup form of methylcobalamin in treating autism. (2) Methods: Methylcobalamin was administered daily at 500 µg dose to autistic children and young adults (n = 25) during a 200-day period. Clinical and psychological status was evaluated by parents and psychologists and plasma levels of reduced and oxidized glutathione, vitamin B12, homocysteine, and cysteine were determined before the treatment, and at day 100 and day 200 of the treatment. (3) Results: Good patient compliance was reported. Methylcobalamin treatment gradually improved the overall clinical and psychological status, with the highest impact in the social domain, followed by the cognitive, behavioral and communication characteristics. Changes in the clinical and psychological status were strongly associated with the changes in the level of reduced glutathione and reduced/oxidized glutathione ratio. (4) Conclusion: A high dose of methylcobalamin administered in syrup form ameliorates the clinical and psychological status of autistic individuals, probably due to the improved oxidative status.

Aggravation of autism-like behavior in BTBR T+tf/J mice by environmental pollutant, di-(2-ethylhexyl) phthalate: Role of nuclear factor erythroid 2-related factor 2 and oxidative enzymes in innate immune cells and cerebellum

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder which manifests itself in early childhood and is distinguished by recurring behavioral patterns, and dysfunction in social/communication skills. Ubiquitous environmental pollutant, di-2-ethylhexyl phthalate (DEHP) is one of the most frequently used plasticizers in various industrial products, e.g. vinyl flooring, plastic toys, and medical appliances. DEHP gets easily released into the environment and leads to human exposure through various routes. DEHP has been described to be linked with oxidative stress in various organs in animal/human studies. Increased concentration of DEHP has also been detected in ASD children which indicates an association between phthalates exposure and ASD. However, effect of DEHP on autism-like behavior has not been investigated previously. Therefore, this study probed the effect of DEHP on autism-like behavior (marble burying, self-grooming and sociability) and innate immune cells (dendritic cells/neutrophils)/cerebellar oxidant-antioxidant balance (NFkB, iNOS, NADPH oxidase, nitrotyrosine, lipid peroxides, Nrf2, SOD, GPx) in BTBR and C57 mice. Our data show that DEHP treatment causes worsening of autism-like behavior in BTBR mice which is associated with enhancement of oxidative stress in innate immune cells and cerebellum with concomitant lack of antioxidant protection. DEHP also causes oxidative stress in C57 mice in both innate immune cells and cerebellar compartment, however there is Nrf2-mediated induction of enzymatic antioxidants which protects them from upregulated oxidative stress. This proposes the notion that ubiquitous environmental pollutants such as DEHP may be involved in the pathogenesis/progression of ASD through dysregulation of antioxidant-antioxidant balance in innate immune cells and cerebellum.

A randomised, double blind, placebo-controlled trial of a fixed dose of N-acetyl cysteine in children with autistic disorder

OBJECTIVE

Oxidative stress, inflammation and heavy metals have been implicated in the aetiology of autistic disorder. N-acetyl cysteine has been shown to modulate these pathways, providing a rationale to trial N-acetyl cysteine for autistic disorder. There are now two published pilot studies suggesting efficacy, particularly in symptoms of irritability. This study aimed to explore if N-acetyl cysteine is a useful treatment for autistic disorder.

METHOD

This was a placebo-controlled, randomised clinical trial of 500 mg/day oral N-acetyl cysteine over 6 months, in addition to treatment as usual, in children with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision diagnosis of autistic disorder. The study was conducted in Victoria, Australia. The primary outcome measures were the Social Responsiveness Scale, Children's Communication Checklist-Second Edition and the Repetitive Behavior Scale-Revised. Additionally, demographic data, the parent-completed Vineland Adaptive Behavior Scales, Social Communication Questionnaire and clinician-administered Autism Diagnostic Observation Schedule were completed.

RESULTS

A total of 102 children were randomised into the study, and 98 (79 male, 19 female; age range: 3.1-9.9 years) attended the baseline appointment with their parent/guardian, forming the Intention to Treat sample. There were no differences between N-acetyl cysteine and placebo-treated groups on any of the outcome measures for either primary or secondary endpoints. There was no significant difference in the number and severity of adverse events between groups.

CONCLUSION

This study failed to demonstrate any benefit of adjunctive N-acetyl cysteine in treating autistic disorder. While this may reflect a true null result, methodological issues particularly the lower dose utilised in this study may be confounders.

Adolescent GBR12909 exposure induces oxidative stress, disrupts parvalbumin-positive interneurons, and leads to hyperactivity and impulsivity in adult mice

The adolescent period in mammals is a critical period of brain maturation and thus represents a time of susceptibility to environmental insult, e.g. psychosocial stress and/or drugs of abuse, which may cause lasting impairments in brain function and behavior and even precipitate symptoms in at-risk individuals. One likely effect of these environmental insults is to increase oxidative stress in the developing adolescent brain. Indeed, there is increasing evidence that redox dysregulation plays an important role in the development of schizophrenia and other neuropsychiatric disorders and that GABA interneurons are particularly susceptible to alterations in oxidative stress. The current study sought to model this adolescent neurochemical "stress" by exposing mice to the dopamine transporter inhibitor GBR12909 (5mg/kg; IP) during adolescence (postnatal day 35-44) and measuring the resultant effect on locomotor behavior and probabilistic reversal learning as well as GABAergic interneurons and oxidative stress in adulthood. C57BL6/J mice exposed to GBR12909 showed increased activity in a novel environment and increased impulsivity as measured by premature responding in the probabilistic reversal learning task. Adolescent GBR12909-exposed mice also showed decreased parvalbumin (PV) immunoreactivity in the prefrontal cortex, which was accompanied by increased oxidative stress in PV+ neurons. These findings indicate that adolescent exposure to a dopamine transporter inhibitor results in loss of PV in GABAergic interneurons, elevations in markers of oxidative stress, and alterations in behavior in adulthood.

Effects of omega-3 PUFA on the vitamin E and glutathione antioxidant defense system in individuals at ultra-high risk of psychosis

BACKGROUND

Oxidative stress and impaired antioxidant defenses are reported in schizophrenia and are associated with disturbed neurodevelopment, brain structural alterations, glutamatergic imbalance, increased negative symptoms, and cognitive impairment. There is evidence that oxidative stress predates the onset of acute psychotic illness. Here, we investigate the effects of omega-3 PUFA on the vitamin E and glutathione antioxidant defense system (AODS).

METHOD

In 64 help-seeking UHR-individuals (13-25 years of age), vitamin E levels and glutathione were investigated before and after 12 weeks of treatment with either 1.2g/d omega-3 (PUFA-E) or saturated fatty acids (SFA-E), with each condition also containing 30.4mg/d alpha-tocopherol to ensure absorption without additional oxidative risk.

RESULTS

In multivariate tests, the effects on the AODS (alpha-tocopherol, total glutathione) were not significantly different (p=0.13, p=0.11, respectively) between treatment conditions. According to univariate findings, only PUFA-E caused a significant alpha-tocopherol increase, while PUFA-E and SFA-E caused a significant gamma- and delta-tocopherol decrease. Total glutathione (GSHt) was decreased by PUFA-E supplementation.

CONCLUSION

Effects of the PUFA-E condition on the vitamin E and glutathione AODS could be mechanisms underlying its clinical effectiveness. In terms of the vitamin E protection system, PUFA-E seems to directly support the antioxidative defense at membrane level. The effect of PUFA-E on GSHt is not yet fully understood, but could reflect antioxidative effects, resulting in decreased demand for glutathione. It is still necessary to further clarify which type of PUFA/antioxidant combination, and in which dose, is effective at each stage of psychotic illness.

Autism biomarkers: challenges, pitfalls and possibilities

Network perspectives, in their emphasis on components and their interactions, might afford the best approach to the complexities of the ASD realm. Categorical approaches are unlikely to be fruitful as one should not expect to find a single or even predominant underlying cause of autism behavior across individuals. It is possible that the complex, highly interactive, heterogeneous and individualistic nature of the autism realm is intractable in terms of identifying clinically useful biomarker tests. It is hopeful from an emergenic perspective that small corrective changes in a single component of a deleterious network/configuration might have large beneficial consequences on developmental trajectories and in later treatment. It is suggested that the relationship between ASD and intellectual disability might be fundamentally different in single-gene versus nonsyndromic ASD. It is strongly stated that available biomarker "tests" for autism/ASD will do more harm than good. Finally, the serotonin-melatonin-oxidative stress-placental intersection might be an especially fruitful area of biological investigation.

Bisphenol A induces oxidative stress and mitochondrial dysfunction in lymphoblasts from children with autism and unaffected siblings

Autism is a behaviorally defined neurodevelopmental disorder. Although there is no single identifiable cause for autism, roles for genetic and environmental factors have been implicated in autism. Extensive evidence suggests increased oxidative stress and mitochondrial dysfunction in autism. In this study, we examined whether bisphenol A (BPA) is an environmental risk factor for autism by studying its effects on oxidative stress and mitochondrial function in the lymphoblasts. When lymphoblastoid cells from autistic subjects and age-matched unaffected sibling controls were exposed to BPA, there was an increase in the generation of reactive oxygen species (ROS) and a decrease in mitochondrial membrane potential in both groups. A further subdivision of the control group into two subgroups-unaffected nontwin siblings and twin siblings-showed significantly higher ROS levels without any exposure to BPA in the unaffected twin siblings compared to the unaffected nontwin siblings. ROS levels were also significantly higher in the autism vs the unaffected nontwin siblings group. The effect of BPA on three important mtDNA genes-NADH dehydrogenase 1, NADH dehydrogenase 4, and cytochrome b-was analyzed to observe any changes in the mitochondria after BPA exposure. BPA induced a significant increase in the mtDNA copy number in the lymphoblasts from the unaffected siblings group and in the unaffected twin siblings group vs the unaffected nontwin siblings. In all three genes, the mtDNA increase was seen in 70% of the subjects. These results suggest that BPA exposure results in increased oxidative stress and mitochondrial dysfunction in the autistic subjects as well as the age-matched sibling control subjects, particularly unaffected twin siblings. Therefore, BPA may act as an environmental risk factor for autism in genetically susceptible children by inducing oxidative stress and mitochondrial dysfunction.

Advanced pharmacotherapy evidenced by pathogenesis of autism spectrum disorder

In clinical practice, pharmacological treatment is mostly focused on behavioral symptoms in everyday life. Nevertheless, persistent effort continues to develop medication for causal treatment. Recent changes in diagnostic criteria from Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSM-IV-TR) to DSM-5 would affect not only diagnosing approaches, but also therapeutic approaches. Because previous pervasive developmental disorders have been integrated into a single entity, the autism spectrum disorder (ASD), we have to prepare for what medications are valuable for the ASD. In this article, we reviewed the following etiological treatment: acetylcholine and glutamate related medicine; amino acid medicine such as secretin, endogenous opioid, and oxytocin; complementary and alternative medicine such as chelating agents, vitamins, and omega-3; promising drugs related to the scope of pharmacogenetics currently under study.

One-carbon metabolism in neurodevelopmental disorders: using broad-based nutraceutics to treat cognitive deficits in complex spectrum disorders

Folate and choline, two nutrients involved in the one-carbon metabolic cycle, are intimately involved in regulating DNA integrity, synthesis, biogenic amine synthesis, and methylation. In this review, we discuss evidence that folate and choline play an important role in normal cognitive development, and that altered levels of these nutrients during periods of high neuronal proliferation and synaptogenesis can result in diminished cognitive function. We also discuss the use of these nutrients as therapeutic agents in a spectrum of developmental disorders in which intellectual disability is a prominent feature, such as in Fragile-X, Rett syndrome, Down syndrome, and Autism spectrum disorders. A survey of recent literature suggests that nutritional supplements have mild, but generally consistent, effects on improving cognition. Intervening with supplements earlier rather than later during development is more effective in improving cognitive outcomes. Given the mild improvements seen after treatments using nutrients alone, and the importance of the genetic profile of parents and offspring, we suggest that using nutraceutics early in development and in combination with other therapeutics are likely to have positive impacts on cognitive outcomes in a broad spectrum of complex neurodevelopmental disorders.

Erythrocyte shape abnormalities, membrane oxidative damage, and β-actin alterations: an unrecognized triad in classical autism

Autism spectrum disorders (ASDs) are a complex group of neurodevelopment disorders steadily rising in frequency and treatment refractory, where the search for biological markers is of paramount importance. Although red blood cells (RBCs) membrane lipidomics and rheological variables have been reported to be altered, with some suggestions indicating an increased lipid peroxidation in the erythrocyte membrane, to date no information exists on how the oxidative membrane damage may affect cytoskeletal membrane proteins and, ultimately, RBCs shape in autism. Here, we investigated RBC morphology by scanning electron microscopy in patients with classical autism, that is, the predominant ASDs phenotype (age range: 6–26 years), nonautistic neurodevelopmental disorders (i.e., “positive controls”), and healthy controls (i.e., “negative controls”). A high percentage of altered RBCs shapes, predominantly elliptocytes, was observed in autistic patients, but not in both control groups. The RBCs altered morphology in autistic subjects was related to increased erythrocyte membrane F₂-isoprostanes and 4-hydroxynonenal protein adducts. In addition, an oxidative damage of the erythrocyte membrane β-actin protein was evidenced. Therefore, the combination of erythrocyte shape abnormalities, erythrocyte membrane oxidative damage, and β-actin alterations constitutes a previously unrecognized triad in classical autism and provides new biological markers in the diagnostic workup of ASDs.

Impaired synthesis and antioxidant defense of glutathione in the cerebellum of autistic subjects: alterations in the activities and protein expression of glutathione-related enzymes

Autism is a neurodevelopmental disorder associated with social deficits and behavioral abnormalities. Recent evidence in autism suggests a deficit in glutathione (GSH), a major endogenous antioxidant. It is not known whether the synthesis, consumption, and/or regeneration of GSH is affected in autism. In the cerebellum tissues from autism (n=10) and age-matched control subjects (n=10), the activities of GSH-related enzymes glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), and glutamate cysteine ligase (GCL) involved in antioxidant defense, detoxification, GSH regeneration, and synthesis, respectively, were analyzed. GCL is a rate-limiting enzyme for GSH synthesis, and the relationship between its activity and the protein expression of its catalytic subunit GCLC and its modulatory subunit GCLM was also compared between the autistic and the control groups. Results showed that the activities of GPx and GST were significantly decreased in autism compared to that of the control group (P<0.05). Although there was no significant difference in GR activity between autism and control groups, 40% of autistic subjects showed lower GR activity than 95% confidence interval (CI) of the control group. GCL activity was also significantly reduced by 38.7% in the autistic group compared to the control group (P=0.023), and 8 of 10 autistic subjects had values below 95% CI of the control group. The ratio of protein levels of GCLC to GCLM in the autism group was significantly higher than that of the control group (P=0.022), and GCLM protein levels were reduced by 37.3% in the autistic group compared to the control group. A positive strong correlation was observed between GCL activity and protein levels of GCLM (r=0.887) and GCLC (r=0.799) subunits in control subjects but not in autistic subjects, suggesting that regulation of GCL activity is affected in autism. These results suggest that enzymes involved in GSH homeostasis have impaired activities in the cerebellum in autism, and lower GCL activity in autism may be related to decreased protein expression of GCLM.

Aspirin: a review of its neurobiological properties and therapeutic potential for mental illness

There is compelling evidence to support an aetiological role for inflammation, oxidative and nitrosative stress (O&NS), and mitochondrial dysfunction in the pathophysiology of major neuropsychiatric disorders, including depression, schizophrenia, bipolar disorder, and Alzheimer's disease (AD). These may represent new pathways for therapy. Aspirin is a non-steroidal anti-inflammatory drug that is an irreversible inhibitor of both cyclooxygenase (COX)-1 and COX-2, It stimulates endogenous production of anti-inflammatory regulatory 'braking signals', including lipoxins, which dampen the inflammatory response and reduce levels of inflammatory biomarkers, including C-reactive protein, tumor necrosis factor-α and interleukin (IL)--6, but not negative immunoregulatory cytokines, such as IL-4 and IL-10. Aspirin can reduce oxidative stress and protect against oxidative damage. Early evidence suggests there are beneficial effects of aspirin in preclinical and clinical studies in mood disorders and schizophrenia, and epidemiological data suggests that high-dose aspirin is associated with a reduced risk of AD. Aspirin, one of the oldest agents in medicine, is a potential new therapy for a range of neuropsychiatric disorders, and may provide proof-of-principle support for the role of inflammation and O&NS in the pathophysiology of this diverse group of disorders.

The promise of N-acetylcysteine in neuropsychiatry

N-Acetylcysteine (NAC) targets a diverse array of factors germane to the pathophysiology of multiple neuropsychiatric disorders including glutamatergic transmission, the antioxidant glutathione, neurotrophins, apoptosis, mitochondrial function, and inflammatory pathways. This review summarises the areas where the mechanisms of action of NAC overlap with known pathophysiological elements, and offers a précis of current literature regarding the use of NAC in disorders including cocaine, cannabis, and smoking addictions, Alzheimer's and Parkinson's diseases, autism, compulsive and grooming disorders, schizophrenia, depression, and bipolar disorder. There are positive trials of NAC in all these disorders, and although many of these require replication and are methodologically preliminary, this makes it one of the most promising drug candidates in neuropsychiatric disorders. The efficacy pattern of NAC interestingly shows little respect for the current diagnostic systems. Its benign tolerability profile, its action on multiple operative pathways, and the emergence of positive trial data make it an important target to investigate.

Targeting the mitochondrial electron transport chain in autism, a systematic review and synthesis of a novel therapeutic approach

Autism is a complex developmental disorder with an unknown etiology and without any curative treatment. The mitochondrial electron transfer chains play a major role in the production of ATP, and the generation and management of reactive oxidative stress (ROS). This paper is a systematic review of the role of the mitochondrial electron transport chain in autism, and a consequent hypothesis for treating autism is synthesized. An electronic search with pre-specified inclusion criteria was conducted in order to retrieve all the published articles about the mitochondrial electron transport chain in autism. The two databases of PUBMED and Google Scholar were searched. From one hundred twenty five retrieved titles, 12 (three case control study and 9 case reports) articles met inclusion criteria. All of the included studies indicated dysfunction of electron transport chain in autism. The mitochondrial electron transfer chain seems impaired in some children with autism and ROS production is additionally enhanced. It is hypothesized that interventions involving alternative electron shuttling may improve autism through lowering the production of ROS. In addition, it is expected that this alternative electron shuttling to cytochrome c might enhance the production of ATP which is impaired in the disorder.

Di-(2-ethylhexyl) phthalate and autism spectrum disorders

ASDs (autism spectrum disorders) are a complex group of neurodevelopment disorders, still poorly understood, steadily rising in frequency and treatment refractory. Extensive research has been so far unable to explain the aetiology of this condition, whereas a growing body of evidence suggests the involvement of environmental factors. Phthalates, given their extensive use and their persistence, are ubiquitous environmental contaminants. They are EDs (endocrine disruptors) suspected to interfere with neurodevelopment. Therefore they represent interesting candidate risk factors for ASD pathogenesis. The aim of this study was to evaluate the levels of the primary and secondary metabolites of DEHP [di-(2-ethylhexyl) phthalate] in children with ASD. A total of 48 children with ASD (male: 36, female: 12; mean age: 11 ± 5 years) and age- and sex-comparable 45 HCs (healthy controls; male: 25, female: 20; mean age: 12 ± 5 years) were enrolled. A diagnostic methodology, based on the determination of urinary concentrations of DEHP metabolites by HPLC-ESI-MS (HPLC electrospray ionization MS), was applied to urine spot samples. MEHP [mono-(2-ethylhexenyl) 1,2-benzenedicarboxylate], 6-OH-MEHP [mono-(2-ethyl-6-hydroxyhexyl) 1,2-benzenedicarboxylate], 5-OH-MEHP [mono-(2-ethyl-5-hydroxyhexyl) 1,2-benzenedicarboxylate] and 5-oxo-MEHP [mono-(2-ethyl-5-oxohexyl) 1,2-benzenedicarboxylate] were measured and compared with unequivocally characterized, pure synthetic compounds (>98%) taken as standard. In ASD patients, significant increase in 5-OH-MEHP (52.1%, median 0.18) and 5-oxo-MEHP (46.0%, median 0.096) urinary concentrations were detected, with a significant positive correlation between 5-OH-MEHP and 5-oxo-MEHP (rs = 0.668, P<0.0001). The fully oxidized form 5-oxo-MEHP showed 91.1% specificity in identifying patients with ASDs. Our findings demonstrate for the first time an association between phthalates exposure and ASDs, thus suggesting a previously unrecognized role for these ubiquitous environmental contaminants in the pathogenesis of autism.

Minocycline: therapeutic potential in psychiatry

Pharmacological interventions to treat psychiatric illness have previously focused on modifying dysfunctional neurotransmitter systems to improve symptoms. However, imperfect understanding of the aetiology of these heterogeneous syndromes has been associated with poor treatment outcomes for many individuals. Growing evidence suggests that oxidative stress, inflammation, changes in glutamatergic pathways and neurotrophins play important roles in many psychiatric illnesses including mood disorders, schizophrenia and addiction. These novel insights into pathophysiology allow new treatment targets to be explored. Minocycline is an antibiotic that can modulate glutamate-induced excitotoxicity, and has antioxidant, anti-inflammatory and neuroprotective effects. Given that these mechanisms overlap with the newly understood pathophysiological pathways, minocycline has potential as an adjunctive treatment in psychiatry. To date there have been promising clinical indications that minocycline may be a useful treatment in psychiatry, albeit from small trials most of which were not placebo controlled. Case reports of individuals with schizophrenia, psychotic symptoms and bipolar depression have shown serendipitous benefits of minocycline treatment on psychiatric symptoms. Minocycline has been trialled in open-label or small randomized controlled trials in psychiatry. Results vary, with findings supporting use in schizophrenia, but showing less benefit for nicotine dependence and obsessive-compulsive disorder. Given the limited data from rigorous clinical trials, further research is required. However, taken together, the current evidence suggests minocycline may be a promising novel therapy in psychiatry.

Downregulating the canonical Wnt/β-catenin signaling pathway attenuates the susceptibility to autism-like phenotypes by decreasing oxidative stress

Although a growing body of evidence supports the importance of the Wnt/β-catenin signaling pathway and oxidative stress in the pathogenesis of autism, it is unclear whether a relationship exists between the Wnt/β-catenin pathway and oxidative homeostasis. The present study examines the effects of sulindac, a small molecule inhibitor of the Wnt/β-catenin signaling pathway, on the oxidative status of rats that are prenatally exposed to valproic acid (VPA), which is used in an animal model of autism. Our data show that sulindac treatment downregulated the canonical Wnt/β-catenin signaling pathway by enhancing the expression of Glycogen Synthase Kinase 3β and attenuating the expression of β-catenin in comparison to levels in VPA-treated rats. Concomitantly, a marker of lipid peroxidation, 4-hydroxynonenal, was reduced as well. Sulindac treatment ameliorated the pain threshold, repetitive/stereotypic activity, learning and memory abilities and behavioral abnormalities of rats in our autism model. Our working model suggests that the upregulation of the Wnt/β-catenin signaling pathway induced by VPA administration during early pregnancy produces an imbalance of oxidative homeostasis that facilitates susceptibility to autism. This information may be instrumental in designing appropriate therapeutic regimens with small molecule inhibitors of the Wnt/β-catenin pathway for the treatment of autism-like behavioral phenotypes.