Methylphenidate ameliorates hypoxia-induced mitochondrial damage in human neuroblastoma SH-SY5Y cells through inhibition of oxidative stress

Changes in Cortisol and in Oxidative/Nitrosative Stress Indicators after ADHD Treatment

Although ADHD is one of the most prevalent diseases during childhood, we still do not know its precise origin; oxidative/nitrosative stress and the hypothalamic-pituitary-adrenal axis are suggested contributors. Methylphenidate, among others, is the main drug used in ADHD patients, but its effects on relevant markers and structures remain unclear. This study, involving 59 patients diagnosed with ADHD according to DSM-5 criteria, aimed to assess changes in cortisol levels (using cortisol awakening response, CAR) and oxidative/nitrosative status with the treatment. Blood samples before and 3 months after treatment with methylphenidate were used to measure oxidative and inflammatory markers, as well as the endogenous antioxidant activity, while saliva samples tracked cortisol awakening response (CAR). The results showed a treatment-related improvement in the redox profile, with the reduction in advanced oxidation protein products (AOPP), lipid peroxidation (LPO), and nitrite plus nitrate (NOx) levels, and the increase in the enzymatic activities of glutathione reductase (GRd) and catalase (CAT). Moreover, the area under the curve (AUC) of CAR increased significantly, indicating increased reactivity of the HPA axis. These results support, for the first time, the involvement of the endogenous antioxidant system in the pathophysiology of ADHD.

From Structural Disparities to Neuropharmacology: A Review of Adult Attention-Deficit/Hyperactivity Disorder Medication Treatment

Adult attention-deficit/hyperactivity disorder (ADHD) is an early-onset disorder with many functional impairments and psychiatric comorbidities. Although no treatment fully mitigates impairments associated with ADHD, effective management is possible with pharmacologic and nonpharmacologic treatments. The etiology and pathophysiology of ADHD are remarkably complex and the disorder is continuously distributed in the population. While these findings have been well documented in studies with predominantly white samples, ADHD may affect racial and ethnic minorities differentially, given diagnostic and treatment disparities. This review provides an updated overview of the epidemiology, etiology, neurobiology, and neuropharmacology of ADHD, addressing racial and ethnic disparities whereby data are available.

Methylphenidate exerts neuroprotective effects through the AMPK signaling pathway

PURPOSE

Cerebral ischemia is the main cause of permanent adult disabilities worldwide. This study investigated the reparative effects and potential mechanisms of methylphenidate (MPH), a medication for the treatment of attention-deficit/hyperactivity disorder.

METHODS

In vitro oxygen-glucose deprivation/reperfusion (OGD/R) and in vivo cerebral ischemia-reperfusion models were established. Sprague-Dawley (SD) rats were randomly divided into four groups (n = 20): Sham, Model, and MPH (0.5 and 1 mg/kg). Rats in MPH groups were treated with 0.5 or 1 mg/kg MPH via intraperitoneal injection for 7 days. Rats in the Sham and Model groups were treated with PBS during the same period. Cell viability was measured using MTT assay. Apoptosis was detected by Annexin V/PI staining. Protein expression was detected by Western blot. The volume of cerebral infarction was detected by triphenyltetrazolium chloride (TTC) staining. The DNA damage in ischemic brain tissues was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.

RESULTS

MPH treatment significantly reduced OGD/R-induced cell damage, shown by the increased cell viability and decreased apoptotic rate. p-AMPK and p-ACC protein expression increased in the OGD/R model after MPH treatment. The addition of AMPK inhibitor largely abolished the neuroprotective effects of MPH, evidenced by the reduced cell viability, increased apoptotic rate, and decreased protein expression of p-AMPK as well as p-ACC. Moreover, MPH treatment significantly alleviated the cerebral ischemia-reperfusion injury and decreased apoptosis in brain tissues, which may be associated with the AMPK/ACC pathway.

CONCLUSIONS

MPH exerted protective activities against oxidative stress in the OGD/R model and ameliorated brain damage of rats in the middle cerebral artery occlusion model, at least in part, through activating the AMPK pathway. These data demonstrated neuroprotective properties of MPH and highlighted it as a potential therapeutic agent against cerebral ischemia-reperfusion injury.

Stimulants cocktail: Methylphenidate plus caffeine impairs memory and cognition and alters mitochondrial and oxidative status

Methylphenidate (MPH) is a psychostimulant widely misused to increase wakefulness by drivers and students. Also, MPH can be found in dietary supplements in a clandestine manner aiming to burst performance of physical exercise practitioners. The abusive use of high doses of caffeine (CAF) in these contexts is equally already known. Here, we demonstrate the behavioral, oxidative and mitochondrial effects after acute exposure to high doses of MPH (80 mg/L) and CAF (150 mg/L), alone or associated (80 mg/L + 150 mg/L, respectively). We used zebrafish as animal model due to its high translational relevance. We evaluated the behavioral effects using the Novel Tank Test (NTT), Social Preference Test (SPT) and Y-maze Task and analyzed biomarkers of oxidative stress and activity of mitochondrial respiratory chain complexes. MPH alone induced antisocial behavior. MPH inhibited lipid peroxidation. The association of MPH + CAF presented memory impairment and anxiogenic behavior. In oxidative status, it inhibited lipid peroxidation, increased protein carbonylation and mitochondrial complex II, III and IV activity. Our results demonstrate that MPH and CAF alone negatively impact the typical behavioral of zebrafish. When associated, changes in cognition, memory, oxidative and mitochondrial status are more relevant.

Mitochondrial DNA copy number may be associated with attention deficit/hyperactivity disorder severity in treatment: a one-year follow-up study

OBJECTIVE

Studies on etiopathogenesis of attention deficit/hyperactivity disorder (ADHD) are increasingly focussing on mitochondrial dysfunction. Children diagnosed with ADHD who had significantly higher mitochondrial DNA (mtDNA) copy numbers than healthy children in our first study were re-examined in 1-year follow-up to investigate effects of severity and treatment of ADHD on mtDNA.

METHODS

Twenty-eight patients who participated in previous study were included in this follow-up study. Patients were equally divided into two groups according to whether they had been receiving treatment. Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version, and Conners Parent Rating Scale (CPRS) were used. Polymerase chain reaction was performed.

RESULTS

Means of the first and second mtDNA copy were similar in all patients. mtDNA copy numbers did not change between two measurements in treated and non-treated groups. There was a correlation between CPRS ADHD index and inattention scores and mtDNA copy number in treated group. mtDNA copy number did not change in patients with ADHD over a period of 1 year regardless of treatment.

CONCLUSIONS

There may be a relationship between decreased ADHD severity with treatment and positive effects of mitochondrial functions. Mitochondrial dysfunction may play a role in pathophysiology of ADHD.KEY POINTSThis was the first study to follow up ADHD patients in order to investigate mitochondrial dysfunction by measuring mtDNA copy numbers 1 year after the initial measurements.mtDNA copy number, one of the best markers of mitochondrial dysfunction, did not change in ADHD patients over a period of 1 year regardless of treatment.Mitochondrial dysfunction may play a role in the pathophysiology of ADHD, where it may be involved with or without treatment.In the treated group, there was an association between decreased ADHD severity and reduced mtDNA copy numbers.There may be a relationship between decreased ADHD severity with treatment and the positive effects of mitochondrial functions.

Increased Alopecia Areata Risk in Children with Attention-Deficit/Hyperactivity Disorder and the Impact of Methylphenidate Use: A Nationwide Population-Based Cohort Study

Alopecia areata (AA) is an autoimmune disease that causes sudden hair loss. Although few studies have reported the association between AA and attention-deficit/hyperactivity disorder (ADHD), the impact of methylphenidate (MPH) on AA has not been examined. This study examined whether AA risk is higher in children with ADHD than in those without ADHD as well as the impact of MPH use on AA risk in children with ADHD. From the Taiwan Maternal and Child Health Database, we enrolled all 1,750,456 newborns from 2004 to 2017 in Taiwan. Of them, 90,016 children received a diagnosis of ADHD whereas the remaining 1,660,440 did not. To compare AA risk in ADHD and the impact of MPH treatment on it, multiple Cox regression with adjustments for covariates (i.e., age, sex, and psychiatric comorbidities) was performed. The results indicated that 88 (0.098%) children with ADHD and 1191 (0.072%) children without ADHD had AA. Nevertheless, after adjustment for the covariates, AA risk was higher in children with ADHD than in those without ADHD (adjusted hazard ratio [aHR]: 1.30, 95% confidence interval [CI]: 1.04–1.64). Our data indicated a considerable reduction in AA risk (aHR: 0.64) among children with ADHD who received MPH than among those who did not receive MPH; however, this difference was nonsignificant, indicated by a wide 95% CI (0.32–1.25). In conclusion, ADHD and AA may share some underlying mechanisms.

Oxidopamine and oxidative stress: Recent advances in experimental physiology and pharmacology

Oxidopamine (6-hydroxydopamine, 6-OHDA) is a toxin commonly used for the creation of experimental animal models of Parkinson's disease, attention-deficit hyperactivity disorder, and Lesch-Nyhan syndrome. Its exact mechanism of action is not completely understood, although there are many indications that it is related to the generation of reactive oxygen species (ROS), primarily in dopaminergic neurons. In certain experimental conditions, oxidopamine may also cause programmed cell death via various signaling pathways. Oxidopamine may also have a significant impact on chromatin structure and nuclear structural organization in some cells. Today, many researchers use oxidopamine-associated oxidative damage to evaluate different antioxidant-based pharmacologically active compounds as drug candidates for various neurological and non-neurological diseases. Additional research is needed to clarify the exact biochemical pathways associated with oxidopamine toxicity, related ROS generation and apoptosis. In this short review, we focus on the recent research in experimental physiology and pharmacology, related to the cellular and animal experimental models of oxidopamine - mediated toxicity.

Uncovering the Anticancer Mechanism of Compound Sophorae Decoction against Ulcerative Colitis-Related Colorectal Cancer in Mice

Compound sophorae decoction (CSD), a traditional Chinese medicine (TCM) formula, has been voluminously used in China to deal with ulcerative colitis and gained significant therapeutic effect. Tremendous explorations have unraveled a contributory role of inflammatory bowel disease (IBD) like ulcerative colitis (UC) and Crohn's disease (CD) at the onset of colorectal cancer, scilicet, and colitis-related cancer (CRC). In light of the anti-inflammatory properties of CSD in UC, we appraised its chemoprevention capacity and underlying mechanism in ulcerative colitis-related colorectal cancer (UCRCC), employing a model of azoxymethane (AOM) plus dextran sulfate sodium- (DSS-) induced colorectal cancer (CRC) in C57BL/6 mice. Rapturously, our results illuminated the ameliorative effect of CSD against UCRCC in mice portrayed by lesser polyps or adenomas, attenuated colonic xenograft tumor growth in company with the preferable well-being of mice in contrast to the Model Group. We examined significant downregulation of proinflammatory cytokines such as TNF-α, NF-κB, IL-6, STAT3, and IL-17 after exposure to CSD, with the concomitant repression of inflammation-associated proteins, including COX-2 and iNOS. Independent of this, treatment with CSD declined the proportion of T helper 17 cells (Th17) and protein level of matrix metallopeptidase 9 (MMP-9). Moreover, transmission electron microscopy (TEM) detected observably suppressed mitophagy in mice administered with CSD and that was paralleled by the pro-apoptotic effect as indicated by upregulating caspase-3 together with caspase-9 and deregulating B-cell lymphoma 2 (Bcl-2). In closing, these findings suggest CSD executes the UCRCC-inhibitory activity through counteracting inflammatory responses and rescuing detuning of apoptosis as well as neutralizing overactive mitophagy, concurring to build up an oncosuppressive microenvironment.