Aerobic exercise reduced oxidative stress in saliva of persons with Down syndrome

The Role of Oxidative Stress in Trisomy 21 Phenotype

Extensive research has been conducted to gain a deeper understanding of the deregulated metabolic pathways in the development of trisomy 21 (T21) or Down syndrome. This research has shed light on the hypothesis that oxidative stress plays a significant role in the manifestation of the T21 phenotype. Although in vivo studies have shown promising results in mitigating the detrimental effects of oxidative stress, there is currently a lack of introduced antioxidant treatment options targeting cognitive impairments associated with T21. To address this gap, a comprehensive literature review was conducted to provide an updated overview of the involvement of oxidative stress in T21. The review aimed to summarize the insights into the pathogenesis of the Down syndrome phenotype and present the findings of recent innovative research that focuses on improving cognitive function in T21 through various antioxidant interventions. By examining the existing literature, this research seeks to provide a holistic understanding of the role oxidative stress plays in the development of T21 and to explore novel approaches that target multiple aspects of antioxidant intervention to improve cognitive function in individuals with Down syndrome. The guides -base systematic review process (Hutton et al. 2015).

Peripheral Oxidation Markers in Down Syndrome Patients: The Better and the Worse

Oxidative stress plays an important role in Down syndrome (DS) pathology since the gene dose effect leads to abnormal levels of certain enzymes and metabolites. In this review, we focused on relatively easy-to-obtain, peripheral markers of oxidative stress and inflammation, in order to compare the levels of these markers in DS patients and chromosomally healthy persons. Studies taking into account age- and sex-matched control groups were of particular interest in this context. We analyzed the factors that influence the levels of said markers in both groups (i.e., the usefulness of the markers), including the age of DS patients, occurrence of regular trisomy 21 or mosaicism, physical activity of patients, and the onset of Alzheimer's disease in DS. This paper was conceived as a handbook-to help for selecting suitable, easy-to-obtain markers for monitoring of the health status of DS patients (e.g., in nutritional studies and during dietary supplementation).

ENDOTHELIAL NITRIC OXIDE CONCENTRATIONS IN THE SALIVA OF JIU-JITSU ATHLETES

ABSTRACT Introduction This article discusses the production of nitric oxide under the influence of sport-specific physical training, measured by the salivary nitrite of Jiu-Jitsu athletes. Objectives To verify the potential of the sport to produce optimal levels of nitric oxide stimulated by exertion, and to quantify training-related nitric oxide concentrations. Method The study participants were 14 volunteer athletes from the Tatame project (extension project), who were monitored for nine months in their training routine, providing samples of unstimulated saliva. Samples were collected each month, in three periods of the day: in the morning upon waking, immediately before training, and immediately after training. Salivary nitrite was quantified by the colorimetric Griess assay. Training heart rates were also monitored in order to establish training intensity. Results Mean monthly salivary nitrite levels showed a significant correlation with mean monthly heart rates, suggesting that salivary nitrite responds to training. However, salivary nitrite concentrations measured immediately after training were always lower than in the pre-training period. Conclusion The post-training reduction in concentrations was due to the nature of the sport studied, since because it involves a fight, the intense sympathetic stimulation inhibited salivary gland activity and irrigation, preventing salivary nitrite from producing an increase in circulating nitric oxide. Level of evidence IV; Case series.

Acute high-intensity exercise test in soccer athletes affects salivary biochemical markers

Saliva has been reported as a potential biological fluid for biochemical monitoring. This study investigated salivary markers of exercise intensity, oral mucosal immunity, and redox homeostasis in soccer athletes subjected to an acute high-intensity interval exercise (HIIE) protocol characterised by a repeated sprint ability test. Thirty-two professional soccer athletes were recruited and saliva aliquots were collected at rest and immediately after HIIE protocol. When compared with pre-test values we observed that HIIE protocol induced moderate changes for total protein (p = .015; effect size (ES) = 0.51; smallest worthwhile change (SWC)_factor = 5.7) and for cortisol levels (p < .0001; ES = 0.49; SWC_factor = 3.9). Lactate levels showed very large changes (p < .000; ES = 1.35; SWC_factor = 10.8), while Ig-A alterations were considered unclear. Besides, transferrin changes were trivial and maintained its levels at rest and after HIIE below the proposed threshold of 0.5 mg/dL. Regarding redox homeostasis we observed unclear effects for TBARs, MDA, GSH, GSSG, CAT, and SOD while uric acid showed large decreases (p = .005; ES = 0.80; SWC_factor = -5.4). HIIE protocol as a physical test conducted in soccer athletes increased salivary concentration of exercise intensity markers, such as lactate, total protein, and cortisol, but did not affect Ig-A levels. Redox homeostasis in saliva seems to be more related with uric acid levels as a possible key factor TBARs homeostasis.

What effect does regular exercise have on oxidative stress in people with Down syndrome? A systematic review with meta-analyses

OBJECTIVE

What effect does regular exercise have on oxidative stress in people with Down syndrome?

DESIGN

Systematic review with meta-analyses.

METHODS

A systematic review with meta-analyses was conducted. Six databases were searched from inception until August 2017. Studies where included if participants with Down syndrome (any age) had completed an exercise program of at least 6 weeks duration and at least one biomarker measured the generation or removal of reactive oxidative species. Data were extracted using a customised form. Risk of bias was assessed using the Cochrane Collaboration's Risk of Bias assessment tool. Effect sizes were calculated and meta-analyses completed for clinically homogeneous data using a random effects model.

RESULTS

Seven studies (11 articles) involving 144 inactive participants investigated the effect of moderate intensity aerobic exercise. No pattern emerged for how most biomarkers responded with non-significant pooled effect sizes and high levels of heterogeneity observed. The exception was catalase which increased significantly after exercise (standardised mean difference 0.39, 95%CI 0.04-0.75; I² 15%). Available studies were at high risk of bias. Two of five studies that measured more than one biomarker reported a decrease in oxidative stress with increased antioxidant activity after exercise but the other three (including one small randomised controlled trial) reported increased oxidative stress with variable change in antioxidant activity.

CONCLUSIONS

There remains uncertainty about the effect of exercise on oxidative stress in people with Down syndrome.

REVIEW REGISTRATION

PROSPERO CRD42016048492.

Oxidative stress and Down syndrome. Do antioxidants play a role in therapy?

Oxidative stress is a phenomenon associated with imbalance between production of free radicals and reactive metabolites (e.g. superoxide and hydrogen peroxide) and the antioxidant defences. Oxidative stress in individuals with Down syndrome (DS) has been associated with trisomy of the 21st chromosome resulting in DS phenotype as well as with various morphological abnormalities, immune disorders, intellectual disability, premature aging and other biochemical abnormalities. Trisomy 21 in patients with DS results in increased activity of an important antioxidant enzyme Cu/Zn superoxide dismutase (SOD) which gene is located on the 21st chromosome along with other proteins such as transcription factor Ets-2, stress inducing factors (DSCR1) and precursor of beta-amyloid protein responsible for the formation of amyloid plaques in Alzheimer disease. Mentioned proteins are involved in the management of mitochondrial function, thereby promoting mitochondrial theory of aging also in people with DS. In defence against toxic effects of free radicals and their metabolites organism has built antioxidant defence systems. Their lack and reduced function increases oxidative stress resulting in disruption of the structure of important biomolecules, such as proteins, lipids and nucleic acids. This leads to their dysfunctions affecting pathophysiology of organs and the whole organism. This paper examines the impact of antioxidant interventions as well as positive effect of physical exercise on cognitive and learning disabilities of individuals with DS. Potential therapeutic targets on the molecular level (oxidative stress markers, gene for DYRK1A, neutrophic factor BDNF) after intervention of natural polyphenols are also discussed.

Assessment of salivary total antioxidant levels and oral health status in children with Down syndrome

Down syndrome (DS) is an autosomal chromosomal disorder caused by trisomy of all or a critical part of chromosome 21. Individuals with DS have high levels of oxidative stress throughout their lifespan. It has been suggested that levels of antioxidants could be altered in response to an infection or disease.

AIM

To assess the total antioxidant capacity (TAC), nitric oxide (NO), and sialic acid (SA) of saliva in children with DS and its relation to their oral health status.

MATERIALS AND METHODS

Thirty-four noninstitutionalized children in the age group of 7-12 years having DS formed the study group. The control group consisted of 34 normal, healthy children. The W.H.O. criteria were used for diagnosis and recording of dental caries. Oral hygiene status was assessed using the simplified oral hygiene index. Estimation of TAC, NO, and SA levels in saliva was done. Data obtained were subjected to statistical analysis.

RESULTS

In comparison to normal children, DS children showed significantly lower TAC of saliva and significantly higher salivary SA levels. In both groups of children, dental caries was higher in primary dentition when compared to their permanent dentition.

Redox processes in neurodegenerative disease involving reactive oxygen species

Much attention has been devoted to neurodegenerative diseases involving redox processes. This review comprises an update involving redox processes reported in the considerable literature in recent years. The mechanism involves reactive oxygen species and oxidative stress, usually in the brain. There are many examples including Parkinson’s, Huntington’s, Alzheimer’s, prions, Down’s syndrome, ataxia, multiple sclerosis, Creutzfeldt-Jacob disease, amyotrophic lateral sclerosis, schizophrenia, and Tardive Dyskinesia. Evidence indicates a protective role for antioxidants, which may have clinical implications. A multifaceted approach to mode of action appears reasonable.

Antioxidants in Down syndrome

Individuals with Down syndrome (DS) have high levels of oxidative stress throughout the lifespan. Mouse models of DS share some structural and functional abnormalities that parallel findings seen in the human phenotype. Several of the mouse models show evidence of cellular oxidative stress and have provided a platform for antioxidant intervention. Genes that are overexpressed on chromosome 21 are associated with oxidative stress and neuronal apoptosis. The lack of balance in the metabolism of free radicals generated during processes related to oxidative stress may have a direct role in producing the neuropathology of DS including the tendency to Alzheimer disease (AD). Mitochondria are often a target for oxidative stress and are considered to be a trigger for the onset of the AD process in DS. Biomarkers for oxidative stress have been described in DS and in AD in the general population. However, intervention trials using standard antioxidant supplements or diets have failed to produce uniform therapeutic effect. This chapter will examine the biological role of oxidative stress in DS and its relationship to abnormalities in both development and aging within the disorder. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.