Effect of 1% H2O2 on Three Salivary Stress Biomarkers, Cortisol, Alpha-Amylase, and sIgA

BACKGROUND

Due to the COVID-19 pandemic, several associations worldwide have been recommending the use of 1% hydrogen peroxide solution as a preprocedural mouth rinse before dental treatments to reduce viral load in saliva. This protocol is also employed in stress studies, especially in the context of dental treatment that uses salivary biomarkers as an indicator. However, the effect of 1% hydrogen peroxide as mouth rinse on salivary biomarkers remains unclear.

OBJECTIVE

This study aims to investigate the effects of 1% hydrogen peroxide solution as a preprocedural mouth rinse on 3 salivary stress biomarkers-salivary cortisol, salivary secretory IgA, and salivary α-amylase-both on chemical influence and mechanical irrigation.

MATERIALS AND METHODS

Ninety healthy participants with confirmed negative Reverse Transcription Polymerase Chain Reaction results for COVID-19 at most 2 days prior to the experiment were included in this study. All participants were randomly allocated into 3 groups: experimental (1% hydrogen peroxide solution), positive control (distilled water), and negative control (no mouth rinse). Saliva samples were collected before and after mouth rinsing with the respective solutions. Salivary biomarkers were analysed using specific enzyme-linked immunosorbent assay kits.

RESULTS

Salivary cortisol and salivary α-amylase did not significantly differ before and after rinsing, whilst salivary sIgA levels decreased in all 3 groups. Nonetheless, there were no significant differences in the changes of these biomarkers across the 3 groups.

CONCLUSIONS

This study shows that using 1% hydrogen peroxide solution as a preprocedural mouth rinse for universal precaution does not alter the levels of these 3 salivary biomarkers.

Electrochemical sensors for cortisol detection: Principles, designs, fabrication, and characterisation

Psychological stress is a major factor contributing to health discrepancies among individuals. Sustained exposure to stress triggers signalling pathways in the brain, which leading to the release of stress hormones in the body. Cortisol, a steroid hormone, is a significant biomarker for stress management due to its responsibility in the body's reply to stress. The release of cortisol in bloodstream prepares the body for a "fight or flight" response by increasing heart rate, blood pressure, metabolism, and suppressing the immune system. Detecting cortisol in biological samples is crucial for understanding its role in stress and personalized healthcare. Traditional techniques for cortisol detection have limitations, prompting researchers to explore alternative strategies. Electrochemical sensing has emerged as a reliable method for point-of-care (POC) cortisol detection. This review focuses on the progress made in electrochemical sensors for cortisol detection, covering their design, principle, and electroanalytical methodologies. The analytical performance of these sensors is also analysed and summarized. Despite significant advancements, the development of electrochemical cortisol sensors faces challenges such as biofouling, sample preparation, sensitivity, flexibility, stability, and recognition layer performance. Therefore, the need to develop more sensitive electrodes and materials is emphasized. Finally, we discussed the potential strategies for electrode design and provides examples of sensing approaches. Moreover, the encounters of translating research into real world applications are addressed.

Steroid hormone profiles and body conditions of migrating male humpback whales (Megaptera novaeangliae)

Simultaneous analysis of multiple steroid hormones from remotely obtained blubber biopsies has the potential to concurrently provide information regarding stress and reproductive status from free-swimming cetaceans, while also investigating correlations between hormone concentrations and other health biomarkers. In this study we measured blubber concentration profiles of eight reproductive and adrenal steroid hormones (17α-hydroxy-progesterone, testosterone, androstenedione, progesterone, cortisol, 11-deoxy-corticosterone, oestrone, and oestradiol) together with body condition, as determined by the inverse Adipocyte Index, of 101 male humpback whales. Whales were sampled randomly at two time points, while migrating to and from their northeast Australian breeding grounds, allowing for intra- and inter-seasonal profile analysis. Testosterone, progesterone and cortisol together with androstenedione 17α-hydroxyprogesterone, and oestrone concentrations (the latter quantified for the first time in live biopsied male humpback whales) decreased between the northward and southward migrations. Decreasing testosterone levels during the height of humpback whale conceptions suggests asynchronicity between blubber testosterone levels and the expected peak of male fertility. Statistically significant relationships between levels of certain steroid analytes were observed and appeared to change between the early and late breeding seasons. During the northward migration, testosterone, progesterone, androstenedione, oestrone and 17α-hydroxyprogesterone levels were positively correlated. Cortisol concentrations correlated positively with those of testosterone during the northward migration, but negatively during the southward migration. Androstenedione and testosterone were positively correlated with adiposity during the late breeding season. These hormone-hormone and hormone-adiposity correlations may be reflective of the activation of certain steroid hormone synthesis pathways, or alternatively, of concomitant physiological stimuli. As steroid hormones work in concert, information on multiple steroid hormones is needed to interpret endocrinological status and understand the relationships between these compounds and ancillary health markers. This study provides steroid hormone profiles of wild male humpback whales, as well as the first insight into seasonal male endocrinology as a function of adiposity.

Stress-Related Changes in the Expression and Activity of Plant Carbonic Anhydrases

The data on stress-related changes in the expression and activity of plant carbonic anhydrases (CAs) suggest that they are generally upregulated at moderate stress severity. This indicates probable involvement of CAs in adaptation to drought, high salinity, heat, high light, C_i deficit, and excess bicarbonate. The changes in CA levels under cold stress are less studied and generally represented by the downregulation of CAs excepting βCA2. Excess Cd²⁺ and deficit of Zn²⁺ specifically reduce CA activity and reduce its synthesis. Probable roles of βCAs in stress adaptation include stomatal closure, ROS scavenging and partial compensation for decreased mesophyll CO₂ conductance. βCAs play contrasting roles in pathogen responses, interacting with phytohormone signaling networks. Their role can be either negative or positive, probably depending on the host-pathogen system, pathogen initial titer, and levels of ·NO and ROS. It is still not clear why CAs are suppressed under severe stress levels. It should be noted, that the role of βCAs in the facilitation of CO₂ diffusion and their involvement in redox signaling or ROS detoxication are potentially antagonistic, as they are inactivated by oxidation or nitrosylation. Interestingly, some chloroplastic βCAs may be relocated to the cytoplasm under stress conditions, but the physiological meaning of this effect remains to be studied.

Do stressed children have a lot on their plates? A cross-sectional study of long-term stress and diet among Finnish preschoolers

We examined the association between hair cortisol concentration (HCC) - an indicator of long-term stress - and diet among preschoolers in a cross-sectional design. The participants were 597 Finnish 3-6-year-olds, and the data were collected in 2015-16. We used 4-cm hair samples to analyze HCC during the past four months. Food consumption was assessed using a food frequency questionnaire, and we used consumption frequencies of selected food groups as well as data-driven dietary pattern scores in the analyses. The parents of the participating children reported their educational level and family income. The researchers measured the children's weight and height. We examined the associations between HCC and diet using multilevel linear mixed models adjusted for age, gender, the highest education in the family, household relative income, and child BMI. Higher HCCs were associated with less frequent consumption of fruit and berries (B estimate -1.17, 95% CI -2.29, -0.05) and lower scores in a health-conscious dietary pattern (B estimate -0.38, 95% CI -0.61, -0,14). Higher HCCs were also associated with more frequent consumption of sugary beverages (B estimate 1.30, 95% CI 0.06, 2.54) in a model adjusted for age, gender and highest education in the family, but the association attenuated after further adjustments. Our results are parallel with previous studies that show a link between stress and unhealthy diet. In the future, longitudinal studies are needed to establish a causal relationship between stress and diet among children.

Synergistic effect of zinc nanoparticles and temperature on acute toxicity with response to biochemical markers and histopathological attributes in fish

In the present study, an experiment was carried out to delineate the lethal concentration of (LC₅₀) zinc nanoparticles (Zn-NPs) alone and with concurrent to high temperature (34 °C) in Pangasianodon hypophthalmus. The lethal concentration of Zn-NPs alone and with high temperature was estimated as 21.89 and 19.74 mg/L respectivey in P. hypophthalmus. The lethal concentration was decided with the help of definite concentration via 16, 18, 20, 22, 24, 26, 28 and 30 mg/L. The Zn-NPs were significantly alter the biochemical and histopathology of different fish tissues. The stress biomarkers such as oxidative stress (catalase superoxide dismutase and glutathione-s-transferase, lipid peroxidation) was studied in the liver, gill and kidney tissue, which was noticeable (p < 0.01) enhanced with higher concentration in both condition (Zn-NPs alone and Zn-NPs-T) in dose dependent manners. The carbohydrate (lactate dehydrogenase and malate dehydrogenase) and protein metabolic enzymes (alanine amino transferase and aspartate amino transferase) were also remarkable enhanced (p < 0.01) with higher concentration of Zn-NPs and Zn-NPs-T. The neurotransmitter (acetylcholine esterase) activities were significant inhibited (p < 0.01) with exposure to Zn-NPs and Zn-NPs-T and digestive enzymes such as protease and amylase were non-significant (p > 0.01) with the exposure of Zn-NPs and Zn-NPs-T, further, lipase were significantly reduced (p < 0.01) with exposure to Zn-NPs and temperature exposure group. The histopathological alteration were also observed in the liver and gill tissue. The present investigation suggested that, essential trace elements at higher concentration in acute exposure led to pronounced deleterious alteration on histopathology and cellular and metabolic activities in fish.

Salivary cortisone, as a biomarker for psychosocial stress, is associated with state anxiety and heart rate

BACKGROUND

Stress activates the central nervous, the autonomic nervous, and the endocrine system. This study aimed to (1) test the usability of salivary cortisone in a standardized psychosocial stressor, (2) create a comprehensive profile of hormonal responses to determine laboratory parameters with high discriminatory power, and (3) analyze their association with psychometric and autonomic stress measures.

METHODS

Healthy young men (18-35 years) completed either the Trier Social Stress Test (TSST) (n = 33) or a Placebo-TSST (n = 34). Blood and saliva were collected at 14 time points along with state-anxiety (STAI) and heart rate. Serum steroids (cortisol*, cortisone*, dehydroepiandrosterone-sulfate, androstenedione*, progesterone*, 17-hydroxyprogesterone*, testosterone, estradiol*, aldosterone*), salivary cortisol* and cortisone*, copeptin*, adrenocorticoptropic hormone*, corticosteroid-binding globulin, and salivary alpha-amylase* were analyzed. We used mixed-design ANOVAs to test group differences, receiver operator characteristic (ROC) curve analyses to assess the discriminatory power of each measure, and Spearman correlation analyses to probe the association between measures.

RESULTS

The largest area under the ROC curve was observed in salivary cortisone at 20 min after the end of the TSST (AUC = 0.909 ± 0.044, p < 0.0001). Significant time-by-group interactions were found in the parameters marked with * above, indicating stress-induced increases. The peak response of salivary cortisone was significantly associated with those of STAI (rho = 0.477, p = 0.016) and heart rate (rho = 0.699, p < 0.0001) in the TSST group.

CONCLUSION

Our study found salivary cortisone to be a stress biomarker with high discriminatory power and significant correlations with subjective and autonomic stress measures. Our results can inform future stress studies of sampling time for different laboratory parameters.

Measuring acute stress response through physiological signals: towards a quantitative assessment of stress

Social and medical problems associated with stress are increasing globally and seriously affect mental health and well-being. However, an effective stress-level monitoring method is still not available. This paper presents a quantitative method for monitoring acute stress levels in healthy young people using biomarkers from physiological signals that can be unobtrusively monitored. Two states were induced to 40 volunteers, a basal state generated with a relaxation task and an acute stress state generated by applying a standard stress test that includes five different tasks. Standard psychological questionnaires and biochemical markers were utilized as ground truth of stress levels. A multivariable approach to comprehensively measure the physiological stress response is proposed using stress biomarkers derived from skin temperature, heart rate, and pulse wave signals. Acute physiological stress levels (total-range 0-100 au) were continuously estimated every 1 min showing medians of 29.06 au in the relaxation tasks, while rising from 34.58 to 47.55 au in the stress tasks. Moreover, using the proposed method, five statistically different stress levels induced by the performed tasks were also measured. Results obtained show that, in these experimental conditions, stress can be monitored from unobtrusive biomarkers. Thus, a more general stress monitoring method could be derived based on this approach. Graphical abstract Stress measurements of different healthy young people throughout a Stress Session that includes a pre-relax stage (BL_s), memory test (ST and MT), stress anticipation time (SA), video display (VD) and arithmetic task.

Effects of silver nanoparticles on stress biomarkers of Channa striatus: immuno-protective or toxic?

Nanotechnology is a novel arena with promising applications in the field of medicine, industry, and agriculture including fisheries. Cross-disciplinary interactions and the application of this technology in biological systems have led to the innovation of novel nanoparticle antioxidants, which are the subject of our study. In context with above background, we designed an experiment on nano-silver to elucidate its role for mitigation of abiotic and biotic stress. Three diets were formulated viz. silver nanoparticles (Ag-NPs) incorporated at 0.5 and 1 mg/kg diet and control diet (Ag-NPs at 0 mg/kg). Fish were exposed to sublethal level of 1/25th of LC₅₀ (4 ppm) of lead (Pb) and temperature at 34 °C. The effect of Ag-NPs on productive performance (weight gain %, feed conversion ratio, protein efficiency ratio, and specific growth rate), stress biomarkers (catalase, super oxide dismutase, glutathione-s-transferase, acetylcholine esterase, cortisol, heat shock protein), biochemical and immunological response (protein and carbohydrate metabolic enzymes, phagocytic activity, serum total protein and albumin: globulin ratio), histopathology alterations in the liver and gill as well as survival of Channa striatus, following challenge with pathogenic bacteria were evaluated. Dietary Ag-NPs at 0.5-mg supplementation improved growth performance, immunity, survival, and reduced stress biomarker such as HSP 70, cortisol, and blood glucose in various fish tissues. Exposure to Pb and high temperature and group fed with Ag-NPs (1 mg/kg diet) demonstrated remarkable changes in the histo-architect of liver such as pyknotic nuclei, pyknosis, leucocyte infiltration, hemorrhage and karyokinesis, blood vessels with nucleated, lipid vacuoles in the liver tissue. Histology of gill displayed hyperplasia, aneurism, blood congestion, severe telengiectiasis, epithelial lifting, curling of secondary lamella, hyperplasia of epithelial cell of secondary lamella in the group exposed to lead and high temperature and supplemented with Ag-NPs at 1 mg/kg diet. In addition to histopathology, feeding with Ag-NPs at 1 mg/kg diet deteriorated and altered all studied parameters including reduced growth performance. Results obtained in the present study suggest that supplementation of Ag-NPs at 0.5 mg/kg diet has a definitive role to play in the mitigation of abiotic and biotic stress in C. striatus.

Stress during slaughter increases lipid metabolites and decreases oxidative stability of farmed rainbow trout (Oncorhynchus mykiss) during frozen storage

The consequences of slaughter on the formation of lipid metabolites and oxidative stability of fish muscle during long term frozen storage (-10 °C) were evaluated using farmed rainbow trout killed by asphyxia in air or percussion. The level of major adenine nucleotides and their related compounds was determined in order to check the stress level during slaughter. Plasma lipid metabolites were studied through the determination of eicosanoids and docosanoids such as prostaglandins, leukotrienes, thromboxanes, isoprostanes, resolvins, hydroxides, hydroperoxides, coming from eicosapentaenoic (EPA), arachidonic (ARA), and docosahexaenoic (DHA) acids. In addition, lipid oxidative stability of fillets was monitored. Results revealed that stress during slaughter can greatly influence oxidative stress and oxidative stability of rainbow trout fillets. In fact, asphyxia, which was the most stressful, induced a higher production of some lipid mediators such as hydroperoxides and EPA-derived prostaglandins, such as 12-HpHEPE/15-HpHEPE and PGD3/PGE3. As a consequence, fillets derived from asphyxiated fish were less stable in terms of oxidative stability and showed lower shelf-life.

Effects of water temperature on perchlorate toxicity to the thyroid and reproductive system of Oryzias latipes

Water temperature is expected to increase in many parts of the world due to global climate change. The change in water temperature may affect ecosystems through alterations of the chemical properties or by affecting the susceptibility of organisms. Perchlorate can disrupt thyroid function of an organism by inhibiting iodide uptake. In the present study, the effect of water temperature on perchlorate toxicity was evaluated using Japanese medaka (Oryzias latipes). Pairs of adult medaka fish were exposed to a sublethal concentration of sodium perchlorate (100mg/L) and a control, at a 'low' (26°C), 'medium' (29°C) or 'high' water temperature (33°C) for seven days. The effects of the water temperature on reproduction, thyroid hormones and cortisol concentrations were determined. Transcription of several genes related to thyroid function and stress were also investigated. Significant down-regulation of thyroid hormone receptor alpha (THR-α) and beta (THR-β) transcripts and up-regulation of deiodinase 2 (DIO2) transcripts were observed in the fish exposed to perchlorate. Thyroxine (T4) concentrations were decreased, while triiodothyronine (T3) levels remained constant following exposure to perchlorate, and this effect became more pronounced under the high water temperature conditions (33°C). Up-regulation of the DIO2 gene may explain these observations. The total number of spawned eggs decreased slightly as the water temperature increased, and this reduction became significant when fish were exposed to perchlorate. Our observations indicate that exposure to perchlorate could affect thyroid function and overall reproductive fitness, and these effects could be aggravated under high water temperatures.