Salivary Nitric Oxide, a Biomarker for Stress and Anxiety?

Stress and its contribution to the development of depression symptoms are reduced in caregivers of elderly with higher educational level

Caregivers of elderly people with neurodegenerative diseases are highly vulnerable to stressful situations and mood disorders due to their work conditions. Stress has been associated with an increased risk of developing depression, and studies have supported that caffeine consumption can act as an independent protective factor for disorder. This study investigated indexes of stress and depression symptoms in caregivers of the elderly with neurodegenerative diseases, their caffeine intake and the association between stress and depressive symptoms with the salivary biomarkers cortisol, nitric oxide and DNA damage. Participants (n = 81) were recruited from the community between July 2018 and April 2019. Stress was assessed using Lipp's Inventory of Stress Symptoms, and depressive symptoms were measured using the Hamilton Depressive Rating Scale. Participants provided a 72-hour recall of their diet to measure caffeine intake. Saliva samples were used to measure cortisol and nitric oxide. DNA damage was measured through micronuclei frequency after swabbing on the buccal mucosa. The majority of caregivers displayed stress and depressive symptoms. Stress was associated with educational level, tobacco use and total DNA damage. The indexes found in this population were not associated with caffeine intake or other salivary biomarkers, indicating that only some salivary molecules could be used as biomarkers for stress-related disorders. Caregivers of the elderly are exposed to stressful situations daily, however, we observed that educational level can reduce the psychological symptoms of stress and thus reduce the negative impact on quality of life.

An Impact of Psychological Stress on the Interplay between Salivary Oxidative Stress and the Classic Psychological Stress-Related Parameters

Both oxidative and psychological (mental) stress are the likely culprits for several acute and chronic health disturbances, and adequate tests mimicking that are needed. Herein, in controlled laboratory surroundings, a PEBL (Psychology Experiment Building Language) test battery was used to evoke stress-related biological responses followed by tracking changes in saliva parameters. The study objectives were to determine the impact of psychological stress on selected salivatory parameters and to assess the correlation between the determined oxidative and stress parameters. The study was conducted on 36 healthy young subjects, mainly females (n = 24). Before and following the completion of a battery of four PEBL tests, subjects' saliva samples were collected. Stress-evoking changes in total antioxidant capacity and nitrite/nitrate levels, as oxidative stress parameters, and cortisol and immunoglobulin A (IgA), as parameters of psychological stress, were established and mutually correlated by comparing the values of the evaluated parameters pre- and post-PEBL test. The results showed that there is no change in the total salivary antioxidant capacity (p > 0.05); however, there was a significant increase in nitrites/nitrates levels after the PEBL test (p = 0.007). On the other hand, the determined cortisol levels after the test battery were found to be statistically significantly increased (p = 0.025) when compared to the values obtained before the test, while the levels of IgA were found to be statistically significantly decreased (p < 0.001). The only statistically significant correlation between the changes in the studied parameters was found to be the one between cortisol and IgA levels (Spearman's Rö = -0.4). These results suggest that the short-term stress induced by the PEBL test does evoke changes in the salivary mental stress-related parameters (an increase in cortisol and nitrite/nitrate levels, and a decrease in IgA), but not in the total antioxidant capacity. They also indicate that the constructed PEBL four-test battery might represent an adequate laboratory stress-inducing paradigm.

Metabolomic Biomarkers in Anxiety Disorders

Anxiety disorders range among the most prevalent psychiatric disorders and belong to the leading disorders in the study of the total global burden of disease. Anxiety disorders are complex conditions, with not fully understood etiological mechanisms. Numerous factors, including psychological, genetic, biological, and chemical factors, are thought to be involved in their etiology. Although the diagnosis of anxiety disorders is constantly evolving, diagnostic manuals rely on symptom lists, not on objective biomarkers and treatment effects are small to moderate. The underlying biological factors that drive anxiety disorders may be better suited to serve as biomarkers for guiding personalized medicine, as they are objective and can be measured externally. Therefore, the incorporation of novel biomarkers into current clinical methods might help to generate a classification system for anxiety disorders that can be linked to the underlying dysfunctional pathways. The study of metabolites (metabolomics) in a large-scale manner shows potential for disease diagnosis, for stratification of patients in a heterogeneous patient population, for monitoring therapeutic efficacy and disease progression, and for defining therapeutic targets. All of these are important properties for anxiety disorders, which is a multifactorial condition not involving a single-gene mutation. This review summarizes recent investigations on metabolomics studies in anxiety disorders.

Salivary cortisol and nitrite concentrations in school teachers: A longitudinal pilot study

OBJECTIVE

Occupational/mental stressors, which may be evaluated with measurements of salivary cortisol concentrations, affect the endothelial function and has implications on cardiovascular health. Nitric oxide (NO) is known to have an important role in cardiac function and may also be assessed in the saliva, but its participation in physiological responses to hypothalamic-pituitary-adrenal (HPA) axis stimulation is still not completely understood. The aim of the present study was to test the hypothesis that salivary NO (as nitrite) and cortisol concentrations in school teachers vary throughout the academic year.

METHODS

Saliva samples were collected from 13 teachers distributed across five secondary schools. The samples were collected at 6:30 a.m., 11:30 a.m., and 5:30 p.m. in the months of March, July, and December. Salivary cortisol levels were measured by enzyme immunoassay (EIA), and salivary NO concentration was determined by the quantification of nitrite. The area under the curve in relation to ground (AUC) was calculated to assess the cortisol and nitrite concentrations throughout the day.

RESULTS

No significant changes were observed in cortisol or nitrite concentrations across the three periods of the school year, while cortisol and nitrite levels showed a low positive and significant correlation (r=0.3455, p=0.0336).

CONCLUSION

The results suggest that changes in salivary cortisol levels are accompanied by changes in salivary nitrite levels. This is the first time that such association has been demonstrated. These results encourage further studies aimed to confirm the importance of salivary NO measurement in relation to occupational stress and cardiovascular health.

The effect of Ginkgo biloba and psycho-education on stress, anxiety and fatigue among refugees

Background:

Refugees and war survivors are at higher risk of developing mental health disorders. Anxiety and stress are caused by many factors, including a stressful environment that could cause fatigue and low quality of life. Despite the existence of many synthetic anxiolytic and antidepressant drugs, symptom management has still not been successful. Ginkgo biloba extract has been used as one of the potential herbal remedies to enhance cognitive functions. Psycho-education plays a significant role in alleviating psychological distress. However, the role of G. biloba in alleviating anxiety, stress and fatigue among refugees was not well studied previously.

Objectives:

In this study, we aimed to compare the effect of G. biloba and psycho-education with only psycho-education on refugees’ anxiety, stress and fatigue.

Methods:

A randomized controlled, pre-test–post-test design was used. Data were measured at baseline and 6 weeks later.

Results:

Providing psycho-education for the control group showed a non-significant improvement in outcome variables. However, adding G. biloba to psycho-education for the experimental group showed a significant reduction in mental, physical, activity fatigue and anxiety.

Conclusion:

The addition of G. biloba to the psycho-education proved superior to psycho-education alone. Therefore, combining the two approaches is beneficial in alleviating anxiety and fatigue.