Markers Of Stress In Humans Research Articles

Salivary Chromogranin A (CgA) Response to the Noradrenaline Transporter Blocker Atomoxetine in Dogs.

Simple SummaryCortisol in peripheral samples (e.g., blood, saliva or hair) is commonly used for the assessment of stress in dogs. It primarily reflects the hypothalamus–pituitary–adrenal (HPA) axis responses and serves as a marker to indicate the rapid response via the sympathetic adrenomedullar system (SAM), which has not yet been well studied in dogs. This study aimed to evaluate chromogranin A (CgA), a known SAM activation marker, in saliva samples from laboratory dogs when the SAM response was pharmacologically induced. A selective noradrenaline transporter blocker, atomoxetine, was orally administered without causing any adverse responses in dogs to see if it increases salivary CgA. Three treatment groups were designed to determine whether CgA was increased only in the treatment with atomoxetine compared to a placebo or with pre-administration of dexmedetomidine followed by atomoxetine. Dexmedetomidine was included in the study because it is a selective alpha-2 adrenoreceptor agonist that inhibits central noradrenaline activity. The results were found to be consistent with our hypothesis and suggest that salivary CgA correlates with central noradrenaline activity, indicating that it can be a useful marker to assess SAM activity in dogs.Since salivary chromogranin A (CgA) is one of the known sympathetic adrenomedullar system (SAM) stress markers in humans and pigs, this study aimed to investigate whether salivary CgA in dogs reflects SAM activation. Our hypothesis was that salivary CgA would increase when central noradrenaline was pharmacologically induced. A selective noradrenaline transporter blocker, atomoxetine, was orally administered without causing any aversive responses in nine laboratory dogs to see if it would increase salivary CgA. Three treatment groups (i.e., atomoxetine, placebo, and pre-administration of a selective alpha-2 adrenoreceptor agonist (dexmedetomidine) followed by atomoxetine) were prepared with a randomized crossover design. Saliva sample collection, heart rate measurement and behavior observation were performed at Time 0 (baseline) and at 30, 60, 90 and 150 min after each treatment administration. The results demonstrated that salivary CgA significantly increased at 90 min in the atomoxetine treatment (p < 0.05), whereas it was not observed in the other two treatments. The present study showed that salivary CgA was increased by atomoxetine-induced SAM activation. However, this increase was blocked if dexmedetomidine was pre-administered. Overall, the results indicate that salivary CgA is a potential candidate for SAM-mediated stress markers in dogs. Further study to determine the dynamics of salivary CgA will be helpful in its practical use.

Coffee Consumption and Oxidative Stress: A Review of Human Intervention Studies.

Research on the potential protective effects of coffee and its bioactives (caffeine, chlorogenic acids and diterpenes) against oxidative stress and related chronic disease risk has been increasing in the last years. The present review summarizes the main findings on the effect of coffee consumption on protection against lipid, protein and DNA damage, as well as on the modulation of antioxidant capacity and antioxidant enzymes in human studies. Twenty-six dietary intervention studies (involving acute and chronic coffee intake) have been considered. Overall, the results suggest that coffee consumption can increase glutathione levels and improve protection against DNA damage, especially following regular/repeated intake. On the contrary, the effects of coffee on plasma antioxidant capacity and antioxidant enzymes, as well as on protein and lipid damage, are unclear following both acute and chronic exposure. The high heterogeneity in terms of type of coffee, doses and duration of the studies, the lack of information on coffee and/or brew bioactive composition, as well as the choice of biomarkers and the methods used for their evaluation, may partially explain the variability observed among findings. More robust and well-controlled intervention studies are necessary for a thorough understanding of the effect of coffee on oxidative stress markers in humans.

Acute effect of sorghum flour-containing pasta on plasma total polyphenols, antioxidant capacity and oxidative stress markers in healthy subjects: A randomised controlled trial

It has been previously reported that pasta containing wholegrain sorghum flour exhibits high content of polyphenols and antioxidant capacity and hence might enhance antioxidant status and reduce markers of oxidative stress in vivo; however no clinical studies have yet been reported. Therefore, the present study assessed the effect of pasta containing red or white wholegrain sorghum flour on plasma total polyphenols, antioxidant capacity and oxidative stress markers in humans. The study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN: 12612000324819). In a randomised crossover design, healthy subjects (n = 20) consumed three test meals of control pasta (CP), 30% red sorghum pasta (RSP) or 30% white sorghum pasta (WSP), 1-2 wk apart. The test meals were consumed as breakfast after an overnight fast. Blood samples were obtained at fasting and 2 h after consumption and analysed for total polyphenols, antioxidant capacity, superoxide dismutase (SOD) activity, protein carbonyl and 8-isoprostanes. Compared to baseline, the 2 h post-prandial levels following the RSP meal of plasma polyphenols, antioxidant capacity and SOD activity were significantly (P < 0.001) higher while the protein carbonyl level was significantly lower (P = 0.035). Furthermore, net changes in polyphenols, antioxidant capacity and SOD activity were significantly (P < 0.001) higher while protein carbonyl were significantly (P = 0.035) lower following consumption of the RSP meal than the CP meal. The results demonstrated that pasta containing red wholegrain sorghum flour enhanced antioxidant status and improved markers of oxidative stress in healthy subjects.

Ebselen exhibits glycation‐inhibiting properties and protects against osmotic fragility of human erythrocytes in vitro

Diabetic status is associated with an increase on oxidative stress markers in humans and animal models. We have investigated the in vitro effects of high concentrations of glucose on the profile of oxidative stress and osmotic fragility of blood from control and diabetic patients; we considered whether its antioxidant properties could afford some protection against glucose-induced osmotic fragility, and whether ebselen could act as an inhibitor of hemoglobin glycation. Raising blood glucose to 5-100 mmol/L resulted in a concentration-dependent increase of glycated hemoglobin (HbA1c; P < 0.001) and thiobarbituric acid reactive species (TBA-RS) content (P < 0.004). Non-protein SH groups (NPSH) also increased significantly as the concentration of glucose increased up to 30 mmol/L (P < 0.001). The osmotic fragility was more pronounced in blood of uncontrolled diabetic patients than in these non-diabetic subjects. Ebselen significantly reduced the glucose-induced increase in osmotic fragility and inhibited HbA1c formation (P < 0.0001). These results indicate that blood from patients with uncontrolled diabetes are more sensitive to osmotic shock than from patients with controlled diabetes and control subjects in relation to increased production of free radicals in vivo.

Beneficial effects of Korean red ginseng on lymphocyte DNA damage, antioxidant enzyme activity, and LDL oxidation in healthy participants: a randomized, double-blind, placebo-controlled trial

BackgroundThe reported health benefits of Korean red ginseng (KRG) include antioxidant, antitumor, antimutagenic, and immunomodulatory activities; however, the effects on oxidative stress have not yet been evaluated. Therefore, we assessed the effect of KRG on antioxidant enzymes and oxidative stress markers in humans.MethodsWe conducted a randomized, double-blind, placebo-controlled study with three groups, including placebo, low-dose (3 g/day), and high-dose (6 g/day), which were randomly assigned to healthy subjects aged 20–65 years. Lymphocyte DNA damage, antioxidative enzyme activity, and lipid peroxidation were assessed before and after the 8-week supplementation.ResultsFifty-seven subjects completed the protocol. Plasma superoxide dismutase (SOD) activity after the 8-week KRG supplementation was significantly higher in the low-and high-dose groups compared to baseline. Plasma glutathione peroxidase (GPx) and catalase activities were also increased after the high-dose supplementation. Furthermore, the DNA tail length and tail moment were significantly reduced after the supplementation (low-dose and high-dose), and plasma oxidized low-density lipoprotein (LDL) levels were reduced in low-dose and high-dose groups, but increased in the placebo group. The net changes in oxidized LDL after the supplementation differed significantly between both KRG supplementation groups and the placebo group. Net changes in GPx, SOD and catalase activities, and DNA tail length and tail moment were significantly different between the high-dose group and the placebo group. Additionally, the net changes in urinary 8-epi-PGF2α were significantly different between the KRG supplementation groups and the placebo group.ConclusionsKRG supplementation may attenuate lymphocyte DNA damage and LDL oxidation by upregulating antioxidant enzyme activity.

Effects of Music on Immunity and Physiological Responses in Healthcare Workers: A Randomized Controlled Trial

Research-based evidence supports the effectiveness of soothing music in improving stress-related psycho-physiological indices in a clinical setting. However, there is currently insufficient scientific knowledge of the effects of music on immune markers of stress in humans. Therefore, the aims of the study were to compare the effects of music and quiet rest on the levels of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), interleukin-10 (IL-10), heart rate and mean arterial pressure among healthcare workers. By using a randomized controlled trial design, 60 nurses were randomly assigned to the stimulating or sedating music or rest groups for 30 min. Participants' psychoneuroimmunological parameters were measured using enzyme-linked immunosorbent assays. General estimating equation was used to analyse data. Results revealed that IL-6, TNF-α and IL-10 were not detectable in this population. No significance differences in heart rate were found among the three groups. However, the stimulating music group had significantly higher mean arterial pressure levels than the sedating music group but no differences between the quiet rest group and the sedating music group. Music with different tempi had little effect on mean arterial pressure. Any effect of music on immune markers of stress requires further research.

Relationships of Plasma Homocysteine Concentration and Oxidative Stress Markers in Korean Collage Students

Elevated plasma concentration of total homocysteine (ptHcy) is known as an independent risk factor of cardiovascular disease (CVD) and oxidative stress is also commonly implicated in CVD. An association between ptHcy and oxidative stress has recently been suggested. The study objective is to examine the relationship between ptHcy and oxidative stress markers in 103 healthy college students (62 males and 41 females). Plasma levels of ptHcy, oxidative stress markers (conjugated diene, erythrocyte catalase, TRAP, lymphocyte DNA damage), antioxidant vitamins (α-tocopherol, γ-tocopherol, carotenoids), and lipid parameters (total cholesterol, triglyceride, HDL cholesterol) were determined. The results show that the concentration of ptHcy was significantly higher in male subjects (22.17 ± 2.14 μmole/L) than in female subjects (12.28 ± 0.45 μmole/L). There was a negative association between ptHcy and plasma βcarotene in male subjects (p < 0.05), but no correlation between ptHcy and other plasma antioxidant vitamin levels in either gender. However, there were the negative correlations between ptHcy and plasma α-carotene or β-carotene, and a positive correlation between ptHcy and lymphocyte DNA damage. A significantly low level of α-carotene or β-carotene was found in male subjects with elevated ptHcy (≥ 15 μmol/L), as compared to those with lower plasma homocysteine. These study results confirmed the views on the association between plasma homocysteine and oxidative stress markers in humans and support the hypothesis that homocysteine promotes the oxidative environment by counteracting the antioxidant defense mechanism. (Korean J Nutr 2010; 43(5): 443 ~ 452)

Acute stress markers in humans: response of plasma glucose, cortisol and prolactin to two examinations differing in the anxiety they provoke.

Although the endocrine response to psychological stressors has been extensively studied both in animals and humans, the sensitivity of these variables to the intensity of stress experienced by exposure to psychologically stressful situations has not been studied in humans. In the present work this was assessed by measuring plasma levels of glucose, cortisol and prolactin in female medical students just before taking two examinations clearly differing in the anxiety they provoke. It was found that both examinations increased anxiety just before taking them, but the physiology examination (EPh) caused higher anxiety than the psychology (EPs). Prolactin increased in response to both examinations as compared to the non-stress condition, but its levels were greater in the EPh than in the EPs. Cortisol followed the same pattern as prolactin, but increased only marginally in the EPs. Finally, glycemia rose to the same extent in response to both examinations. A significant positive correlation was found between anxiety and glucose, and between cortisol and prolactin when data from all situations were included. On the basis of these results, it appears that the three variables might be useful as putative markers of stress in humans, although glucose might reflect different underlying psychological processes than cortisol and prolactin. In addition, it was found for the first time that prolactin is able to discriminate between stressful situations of different intensity. The response of these physiological variables to other stressful situations differing both in quantitative and in qualitative terms merits to be studied in further work.