Reduced glucocorticoid sensitivity of monocyte interleukin-6 release in male employees with high plasma levels of tumor necrosis factor-alpha

Dark chocolate attenuates intracellular pro-inflammatory reactivity to acute psychosocial stress in men: A randomized controlled trial

Flavanol-rich dark chocolate consumption relates to lower risk of cardiovascular mortality, but underlying mechanisms are elusive. We investigated the effect of acute dark chocolate consumption on inflammatory measures before and after stress. Healthy men, aged 20-50years, were randomly assigned to a single intake of either 50g of flavanol-rich dark chocolate (n=31) or 50g of optically identical flavanol-free placebo-chocolate (n=34). Two hours after chocolate intake, both groups underwent the 15-min Trier Social Stress Test. We measured DNA-binding-activity of the pro-inflammatory transcription factor NF-κB (NF-κB-BA) in peripheral blood mononuclear cells, as well as plasma and whole blood mRNA levels of the pro-inflammatory cytokines IL-1β and IL-6, and the anti-inflammatory cytokine IL-10, prior to chocolate intake as well as before and several times after stress. We also repeatedly measured the flavanol epicatechin and the stress hormones epinephrine and cortisol in plasma and saliva, respectively. Compared to the placebo-chocolate-group, the dark-chocolate-group revealed a marginal increase in IL-10 mRNA prior to stress (p=0.065), and a significantly blunted stress reactivity of NF-κB-BA, IL-1β mRNA, and IL-6 mRNA (p's⩽0.036) with higher epicatechin levels relating to lower pro-inflammatory stress reactivity (p's⩽0.033). Stress hormone changes to stress were controlled. None of the other measures showed a significant chocolate effect (p's⩾0.19). Our findings indicate that acute flavanol-rich dark chocolate exerts anti-inflammatory effects both by increasing mRNA expression of the anti-inflammatory cytokine IL-10 and by attenuating the intracellular pro-inflammatory stress response. This mechanism may add to beneficial effects of dark chocolate on cardiovascular health.

Effect of the smell of Seirogan, a wood creosote, on dermal and intestinal mucosal immunity and allergic inflammation

Seirogan, a wood creosote, has been used as an antidiarrhetic drug in Asian countries including Japan for many years. This antidiarrhetic has recently been used as a sugar-coated pill because Seirogan has a strong smell. The strong smell of the uncoated form of Seirogan may modulate the defense systems of animals because the sense of smell is important for the detection of toxic metabolites in foods contaminated with pathogens. This study examined the effect of the sugar-coated and uncoated forms of this antidiarrhetic on the immunological response and inflammatory reactions in mice that had been sensitized with either fluorescein isothiocyanate or oxazolone. The sensitization of mice with either FITC or oxazolone markedly increased the plasma levels of tumor necrosis factor-α and mucosal IgA and elicited severe inflammation in the colon by a mechanism that could be suppressed by exposure of animals to the smell of uncoated Seirogan as effectively as the oral administration of the agent. Dermal inflammation in the FITC- and oxazolone-sensitized mice was also suppressed effectively either by the exposure to the smell or oral administration of the agent. Biochemical and histochemical analyses revealed that the elevated levels of plasma tumor necrosis factor-α and mucosal IgA were significantly decreased by exposure to the smell of uncoated Seirogan as well as by oral administration of the agent. Exposure of mice to the smell of Seirogan but not oral administration of the agent selectively increased plasma levels of adrenocorticotropic hormone and cortisol, particularly in the sensitized animals. These observations suggest that exposing the animals to the smell of Seirogan per se activated the hypothalamo-pituitary-adrenal axis and systemically modulated immunological reactions to suppress the allergic reactions.

Therapeutic manipulation of glucocorticoid metabolism in cardiovascular disease

The therapeutic potential for manipulation of glucocorticoid metabolism in cardiovascular disease was revolutionized by the recognition that access of glucocorticoids to their receptors is regulated in a tissue-specific manner by the isozymes of 11beta-hydroxysteroid dehydrogenase. Selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 have been shown recently to ameliorate cardiovascular risk factors and inhibit the development of atherosclerosis. This article addresses the possibility that inhibition of 11beta-hydroxsteroid dehydrogenase type 1 activity in cells of the cardiovascular system contributes to this beneficial action. The link between glucocorticoids and cardiovascular disease is complex as glucocorticoid excess is linked with increased cardiovascular events but glucocorticoid administration can reduce atherogenesis and restenosis in animal models. There is considerable evidence that glucocorticoids can interact directly with cells of the cardiovascular system to alter their function and structure and the inflammatory response to injury. These actions may be regulated by glucocorticoid and/or mineralocorticoid receptors but are also dependent on the 11beta-hydroxysteroid dehydrogenases which may be expressed in cardiac, vascular (endothelial, smooth muscle) and inflammatory (macrophages, neutrophils) cells. The activity of 11beta-hydroxysteroid dehydrogenases in these cells is dependent upon differentiation state, the action of pro-inflammaotory cytokines and the influence of endogenous inhibitors (oxysterols, bile acids). Further investigations are required to clarify the link between glucocorticoid excess and cardiovascular events and to determine the mechanism through which glucocorticoid treatment inhibits atherosclerosis/restenosis. This will provide greater insights into the potential benefit of selective 11beta-hydroxysteroid dehydrogenase inhibitors in treatment of cardiovascular disease.

The relationship between job stress and urinary cytokines in healthy nurses: a cross-sectional study

Cytokines such as angiogenin (ANG) and interleukin (IL-8) have been shown to be related to depressive symptoms and inflammatory diseases like coronary heart disease. They may thus be used as stress biomarkers to identify and prevent health problems. To investigate the relationship between cytokines and nurses' job-related stress, levels of urinary ANG and IL-8 were measured in healthy female hospital nurses in Japan. The level of job-related stress of the subjects was evaluated using the Nursing Stress Scale (NSS), with the participants being classified into high- or low-stress groups for each subscale according to their scores. The participants' subjective psychological states were assessed using the Profile of Mood States--Short Form Japanese version (POMS-SFJ). Urinary ANG, IL-8, and cortisol levels and subjective psychological states for two groups were compared for each NSS subscale. The fatigue and depression scores of POMS-SFJ subscales in the present study were higher than those of the general healthy Japanese population. Based on the mean score of the combined participants, nurses were experiencing the highest stress related to the pressure of having responsibility for patients' life support care (PPLC). Nurses reporting high levels of stress related to PPLC and conflict with physicians had high levels of urinary ANG. Urinary ANG levels may thus be associated with high levels of job stress.

Variations in anticipatory cognitive stress appraisal and differential proinflammatory cytokine expression in response to acute stress

OBJECTIVE

Anticipatory cognitive appraisal can affect the stress-induced release of stress hormones and stress hormones can modulate monocyte cytokine expression. We investigated whether anticipatory cognitive appraisal processes would predict changes in monocyte cytokine expression following psychosocial stress in relation to stress hormone release.

METHODS

Forty-four men (mean age 43+/-2 years; mean arterial blood pressure (MAP) 102+/-2 mmHg; mean body mass index (BMI) 26+/-.4kg/m(2)) completed the Primary Appraisal Secondary Appraisal (PASA) scale before undergoing the Trier Social Stress Test (combination of mock job interview and mental arithmetic task). Lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 expression by monocytes was assessed in vitro immediately before and after stress, and during recovery up to 60min post-stress. Moreover, we repeatedly measured salivary cortisol as well as plasma epinephrine and norepinephrine levels.

RESULTS

Stress hormones increased and cytokines decreased following stress (all p<0.05). Correlation analyses showed that a higher PASA "stress index" was associated with higher expression (area under the curve, AUC) of total LPS-stimulated TNF-alpha (r=.33, p=.03) and IL-6 (r=.32, p=.33) between rest and 60min post-stress. While controlling for age, BMI, and MAP, higher values in the primary PASA scale "control expectancy" predicted lower TNF-alpha expression following stress (ss=-.42, p=0.003). Higher "control expectancy" (ss=-.32, p=0.031) and lower "challenge" (ss=.30, p=0.046) predicted lower IL-6 expression. None of the stress hormones predicted expression of any cytokine.

CONCLUSIONS

We found that anticipatory cognitive stress appraisal modulates monocyte inflammatory activity following stress suggesting that interventions aiming at improving coping skills might modify the monocyte cytokine response.

High dexamethasone concentration prevents stimulatory effects of TNF-alpha and LPS on IL-6 secretion from the precursors of human muscle regeneration

A frequent finding in patients surviving critical illness myopathy is chronic muscle dysfunction. Its pathogenesis is mostly unknown; one explanation could be that muscle regeneration, which normally follows myopathy, is insufficient in these patients because of a high glucocorticoid level in their blood. Glucocorticoids can prevent stimulatory effects of proinflammatory factors on the interleukin (IL)-6 secretion, diminishing in this way the autocrine and paracrine IL-6 actions known to stimulate proliferation at the earliest, myoblast stage of muscle formation. To test this hypothesis, we compared the effects of major proinflammatory agents [tumor necrosis factor (TNF)-alpha and endotoxin lipopolysaccharide (LPS)] on the IL-6 secretion from the muscle precursors and then studied the influence of dexamethasone (Dex) on these effects. Mononuclear myoblasts, which still proliferate, were compared with myotubes in which this capacity is already lost. For correct interpretation of results, cultures were examined for putative apoptosis and necrosis. We found that constitutive secretion of IL-6 did not differ significantly between myoblasts and myotubes; however, the TNF-alpha- and LPS-stimulated IL-6 release was more pronounced (P < 0.001) in myoblasts. Dex, applied at the 0.1-100 nM concentration range, prevented constitutive and TNF-alpha- and LPS-stimulated IL-6 release at both developmental stages but only at high concentration (P < 0.01). Although there are still missing links to it, our results support the concept that high concentrations of glucocorticoids, met in critically ill patients, prevent TNF-alpha- and LPS-stimulated IL-6 secretion. This results in reduced IL-6-mediated myoblast proliferation, leading to the reduced final mass of the regenerated muscle.