Stress immune system affected

Psychological stress may influence the immune system by activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary axis (SAM). The well-described innervation of primary and secondary lymphoid tissues by the autonomic nervous system also has been implicated in stress-related modulation of the immune response. These pathways operate by producing biological mediators that interact with and affect cellular components of the immune system.13... 

Numerous physiological and environmental factors such as age, stress, nutritional deficiency, and infections may affect the immune system (Sullivan, 1989). Thus, adverse findings in animal studies may reflect these indirect immunotoxic effects rather than the direct immunotoxic potential of a chemical or drug. Indirect immunotoxic effects may be assessed through histopathologic evaluations of endocrine organs such as the adrenals and pituitary. 

Chinese angelica Angelica sinensis) is the most important female tonic remedy in Chinese medicine. The elfects of angelica EO in three assays in mice (elevated plus maze, light/dark and stress-induced hyperthermia test) suggested that angelica EO exhibited an anxiolytic-like effect [391]. A link to emotion and cognitive performance with the olfactory system was reported [392]. Moreover, the EOs could affect mood, concentration and sleep [393], while other studies had shown that EOs were potentially important to boost the immune system [394, 395]. 

It now seems probable that specific disturbances occur in the immune system in psychiatric illness that are not artefacts of non-specific stress factor, institutionalization or medication. The known effects of the neuroendocrine system on the immune response, and the recent evidence that receptor sites for neurotransmitters and neuroendocrine factors occur on lymphocytes and macrophages, support the hypothesis that immunological abnormalities may assist in precipitating the symptoms of anxiety and depression, commonly symptoms of major affective disorders. 

But the reality is a causality of interaction of environmental issues (stress, diet) and a bacterial trigger, further affected by a genetic predisposition or weakening of the immune system. This complexity characterizes almost all of modern medical theory and has a profound influence on future drug submissions. 

Oxidative stress is another type of environmental stress which can negatively (either directly or indirectly) affect the immune system. Oxidative stress is thought to be a factor influencing many inflammatory responses, including arachidonic acid (AA) release and prostaglandin E2 release (Pawliczak et al. 2002) (see also Section 2.2). 

The activation of the stress systems affects all tissues of the organism, and the peripheral immune system is no exception. These effects are mediated through at least tw o pathways via the HPA axis and by virtue of the innervation of lymphatic tissues by autonomic nerve fibers, especially from the sympathetic nervous system. All lymphoid tissues, primary (bone marrow and thymus) as well as secondary (spleen, lymph nodes, and gut-associated lymphoid tissue) are innervated by sympathetic nerve fibers. As discussed above, most lymphoid cells express catecholamine receptors, including B-lymphocytes, CD4- and CD 8-positive T cells, dendritic cells, monocytes, and macrophages. 

The mechanisms for these interactions are not well defined, although numerous hypotheses have been advanced. It should be noted at the outset that attempts to determine the relationship between depression and altered immune function are confounded by the multiplicity of factors known to be associated with both and that may alter the interrelationship. Examples include age, gender, sleep status, the likelihood that depression represents a complex of disease states with varying involvement of the immune system, and the frequent presence of other psychiatric or physical disorders which can affect both psychological status and immune function. A detailed review of this topic has been published (hwin, 2001). Indeed, it has been pointed out by Irwdn that current data suggest immune changes in MDD specifically correlated with the disorder are also seen with stress and other psychiatric disorders, suggesting some common characteristic(s) shared by these problems (hwin, 2001). 

The immune system is subject to modulation by a number of environmental cues including, but not limited to, microbial infections, toxic agents, stress, drugs and trauma. Endogenous immunoregulatory factors include those produced by the nervous and endocrine systems. This chapter discusses how these factors, as well as drugs targeting the immune, autonomic and central nervous systems, affect the immune system. 

Flavonoids affect the immune system and the body s inflammatory cells. This function is partly accomplished through the effects on enzymes involved in the immune response and the generation of inflammatory cells. Balentine et al. (1999) recently reported that only the aglycon cyanidin, not the anthocyanin glycoside, showed inhibitory effects on enzymes involved in inflammatory activity. The anthocyanins can be metabolized into their glycoside-free constituents either before or after absorption in the gut and may thereby act as anti-inflammatory agents in the body. Middleton and Kandaswami (1994) stress the fact, however, that as most of these studies have been carried out as in vitro experiments, care should be taken not to draw too extensive conclusions for the in vivo actions of flavonoids. Fundamental biochemical research is needed before the mechanisms behind the diverse actions of flavonoids are fully understood. 

Alopecia areata, another form of hair loss, is believed to be related to the immune system (e.g., autoimmunity). This disease generally occurs as patchy baldness on an otherwise normal scalp, although sometimes hair of other body regions is affected. When the entire scalp is involved, the condition is called alopecia totalis. If terminal hair loss occurs over the entire body, a rare condition, it is called alopecia universalis. Emotional stress has been shown to be one of the initiating causes of areata. Topical application of steroids is sometimes used to treat this condition. 

Some of these compounds, because of their high lipophilicity, accumulate in animal tissues, particularly in predators occupying the top of the food chains. In addition, they may be dispersed over great distances by winds and water currents. These chemicals can also affect the ability of living organisms to reproduce, to develop, and to withstand the many other stress factors in their environment, by depressing their nervous, endocrine, and/or immune systems. 

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