Their Immune Function

Researchers also have difficulty correlating a diminished immune function with THC exposure. Some found that the short-term immunosuppressive effects of THC were not well established. Others note that because heavy marijuana smokers can tend to have erratic lifestyles, they may increase their chances of infection or illness simply by lowering their immune function through poor sleep and nutrition. 

The endogenous opioids are another family of peptides involved in different physiological processes including pain regulation, respiratory control, stress responses, appetite, thermoregulation, and humoral and cellular immune function (Bodnar RJ., 2008). Opioids act through their receptors, which are also members of the GPCR family, and are expressed in the central and peripheral nervous system as well as on cells of the immune system (Henriksen and Willoch 2008 Hauser... 

The above scientific information on rice bran phytochemicals indicates that a multitude of mechanisms are operating at the cellular level to bring about specific health effects. Several health benefits of rice bran appear to be the result of the synergistic function of the many phytochemicals, antioxidants, vitamins and minerals which operates through a specific immune response. Their role in the biochemical mechanisms at the cellular level which result in major health effects is shown in Fig. 17.1. A short overview summarizing the effect of the various phytochemicals on major health issues such as cancer, immune function, cardiovascular disease, diabetes, altered liver function and gastrointestinal and colon disease will be given below. 

In the Unites States, the daily intake of 3-carotene is around 2 mg/day Several epidemiological studies have reported that consumption of carotenoid-rich foods is associated with reduced risks of certain chronic diseases such as cancers, cardiovascular disease, and age-related macular degeneration. These preventive effects of carotenoids may be related to their major function as vitamin A precursors and/or their actions as antioxidants, modulators of the immune response, and inducers of gap-junction communications. Not all carotenoids exert similar protective effects against specific diseases. By reason of the potential use of carotenoids as natural food colorants and/or for their health-promoting effects, research has focused on better understanding how they are absorbed by and metabolized in the human body. 

Finally, persons with diabetes have altered immune function that predisposes them to infection. Although their humoral immune responses remain intact, leukocyte function and cell-mediated immunity are compromised in poorly controlled disease. Achieving and maintaining tightly controlled blood glucose levels can wholly or partially reverse diabetic immunopathy. 

The antibody preparations could be administered unaltered or (more commonly) after their conjugation to radioisotopes or toxins. Binding of unaltered monoclonal antibodies to a tumour surface alone should facilitate increased destruction of tumour cells (Figure 13.4). This approach, however, has yielded disappointing results, as the monoclonal antibody preparations used to date have been murine in origin. The Fc region of such mouse antibodies is a very poor activator of human immune function. Technical advances, allowing the production of human/humanized monoclonals (see later) may render this therapeutic approach more attractive in the future. 

Ross, RS. et al., Immune function in free-ranging harbor seal (Phoca vitulina) mothers and their pups during lactation, J. Wildlife. Dis., 29, 21, 1993. 

The sympathetic nervous system (SNS) and the hypothalamic-pituitary axis work together as important modulators of the immune system after exposure to stressors. Norepinephrine (NE) and epinephrine (EPI) (catecholamines from the SNS) and neuroendocrine hormones modulate a range of immune cell activities, including cell proliferation, cytokine and antibody production, lytic activity, and migration. This chapter will focus on these two major pathways of brain-immune signaling, briefly summarizing the evidence for SNS and hypothalamic-pituitary-adrenal (HPA) modulation of immune function, their influence on immune-mediated diseases, immune modulation in aging, and early life influences on these pathways. 

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