Immunomodulation Effects Major function of the immune system in humans and animals is protection against diseases by identifying and killing pathogens and tumor cells. For these purposes, two types of immune responses have evolved: the innate and the adaptive immune responses. The innate immune system comprises certain cells and mechanisms that defend the host from infection by other organisms in a non-specific manner, that is, the cells of the innate system recognize and respond to a pathogen in a generic way without conferring long-lasting or protective immunity to the host. The major functions of the innate immune system include: phagocytosis, inflammation, complement activation and induction of cell death. The main classes of phagocytes are neutrophils, dendritic cells and macrophages. The chemical messengers produced by the above or other cells (for example cytokines) play an important role in the initiation of an inflammatory response. The killing of cancer cells or virus-infected cells is accomplished by natural killer (NK) cells. The adaptive immune system is composed of highly specialized cells and processes that eliminate or prevent pathogenic challenges by becoming stronger and faster in subsequent encounters of a particular antigen. The cells of the adaptive immune system are lymphocytes B and T. B cells produce antibodies, which neutralize pathogens or stimulate their elimination by other cells. T cells, which are classified into helper T cells and cytotoxic T cells, are responsible for providing help to macrophages in killing pathogens, in inducing B cell antibody production and in eliminating infected cells by initiating apoptosis. In vitro or in vivo experimental results performed with animals or humans with whole Spirulina cells, Spirulina extracts or Spirulina constituents (polysaccharides, phycocyanin) have shown that Spirulina is very efficient in stimulating a variety of immune functions, including phagocytosis, production of cytokines and other inflammatory mediators, NK cell activity, B cell antibody production and T cellproliferation. Despite its ability to induce proinflammatory cytokines, Spirulina has also been shown to significantly inhibit anti-inflammatory responses in a variety of animal models, including models of rheumatoid arthritis, colitis, and IgE-mediated local and systemic allergic reactions. These results may indicate that Spirulina possesses immunomodulatory activities, enhancing suboptimal immune responses, while dampening immune system hyperactivity. It has been shown recently that consumption of a commercial Spirulina extract containing high Molecular Weight polysaccharides (Immulina®), by healthy male volunteers caused an age-dependent temporary enhancement of adaptive immune responses. Moreover, it has been shown that consumption of Spirulina water extract by healthy male volunteers activates the innate immune system by augmentation of interferon-γ (IFN-γ) production and NK cytotoxicity. Further clinical studies with humans indicate that short-term oral consumption of Immulina®, which has been proven to contain as a principal active component Braun-type lipoproteins, can impact both gut mucosal and systemic immune functions and suggest that it may be useful for the enhancement of innate immune function for the prevention of infections in elderly and in other immune-suppressed individuals. Moreover, this polysaccharide and lipoprotein containing Spirulina extractcan be used for complementary therapy supporting optimal NK cell activity in cancerpatients
Posted on: Sat, 27 Sep 2014 19:02:17 +0000
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