Research progress in immune regulation mechanism of Polygonati Rhizoma polysaccharide / 中国药理学与毒理学杂志

ABSTRACT

Polygonati Rhizoma is the dry rhizome of Liliaceae plants Polygonatum kingianum coil ethemsl, Polygona?tum sibiricum Redoute and Polygonatum cyrtonem Hua. It tastes sweet and has a flat nature. It belongs to the spleen, lung and kidney channels. Polygonati Rhizoma contains a variety of chemical components, including polysaccharides, alkaloids, steroidal saponins, lignans, phytosterols, and so on. Polygonati Rhizoma polysaccharide (PSP) is one of the main bioactive components of Polygonati Rhizoma. It is widely used. It has the effects of enhancing immunity, anti-inflammatory, anti-virus and regulating blood lipid. In recent years, the immunomodulatory function of PSP has been paid more and more attention by researchers. PSP can play an immunomodulatory role through a variety of mecha?nisms. (1) Effects of PSP on innate immunity. ① Macrophages have a strong ability to phagocytize and clear foreign bodies. When polysaccharides bind to macrophage specific membrane receptors, the immune response will be officially activated. RAW264.7 cells can be activated by PSP MR and TLR4 mediated signal pathway to improve the pinocytosis and phagocytosis of RAW264.7 cells. ② Natural killer cell (NK cell) is a very important immune cell in the body. It is a non-specific immune killer cell naturally existing in the body. It has the dual functions of immune regulation and cytotoxic?ity. It was found that the signal pathway mediated by PSP CR3 and TRL2 may play a major role in the stimulation of NK cells. (2) Effects of PSP on adaptive immune response. ① Lymphocytes can be divided into two forms: T cells and B cells due to different differentiation and maturation sites. T lymphocytes are the general name of thymus dependent lym?phocytes. B lymphocytes differentiate and mature from animal bone marrow cells and exert their humoral immune func?tion by secreting different antibodies. It was found that PSP could activate T/B lymphocytes and increase the ratio of CD4+/CD8+in lymph cells to promote the regulation of immune system.②Thymus and spleen index refers to the level of body immunity through the development of immune organs and the functional status of immune cells. The higher the index of thymus and spleen, the higher the immune activity. A large number of studies have found that PSP can improve immune activity by promoting the proliferation of spleen lymphocytes and regulating organ index, so as to increase the weight and index of thymus and spleen induced by CY. ③ Antibody is a glycoprotein secreted by B cells after antigen stimulation and a series of proliferation and differentiation into plasma cells. Antibody production level is one of the main indicators of nonspecific immune function. PSP can not only improve the serum antibody level of mice by regulating the phagocytosis of mouse macrophages and the level of serum hemolysin, but also enhance the concentration of IL-2 secreted by spleen lymphocytes in vitro to increase the level of antibody response, and then improve the humoral immune function of the body. (3) Effect of PSP on cytokines. ① A large number of experiments have proved that PSP has a significant effect on promoting the production of interleukin (IL). PSP can combine with specific receptors on the surface of immune cells to activate various intracellular signal transduction pathways, enhance the secretion of cytokines such as IL-2, IL-4, IL-6 and IL-10 by spleen lymphocytes in vitro, make them directly kill target cells and regulate the immune function of the body at the molecular level. ② Interferon (IFN) is a special protein or glycoprotein produced by human or animal cells in response to various stimuli. It plays an important role in anti-virus, immune regulation and cell proliferation control. It was found that PSP could increase IFN-γsecreted by T cells and NK cells, activate macrophages to regulate immune function. ③ Tumor necrosis factor (TNF) is mainly produced by activated macrophages, NK cells and activated T cells. It is a cytokine with important biological activity in antitumor immune response.④ Tumor necrosis factor (TNF) is mainly produced by activated macrophages, NK cells and activated T cells. It is a cytokine with important biological activity in antitumor immune response. PSP can promote the proliferation and phagocytic activity of macro?phage RAW264.7 to reduce its apoptosis rate. By increasing the secretion of TNF-α, PSP can promote the dissociation between NF-κВprotein and IκВp65 protein after phosphorylation, so as to start the expression and transcription of related immune genes. In conclusion, PSP can improve immunity and has a good application prospect in the development of immunomodulatory drugs.