Immunomodulatory Effects of Konjac Polysaccharides and Locust Bean Gum in Cell Models
| Autor: | CHEN, WEI-LIN, 陳瑋琳 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Mannan, a main component of the polysaccharides of Amorphophallus konjac and locust bean gum (LBG), has long been considered non-toxic. Nonetheless, a variety of polysaccharides have been reported recently to have the ability to modulate the human immune responses. Therefore, the purpose of this study is to investigate the immunomodulatory effects of konjac polysaccharides and LBG on mouse macrophage RAW 264.7 and rat mast cell RBL-2H3. In this study, the enzymatic hydrolysates of konjac polysaccharides and LBG were prepared by using a thermostable mannanase. Konjac polysaccharides and LBG both enhance the proliferation of RAW 264.7 cells and stimulate the cells to produce tumor necrosis factor-alpa (TNF-α) but not nitric oxide. Both konjac polysaccharides and LBG decrease the release of nitric oxide from RAW 264.7 cells that have been co-stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN-γ). In fact, the effect on nitric oxide production varies, depending also on the way of pretreatment of RAW 264.7 cells. Konjac polysaccharides significantly inhibit the release of nitric oxide from LPS-stimulated RAW 264.7 cells. By contrast, LBG increases the release of nitric oxide from IFN-γ-stimulated RAW 264.7 cells. Besides, the konjac hydrolysates stimulate RAW 264.7 cells to secret TNF-α. LBG inhibits the LPS-treated RAW 264.7 cells to secrete TNF-α and interleukine-1 beta (IL-1β); however, no significant change in the cytokine production was observed when konjac polysaccharides, konjac hydrolysates, or LBG hydrolysates were used. In allergic activity assays, konjac polysaccharides, konjac hydrolysates and LBG hydrolysates reduce the secretion of β-hexosaminidase by RBL-2H3 cells; however, LBG exerts an opposite effect. In specific, 0.3% konjac polysaccharides can inhibit the histamine release from RBL-2H3 cells by 57%. Intracellular calcium ion concentrations were decreased to 25.7% and 22.1% by the addition of konjac hydrolysates and LBG hydrolysates, respectively, in the culture medium. Future application of konjac and LBG in the food and cosmetics industry should be noted that they may trigger an inflammation or allergic reaction. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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