Polysaccharides are a type of natural macromolecule widely existing in nature, and its pharmacological activity has attracted wide research attention. In this study, Brassica rapa L. polysaccharides were taken as the research object, and a preliminary study of the immune activity and mechanism of the antitumor activity of these polysaccharides in vitro was carried out. Five polysaccharides, namely, BRP, BRNP-1, BRNP-2, BRAP-1, and BRAP-2, were compared in terms of their ability to inhibit the growth of three types of cancer cells, namely, A549, AGS, and HepG2. The most effective polysaccharides were screened out, and their mechanism was studied. Immunoassay results showed that the five polysaccharides not only promoted the growth of RAW264.7 cells but also stimulated their endocytic/pinocytosis activity and released NO, TNF, IL-6 cytokines, especially BRP. In vitro antitumor experiments showed that BRP has a significant inhibitory effect (*P < 0.05) on the growth of A549 cells, especially at high concentrations (500-2000 μg/mL). BRP can also induce A549 cells to release reactive oxygen species, cause mitochondrial membrane potential, and effect the expression of Bax, caspase-9, caspase-3, p53, and B-cell lymphoma 2. Immunological experiments showed that the five groups of polysaccharides are not cytotoxic to normal cells and have immunostimulatory effects. Mitochondria represent one of the more important endogenous pathways in the apoptotic process. The results suggested that BRP participates in mitochondria -mediated apoptosis and induces A549 cell apoptosis. This study lays a theoretical foundation for further research on the mechanisms of BRP immunoregulation and antitumor activity in vitro and in vivo.

中文翻译：

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甘蓝型油菜多糖对RAW264.7巨噬细胞和肿瘤细胞的生物活性。

多糖是自然界中广泛存在的一种天然大分子，其药理活性引起了广泛的研究关注。本研究以甘蓝型油菜多糖为研究对象，并对这些多糖的体外免疫活性和抗肿瘤活性机理进行了初步研究。比较了五种多糖，即BRP，BRNP-1，BRNP-2，BRAP-1和BRAP-2，它们具有抑制三种癌细胞A549，AGS和HepG2生长的能力。 。筛选出最有效的多糖，并研究其机理。免疫测定结果表明，这5种多糖不仅促进RAW264.7细胞的生长，而且还刺激其内吞/胞饮活性，并释放NO，TNF，IL-6细胞因子。特别是BRP。体外抗肿瘤实验表明，BRP对A549细胞的生长具有明显的抑制作用（* P <0.05），尤其是在高浓度（500-2000μg/ mL）时。BRP还可以诱导A549细胞释放活性氧，引起线粒体膜电位，并影响Bax，caspase-9，caspase-3，p53和B细胞淋巴瘤2的表达。免疫学实验表明，这五组多糖对正常细胞无细胞毒性，并具有免疫刺激作用。线粒体代表凋亡过程中更重要的内源性途径之一。结果提示BRP参与线粒体介导的细胞凋亡并诱导A549细胞凋亡。