芜菁中性多糖对A549荷瘤小鼠免疫功能的影响

Effects of neutral polysaccharide from Brassica rapa L.on immune function of A549 tumor-bearing mice

目的探究芜菁中性多糖对A549小鼠移植瘤模型肿瘤微环境及凋亡相关蛋白、细胞因子水平的影响。方法实验采用酶联免疫法、HE染色法、免疫组化法,检测半胱氨酸天冬氨酸蛋白酶3(cysteinyl aspartate specific proteinase 3,caspase-3)、白细胞介素2(interleukin-2,IL-2)、白细胞介素6(interleukin-6,IL-6)、白细胞介素12(interleukin-12,IL-12)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)含量及B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)相对表达水平,计算免疫器官指数、抑瘤率。结果芜菁中性多糖中、高剂量组能使A549荷瘤小鼠肿瘤组织caspase-3蛋白含量显著增加(P<0.01);使小鼠血清中IL-2、IL-6、IL-12、TNF-α含量升高(P<0.01);Bcl-2蛋白表达水平降低,Bax蛋白表达水平升高(P<0.01)。结论芜菁中性多糖对人肺腺癌细胞A549生长具有抑制作用,可提高A549荷瘤小鼠的脾脏指数和胸腺指数,下调Bcl-2蛋白,上调Bax蛋白的表达,减轻荷瘤小鼠脏器病理损伤。

Objective To study the effects of Brassica rapa L.neutral polysaccharide on apoptosis-related polypeptide and cytokines of transplanted mice model of A549 carcinoma in vitro.Methods Enzyme-linked immunosorbent assay,HE staining and immunohistochemistry were used to detect cysteinyl aspartate specific proteinase 3(caspase-3),interleukin-2(IL-2),interleukin-6(IL-6),interleukin-12(IL-12),and tumor necrosis factor-α(TNF-α)content and B-cell lymphoma-2(Bcl-2),the relative expression level of Bcl-2 associated X protein(Bax),and the immune organ index and tumor inhibition rate were calculated.Results The moderate and high dose groups of Brassica rapa L.neutral polysaccharide could significantly increase the caspase-3 protein content in A549 tumor-bearing mice(P<0.01).The content of IL-2,IL-6,IL-12 and TNF-αin serum of mice were increased(P<0.01).The expression level of Bcl-2 protein was decreased,while that of Bax protein was increased(P<0.01).Conclusion Brassica rapa L.neutral polysaccharides can inhibit growth of A549 human lung adenocarcinoma cells,increase the spleen index and thymus index of A549 tumor-bearing mice,increase the expression of Bax protein through downregulation of Bcl-2 protein,and reduce the pathological damage in tumor-bearing mice.