目的 通过幽门螺杆菌(Hp)感染小鼠建立Hp相关胃炎模型,探讨猪苓多糖的保护作用及机制。方法 将C57BL/6小鼠随机分为4组:对照组、模型组、猪苓多糖(250 mg·kg^-1)组、核转录因子-κB (NF-κB)通路的抑制剂——吡咯烷二硫代甲酸铵(PDTC,阳性对照,100 mg·kg^-1)组。除对照组外,其余各组小鼠ig给予Hp悉尼株1(SS1)菌液(1×10⁹ CFU·mL^-1),第1天每只0.4 mL,以后连续3 d每天ig 1次,每次0.2 mL。ig Hp完成4周后,猪苓多糖组和PDTC组给予相应剂量的药物,对照组和模型组小鼠给予无菌水,每只0.4 mL,每天1次持续14 d。将胃取出,沿胃大弯切开,肉眼观察胃黏膜变化;吉姆萨染色验证Hp在小鼠胃黏膜的定植;HE染色观察小鼠胃黏膜组织的炎症浸润状态;免疫组化检测核因子-κB(NF-κB) p65的表达;Western blotting法检测小鼠胃腺组织炎症因子白细胞介素-8(IL-8)蛋白表达;酶联免疫吸附法(ELISA)检测小鼠血清中IL-8的表达。结果 与模型组比较,猪苓多糖组小鼠胃黏膜褶皱整齐,出血点消失,黏膜光滑,胃黏膜颜色红润有光泽;炎症细胞浸润和其他组织损伤明显减少;细菌定植数量明显减少;胃上皮细胞中NF-κB p65的表达减弱;胃腺组织IL-8蛋白表达水平显著降低(P<0.001);小鼠血清中IL-8表达水平显著降低(P<0.001)。结论 猪苓多糖可能通过抑制炎症信号通路NF-κB相关分子的表达在Hp相关胃炎中发挥保护作用。

Objective To investigate the protective effect and preliminary mechanism of Polyporus polysaccharide (PPS) in Helicobacter pylori (Hp)-associated gastritis by simulating Hp infection in gastric mucosal epithelium in vitro. Methods C57BL/6 mice were randomly divided into four groups:control group, model group, PPS (250 mg·kg^-1) group, and positive control group:pyrrolidinedithiocarbamate ammonium (PDTC, 100 mg·kg^-1, the inhibitor of NF- κB pathway). Except for control group, other groups were ig given SS1 solution (1×10⁹ CFU·mL^-1), 0.4 mL for the first day, and 0.2 mL for each time, once a day for consecutive 3 days. Four weeks after ig Hp, PPS group and PDTC group were given corresponding doses of drugs, control group and model group mice given a sterile water, each only 0.4 mL, once a day for 14 d. The stomach was removed, cut along the greater curvature of the stomach, and the changes of gastric mucosa were observed by naked eye. After successful modeling, the gastric mucosa tissues of mice were collected and HE staining was performed to observe the inflammatory infiltration status of gastric mucosa tissues of mice. The colonization of Hp in gastric mucosa of mice was verified by Giemsa staining. The expression of NF-κB was detected by immunohistochemistry (IHC). The expression of inflammatory factor interleukin-8 (IL-8) protein in gastric glands of mice was detected by Western blotting. At the same time, Elisa was used to detect the expression of IL-8 in serum of mice. Results Compared with model group, the gastric mucosa of PPS group was folded neatly, hemorrhagic points disappeared, the gastric mucosa was smooth, and the gastric mucosa was ruddy and shiny. Inflammatory cells infiltration and other tissue damage of PPS group decreased significantly compared with model group. The number of bacterial colonization of PPS group decreased significantly compared with model group. The expression of NF- κB p65 of PPS group was decreased in gastric epithelial cells compared with model group. The expression level of IL-8 protein in gastric glandular tissue of PPS group was significantly decreased compared with model group (P<0.001). Serum IL-8 expression was significantly decreased of PPS group in mice compared with model group (P<0.001). Conclusion PPS may inhibit the expression of inflammatory signal pathway NF-κBrelated molecules plays a protective role in Hp related gastritis.

R285.5

国家自然科学基金项目(81971533);江苏省中医药局科技项目(YB2015166)