原花青素对幽门螺杆菌所致小鼠胃黏膜损伤的作用及机制

Effect and mechanism of Proanthocyanidins on Helicobacter pylori-induced gastric mucosal injury in mice

背景原花青素(proanthocyanidins,PAs)可改善乙醇诱导的胃溃疡,而目前尚不清楚其能否在幽门螺杆菌(Helicobacter pylori,H.pylori)感染所致的胃黏膜损伤发挥修复作用.目的探讨PAs对H.pylori所致小鼠胃黏膜损伤的保护作用及作用机制.方法选取SPF级雄性C57BL/6小鼠43只,随机分为对照组、模型组、及低、中、高剂量PAs干预组(PAs-L、PAs-M、PAs-H).通过灌胃法定植H.pylori构建小鼠胃炎模型,并灌胃给予PAs干预4 wk.快速尿素酶试验及Warthin-Starry染色法评估H.pylori感染情况,HE染色观察小鼠胃黏膜组织的病理学表现,试剂盒测定小鼠胃黏膜组织氧化应激水平及血清中炎症因子[肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白介素(interleukin,IL)-1β,IL-8]的水平,TUNEL染色检测黏膜上皮细胞凋亡,Western blot检测胃黏膜组织中B细胞淋巴瘤-2(B cell lymphoma-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 assaciated X protein,Bax)及裂解的半胱氨酸蛋白酶3(cleaved cysteine protease 3,cleaved-caspase 3)的表达.结果H.pylori定植感染可致小鼠胃黏膜出现损伤,表现为黏膜明显的出血点、糜烂及溃疡面,同时腺体数量减少,排列紊乱,有明显的炎性浸润;PAs干预可显著改善H.pylori所致的胃黏膜损伤.与模型组相比,PAs干预组小鼠血清中的TNF-α、IL-1β和IL-8水平以及胃黏膜组织中的氧化应激水平、胃黏膜细胞凋亡、Bax和cleaved-caspase3的表达均显著降低,而Bcl-2的表达明显增加,并且这种变化呈现出剂量依赖性.结论PAs可改善H.pylori感染所致的胃黏膜损伤,机制可能与其降低H.pylori感染所致的胃黏膜氧化应激和炎症反应并调控凋亡相关蛋白的表达抑制胃黏膜细胞凋亡有关.

BACKGROUND Proanthidins(PAs)have been shown to ameliorate ethanol-induced gastric ulcers;however,their potential for repairing gastric mucosal injury caused by Helicobacter pylori(H.pylori)infection remains uncertain.AIM To investigate the protective effect and mechanism of PAs on H.pylori-induced gastric mucosal injury in mice.METHODS Forty-three specific pathogen-free male C57BL/6 mice were randomly divided into control group,model group,and low,medium,and high dose PAs intervention groups(PAS-L,PAS-M,and PAS-H,respectively).A mouse model of gastritis was constructed by orally administering H.pylori,and then the mice received gavage of PAs for 4 wk.The rapid urease test and Warthin-Starry staining were used to assess H.pylori infection,and the pathological changes in mouse gastric mucosa tissue were observed after hematoxylin-eosin staining.The oxidative stress level in mouse gastric mucosal tissue and the levels of inflammatory factors[tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,and IL-8]in serum were measured with commercial kits.TUNEL staining was employed to evaluate the apoptosis of mucosal epithelial cells,and Western blot was used to detect the expression of B cell lymphoma-2(Bcl-2),Bcl-2 assaciated X protein(Bax),and cleaved cysteine protease 3(cleaved-caspase3)in gastric mucosal tissue.RESULTS H.pylori infection caused damage to the gastric mucosa of mice,characterized by obvious bleeding points,erosion and ulceration,decrease in glandular quantity,disordered glandular arrangement,and obvious inflammatory infil-tration.Compared to the model group,the PAs intervention groups exhibited a significant dose-dependent decrease in serum levels of TNF-α,IL-1β,and IL-8.Additionally,there was a notable reduction in oxidative stress levels in the gastric mucosa,apoptosis of gastric mucosa cells,as well as expression of Bax and cleaved-caspase3.Conversely,the expression of Bcl-2 showed a significant increase after treatment with PAs.CONCLUSION PAs can improve gastric mucosal injury caused by H.pylori infection,and its mechanism may be related to reducing oxidative stress and inflammatory response of the gastric mucosa caused by H.pylori infection and regulating the expression of apoptosis-related proteins to inhibit gastric mucosal cell apoptosis.