本研究旨在探讨合欢草皂苷对乙醇致大鼠急性胃溃疡的保护作用及其机制。SD大鼠在实验前24小时被剥夺水。对照组和模型组给予灌胃水,阳性药物组给予雷贝拉唑钠溶液(40mg·kg~(-1))灌胃。实验组给予不同剂量的合欢草皂苷溶液(3、10、30mg·kg~(-1))。30分钟后,对照组灌胃1.5mL水,而其他组给予等体积的95%乙醇进行建模。六个小时后,老鼠被颈椎脱位杀死,收集了胃。测量溃疡面积,计算溃疡指数。进行苏木精-伊红(HE)染色以评估胃组织的组织病理学变化。采用周期性酸性希夫(PAS)染色评价胃粘膜表面粘液的分布。采用酶联免疫吸附测定(ELISA)来测量胃粘膜中磷脂和氨基己糖的水平。进行蛋白质印迹以确定碳酸氢盐转运蛋白的表达水平,基质金属蛋白酶,和胃组织中的紧密连接相关蛋白。进行免疫组织化学(IHC)染色以定量分泌的粘蛋白和紧密连接相关蛋白的阳性细胞的数量。结果表明,对照组大鼠胃组织表面光滑,无溃疡,模型组大鼠胃溃疡指数为35±11。3、10和30mg·kg〜(-1)的合欢草皂苷对胃溃疡的抑制率为46%(P&lt;0.01),85%(P<0.001),和100%(P<0.001),分别。模型组胃粘膜结构严重破坏,粘液层缺失。与模型组相比,合欢草皂苷组显示完整的胃粘膜表面粘液层,粘液中磷脂和氨基己糖的含量显着增加,MUC5AC阳性细胞数增加,并上调碳酸氢盐转运蛋白SLC26A3和CFTR的表达水平。它还显示JNK和c-Jun的磷酸化降低,MMP-8的表达水平降低,TIMP-1的表达升高,Occludin和ZO-1的表达水平升高。总之,合欢草皂苷通过上调MUC5AC的含量来增强粘液-碳酸氢盐屏障的功能,磷脂,和氨基己糖并增加碳酸氢盐转运蛋白SLC26A3和CFTR的表达水平。此外,合欢草皂苷通过抑制JNK信号通路,防止MMP-8的过度活化,从而减少Occludin和ZO-1的降解,增强黏膜屏障功能,发挥其对胃溃疡的保护作用。总之,合欢草皂苷通过同时增强粘液屏障和粘膜屏障发挥其抗胃溃疡作用。
This study aims to explore the protective effect of Albizia chinensis saponin on ethanol-induced acute gastric ulcer in rats and elucidate its mechanisms. SD rats were deprived of water for 24 hours before the experiment. The control group and model group were administered water by gavage, and the positive drug group received rabeprazole sodium solution(40 mg·kg~(-1)) by gavage. The experimental groups were given different doses of Albizia chinensis saponin solution(3, 10, and 30 mg·kg~(-1)). After 30 minutes, the control group received 1.5 mL of water by gavage, while the other groups were administered an equal volume of 95% ethanol for modeling. After six hours, the rats were killed by cervical dislocation, and the stomachs were collected. The ulcer area was measured, and the ulcer index was calculated. Hematoxylin-eosin(HE) staining was performed to assess histopathological changes in gastric tissue. Periodic acid-Schiff(PAS) staining was used to evaluate the distribution of gastric mucosal surface mucus. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of phospholipids and aminohexose in the gastric mucosa. Western blot was performed to determine the expression levels of the bicarbonate transporter, matrix metalloproteinase, and tight junction-associated proteins in gastric tissue. Immunohistochemistry(IHC) staining was conducted to quantify the number of positive cells for secreted mucin and tight junction-associated proteins. The results showed that the gastric tissue surface of rats in the control group was smooth without ulceration, and the gastric ulcer index of rats in the model group was 35±11. Albizia chinensis saponin at doses of 3, 10, and 30 mg·kg~(-1) resulted in inhibition rates of gastric ulcer of 46%(P<0.01), 85%(P<0.001), and 100%(P<0.001), respectively. Severe disruption of gastric mucosal structure and absence of the mucus layer were observed in the model group. Compared with the model group, the Albizia chinensis saponin group showed intact gastric mucosal surface mucus layer, significantly increased levels of phospholipids and aminohexose in the mucus, increased number of MUC5AC positive cells, and upregulated expression levels of the bicarbonate transporter SLC26A3 and CFTR. It also showed decreased phosphorylation of JNK and c-Jun, reduced expression levels of MMP-8, elevated expression of TIMP-1, and increased expression levels of Occludin and ZO-1. In conclusion, Albizia chinensis saponin enhances the function of the mucus-bicarbonate barrier by upregulating the content of MUC5AC, phospholipids, and aminohexose and increasing the expression levels of the bicarbonate transporter SLC26A3 and CFTR. Moreover, Albizia chinensis saponin exerts its protective effects on gastric ulcers by inhibiting the JNK signaling pathway to prevent excessive activation of MMP-8, thereby reducing the degradation of Occludin and ZO-1 and enhancing the mucosal barrier function. In summary, Albizia chinensis saponin exerts its anti-gastric ulcer effects by simultaneously enhancing the mucus barrier and the mucosal barrier.