桔梗枳壳汤加味对反流性食管炎模型大鼠PI3K/Akt信号通路及胃肠动力的影响

Effect of Modified Jiegeng Zhike Decoction(桔梗枳壳汤加味)on PI3K/Akt Signal Pathway and Gastrointestinal Motility in Rats with Reflux Esophagitis

目的:探讨桔梗枳壳汤加味对反流性食管炎(RE)模型大鼠磷脂酰肌醇-3激酶(PI3K)/丝氨酸-苏氨酸蛋白激酶(Akt)信号通路及胃肠动力的影响。方法:SD大鼠随机分为假手术(Sham)组及造模大鼠,造模成功大鼠随机分为RE组(半幽门结扎术和贲门部分肌层切开术)、桔梗枳壳汤加味低剂量组(0.35 g/kg)、桔梗枳壳汤加味中剂量组(0.70 g/kg)、桔梗枳壳汤加味高剂量组(1.40 g/kg)、阳性组[莫沙必利(7.80 mg/kg)+埃索美拉唑(20.80mg/kg)],每组10只。Sham组和RE组每天灌胃给予生理盐水,其余各组均灌胃给予相应剂量药物,2次/d,共2周。苏木精-伊红染色(HE)法检测各组大鼠食管组织病理变化;蛋白免疫印迹法(Western blot)检测食管组织中PI3K/Akt通路蛋白表达情况;酶联免疫(ELISA)试剂盒检测大鼠食管组织血管生长因子(VEGF)及血清胃肠激素胃动素(MTL)、胃泌素(GAS)、胆囊收缩素(CCK)含量;葡聚糖蓝标记法检测胃排空率和小肠推进率。结果:与Sham组比较,RE组大鼠可见食管下段黏膜溃烂、炎性细胞浸润、基底层增厚等病理损伤,食管组织VEGF含量、p-PI3K/PI3K、p-Akt/Akt蛋白水平及血清CCK含量均明显升高(P<0.05),血清MTL含量、血清GAS含量、胃排空率、小肠推进率均明显下降(P<0.05)。与RE组比较,桔梗枳壳汤加味低、中、高剂量组及阳性组大鼠食管下段黏膜病理损伤减轻,食管组织VEGF含量、p-PI3K/PI3K、p-Akt/Akt蛋白水平及血清CCK含量均明显降低(P<0.05),血清MTL含量、血清GAS含量、胃排空率、小肠推进率均明显升高(P<0.05)。与梗枳壳汤加味低剂量组比较,桔梗枳壳汤加味中、高剂量组及阳性组大鼠食管下段黏膜病理损伤减轻,食管组织VEGF含量、p-PI3K/PI3K、p-Akt/Akt蛋白水平及血清CCK含量均明显降低(P<0.05),血清MTL含量、血清GAS含量、胃排空率、小肠推进率均明显升高(P<0.05)。结论:桔梗枳壳汤加味可能通过抑制PI3K/Akt信号通路激活、降低VEGF含量,调节胃肠激素,增强胃肠动力,从而改善RE所致食管病变。

Objective:To investigate the effects of modified Jiegeng Zhike decoction on phosphatidylinositol-3 kinase(PI3K)/serine-threonine protein kinase(Akt)signaling pathway and gastrointestinal motility in reflux esophagitis(RE)model rats.Methods:SD rats were randomly divided into sham operation group and model group.Rats with successful modeling were randomly divided into RE group(semi-pylorus ligation and partial myocardial incision of cardia),modified Jiegeng Zhike decoction low-dose group(0.35 g/kg),modified Jiegeng Zhike decoction medium-dose group(0.70 g/kg),modified Jiegeng Zhike decoction high-dose group(1.40 g/kg),positive group[mosapride(7.80 mg/kg)+esomeprazole(20.80 mg/kg)],with 20 mice in each group.Sham group and RE group were given saline by intragastric administration every day,and the other groups were given intragastric administration of the corresponding dosage twice a day for 2 weeks.Hematoxylin-eosin staining(HE)method was used to detect the pathological changes of esophageal tissues in various groups of rats.Western blotting was used to detect the expression of PI3K/Akt pathway protein in esophageal tissues.The levels of vascular endothelial growth factor(VEGF),serum gastrointestinal hormones motilin(MTL),gastrin(GAS)and cholecystokinin(CCK)in rat esophagus were detected by ELISA,and the gastric emptying rate and small intestine propulsion rate were detected by dextran blue labeling.Results:Compared with the Sham group,rats in the RE group showed pathological lesions such as lower esophageal mucosal ulceration,inflammatory cell infiltration,thickening of the basal layer,the levels of VEGF,p-PI3K/PI3K,p-Akt/Akt protein,and CCK in serum were increased significantly(P<0.05),and the contents of serum MTL,GAS,gastric emptying rate and small intestine propulsion rate decreased significantly(P<0.05).Compared with the RE group,the pathological damage of the lower esophageal mucosa was reduced in the modified Jiegeng Zhike decoction low,medium,high-dose and positive groups,the levels of VEGF,p-PI3K/PI3K,p-Akt/Akt protein,and CCK of serum in the esophageal tissue were reduced significantly(P<0.05),and the contents of serum MTL,GAS,gastric emptying rate and small intestine propulsion rate were increased significantly(P<0.05).Compared with the modified Jiegeng Zhike decoction low-dose group,the pathological damage of lower esophageal mucosa of rats in the modified Jiegeng Zhike decoction medium,high-dose and positive groups was reduced,the levels of VEGF,p-PI3K/PI3K,p-Akt/Akt protein,and CCK of serum in the esophageal tissue were reduced significantly(P<0.05),and the contents of serum MTL,GAS,gastric emptying rate and small intestine propulsion rate were increased significantly(P<0.05).Conclusions:The modified Jiegeng Zhike decoction may regulate gastrointestinal hormones and enhance gastrointestinal motility by inhibiting the activation of PI3K/Akt signal pathway and reducing the content of VEGF,so as to improve the esophageal lesions caused by RE.