痛泻要方对肝郁脾虚型D-IBS大鼠结肠组织p38 MAPK信号通路相关蛋白及其靶基因表达的影响

目的:探讨痛泻要方对肝郁脾虚型腹泻型肠易激综合征(D-IBS)大鼠模型结肠组织中p38丝裂原活化蛋白激酶(p38 MAPK),丝裂原和应激蛋白激酶1(MSK1),环磷腺苷效应元件结合蛋白(CREB)mRNA和蛋白表达,白细胞介素-1β(IL-1β),白细胞介素-6(IL-6),肿瘤坏死因子-α(TNF-α)含量的影响,以及血清总超氧化物歧化酶(T-SOD),丙二醛(MDA)含量的影响。方法:将60只SPF级Wistar大鼠随机分为6组,每组10只。除空白组外,其余各组大鼠用番泻叶灌胃联合慢性束缚应急法复建肝郁脾虚型D-IBS模型,连续14 d后开始给药。痛泻要方低、中、高剂量组(2.25,4.5,9 g·kg^-1)每日灌胃,匹维溴铵组(0.02 g·kg^-1)每日灌胃;空白组和模型组每日同体积生理盐水灌胃,共21 d,末次灌胃18 h后,心脏采血及剖取结肠组织,采用实时荧光定量聚合酶链式反应(Real-time PCR)检测各组大鼠结肠p38 MAPK,MSK1,CREB mRNA的表达,蛋白免疫印迹法(Western blot)检测大鼠p38 MAPK,MSK1,CREB蛋白的表达;采用酶联免疫吸附测定(ELISA)检测大鼠结肠IL-1β,IL-6和TNF-α的含量;羟胺法检测大鼠血清T-SOD水平;硫代巴比妥酸法(TBA)检测MDA的含量;苏木素-伊红(HE)染色观察结肠病理形态学改变。结果:与正常组比较,模型组大鼠结肠组织中p38 MAPK,MSK1,CREB mRNA表达及蛋白含量明显上升,同时IL-1β,IL-6,TNF-α含量明显升高(P<0.05);血清T-SOD水平明显下降,MDA含量明显升高(P<0.05);与模型组比较,痛泻要方中、高剂量组可明显降低结肠组织中p38 MAPK mRNA表达,p38 MAPK,CREB蛋白及IL-1β,IL-6,TNF-α的含量(P<0.05),升高血清SOD水平,降低MDA含量(P<0.05);痛泻要方高剂量组可明显减低MSK1,CREB mRNA表达及MSK1蛋白含量(P<0.05);病理组织学结果显示,各组大鼠结肠形态结构未见明显的器质性病变,符合IBS的形态学特点。结论:痛泻要方对肝郁脾虚型D-IBS大鼠的治疗在一定范围内呈明显的剂量效应关系,究其治疗作用可能与提高机体抗氧化应激效应和抑制p38 MAPK信号通路,调节其下游炎性因子的水平有关。

Effect of Tongxie Yaofang on p38 MAPK Pathway Associated Protein and Its Target Gene Expression in Colon Tissues of D-IBS Rats with Liver-stagnation and Spleen-deficiency

Objective:To explore the effect of Tongxie Yaofang on p38 mitogen activated protease(p38 MAPK),mitogen and stress protein kinase 1(MSK1),cyclic adenosine effector response element binding protein(CREB)mRNA and protein expression in colon tissue of diarrhea type irritable bowel syndrome(D-IBS)rat model with liver depression and spleen deficiency(GYPX),and interleukin-1β(IL-1β),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and the content of total superoxide dismutase(T-SOD)and malondialdehyde(MDA)in serum.Method:The 60 SPF Wistar rats were randomly divided into 6 groups,with 10 rats in each group.Except the normal group,rats in the other groups were given by gavage with folium sennae and chronic bondage to establish D-IBS with GYPX for 14 days.The low,medium,and high doses Tongxie Yaofang were administered to Tongxie Yaofang(2.25,4.5,9 g·kg^-1)gavage respectively.The piveronium bromide group was given piveronium bromide tablets suspension(0.02 g·kg^-1)gavage.The normal group group and model group were given the same volume normal saline for 21 days.After the last gavage for 18 hours,the heart blood was collected and the colon tissue was dissected.Real-time PCR was used to observe the expression of p38 MAPK,MSK1 and CREB mRNA in rat colon.Western blot was used to observe the expression of p38 MAPK,MSK1 and CREB protein.ELISA was used to observe the contents of IL-1β,IL-6 and TNF-αin colon.Hydroxylamine was used to observe the T-SOD level in serum,thiobarbituric acid(TBA)was used to observe the MDA content in serum.hematoxyl in-eosin(HE)staining was used to observe the morphological changes of colon tissues.Result:Compared with normal group,the expression of p38 MAPK,MSK1,CREB mRNA and the protein content of p38 MAPK,MSK1 and CREB in the colon tissue of model group rats increased significantly,while the content of IL-1β,IL-6 and TNF-αincreased significantly(P<0.05).The level of serum T-SOD decreased significantly,and the content of MDA increased significantly(P<0.05).Compared with the model group,the medium and high dose group of Tongxie Yaofang significantly decreased the expression of p38 MAPK mRNA,content of p38 MAPK,CREB protein and IL-1β,IL-6,TNF-αin colon tissue(P<0.05).The level of serum T-SOD increased significantly,and the content of MDA decreased significantly(P<0.05).High dose group of Tongxie Yaofang can significantly decreased the expression of MSK1,CREB mRNA,content of MSK1 protein(P<0.05).Histopathological observation showed that no significant organic lesions were observed in the colonic morphology of each group of rats,which was consistent with the morphological characteristics of IBS.Conclusion:Tongxie Yaofang has a significant dose-effect relationship in the treatment of D-IBS rats with GYPX in a certain range,which may be related to its increases antioxidant stress and inhibit activation of p38 MAPK signaling pathway and reducing the level of downstream inflammatory factors.