基于Keap1/Nrf2信号通路的红芪多糖对糖尿病胃轻瘫大鼠氧化损伤的影响

Effects of Hedysarum Polybotrys Saccharide on Oxidative Damage in Diabetic Gastroparesis Rats Based on Keap1/Nrf2 Signaling Pathway

目的观察红芪多糖对糖尿病胃轻瘫大鼠氧化损伤的影响,初步探讨其作用机制。方法72只雄性Wistar大鼠随机分为空白组12只和造模组60只。采用链脲佐菌素注射联合高糖高脂饲料不规则喂养诱导糖尿病胃轻瘫大鼠模型。将成模大鼠随机分为模型组、阳性药组和红芪多糖高、中、低剂量组。阳性药组予枸橼酸莫沙必利溶液3.5 mg/kg灌胃,红芪多糖高、中、低剂量组予红芪多糖溶液0.12、0.06、0.03 g/kg灌胃,正常组和模型组予等体积纯净水灌胃,每日1次,连续8周。测定小肠组织肌电慢波频率、振幅,ELISA检测小肠组织活性氧(ROS)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)、8-羟基脱氧鸟苷酸(8-OHdG)水平,Western blot检测小肠组织Kelch样环氧氯丙烷相关蛋白-1(Keap1)、核因子E2相关因子(Nrf2)、血红素加氧酶-1(HO-1)、硫氧还蛋白(Trx)表达。结果与空白组比较,模型组大鼠小肠组织肌电慢波频率和振幅明显降低(P<0.01),小肠组织ROS、8-OHdG及MDA水平明显升高,SOD、GSH-Px水平明显降低(P<0.01),Keap1蛋白表达明显升高(P<0.01),Nrf2、HO-1、Trx蛋白表达明显降低(P<0.01);与模型组比较,阳性药组和红芪多糖高、中剂量组大鼠小肠组织肌电慢波频率和振幅明显升高(P<0.01),小肠组织ROS、8-OHdG及MDA水平明显降低,SOD、GSH-Px水平明显升高(P<0.05,P<0.01),Keap1蛋白表达明显降低,Nrf2、HO-1、Trx蛋白表达明显升高(P<0.05,P<0.01)。结论红芪多糖对链脲佐菌素联合高糖高脂不规则喂养诱导的糖尿病胃轻瘫大鼠氧化损伤具有保护作用,其作用机制可能与调控Keap1/Nrf2信号通路和抑制氧化应激有关。

Objective To observe the effects of hedysarum polybotrys saccharide(HPS) on the oxidative damage in rats with diabetic gastroparesis(DGP);To preliminarily explore its mechanism of action. Methods Totally 72 male Wistar rats were randomly divided into blank group(12 rats) and modeling group(60 rats). A rat model of DGP induced by streptozotocin injection combined with irregular feeding of high-sugar and high-fat diet. The modeling rats were randomly divided into model group, positive medicine group, and HPS high-, medium-, and low-dosage groups. The positive medicine group was given 3.5 mg/kg of mosapride citrate solution by gavage, HPS high-,medium-, and low-dosage groups were given 0.12, 0.06, and 0.03 g/kg of HPS solution by gavage, and the blank group and model group were given an equal volume of purified water by gavage, once a day, for 8 consecutive weeks.The frequency and amplitude of electromyogram slow wave in small intestine tissue were measured;the levels of reactive oxygen species(ROS), superoxide dismutase(SOD), glutathione peroxidase(GSH-Px), malondialdehyde(MDA), and 8-hydroxydeoxyguanylate(8-OHdG) in small intestine tissue were detected by ELISA;Western blot was used to detect the expressions of Kelch-like epichlorohydrin-related protein-1(Keap1), nuclear factor E2-related factor(Nrf2), heme oxygenase-1(HO-1) and thioredoxin(Trx) protein in small intestine tissue. Results Compared with the blank group, the frequency and amplitude of electromyogram slow wave in small intestine tissue of rats in the model group significantly decreased(P<0.01), the levels of ROS, 8-OHdG and MDA in the small intestine tissue increased significantly, the levels of SOD and GSH-Px decreased significantly(P<0.01), the expression of Keap1protein increased significantly(P<0.01), and the expression of Nrf2, HO-1, Trx protein decreased significantly(P<0.01). Compared with the model group, the frequency and amplitude of electromyogram slow wave in small intestine tissue of rats in the positive medicine group, HPS high-and medium-dosage groups significantly increased(P<0.01),the levels of ROS, 8-OHdG and MDA in small intestine tissue significantly decreased, the levels of SOD and GSH-Px significantly increased(P<0.05, P<0.01), the protein expression of Keap1 significantly decreased, and the proteins expression of Nrf2, HO-1 and Trx significantly increased(P<0.05, P<0.01). Conclusion HPS has a protective effect on the oxidative damage of diabetic gastroparesis induced by streptozotocin combined with highsugar and high-fat irregular feeding. Its mechanism may be related to the regulation of Keap1/Nrf2 signaling pathway and inhibition of oxidative stress.