青钱柳叶对2型糖尿病大鼠骨骼肌炎症反应、胰岛素通路蛋白及糖原合成的影响

Influence of Qingqianliuye(leaf of Cyclocarya paliurus ) on skeletal muscle inflammatory response,insulin pathway proteins and glycogen synthesis in T2DM rats

目的研究青钱柳叶水提物对2型糖尿病(T2DM)大鼠骨骼肌炎症反应、胰岛素通路蛋白及糖原合成的影响。方法高脂饲料喂养8周加单次腹腔注射小剂量链脲佐菌素(30 mg/kg)建立T2DM大鼠模型,将成模大鼠随机分为模型组,二甲双胍组,青钱柳叶水提物低、中、高剂量组,每组10只;正常组和模型组给予0. 9%氯化钠溶液,二甲双胍组给予二甲双胍混悬液(0. 3 g/kg),青钱柳叶水提物低、中、高剂量组分别给予青钱柳叶水提物(0. 25、0. 5、1 g/kg),连续给药4周。处死大鼠,骨骼肌匀浆比色法检测游离脂肪酸(FFA)、糖原;放射性免疫法检测肿瘤坏死因子α(TNF-α)、白介素6(IL-6),白介素1β(IL-1β);酶联免疫吸附法检测IκB激酶(IKK)、核转录因子κB(NF-κB)、c-Jun氨基端激酶1(JNK1)、胰岛素受体底物1(IRS1)、磷酸化胰岛素受体底物1(P-IRS1)、磷脂酰肌醇3激酶(PI3K)、葡萄糖转运蛋白4(GLUT4)、糖原合成酶(GS)含量。结果与模型组比较,青钱柳叶水提物低、中、高剂量组FFA、TNF-α、IL-6、IL-1β显著降低(P <0. 05,P <0. 01);炎症通路蛋白IKK、NF-κB、JNK1含量显著降低(P <0. 05,P <0. 01); IRS1、P-IRS1、PI3K、GLUT4、GS的蛋白表达量和糖原含量显著提高(P <0. 05,P <0. 01)。结论青钱柳叶水提物提高T2DM大鼠骨骼肌中胰岛素通路及糖原合成蛋白的含量,增加肌糖原的合成,其机制可能与青钱柳叶水提物可降低骨骼肌中促炎症因子的含量、抑制炎症通路蛋白的表达、缓解代谢性炎症反应有关。

Objective To study the influence of Qingqianliuye( leaf of Cyclocarya paliurus) aqueous extract( CPAE) on skeletal muscle inflammatory response,insulin pathway proteins and glycogen synthesis in rats with type 2 diabetes mellitus( T2 DM). Methods T2 DM rat model was established by high-fat diet for 8 weeks and intraperitoneal injection of low-dose STZ( 30 mg/kg). The control rats were included into normal group,and modeled rats were divided into model group,metformin group,lowdose,mid-dose and high-dose CPAE groups. The normal group and model group were given 0. 9% NaCI solution,metformin group was given metformin suspension( 0. 3 g/kg),and CPAE groups were given,respectively,CPAE( 0. 25 g/kg,0. 5 g/kg and 1 g/kg) for 4 weeks. After executed rats,the levels of free fatty acid( FFA) and glycogen in skeletal muscle homogenate were detected by using chromatoptometry. The levels of tumor necrosis factor-α( TNF-α), interleukin-6( IL-6) and interleukin-1β( IL-1β) were detected by using radioimmunoassay( RIA). The content of IκB kinase( IKK),nuclear factor-κB( NF-κB),c-Jun N-terminal kinase 1( c-JNK1),insulin receptor substrate 1( IRS1),phosphorylated insulin receptor substrate 1( P-IRS1),phosphatidylinositol 3-kinase( PI3 K),glucose transporter 4( GLUT4) and glycogen synthase( GS) were detected by using ELISA. Results Compared with model group,the levels of FFA,TNF-α,IL-6 and IL-1β decreased significantly in all CPAE groups( P < 0. 05,P < 0. 01). The content of IKK,NF-κB and JNK1 proteins of inflammatory pathway decreased significantly in all CPAE groups( P < 0. 05,P < 0. 01). The protein expressions of IRS1,P-IRS1,PI3 K,GLUT4 and GS,and glycogen content increased significantly in all CPAE groups( P < 0. 05,P < 0. 01). Conclusion CPAE raises the content of skeletal muscle insulin pathway proteins and glycogen synthesis protein,inhibits expressions of inflammatory pathway proteins,and improves glycogen synthesis in T2 DM rats. The mechanism may be related to that CPAE can reduce content of skeletal muscle pro-inflammatory factors,inhibit expressions of inflammatory pathway proteins,and relieve metabolic inflammatory response.