Echinacoside regulates SIRT1/STAT3 signaling pathway to improve liver injury and glucose metabolism disorder in CLP rats / 中国医师杂志

ABSTRACT

Objective:To observe the therapeutic effect of echinacoside (ECH) on liver injury and glucose metabolism disorder in sepsis rats induced by cecal ligation and puncture (CLP), and to explore its possible mechanism.Methods:Forty eight male Sprague Dawley (SD) rats were randomly divided into four groups sham group (sham), model group (CLP), treatment group (CLP+ ECH) and inhibitor group (CLP+ ECH+ EX527). The sham group only received laparotomy, and the model group underwent CLP. The treatment group was intragastric administration of echinacea (30 mg/kg) every day after CLP modeling. The inhibitor group was injected with silence information regulator 1 (SIRT1) inhibitor EX527 (5 mg/kg) one hour before CLP, and then treated the same as the treatment group. Fasting blood glucose, insulin and serum biochemical indexes were detected in virous groups. The serum levels of interleukin (IL)-1 β, IL-6 and tumor necrosis factor-α(TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). 2′, 7′- dichlorofluorescein diacetate (DCFH-DA) staining was used to observe the production of reactive oxygen species (ROS) in liver tissue of rats in each group; hematoxylin-eosin (HE) staining was used to observe the pathological changes of liver tissue in each group; The expressions of SIRT1, glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), phosphorylated signal transducers and activators of transcription 3 (p-STAT3) and phosphorylated protein ki-nase B(p-AKT) were detected by Western blot.Results:Compared with sham group, the levels of serum glucose, serum insulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), ROS, IL-1β, IL-6 and TNF-α in model group increased, while the liver glycogen and survival rate decreased (all P<0.05). After echinacoside treatment, the serum glucose, serum insulin, ALT, AST, ROS , IL-1β, IL-6 and TNF-α levels decreased, and the liver glycogen and survival rate increased (all P<0.05); After SIRT1 inhibitor intervention, the levels of serum insulin, ALT, AST, IL-6 and ROS in the inhibitor group increased ( P<0.05). HE staining showed that there were infiltration and necrosis of inflammatory cells in the liver tissue of model group, and echinacoside could significantly reduce the focal and massive necrosis; Western blot showed that compared with the sham group, the expression levels of SIRT1, p-STAT3 and p-AKT protein in the model group decreased, while the expression levels of G6Pase and PEPCK protein increased ( P<0.05); After echinacoside treatment, the expression levels of SIRT1, p-STAT3 and p-AKT increased, while the expression levels of G6Pase and PEPCK decreased ( P<0.05). After SIRT1 inhibitor intervention, the expression of SIRT1, p-STAT3 and p-AKT protein decreased, and the expression of G6Pase and PEPCK protein increased in the inhibitor group ( P<0.05). Conclusions:Echinacoside is a potential therapeutic agent for sepsis associated liver injury and glucose metabolism disorders, which may play a role by targeting SIRT1 to activate STAT3 and AKT in the liver.