Clean-DM1, a Korean Polyherbal Formula, Improves High Fat Diet-Induced Diabetic Symptoms in Mice by Regulating IRS/PI3K/AKT and AMPK Expressions in Pancreas and Liver Tissues.

Abstract

To investigate the effects of Clean-DM1 (C-DM1), a polyherbal formulation of Radix Scrophulariae, Radix Astragali, Rhizoma Atractylodis, and Radix Salviae Miltiorrhizae, on high-fat diet (HFD)-induced diabetes mice. The information about active components of C-DM1 extract and molecular mechanism was obtained from network pharmacology analysis. Main compounds of C-DM1 extract by high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis were conducted for quality control. For in vivo study, mice were induced diabetes by HFD for 12 weeks. The mice in the normal group (Nor) were maintained with a regular diet and treated with saline by gavage. The HFD model mice were randomly divided into 3 groups, including a HFD diabetic model group, a C-DM1 extract-administered group (C-DM1, 500 mg/kg), and metformin-administered groups (Met, 500 mg/kg), 8 mice in each group. Food intake, body weight (BW), and fasting blood glucose (FBG) levels were recorded weekly for 4 weeks. After 4 weeks of treatment, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood glucose, low-density lipoprotein cholesterol (LDL-C) were determined using an automated clinical chemistry analyzer, and homeostatic model for assessing insulin resistance (HOMA-IR) levels and oral glucose tolerance test (OGTT) were detected. The histopathological changes of liver and pancreatic tissues were observed by hematoxylin-eosin staining. Insulin receptor substrate (IRS)/phosphatidylinositol 3 kinase (PI3K)/ protein kinase B (AKT) and adenosine 5'-monophosphate-activated protein kinase (AMPK) expressions in liver and pancreas tissues were detected by Western blot analysis. HPLC-MS identified dihydroisotanshinone, dihydroisotanshinone I, cryptotanshinone, harpagoside, and atractyloside A in C-DM1 extract. The administration of C-DM1 extract significantly decreased body weight, calorie intake, and the levels of blood glucose and insulin in the diabetic mice (P<0.05 or P<0.01). The C-DM1 extract administration improved the impaired glucose tolerance and insulin resistance in the diabetic mice and significantly decreased the levels of LDL-C, ALT and AST (P<0.01). The C-DM1 extract inhibited the histopathological changes of fatty liver and hyperplasia of pancreatic islets in the diabetic mice. The C-DM1 extract significantly increased the phosphorylation of IRS, AKT, and AMPK and the expression of PI3K in pancreas and liver tissues (P<0.05 or P<0.01), which was consistent with the analysis results of network pharmacology. C-DM1 extract improved diabetes symptoms in long-term HFD-induced mice by regulation of IRS/PI3K/AKT and AMPK expressions in pancreas and liver tissues, suggesting that C-DM1 formulation may help prevent the progression of T2DM.