ABSTRACT
ObjectiveTo explore the effect of Zishenwan on glucose and lipid metabolism in spontaneous type 2 diabetes （db/db） mice and investigate the underlying mechanism for improving diabetes based on intestinal barrier function and skeletal muscle transcriptome sequencing results. MethodLiquid chromatography-tandem mass spectrometry （LC-MS/MS） was used to analyze the components of Zishenwan. Sixteen 6-week-old db/db mice were divided into a model group and a Zishenwan group， while eight wild-type mice were assigned to the normal group. The Zishenwan group received oral administration of drugs for six weeks， during which fasting blood glucose， body weight， and food intake were measured. Serum total cholesterol （TC） and triglyceride （TG） levels were determined， and fasting insulin levels were measured to calculate the homeostatic model assessment of insulin resistance （HOMA-IR）. After the treatment， skeletal muscle and ileum tissues were collected， followed by hematoxylin-eosin （HE） staining. Immunohistochemistry was used to detect the expression of tight junction proteins occludin and zonula occludens-1 （ZO-1） in the ileum. Transcriptome sequencing was performed to detect the skeletal muscle transcriptome， and enrichment analysis was conducted for differentially expressed genes. ResultMultiple active components were identified in Zishenwan. Compared with the normal group， the model group showed increased fasting blood glucose， body weight， TC， TG， and HOMA-IR （P<0.01）. Compared with the model group， Zishenwan significantly reduced fasting blood glucose， body weight， TC， TG， and HOMA-IR in db/db mice （P<0.01）， while there was no statistically significant difference in food intake. Compared with the normal group， the model group exhibited lipid deposition in skeletal muscle， as well as structural changes in the ileum， with significant decreases in the protein expression levels of intestinal occludin and ZO-1 （P<0.01）. Compared with the model group， Zishenwan improved the pathological changes in skeletal muscle and ileum， and increased the protein expression of occludin and ZO-1 in the ileum （P<0.01）. Transcriptome analysis suggested that Zishenwan might improve skeletal muscle metabolism and increase insulin sensitivity in mice. ConclusionZishenwan can improve glucose and lipid metabolism in db/db mice， and this effect may be related to its protection of intestinal barrier function and transcriptional regulation of skeletal muscle metabolism-related genes.
ABSTRACT
OBJECTIVE: To observe the effects of the flower of Edgeworthia gardneri (Wall.) Meisn (EWM) on glucose and lipid metabolism in KK/upj-Ay/J (KKAy) mice and investigate the possible mechanism of EWM in the liver of KKAy mice by transcriptome analysis. METHODS: Forty KKAy mice were fed a high-sugar and high-fat diet for 3 weeks to establish the animal model of metabolic syndrome. After 5 weeks of continuous administration of EWM, serum high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), total cholesterol (TC), and free fatty acids (FFA) were detected by radioimmunoassay. Serum fasting insulin (Fins) and adiponectin levels were measured by enzyme-linked immunosorbent assay. Liver tissue fixed with paraformaldehyde was stained with hematoxylin-eosin and oil red O. Transcriptome analysis was used to evaluate the liver tissue. The expressions of lipoprotein lipase (LPL), peroxisome proliferator-activated receptor-γ (PPARγ), adenosine 5'-monophosphate-activated protein kinase (AMPK), sterol regulatory element binding protein-1c (SREBP-1c), and fatty acid synthase (Fas) mRNA and protein in liver tissue were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. RESULTS: EWM slightly reduced FBG and Fins in KKAy mice. Furthermore, EWM was able to downregulate serum LDL, TG, TC, and FFA and upregulate the expression of serum HDL and adiponectin. Transcriptome analysis revealed the following differential pathways: the peroxisome proliferator-activated receptor (PPAR) signaling pathway and the AMPK signaling pathway. RT-PCR and western blot analysis detected the associated genes and proteins. In addition, EWM was able to upregulate the expression of AMPK and downregulate the expression of PPARγ, SREBP1c, and Fas mRNA and protein and upregulate the expression of LPL mRNA. CONCLUSIONS: EWM can alleviate lipid metabolism disorders and to some extent improve glucose metabolism disorders in KKAy mice. These effects may be related to regulating PPARγ/LPL and activating the AMPK/SREBP1c/Fas pathway.
