ABSTRACT
Our previous studies have shown that puerarin, an active component of the traditional Chinese medicine-Pueraria Lobata, can improve glycometabolism in high-fat diet (HFD) mice with diabetes by activating the glucagon-like peptide-1 receptor (GLP-1R) pathway. This study intends to further evaluate the effect of puerarin on depressive symptoms in HFD mice. Long-term HFD induces type 2 diabetes and depressive-like symptoms in mice. Animal welfare and experimental procedures follow the regulations of the Animal Ethics Committee of the Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine (approval No. AEWC-025). The experiment was divided into: control group, model group, model/puerarin (150 mg·kg-1·day-1) group, and model/fluoxetine (15 mg·kg-1·day-1) group. The oral glucose tolerance test (OGTT) and behavioral experimental analysis were performed after 6 weeks of continuous administration. Afterwards, enzyme-linked immunosorbent assay (ELISA) was used to detect interleukin-1β (IL-1β), interleukin-6 (IL-6), 5-hydroxytryptamine (5-HT), and corticosterone (CORT) in serum of mice for each group. Western blot assays were used to detect the level of activation and expression of proteins related to neuroplasticity and depressive disorder in the hippocampus. Moreover, HT-22 cell line was used to investigate the protective effect of puerarin on cell morphology and survival. The results show that puerarin can effectively maintain the survival of HT22 in an environment with high glucose and corticosterone. Meantime, the glycemic regulation of diabetic mice was improved after treatment of puerarin, the depressive symptoms were alleviated, the 5-HT increased, and the corticosterone, IL-1β, and IL-6 decreased in the serum. The up-regulation of related proteins in GLP-1R/Wnt/mTOR (mammalian target of rapamycin) signaling in hippocampus suggests that its effect on ameliorating depression in diabetic mice may be related to the activation of GLP-1R/Wnt/mTOR signaling pathway. This study shows that puerarin can significantly ameliorate the depressive symptoms of HFD induced diabetic mice which might be achieved through activating the GLP-1R/Wnt/mTOR signaling pathway and improving hippocampal neuroplasticity.
ABSTRACT
Metabolomics based on liquid chromatography coupled with mass spectrometry (LC-MS) was used to study the initiation and development of diabetes in rats, and the ability of Ginkgo biloba extract (GBE) to ameliorate this pathology. Diabetes mellitus (DM) was induced by intra-peritoneal injection of streptozotocin. The rats were randomly divided into a normal control group treated with drug-free solution (NC), a normal control group treated with GBE (N-GBE), a DM group treated with drug-free solution (DM), and a DM group treated with GBE (D-GBE); rats were maintained on this protocol for 9 weeks. Rat plasma was collected from the sixth week to the ninth week and then analyzed with LC-MS. Animal experimentation was approved by the Committee on the Ethics of Animal Experiments of Xuzhou Medical University. Twelve plasma metabolites with continuous differentiation were monitored to indicate dysfunction of metabolic pathways including fatty acid metabolism, phospholipid metabolism, amino acid metabolism, tricarboxylic acid cycle activity, bile acid metabolism, and purine metabolism to confirm the occurrence and development of DM. Treatment with GBE partially reversed the changes seen in five metabolites in DM rats, indicating that GBE could prevent the occurrence and development of DM by acting on fatty acid metabolism, phospholipid metabolism, amino acid metabolism, and the tricarboxylic acid cycle.
ABSTRACT
Thiazolidinediones (TZDs) are currently the only recognized insulin sensitizers available for the clinical treatment of type 2 diabetes. Although their advantages are recognized, the profiles of numerous adverse effects hinder the continued use of these drugs. Peroxisome proliferator-activated receptor γ (PPARγ) is known as a receptor for TZDs, and its underlying mechanisms of pharmacological actions and adverse effects have been deeply explored. To maximally preserve the PPARγ-mediated insulin sensitizing effects and reduce the occurrence of related adverse effects, the concept of "selective PPARγ modulators (SPPARMs)" has been proposed and developed, guiding the development of new drugs. In this review, we summarize the recent research progress in the definition of SPPARMs, the candidate classification and the molecular underpinnings, as well as present the discovery of the YR series compounds as an example, and discuss the potential application prospects of SPPARMs.
ABSTRACT
Diabetes is characterized by hyperglycemia, resulting from insulin deficiency or resistance, or both. Insulin plays an irreplaceable role in the treatment of diabetes. Subcutaneous injection is the main route of insulin administration, but usually leads to poor compliance and many side effects. Oral insulin is safer and more convenient, which has always been the Holy Grail for people to explore. After oral administration, insulin is absorbed into the hepatic portal vein and transported to the liver, which can activate the normal physiological functions and reduce the risk of hypoglycemia, insulin resistance, and improve patient compliance. However, the gastrointestinal tract has multiple absorption barriers such as chemical barrier, enzyme barrier, and permeation barrier. Due to the physical and chemical properties of insulin, it is difficult to achieve desired oral bioavailability. This article reviews the recent attempts and progress in the field of oral administration of insulin driven by innovative drug delivery technologies and biomaterials, including structural modification, enzyme inhibitors, absorption enhancers, various nanoparticles, liposomes, microspheres, and even microorganisms. Some clinical researches on oral insulin are also introduced.
ABSTRACT
Seven main components in eleutheroside were used as research objects, and the mechanism of action of total eleutheroside for treatment of diabetes mellitus type 2 was investigated by network pharmacology. The SwissTargetPrediction, GeneCard, and String platforms were used to predict the 35 potential targets of these 7 components that are related to diabetes mellitus type 2. Then we used cytoscape 3.6.1 to build a "component-target" network map and used the Networkanalyzer tool for topology analysis. Gene ontology (GO) enrichment analysis and KEGG pathway enrichment analysis were performed on the DAVID6.8 platform, and the "component-target-path" network map was constructed based on the enrichment results. Those components mainly used in diabetes mellitus type 2 were screened as core components, and the core components were docked with key disease target proteins to verify the potential mechanism of the total eleutheroside. After screening, 8 important pathways associated with diabetes mellitus type 2 were identified. This study showed that eleutheroside A, eleutheroside D, eleutheroside E and sesamin played key roles in insulin resistance, apoptosis and inflammation pathways. The total eleutheroside may ameliorate type 2 diabetes mainly through regulating signal transducer and activator of transcription factors (STATs), non-receptor protein tyrosine phosphatase (PTPN) 1, PTPN2, c-Jun N-terminal kinase (JNK), and p38 mitogen activate protein kinase. These components worked together through multiple signaling pathway. Based on our data, eleutheroside is proposed as a novel therapeutic strategy for treatment of type 2 diabetes.