title: Anti-diabetic effect of mulberry leaf polysaccharide by inhibiting pancreatic islet cell apoptosis and ameliorating insulin secretory capacity in diabetic rats.
abstract: Diabetes mellitus is a clinically complex disease characterized by chronic hyperglycemia with metabolic disturbances. In this study, we investigated the effect of mulberry leaf polysaccharide (MLPII) on pancreatic islet cell apoptosis and insulin secretory function in diabetic rats induced by a high fat diet and streptozotocin. Our results showed that MLPII treatment inhibited pancreatic islet cell apoptosis and ameliorated insulin secretory capacity of pancreatic β-cells in diabetic rats. And further study demonstrated that chronic treatment of diabetic rats with MLPII resulted in up-regulation of anti-apoptotic B-cell leukaemia/lymphoma 2 (Bcl-2) protein and down-regulation of pro-apoptotic Bcl2-associated X (Bax) and caspase-3 protein in pancreatic islet cells. Moreover, MLPII significantly restored pancreatic duodenal homeobox-1 (PDX-1) protein nuclear localization, and increased mRNA and protein expression of PDX-1 and its downstream targets, glucose transporter 2 (GLUT2) and glucokinase (GCK) in pancreatic islet cells of diabetic rats. These findings suggested that MLPII might play a critical role in protecting pancreatic islet cell from apoptosis via elevation of Bcl-2/Bax ratio, and ameliorating insulin secretory capacity of pancreatic β-cells via restoration of PDX-1 nuclear localization and expression levels in diabetic rats. This is the first report to explore the potential molecular mechanism involved in the hypoglycemic activity of the polysaccharide from mulberry leaves.
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China; College of Life Science, Shandong Agricultural University, Taian 271018, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China.
authors.forename: Chunjiu
authors.initials: C
authors.lastname: Ren
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China.
authors.forename: Guobing
authors.initials: G
authors.lastname: Lu
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China. Electronic address: lz20011022@126.com.
authors.forename: Zhimei
authors.initials: Z
authors.lastname: Mu
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China. Electronic address: wzcui88@163.com.
authors.forename: Weizheng
authors.initials: W
authors.lastname: Cui
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China.
authors.forename: Huiju
authors.initials: H
authors.lastname: Gao
authors.affiliation: College of Forestry, Shandong Agricultural University Taian 271018, China.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Wang
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000188:drug therapy* / Q000378:metabolism; D059305:Diet, High-Fat; D005941:Glucokinase / Q000378:metabolism; D051273:Glucose Transporter Type 2 / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000502:physiology; D008297:Male; D031625:Morus / Q000276:immunology*; D018515:Plant Leaves; D011134:Polysaccharides / Q000627:therapeutic use*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000008:administration & dosage; D015534:Trans-Activators / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D051273:Glucose Transporter Type 2; D018398:Homeodomain Proteins; D007004:Hypoglycemic Agents; D007328:Insulin; D011134:Polysaccharides; D019253:Proto-Oncogene Proteins c-bcl-2; D015534:Trans-Activators; D051028:bcl-2-Associated X Protein; C084010:pancreatic and duodenal homeobox 1 protein; D013311:Streptozocin; D005941:Glucokinase
keywords: Apoptosis; Diabetes; Insulin secretion; Mulberry leaf polysaccharide