title: Eicosapentaenoic acid-enriched phosphatidylcholine isolated from Cucumaria frondosa exhibits anti-hyperglycemic effects via activating phosphoinositide 3-kinase/protein kinase B signal pathway.
abstract: Eicosapentaenoic acid-enriched phosphatidylcholine was isolated from the sea cucumber Cucumaria frondosa (Cucumaria-PC) and its effects on streptozotocin (STZ)-induced hyperglycemic rats were investigated. Male Sprague-Dawley rats were randomly divided into normal control, model control (STZ), low- and high-dose Cucumaria-PC groups (STZ + Cucumaria-PC at 25 and 75 mg/Kg·b·wt, intragastrically, respectively). Blood glucose, insulin, glycogen in liver and gastrocnemius were determined over 60 days. Insulin signaling in the rats' gastrocnemius was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. The results showed that Cucumaria-PC significantly decreased blood glucose level, increased insulin secretion and glycogen synthesis in diabetic rats. RT-PCR analysis revealed that Cucumaria-PC significantly promoted the expressions of glycometabolism-related genes of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phosphoinositide 3-kinase (PI3K), protein kinase B (PKB), and glucose transporter 4 (GLUT4) in gastrocnemius. Western blotting assay demonstrated that Cucumaria-PC remarkably enhanced the proteins abundance of IR-β, PI3K, PKB, GLUT4, as well as phosphorylation of Tyr-IR-β, p85-PI3K, Ser473-PKB (P < 0.05 and P < 0.01). These findings suggested that Cucumaria-PC exhibited significant anti-hyperglycemic activities through up-regulating PI3K/PKB signal pathway mediated by insulin. Nutritional supplementation with Cucumaria-PC, if validated for human studies, may offer an adjunctive therapy for diabetes mellitus.
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China.
authors.forename: Shiwei
authors.initials: S
authors.lastname: Hu
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Xu
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China.
authors.forename: Di
authors.initials: D
authors.lastname: Shi
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China. Electronic address: jfwang@ouc.edu.cn.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China.
authors.forename: Qiaoming
authors.initials: Q
authors.lastname: Lou
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No. 5, Yu Shan Road, Qingdao, Shandong Province 266003, China.
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D048016:Cucumaria / Q000737:chemistry*; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000188:drug therapy; D015118:Eicosapentaenoic Acid / Q000302:isolation & purification / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006003:Glycogen / Q000096:biosynthesis / Q000378:metabolism; D006943:Hyperglycemia / Q000139:chemically induced / Q000188:drug therapy*; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism; D055504:Insulin Receptor Substrate Proteins / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000096:biosynthesis / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011972:Receptor, Insulin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D007004:Hypoglycemic Agents; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; D010713:Phosphatidylcholines; D006003:Glycogen; D015118:Eicosapentaenoic Acid; D019869:Phosphatidylinositol 3-Kinases; D011972:Receptor, Insulin; D051057:Proto-Oncogene Proteins c-akt
keywords: Blood glucose; Cucumaria frondosa; Eicosapentaenoic acid-enriched phosphatidylcholine; Insulin; Phosphoinositide 3-kinase; Protein kinase B