1. Eugenosedin-A improves glucose metabolism and inhibits MAPKs expression in streptozotocin/nicotinamide-induced diabetic rats
- Author
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Li-Mei An, Su-Ling Hsieh, Kuo-Ping Shen, Hsueh-Wei Yen, Bin-Nan Wu, and Hui-Li Lin
- Subjects
Blood Glucose ,Male ,0301 basic medicine ,Type II diabetes mellitus ,endocrine system diseases ,medicine.medical_treatment ,Piperazines ,MAPKs pathway ,Rats, Sprague-Dawley ,0302 clinical medicine ,Glucokinase ,Insulin ,Glucose metabolism ,lcsh:R5-920 ,Glucose Transporter Type 4 ,biology ,Kinase ,General Medicine ,Eugenosedin-A ,Liver ,Mitogen-Activated Protein Kinases ,lcsh:Medicine (General) ,Signal Transduction ,medicine.drug ,Niacinamide ,medicine.medical_specialty ,030209 endocrinology & metabolism ,Carbohydrate metabolism ,Diet, High-Fat ,Streptozocin ,Diabetes Mellitus, Experimental ,03 medical and health sciences ,Internal medicine ,medicine ,Animals ,Hypoglycemic Agents ,Muscle, Skeletal ,Protein kinase A ,business.industry ,Glycogen Synthase Kinases ,Transcription Factor RelA ,nutritional and metabolic diseases ,AMPK ,Streptozotocin ,Receptor, Insulin ,Rats ,PPAR gamma ,Insulin receptor ,030104 developmental biology ,Endocrinology ,Gene Expression Regulation ,Hyperglycemia ,Insulin Receptor Substrate Proteins ,biology.protein ,business - Abstract
This study examined the effects of eugenosedin-A (Eu-A) in a streptozotocin (STZ)/nicotinamide-induced rat model of type II diabetes mellitus (T2DM). Six-week-old Sprague–Dawley rats were randomly divided into three groups: (1) RD group, normal rats fed a regular diet (RD), (2) DM group, T2DM rats fed a high-fat diet, and (3) Eu-A group, T2DM rats fed a high fat diet plus oral Eu-A (5 mg/kg/day). After 30 days, the DM group had higher body weight, higher blood glucose and lower insulin levels than the RD group. The DM group also had increased protein expression of glycogen synthase kinase (GSK) in liver and skeletal muscle and decreased protein expression of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), IRS-2, AMP-activated protein kinase (AMPK), glucose transporter-4 (GLUT-4), glucokinase (GCK), and peroxisome proliferator-activated receptor γ (PPAR-γ). STZ/nicotinamide-induced T2DM increased the expression of mitogen-activated protein kinases (MAPKs: p38, ERK, JNK) and inflammatory p65 protein. In the Eu-A treated T2DM rats, however, blood glucose was attenuated and the insulin concentration stimulated. Changes in IR, IRS-1 and IRS-2 proteins as well as AMPK, GLUT-4, GCK, GSK, PPAR-γ, MAPKs, and inflammatory p65 proteins were ameliorated. These results suggested that Eu-A alleviates STZ/nicotinamide-induced hyperglycemia by improving insulin levels and glucose metabolism, and inhibiting the MAPKs- and p65-mediated inflammatory pathway.
- Published
- 2018