title: Pterostilbene improves glycaemic control in rats fed an obesogenic diet: involvement of skeletal muscle and liver.
abstract: This study aims to determine whether pterostilbene improves glycaemic control in rats showing insulin resistance induced by an obesogenic diet. Rats were divided into 3 groups: the control group and two groups treated with either 15 mg kg(-1) d(-1) (PT15) or 30 mg kg(-1) d(-1) of pterostilbene (PT30). HOMA-IR was decreased in both pterostilbene-treated groups, but this reduction was greater in the PT15 group (-45% and -22% respectively vs. the control group). The improvement of glycaemic control was not due to a delipidating effect of pterostilbene on skeletal muscle. In contrast, GLUT4 protein expression was increased (+58% and +52% vs. the control group), suggesting an improved glucose uptake. The phosphorylated-Akt/total Akt ratio was significantly enhanced in the PT30 group (+25%), and therefore a more efficient translocation of GLUT4 is likely. Additionally, in this group the amount of cardiotrophin-1 was significantly increased (+65%). These data suggest that the effect of pterostilbene on Akt is mediated by this cytokine. In the liver, glucokinase activity was significantly increased only in the PT15 group (+34%), and no changes were observed in glucose-6-phosphatase activity. The beneficial effect of pterostilbene on glycaemic control was more evident with the lower dose, probably because in the PT15 group both the muscle and the liver were contributing to this effect, but in the PT30 group only the skeletal muscle was responsible. In conclusion, pterostilbene improves glycaemic control in rats showing insulin resistance induced by an obesogenic diet. An increase in hepatic glucokinase activity, as well as in skeletal muscle glucose uptake, seems to be involved in the anti-diabetic effect of this phenolic compound.
authors.affiliation: Nutrition and Obesity Group, Department of Nutrition and Food Science, University of the Basque Country (UPV/EHU), Vitoria, Spain. mariapuy.portillo@ehu.eus.
authors.forename: S
authors.initials: S
authors.lastname: Gómez-Zorita
authors.forename: A
authors.initials: A
authors.lastname: Fernández-Quintela
authors.forename: L
authors.initials: L
authors.lastname: Aguirre
authors.forename: M T
authors.initials: MT
authors.lastname: Macarulla
authors.forename: A M
authors.initials: AM
authors.lastname: Rimando
authors.forename: M P
authors.initials: MP
authors.lastname: Portillo
mesh_terms: D000818:Animals; D016207:Cytokines / Q000819:agonists / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects; D019422:Dietary Sucrose / Q000009:adverse effects; D019587:Dietary Supplements; D005941:Glucokinase / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000819:agonists / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007333:Insulin Resistance; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D009765:Obesity / Q000097:blood / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D009928:Organ Specificity; D010766:Phosphorylation; D011236:Prediabetic State / Q000209:etiology / Q000517:prevention & control*; D011499:Protein Processing, Post-Translational; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011897:Random Allocation; D017208:Rats, Wistar; D013267:Stilbenes / Q000008:administration & dosage / Q000627:therapeutic use*; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D019422:Dietary Sucrose; D051275:Glucose Transporter Type 4; D007004:Hypoglycemic Agents; C495694:Slc2a4 protein, rat; D013267:Stilbenes; C107773:pterostilbene; C092073:cardiotrophin 1; D005941:Glucokinase; C494920:Akt1 protein, rat; D051057:Proto-Oncogene Proteins c-akt