title: Chard (Beta vulgaris L. var. cicla) extract ameliorates hyperglycemia by increasing GLUT2 through Akt2 and antioxidant defense in the liver of rats.
abstract: Chard is a plant used as an alternative hypoglycemic agent by diabetic people in Turkey. The aim of this study was to examine the molecular mechanism of hypoglycemic effects of chard extract. Male Sprague-Dawley rats (6-7 months old) were divided into five groups for this investigation: (1) control, (2) hyperglycemic, (3) hyperglycemic+chard, (4) hyperglycemic+insulin, (5) hyperglycemic+chard+insulin. Fourteen days after animals were rendered hyperglycemic by intraperitoneal injection of 60 mg/kg streptozotocin, the chard water extract (2 g/kg/day) or/and insulin (6 U/kg/day) was administered for 45 days. Hypoglycemic effect of chard extract was demonstrated by a significant reduction in the fasting blood glucose and increased glycogen levels in liver of chard extract-treated hyperglycemic rats. Moreover, activity of adenosine deaminase, which is suggested as an important enzyme for modulating the bioactivity of insulin, was decreased by chard treatment. Immunostaining analysis showed increased nuclear translocation of Akt2 and synthesis of GLUT2 in the hepatocytes of chard or/and insulin-treated hyperglycemic rats. The oxidative stress was decreased and antioxidant defense was increased by chard extract or/and insulin treatment to hyperglycemic rats according to the decreased malondialdehyde formation, the activities of catalase, superoxide dismutase, myeloperoxidase and increased glutathione levels. These findings suggest that chard extract might improve glucose response by increasing GLUT2 through Akt2 and antioxidant defense in the liver.
authors.affiliation: Department of Biology, Faculty of Science, Istanbul University, 34134 Vezneciler, Istanbul, Turkey. Electronic address: selgez@istanbul.edu.tr.
authors.forename: Selda
authors.initials: S
authors.lastname: Gezginci-Oktayoglu
authors.affiliation: Department of Chemistry, Faculty of Engineering, Istanbul University, 34320 Avcilar, Istanbul, Turkey.
authors.forename: Ozlem
authors.initials: O
authors.lastname: Sacan
authors.affiliation: Department of Biology, Faculty of Science, Istanbul University, 34134 Vezneciler, Istanbul, Turkey.
authors.forename: Sehnaz
authors.initials: S
authors.lastname: Bolkent
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Marmara University, Istanbul, Turkey.
authors.forename: Yesim
authors.initials: Y
authors.lastname: Ipci
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Marmara University, Istanbul, Turkey.
authors.forename: Levent
authors.initials: L
authors.lastname: Kabasakal
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Marmara University, Istanbul, Turkey.
authors.forename: Goksel
authors.initials: G
authors.lastname: Sener
authors.affiliation: Department of Chemistry, Faculty of Engineering, Istanbul University, 34320 Avcilar, Istanbul, Turkey.
authors.forename: Refiye
authors.initials: R
authors.lastname: Yanardag
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D027461:Beta vulgaris / Q000737:chemistry*; D002374:Catalase / Q000378:metabolism; D002467:Cell Nucleus / Q000201:enzymology; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy; D004353:Drug Evaluation, Preclinical; D051273:Glucose Transporter Type 2 / Q000378:metabolism*; D006943:Hyperglycemia / Q000188:drug therapy*; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D018384:Oxidative Stress; D009195:Peroxidase / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D013311:Streptozocin; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D051273:Glucose Transporter Type 2; D007004:Hypoglycemic Agents; D010936:Plant Extracts; C495683:Slc2a2 protein, rat; D013311:Streptozocin; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; C494923:Akt2 protein, rat; D051057:Proto-Oncogene Proteins c-akt
keywords: Akt2; Chard extract; GLUT2; Hyperglycemia; Liver; Oxidative stress