title: Flaxseed Protects Against Diabetes-Induced Glucotoxicity by Modulating Pentose Phosphate Pathway and Glutathione-Dependent Enzyme Activities in Rats.
abstract: This study investigated the effects of flaxseed (Linum usitatissimum L.) intake on general metabolism, pentose phosphate pathway (PPP) and glutathione-dependent enzymes in diabetic rats. Diabetes was induced by streptozotocin injection (40 mg/kg, i.p.) and the enzyme activities were determined spectrophotometrically. Diabetic and control rats were divided in two subgroups, one untreated, and one treated with flaxseed (0.714 g/kg body weight/day; orally) for 12 weeks. Flaxseed ameliorated decreased body weight (p < .05) and increased blood glucose (p < .001), triglyceride (p < .001), ALT (p < .001) and AST (p < .001) in diabetic rats. Diabetes resulted in increased glucose-6-phosphate dehydrogenase (G6PD) (p < .05) and decreased glutathione-S-transferase (GST) (p < .01), but unchanged 6-phosphogluconate dehydrogenase (6PGD) and glutathione reductase (GR) in the brain of rats. These alterations were partially improved by flaxseed in comparison to diabetic untreated group (p < .05). G6PD, 6PGD, GR were elevated (p < .001), while GST unchanged in the lung of diabetic untreated group compared to control. Flaxseed partially prevented the increase in 6PGD (p < .05) and GR (p < .01), but unaffected G6PD in the lung of diabetic rats. G6PD (p < .001), 6PGD (p < .05), GR (p < .001) were augmented, while GST showed a significant (p < .001) depletion in the pancreas of diabetic untreated rats compared to control. Diabetic alterations observed in pancreatic enzyme activities were significantly prevented by flaxseed. Furthermore, a remarkable decrease in 6PGD (p < .001) and an increase in G6PD (threefold of control) were found in the lens of diabetic untreated group that were completely prevented by flaxseed (p < .001). Flaxseed has beneficial effects against diabetes-induced glucotoxicity by modulating G6PD, 6PGD, GR and GST activities in tissues.
authors: a Department of Biochemistry, Faculty of Medicine , Hacettepe University , Ankara , Turkey.
authors: Müslüm
authors: M
authors: Gök
authors: b Department of Biochemistry , School of Medicine, Koç University , Istanbul , Turkey.
authors: Nuray N
authors: NN
authors: Ulusu
authors: c Department of Pharmacology, Faculty of Pharmacy , Ankara University , Ankara , Turkey.
authors: Nilay
authors: N
authors: Tarhan
authors: c Department of Pharmacology, Faculty of Pharmacy , Ankara University , Ankara , Turkey.
authors: Can
authors: C
authors: Tufan
authors: c Department of Pharmacology, Faculty of Pharmacy , Ankara University , Ankara , Turkey.
authors: Gülgün
authors: G
authors: Ozansoy
authors: c Department of Pharmacology, Faculty of Pharmacy , Ankara University , Ankara , Turkey.
authors: Nuray
authors: N
authors: Arı
authors: d Cellular Stress Response & Signal Transduction Research Laboratory , Gazi University, Faculty of Medicine, Department of Medical Pharmacology , Ankara , Turkey.
authors: Çimen
authors: Ç
authors: Karasu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use; D001786:Blood Glucose / Q000378:metabolism*; D001835:Body Weight / Q000187:drug effects; D048909:Diabetes Complications / Q000378:metabolism / Q000517:prevention & control*; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D019597:Flax; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use; D018384:Oxidative Stress / Q000187:drug effects; D010427:Pentose Phosphate Pathway / Q000187:drug effects*; D010734:Phosphogluconate Dehydrogenase / Q000378:metabolism; D028321:Plant Preparations / Q000494:pharmacology / Q000627:therapeutic use; D017208:Rats, Wistar; D012639:Seeds; D000637:Transaminases / Q000097:blood; D014280:Triglycerides / Q000097:blood
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D028321:Plant Preparations; D014280:Triglycerides; D010734:Phosphogluconate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005980:Glutathione Reductase; D000637:Transaminases; D005978:Glutathione
keywords: diabetic rat; flaxseed; glucotoxicity; glutathione-dependent enzymes; pentose phosphate pathway