title: Supplementation of coenzyme Q10 and alpha-tocopherol lowers glycated hemoglobin level and lipid peroxidation in pancreas of diabetic rats.
abstract: The importance of nutritional supplementation in diabetes remains an unresolved issue. The present study was undertaken to examine the effects of alpha-tocopherol and CoQ(10), powerful antioxidants, on metabolic control and on the pancreatic mitochondria of GK rats, a model of type 2 diabetes. We also evaluated the efficacy of these nutrients in preventing the diabetic pancreatic lesions observed in GK rats. Rats were divided into 4 groups, a control group of diabetic GK rats and 3 groups of GK rats administered with alpha-tocopherol and CoQ(10) alone or both in association, during 8 weeks. Fasting blood glucose levels were not significantly different between the groups, nor were blood glucose levels at 2 hours after a glucose load. HbA1c level was significantly reduced in the group supplemented with both antioxidants. Diabetes induced a decrease in coenzyme Q plasma levels that prevailed after treatment with antioxidants. In addition, the plasma alpha-tocopherol levels were higher after treatment with the antioxidants. An increment in some components of the antioxidant defense system was observed in pancreatic mitochondria of treated GK rats. Moreover, the antioxidants tested either alone or in association failed to prevent the pancreatic lesions in this animal model of type 2 diabetes. In conclusion, our results indicate that CoQ(10) and alpha-tocopherol decrease glycated HbA1c and pancreatic lipid peroxidation. These antioxidants increase some components of the antioxidant defense system but do not prevent pancreatic lesions. Thus, we cannot rule out the potential benefit of antioxidant treatments in type 2 diabetes in the prevention of their complications.
authors.affiliation: Institute of Physiology, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal. csena@ci.uc.pt
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Sena
authors.forename: Elsa
authors.initials: E
authors.lastname: Nunes
authors.forename: Aline
authors.initials: A
authors.lastname: Gomes
authors.forename: Maria S
authors.initials: MS
authors.lastname: Santos
authors.forename: Teresa
authors.initials: T
authors.lastname: Proença
authors.forename: Maria I
authors.initials: MI
authors.lastname: Martins
authors.forename: Raquel M
authors.initials: RM
authors.lastname: Seiça
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D019587:Dietary Supplements; D004195:Disease Models, Animal; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000187:drug effects* / Q000378:metabolism; D007328:Insulin / Q000097:blood; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D010179:Pancreas / Q000187:drug effects* / Q000473:pathology; D011897:Random Allocation; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D014451:Ubiquinone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D014451:Ubiquinone; D024502:alpha-Tocopherol; C024989:coenzyme Q10