Antioxidant alpha-tocopherol ameliorates glycemic control of GK rats, a model of type 2 diabetes.
We have shown recently that oxidative stress by chronic hyperglycemia damages the pancreatic beta-cells of GK rats, a model of non-obese type 2 diabetes, which may worsen diabetic condition and suggested the administration of antioxidants as a supportive therapy. To determine if natural antioxidant alpha-tocopherol (vitamin E) has beneficial effects on the glycemic control of type 2 diabetes, GK rats were fed a diet containing 0, 20 or 500 mg/kg diet alpha-tocopherol. Intraperitoneal glucose tolerance test revealed a significant increment of insulin secretion at 30 min and a significant decrement of blood glucose levels at 30 and 120 min after glucose loading in the GK rats fed with high alpha-tocopherol diet. The levels of glycated hemoglobin A1c, an indicator of glycemic control, were also reduced. Vitamin E supplementation clearly ameliorated diabetic control of GK rats, suggesting the importance of not only dietary supplementation of natural antioxidants but also other antioxidative intervention as a supportive therapy of type 2 diabetic patients.
Ihara
Y
Y
Department of Metabolism and Clinical Nutrition, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan. ihara@metab.kuhp.kyoto-u.ac.jp
Yamada
Y
Y
Toyokuni
S
S
Miyawaki
K
K
Ban
N
N
Adachi
T
T
Kuroe
A
A
Iwakura
T
T
Kubota
A
A
Hiai
H
H
Seino
Y
Y
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use*; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000178:diet therapy* / Q000473:pathology / Q000503:physiopathology; D019587:Dietary Supplements; D004195:Disease Models, Animal; D005215:Fasting; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D007328:Insulin / Q000097:blood; D008297:Male; D010179:Pancreas / Q000737:chemistry / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D014810:Vitamin E / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use*
D000975:Antioxidants; D001786:Blood Glucose; D005947:Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D014810:Vitamin E