Antidiabetic and antioxidant effects of polyphenols in brown alga Ecklonia stolonifera in genetically diabetic KK-A(y) mice.
The dietary intake and control of blood glucose levels are very important in hyperglycemic patients and alpha-glucosidase inhibitors are a cost-effective means to preventing the progression of diabetes. In search of a natural inhibitor from food materials, alpha-glucosidase inhibitory activity and the anti-hyperglycemic effects of a brown alga, Ecklonia stolonifera, were investigated using non-insulin dependent diabetic mice. Methanolic extract of E. stolonifera (MEE), which contains a high content of polyphenols, showed strong inhibition of alpha-glucosidase in vitro. Male KK-A(y) mice, a genetically non-insulin dependent diabetic model, showed hyperglycemia with aging, but the ingestion of MEE suppressed the increase in plasma glucose and lipid peroxidation levels in unfasted KK-A(y) mice dose dependently. In KK-A(y) mice, which were fed the MEE diet for 4 weeks, MEE moderated the elevation of plasma glucose levels after the oral administration of maltose. The polyphenols in MEE were estimated to be phlorotannins by HPLC-PDA and LC/MS analyses. These results demonstrate that E. stolonifera, seaweed typically used as a health food, has strong antidiabetic and antioxidant effects in vivo, thus, it may have beneficial properties in the prevention of diabetes and could be useful in the development of an antidiabetic pharmaceutical and functional food.
Iwai
Kunihisa
K
Department of Nutrition, Faculty of Health Sciences, Aomori University of Health and Welfare, Hamadate, Aomori, Japan. k_iwai@auhw.ac.jp
D000818:Animals; D030801:Animals, Genetically Modified; D000975:Antioxidants / Q000032:analysis / Q000627:therapeutic use*; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000032:analysis / Q000627:therapeutic use*; D058870:Food, Organic; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents / Q000032:analysis / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D008297:Male; D051379:Mice; D000459:Phaeophyceae / Q000737:chemistry*; D010636:Phenols / Q000032:analysis / Q000627:therapeutic use*; D059808:Polyphenols; D011897:Random Allocation; D016896:Treatment Outcome
D000975:Antioxidants; D001786:Blood Glucose; D005419:Flavonoids; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D007328:Insulin; D010636:Phenols; D059808:Polyphenols