Antidiabetic and Antioxidant Effects of Polyphenols in Brown Alga Ecklonia stolonifera in Genetically Diabetic KK-Ay Mice

  • Kunihisa IwaiEmail author
Original Paper


The dietary intake and control of blood glucose levels are very important in hyperglycemic patients and α-glucosidase inhibitors are a cost-effective means to preventing the progression of diabetes. In search of a natural inhibitor from food materials, α-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 α-glucosidase in vitro. Male KK-Ay 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-Ay mice dose dependently. In KK-Ay 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.


α-Glucosidase Antioxidant Diabetes Ecklonia stolonifera KK-Ay mouse Polyphenol 





high performance liquid chromatography with photodiode array detection


liquid chromatography mass spectrometry


methanolic extract of E. stolonifera


thiobarbituric acid reactive substance


water extract of E. stolonifera


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Copyright information

© Springer Science+Business Media, LLC. 2008

Authors and Affiliations

  1. 1.Department of Nutrition, Faculty of Health SciencesAomori University of Health and WelfareAomoriJapan

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