Antidiabetic effect of polyphenols from brown alga Ecklonia kurome in genetically diabetic KK-Ay mice

Context: Prevalence of diabetes mellitus type 2 (DM-II) is increasing in Japan. Brown alga Ecklonia kurome Okamura (Laminariaceae) (kurome in Japanese) is rich in phlorotannins, a kind of polyphenol. Phlorotannins have been reported to possess various bioactivities; however, few studies have reported its effect on DM-II.Objective: The present study was conducted to investigate the antidiabetic effect of polyphenols from E. kurome (KPP) on KK-Ay mice, the animal model for human DM-II.Materials and methods: Inhibitory activities of KPP against α-amylase and α-glucosidase in vitro, and effects on oral carbohydrate tolerance test in vivo were investigated. KK-Ay mice were fed with 0.1% KPP containing water for 5 weeks. A glucose tolerance test was conducted at week 4 of the 5-week period. At the end of experiment, blood biochemical parameters, including blood glucose, insulin, glycoalbumin, and fructosamine were determined. Furthermore, the kidneys and pancreatic islets were histologically examined.Results: K...