Effect of Undaria pinnatifida extract on glucose tolerance and insulin secretion in the neonatal Streptozotocin‐induced diabetic rats fed a high‐fat diet

Abstract

The purpose of this study was to determine anti‐diabetic activities of Undaria pinnatifida extract. Neonatal diabetes was induced by i.p. injection of Streptozotocin (80mg/kg body weight) to the male Sprague‐Dawley rats at the age of 1 day. When the rats were grown to the adult (about 300g body weights), a high‐fat diet (40 % fat by kcal) was fed for two weeks. Then, rats were divided into two diet groups; one group fed a high‐fat diet with 5% of Undaria pinnatifida extract (UPEX) for the next four weeks, and the other group fed only a high‐fat diet as a control. The glucose tolerance was evaluated using an oral glucose tolerance test, and the glucose curves were compared among the diabetic rats which have similar fasting blood glucose levels. Insulin secretion was also measured using an in vitro pancreas perfusion. In results, rats in the UPEX group showed the lower glucose curves compared to the rats in the control group. Moreover, the amount of insulin secreted from the pancreas stimulated with glucose (200mg/dL) was greater in the UPEX group than those in the control group (P<0.05). These results are suggesting that Undaria pinnatifida extract has a beneficial effect on the glucose control and insulin secretion. (This work was supported by Korea Research Foundation Grant KRF‐F00014, Brain Korea 21, NURI, and FIRST of the Inje Research and Scholarship Foundation.)