Effects of Gametophytes of Ecklonia Kurome on the Levels of Glucose and Triacylglycerol in db/db, Prediabetic

Abstract

We have studied edible algae that have the potential to down-regulate blood glucose. In Japan, Ecklonia species have been believed to improve the circulation of blood. In this study, we used leptin receptor deficient type 2 diabetes model mice (db/db) and prediabetic C57BL/6J mice. We also focused on the role of IFN-γ in the control of blood levels of triacylglycerol and glucose, because it is reportedly engaged in the regulation of energy consumption together with leptin. We report that gametophytes of Eckloniakurome down-regulate the blood level of glucose and serum level of triacylglycerol in db/db. We also report that gametophytes of Eckloniakurome down-regulate the level of glucose but not the level of triacylglycerol in prediabetic C57BL/6J mice induced by a high fat diet. They increased the level of triacylglycerol compared to that of control group in C57BL/6J, but not in IFN-γ KO mice. Gametophytes of Eckloniakurome were administered orally to prediabetic C57BL/6J and IFN-γ KO mice and oral glucose tolerance tests were performed to evaluate the effects of algae. During the administration of the normal diet, we found a higher level of blood glucose in a glucose tolerance test of IFN-γ KO mice compared with that of C57BL/6J. Although a high fat diet induced a higher level of blood glucose compared with a normal diet group in a glucose tolerance test of C57BL/6J mice, this effect of high fat diet was not observed clearly at first but appeared three hours after glucose administration in IFN-γ KO mice. Gametophytes of Eckloniakurome down-regulated the level of blood glucose in both C57BL/6J and IFN-γ KO mice, when administered a normal diet after making them prediabetic. These results suggest that Eckloniakurome are effective to down-regulate the blood glucose and IFN-γ is involved in the regulation of blood glucose and triacylglycerol