The Effects of EGCG in Complexes with β-Lactoglobulin on Prevention of Obesity and Insulin Resistance

Enriching food with health promoting compounds is an important goal. Great health benefits, such as prevention of obesity, diabetes, and neurodegenerative diseases are attributed to (-)-Epigallocatechin-3-gallate (EGCG), the most abundant catechin found in green tea. However, EGCG is quickly degraded. To provide it with the necessary protection, we have developed a novel technology for complexation of EGCG with heat-denatured β-Lactoglobulin (β-Lg). In this study, we investigated the role of EGCG in milk fortified with EGCG-β-Lg complexes vs. milk fortified with free EGCG in prevention of obesity and insulin resistance, using a mouse model. Several groups of mice were fed a normal diet (ND) while others received high fat diet (HFD). Body weight gain, body fat percentage and fecal lipids concentration were similar between mice which received milk enriched with EGCG-β-Lg complexes, and mice which received milk enriched by free EGCG. However, during glucose tolerance test (GTT), after 4 weeks of study, the maximal glucose concentration (MGC) in the serum of the HFD comp+milk group was significantly lower compared with that of the HFD EGCG+milk group (P<0.05). Additionally, during the GTT after 12 weeks of study, the MGC of the ND comp+milk group and 0-30 minute area under-the-curve were significantly lower compared with those of the ND EGCG+milk group. The profile of blood glucose concentration describing the comp+milk groups fed, either ND or HFD, was consistently moderate compared with other groups. Our results indicate that long-term consumption of milk fortified with EGCG-β-Lg complexes improved glucose homeostasis and increased the sensitivity to insulin, significantly more than consumption of milk fortified with free EGCG. This study highlights advantages of diet enrichment with EGCG-β-Lg complexes for preventive medicine.