Anti-obesity effects of green tea EGCG, orange peel extract, black tea extract and caffeine in mice fed on a high-fat diet

Abstract

In this study, we elucidate the anti-obesity effects of EGCG (Epigallocatechin-3-gallate), orange peel extracts (OPE), black tea extracts (BTE), and caffeine (CF) by oral feeding to female CD-1 mice. Female CD-1 mice were fed on high-fat diets containing 0.1% EGCG, 0.2% orange peel extract, 0.2% black tea extract and 0.05% caffeine, singly and in combination for 10 weeks. The body weight gain and weights of abdominal fat and brown adipose tissue were significantly reduced by the diets containing orange peel extract, black tea extract, caffeine, OPE + BTE and OPE + CF. Noticeably, our result also found that mice fed with high-fat diet supplemented daily among the combination of 0.2% OPE + 0.2% BTE + 0.05% CF prevented the body weight gain by 48.8%, the parametrial fat pad weight by 88.2%, retroperitoneal fat pad weight by 82.8% and brown adipose tissue by 63.7% compared to mice fed on high-fat diet. On the basis of these finding, it was supported that oral feeding of orange peel extracts, black tea extracts and caffeine had anti-obesity effects by suppressing body weigh growth and adipose tissue formation. Moreover, it was shown that orange peel extract, black tea extract and caffeine were synergistic in anti-obesity actions. To clarify the anti-obesity action of orange peel extract, female CD-1 mice were fed on various degrees of orange peel extracts and different composition of orange peel extract for 17 weeks. Our results showed that feeding of different degrees of orange peel extracts to female CD-1 mice fed high-fat diet results in the reduction of body weight, white adipose tissue, brown adipose tissue as well as lipid profile includes total cholesterol, triglyceride, LDL and HDL in blood. Furthermore, long term consumption of dietary orange peel extracts intake considerably decreases diet-induced obesity, hyperglycemia, and hypercholesterolemia in mice without a dose-dependent manner.