Matsuoka Ryosuke, Shirouchi Bungo, Umegatani Minami, Fukuda Meguri, Muto Ayano, Masuda Yasunobu, Kunou Masaaki, Sato Masao
1R&D Division,Kewpie Corporation,Sengawa Kewport,2-5-7 Sengawa-cho,Chofu-shi,Tokyo,182-0002,Japan.
2Laboratory of Nutrition Chemistry,Department of Bioscience and Biotechnology,Faculty of Agriculture, Graduate School,Kyushu University,6-10-1 Hakozaki,Higashi-ku,Fukuoka 812-8581,Japan.
Br J Nutr. 2017 Sep;118(6):423-430. doi: 10.1017/S0007114517002306.
Egg-white protein (EWP) is known to reduce lymphatic TAG transport in rats. In this study, we investigated the effects of dietary EWP on body fat mass. Male rats, 4 weeks old, were fed diets containing either 20 % EWP or casein for 28 d. Carcass protein levels and gastrocnemius leg muscle weights in the EWP group were significantly higher than those in the casein group. In addition, carcass TAG levels and abdominal fat weights in the EWP group were significantly lower than those in the casein group; adipocyte size in abdominal fat in the EWP group was smaller than that in the casein group. To identify the involvement of dietary fat levels in the rats, one of two fat levels (5 or 10 %) was added to their diet along with the different protein sources (EWP and casein). Abdominal fat weight and serum and hepatic TAG levels were significantly lower in the EWP group than in the casein group. Moreover, significantly higher values of enzymatic activity related to β-oxidation in the liver were observed in the EWP group compared with the casein group. Finally, abdominal fat weight reduction in the EWP group with the 10 % fat diet was lower than that in the EWP group with the 5 % fat diet. In conclusion, our results indicate that, in addition to the inhibition of dietary TAG absorption reported previously, dietary EWP reduces body fat mass in rats through an increase of body protein mass and the acceleration of β-oxidation in the liver.
已知蛋清蛋白（EWP）可降低大鼠的淋巴甘油三酯转运。在本研究中，我们调查了日粮中EWP对体脂量的影响。给4周龄雄性大鼠喂食含20%EWP或酪蛋白的日粮，持续28天。EWP组的胴体蛋白水平和腓肠肌重量显著高于酪蛋白组。此外，EWP组的胴体甘油三酯水平和腹部脂肪重量显著低于酪蛋白组；EWP组腹部脂肪中的脂肪细胞大小小于酪蛋白组。为了确定日粮脂肪水平在大鼠中的作用，在其日粮中添加两种脂肪水平（5%或10%）之一以及不同的蛋白质来源（EWP和酪蛋白）。EWP组的腹部脂肪重量、血清和肝脏甘油三酯水平显著低于酪蛋白组。此外，与酪蛋白组相比，EWP组肝脏中与β-氧化相关的酶活性值显著更高。最后，10%脂肪日粮的EWP组腹部脂肪重量的减少低于5%脂肪日粮的EWP组。总之，我们的结果表明，除了先前报道的抑制日粮甘油三酯吸收外，日粮EWP还通过增加体蛋白量和加速肝脏中的β-氧化来降低大鼠的体脂量。
