Taniguchi Hirokazu, Akiyama Nao, Ishihara Kengo
Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University.
Faculty of Agriculture, Ryukoku University.
J Nutr Sci Vitaminol (Tokyo). 2019;65(6):515-525. doi: 10.3177/jnsv.65.515.
Previous studies suggest that circulating fibroblast growth factor 21 (FGF21) levels are elevated in patients with fatty liver, while fasting-induced secretion of FGF21 is lower in obese patients. It has been reported that soy protein prevents hepatic fat accumulation and induces FGF21 secretion. The present study was designed to evaluate the response of circulating FGF21 levels to feeding and fasting in mice fed soy protein-rich diets. For this, C57BL/6J mice were distributed into control, high-fat high-sucrose (HFHS)-casein protein, HFHS-soy protein, and HFHS-β-conglycinin diet groups. Plasma samples were collected after 10 and 11 wk either in dark periods with feeding conditions or light periods under fasting conditions using a crossover design. After a 12-wk period of feeding, HFHS-induced hepatic fat accumulation was significantly reduced in the groups fed HFHS-soy protein and HFHS-β-conglycinin as compared to that in the HFHS-casein-fed group (p<0.05). Plasma FGF21 concentration was significantly higher in the dark/feeding periods in the HFHS-casein group (p<0.05), while in the HFHS-β-conglycinin group it was higher in the light/fasting periods (p<0.05). The amount of mesenteric fat was significantly lower in the HFHS-β-conglycinin group than in the HFHS-casein and HFHS-soy protein groups (p<0.01). The fasting-induced FGF21 secretion was significantly and negatively correlated with hepatic fat content (p<0.05). The present study revealed that hepatic fat accumulation was associated with lower fasting-induced FGF21 secretion, which was regulated better by dietary intake of soy protein. These results support the preventive effects of soy protein on central obesity.
先前的研究表明，脂肪肝患者循环中成纤维细胞生长因子21（FGF21）水平升高，而肥胖患者中禁食诱导的FGF21分泌较低。据报道，大豆蛋白可预防肝脏脂肪堆积并诱导FGF21分泌。本研究旨在评估富含大豆蛋白饮食喂养的小鼠中循环FGF21水平对进食和禁食的反应。为此，将C57BL/6J小鼠分为对照组、高脂高糖（HFHS）-酪蛋白组、HFHS-大豆蛋白组和HFHS-β-伴大豆球蛋白饮食组。采用交叉设计，在10周和11周后，分别于进食条件下的黑暗期或禁食条件下的光照期采集血浆样本。经过12周的喂养后，与HFHS-酪蛋白喂养组相比，HFHS-大豆蛋白组和HFHS-β-伴大豆球蛋白组中HFHS诱导的肝脏脂肪堆积显著减少（p<0.05）。HFHS-酪蛋白组在黑暗/进食期血浆FGF21浓度显著更高（p<0.05），而HFHS-β-伴大豆球蛋白组在光照/禁食期更高（p<0.05）。HFHS-β-伴大豆球蛋白组的肠系膜脂肪量显著低于HFHS-酪蛋白组和HFHS-大豆蛋白组（p<0.01）。禁食诱导的FGF21分泌与肝脏脂肪含量显著负相关（p<0.05）。本研究表明，肝脏脂肪堆积与较低的禁食诱导FGF21分泌有关，大豆蛋白的饮食摄入对其调节作用更好。这些结果支持了大豆蛋白对中心性肥胖的预防作用。
