Feeding Rats Medium-Chain Triglycerides and Tomato Powder Increases Liver Lycopene Content and Reduces the Expression of Genes Related to Lipid Metabolism in the Liver

Lycopene quenches reactive oxygen species effectively; however, its bioavailability is low owing to its high lipid solubility. Here, we assessed whether feeding Sprague–Dawley rats medium-chain triglycerides (MCTs), which promote the emulsification of lipid-soluble food components and are metabolized more rapidly than long-chain triglycerides (LCTs), along with tomato powder (T) affects lycopene accumulation and metabolism in the liver. Liver lycopene contents were higher in MCT+T-fed rats than in LCT+T-fed rats. Serum levels of high molecular weight adiponectin were markedly higher in MCT+T-fed rats than in the other groups. MCT+T-fed rats exhibited lower liver triglycerides compared with LCT+T-fed rats. Furthermore, the elevated Acaca and Scd1 mRNA expression levels observed in rats fed MCTs were decreased in rats fed MCT+T. These results suggest that feeding rats MCTs and T increased the liver lycopene content and systemic insulin sensitivity, improving lipid metabolism in the liver.

番茄红素（Lycopene）可有效清除活性氧物种（reactive oxygen species），但因其高脂溶性，生物利用度较低。本研究旨在探究：给斯普拉格-道利大鼠（Sprague–Dawley rats）饲喂可促进脂溶性食品组分乳化、且代谢速率快于长链甘油三酯（long-chain triglycerides，LCTs）的中链甘油三酯（medium-chain triglycerides，MCTs），并联合番茄粉（tomato powder，T），是否会影响肝脏中番茄红素的积累与代谢。结果显示，饲喂MCT+T组大鼠的肝脏番茄红素含量高于LCT+T组大鼠。MCT+T组大鼠的血清高分子量脂联素（high molecular weight adiponectin）水平显著高于其他各组。相较LCT+T组大鼠，MCT+T组大鼠的肝脏甘油三酯水平更低。此外，仅饲喂MCTs的大鼠中上调的Acaca与Scd1 mRNA表达水平，在MCT+T饲喂组大鼠中出现下调。上述结果表明，给大鼠饲喂MCTs与T可提升肝脏番茄红素含量与全身胰岛素敏感性，改善肝脏脂质代谢。