Metabolomic analyses of plasma and liver of mice fed with immature <i>Citrus tumida</i> peel

In this study, we investigated the effects of dietary supplementation of Citrus tumida hort. ex Tanaka on food intake, body and fat tissue weights, and metabolic profiles of plasma and liver in mice. Supplementation with 5% (w/w) of peels of immature C. tumida (PIC) for 4 weeks significantly suppressed body weight gain and decreased adipose tissue weight in epididymal, perirenal, and subcutaneous fats. Metabolome analyses showed that 2-hydroxyvaleric acid levels were reduced in the blood plasma of mice fed with PIC. PIC supplementation significantly elevated dipeptide (Thr-Asp, Ser-Glu, and Ala-Ala), glucuronic acid, and S-methylglutathione levels, and significantly reduced betaine aldehyde levels in the liver. In conclusion, PIC supplementation affects the metabolism of fatty acids, pectin, glutathione, and choline, showing potential beneficial effects for metabolic syndrome and obesity. PIC may be developed as a functional food and used in the treatment of these diseases. Peel of immature C. tumida supplementation impacts body weight followed by metabolic changes.本研究探究了土蜜橘（Citrus tumida hort. ex Tanaka）膳食添加对小鼠摄食量、体质量及脂肪组织重量，以及血浆与肝脏代谢谱的影响。以5%（质量比w/w）比例添加未成熟土蜜橘果皮（peels of immature C. tumida，简称PIC）对小鼠进行4周干预后，可显著抑制体质量增长，并降低附睾、肾周及皮下脂肪的脂肪组织重量。代谢组学分析显示，喂食PIC的小鼠血浆中2-羟基戊酸（2-hydroxyvaleric acid）水平显著降低。PIC补充干预可显著提升小鼠肝脏中二肽（苏氨酸-天冬氨酸Thr-Asp、丝氨酸-谷氨酸Ser-Glu及丙氨酸-丙氨酸Ala-Ala）、葡萄糖醛酸（glucuronic acid）以及S-甲基谷胱甘肽（S-methylglutathione）的水平，并显著降低甜菜碱醛（betaine aldehyde）的水平。综上，PIC补充干预可影响脂肪酸、果胶、谷胱甘肽与胆碱的代谢，对代谢综合征与肥胖具有潜在的有益作用，有望开发为功能性食品并用于上述疾病的治疗。未成熟土蜜橘果皮补充干预可影响小鼠体质量，并伴随代谢变化。