Yao Junpeng, Hu Pengcheng, Zhu Yanhong, Xu Yingyan, Tan Qingsong, Liang Xufang
College of Fisheries, Huazhong Agricultural University/Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, China/Hubei Provincial Engineering Laboratory for Pond Aquaculture/Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, China.
Front Physiol. 2020 Dec 4;11:584782. doi: 10.3389/fphys.2020.584782. eCollection 2020.
Compared with wild grass carp (), intensively cultured fish displayed disordered lipid metabolism, showing excess lipid deposition in the hepatopancreas and muscle. Lotus leaf prevents fat accumulation in humans and may have similar effects on fish. This study explored the regulatory mechanisms by which the dietary addition of an alcoholic extract of lotus leaf (AELL) reduced lipid deposition in the hepatopancreas and muscle of juvenile grass carp. The fish (average initial weight: 34.00 ± 0.40 g) were fed four experimental diets containing different AELL levels (0, 0.07, 0.14, and 0.21%) for 8 weeks. Serum components, lipid droplet size, triacylglycerol (TAG) content, enzymatic activities, and mRNA levels of genes related to lipid metabolism in the hepatopancreas and muscle were analyzed. The results show that dietary AELL supplementation significantly reduced the TAG content and lipid droplet area in the histological sections as well as the fatty acid synthase (FAS) activity in both the hepatopancreas and muscle but enhanced the activities of lipoprotein lipase (LPL) and carnitine palmitoyltransferase I (CPT1) in both tissues. In addition, dietary AELL supplementation decreased the mRNA expression of genes involved in fatty acid uptake (, , , ) and lipid synthesis (, , and ) as well as the transcription factors and in the hepatopancreas and muscle but increased the mRNA levels of genes relating to lipid catabolism (, , , ), lipid transportation (), and the transcription factor in both tissues. In conclusion, dietary AELL supplementation reduced lipid accumulation in the hepatopancreas and muscle by affecting the gene expression of proteins with known effects on lipid metabolism in juvenile grass carp.
与野生草鱼相比，集约化养殖的鱼呈现出脂质代谢紊乱，表现为肝胰腺和肌肉中脂质过度沉积。荷叶可防止人体脂肪堆积，对鱼类可能有类似作用。本研究探讨了在饲料中添加荷叶乙醇提取物（AELL）减少草鱼幼鱼肝胰腺和肌肉脂质沉积的调控机制。将鱼（平均初始体重：34.00±0.40克）投喂含不同AELL水平（0、0.07、0.14和0.21%）的四种实验饲料，为期8周。分析了血清成分、脂滴大小、三酰甘油（TAG）含量、酶活性以及肝胰腺和肌肉中与脂质代谢相关基因的mRNA水平。结果表明，饲料中添加AELL显著降低了组织切片中的TAG含量和脂滴面积，以及肝胰腺和肌肉中的脂肪酸合酶（FAS）活性，但增强了两个组织中脂蛋白脂肪酶（LPL）和肉碱棕榈酰转移酶I（CPT1）的活性。此外，饲料中添加AELL降低了肝胰腺和肌肉中参与脂肪酸摄取（、、、）和脂质合成（、、和）的基因以及转录因子和的mRNA表达，但增加了两个组织中与脂质分解代谢（、、、）、脂质转运（）相关基因以及转录因子的mRNA水平。总之，饲料中添加AELL通过影响对草鱼幼鱼脂质代谢有已知作用的蛋白质的基因表达，减少了肝胰腺和肌肉中的脂质积累。
