柴胡皂苷a对石斑鱼肝细胞脂肪沉积的调节作用

Regulation of saikosaponin a on lipid emulsions and immune response of grouper hepatocytes

脂肪过度积累严重危害鱼类健康,是人工养殖鱼类中常见的营养性疾病,目前对鱼类脂肪变性的形成和调控机制还不甚明确.为了阐明柴胡皂苷a(Saikosaponin a,SSa)对鱼类肝脏的保护作用,建立了2 ml/L脂质乳(Lipid emulsions,LE)诱导的虎龙杂交石斑鱼原代肝细胞脂肪变性模型,并探讨了SSa对肝细胞存活率、细胞内脂肪含量、线粒体功能以及脂质代谢和免疫反应的影响.研究结果表明,SSa可以显著提高肝细胞的存活率,减少细胞内脂滴的积累,不同程度地增强线粒体呼吸链Ⅰ~Ⅳ及ATP的含量,抑制线粒体肿胀;同时显著的抑制脂肪合成基因(G6PD,ME1和DGAT2)的上调,抑制脂肪分解基因(ATGL,ACO1和LXRα)的下调.数据统计结果表明,SSa的添加质量浓度为200 ng/mL组的保护效果好.综合以上结果,SSa可缓解石斑鱼肝细胞脂肪变性,为鱼类肝脏脂肪代谢异常机理的研究和保肝护肝药物的筛选提供第一手数据和新思路.

Excessive accumulation of lipid seriously harms fish health and is a common nutritional disease in cultured fish.the formation and regulation mechanism of fatty liver in fish is still not clear.To clarify the protective effect of Saikosaponin a(SSa)on the liver of fish,a model of hepatocyte steatosis of hybrid grouper(Epinephelus lanceolatus♂×Epinephelus fuscoguttatus♀)induced bylipid emulsions(LE)with 2 ml/L was established,and the effects of SSa on hepatocyte survival rate,intracellular lipid content,mitochondrial function,lipid metabolism and immune response of hybrid grouper were investigated.The results showed that SSa could significantly improve the survival rate of hepatocytes,reduce the accumulation of intracellular lipid droplets,enhance the contents of mitochondrial respiratory chainⅠ-Ⅳand ATP to varying degrees,and inhibit mitochondrial swelling.It also significantly inhibited the up-regulation of adipogenic genes(G6PD,ME1 and DGAT2)and down-regulation of adipogenic genes(ATGL,ACO1 and LXRα).Statistical results showed that the group with 200 ng/mL SSa had better protective effect.In conclusion,SSa has a protective effect on grouper hepatocyte steatosis,which can provide first-hand data and new ideas for the study of fish abnormal lipid metabolism mechanisms and the research and development of liver-protecting drugs.