不同来源虾青素对虹鳟红肌抗氧化和脂质代谢的影响

Effects of astaxanthin from different sources on antioxidation and lipid metabolism in red muscle of rainbow trout

为研究人工合成虾青素和红发夫酵母(Phaffia rhodozyma)虾青素对虹鳟红肌抗氧化和脂质代谢的影响,在基础饲料中分别添加31.50 mg/kg红发夫酵母虾青素(P-AST)和32.96 mg/kg人工合成虾青素(S-AST),饲喂虹鳟16周后,分析虹鳟红肌中抗氧化指标、抗氧化及脂质代谢相关基因表达的变化。结果表明:P-AST组总超氧化物歧化酶(T-SOD)活性较对照组提高38.04%(P<0.05),且P-AST组SOD1 mRNA水平较对照组增加58.54%(P<0.05)。与对照组相比,P-AST组和S-AST组过氧化氢酶(CAT)活性无显著性变化,但S-AST组和P-AST组CAT基因表达分别低于对照组30.23%和31.78%(P<0.05)。P-AST组总谷胱甘肽(T-GSH)、氧化型谷胱甘肽(GSSG)、还原型谷胱甘肽(GSH)含量均低于其他两组,其中GSSG含量较对照组降低24.73%(P<0.05)。与对照组相比,S-AST组过氧化物酶体增殖物激活受体(pparα1)基因表达高于对照组147.69%(P<0.05)、P-AST组sirtuin1(Sirt1)基因表达高于对照组49.37%(P<0.05),而pparα2、肉碱棕榈酰基转移酶1(CPT1)和脂肪酸合成酶(FASN)基因的表达无显著性变化。上述结果表明,S-AST和P-AST均能够调节虹鳟红肌抗氧化系统的功能及脂质代谢相关基因的表达,但是两种虾青素之间存在差异。

A feeding experiment with supplemented Phaffia rhodozyma and synthetic astaxanthin was conducted to determine antioxidant capacity and lipid metabolism in red muscle of rainbow trout.Three diets were formulated with or without 31.50 mg/kg Phaffia rhodozyma(P-AST)and 32.96 mg/kg synthetic astaxanthin(S-AST)supplemented to feed fish for 16 weeks.The results showed that the activity of total superoxidase-dismutase(T-SOD)in P-AST group was 38.04%higher than control group(P<0.05),while the level of SOD1 mRNA in P-AST group was 58.54%higher than control group(P<0.05).Compared with the control group,there was no significant difference in catalase(CAT)activity treated with P-AST and S-AST,but the expression of CAT gene in S-AST group and P-AST group was 30.23%and 31.78%lower than control group,respectively(P<0.05).The content of oxidized glutathione(GSSG)in P-AST treatment was 24.73%lower than control group(P<0.05),however,total glutathione(T-GSH),GSH were no apparent changes.Peroxisome proliferator activated receptorα1(pparα1)in S-AST group significantly 147.69%higher than control group(P<0.05).The expression of sirtuin1(Sirt1)gene increased 49.37%in P-AST group(P<0.05),but there was no significant change in the expression of carnitine acyltransferase 1(CPT1)and fatty acid synthase(FASN)genes.These results suggested that dietary Phaffia rhodozyma and synthetic astaxanthin affected the antioxidant capacity of red muscle and regulated lipid metabolism related genes transcription.