Korošec Tamara, Tomažin Urška, Horvat Simon, Keber Rok, Salobir Janez
University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, 1230 Domžale, Slovenia.
Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia.
Poult Sci. 2017 Mar 1;96(3):667-680. doi: 10.3382/ps/pew296.
α-Tocopherol is the form of vitamin E with the highest biological value and is almost exclusively considered as vitamin E in feed and feed supplements. Because γ-tocopherol, the predominant form of vitamin E naturally present in chicken feed, is not considered as a source of vitamin E, its re-evaluation with newer methods might be important.Despite γ-tocopherol's lower estimated biological value, it has been shown to be effective in reducing reactive nitrogen species, regulating immune and inflammatory processes, and diminishing the risk of metabolic perturbations and associated diseases. A 30-day nutritional trial in broiler chickens (Ross 308) was conducted to investigate how specific forms of vitamin E (α- and γ-tocopherol) and their combination impact liver gene expression when oxidative susceptibility of the organism is induced by high n-3 polyunsaturated fatty acids (PUFA) intake (linseed oil). Thirty-six one-day-old male broilers were fed a diet enriched with 5% linseed oil. A control group (Cont; N = 10) was used as a reference group, Tα (N = 10) was supplemented with 67 mg/kg RRR-α-tocopherol, Tγ (N = 8) with 67 mg/kg RRR-γ-tocopherol, and Tαγ (N = 8) with a combination of 33.5 mg/kg of each tocopherol. Beside oxidative stress indicators, whole chicken genome microarray analysis was performed on liver RNA and selected differentially expressed genes were confirmed by real time quantitative PCR. α-Tocopherol alone and in combination with γ-tocopherol was able to prevent lipid oxidation, which was also supported by transcriptome analysis. The effect of γ-tocopherol was evident in the expression of genes involved in inflammatory processes and immune response, while α-tocopherol affected genes involved in lipid and cholesterol metabolism. Both isomers of vitamin E influenced the transcription of genes, which are related to improved fat oxidation and enhanced glucose sparing.
α-生育酚是维生素E中具有最高生物学价值的形式，在饲料和饲料补充剂中几乎被唯一视为维生素E。由于γ-生育酚是鸡饲料中天然存在的主要维生素E形式，但不被视为维生素E的来源，因此用更新的方法对其进行重新评估可能很重要。尽管γ-生育酚的估计生物学价值较低，但已证明它在减少活性氮物质、调节免疫和炎症过程以及降低代谢紊乱和相关疾病风险方面是有效的。进行了一项为期30天的肉鸡（罗斯308）营养试验，以研究维生素E的特定形式（α-和γ-生育酚）及其组合在高n-3多不饱和脂肪酸（PUFA）（亚麻籽油）摄入诱导机体氧化易感性时如何影响肝脏基因表达。36只1日龄雄性肉鸡被喂食富含5%亚麻籽油的日粮。对照组（Cont；N = 10）用作参考组，Tα（N = 10）补充67 mg/kg RRR-α-生育酚，Tγ（N = 8）补充67 mg/kg RRR-γ-生育酚，Tαγ（N = 8）补充每种生育酚33.5 mg/kg的组合。除了氧化应激指标外，还对肝脏RNA进行了全鸡基因组微阵列分析，并通过实时定量PCR确认了选定的差异表达基因。单独的α-生育酚以及与γ-生育酚组合都能够预防脂质氧化，转录组分析也支持这一点。γ-生育酚在参与炎症过程和免疫反应的基因表达中作用明显，而α-生育酚影响参与脂质和胆固醇代谢的基因。维生素E的两种异构体均影响与改善脂肪氧化和增强葡萄糖节约相关的基因转录。
