title: The diverse effects of α- and γ-tocopherol on chicken liver transcriptome.
abstract: 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.
authors: University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, 1230 Domžale, Slovenia.
authors: Tamara
authors: T
authors: Korošec
authors: Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia.
authors: Urška
authors: U
authors: Tomažin
authors: University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, 1230 Domžale, Slovenia.|National Institute of Chemistry, Hajdrihova 19, 1001 Ljubljana, Slovenia.
authors: Simon
authors: S
authors: Horvat
authors: Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan.
authors: Rok
authors: R
authors: Keber
authors: University of Ljubljana, Biotechnical Faculty, Department of Animal Science, Groblje 3, 1230 Domžale, Slovenia.
authors: Janez
authors: J
authors: Salobir
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002645:Chickens / Q000235:genetics / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage; D008043:Linseed Oil / Q000008:administration & dosage; D008099:Liver / Q000378:metabolism*; D008297:Male; D059467:Transcriptome; D024502:alpha-Tocopherol / Q000378:metabolism*; D024504:gamma-Tocopherol / Q000378:metabolism*
chemical_list: D015525:Fatty Acids, Omega-3; D008043:Linseed Oil; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol
keywords: broiler chicken; gene expression; lipid oxidation; α-tocopherol; γ-tocopherol