title: Effect of Different Selenium Supplementation Levels on Oxidative Stress, Cytokines, and Immunotoxicity in Chicken Thymus.
abstract: This study assessed the effects of different selenium (Se) supplementation levels on oxidative stress, cytokines, and immunotoxicity in chicken thymus. A total of 180 laying hens (1 day old; Mianyang, China) were randomly divided into 4 groups (n = 45). The chickens were maintained either on a basic diet (control group) containing 0.2 mg/kg Se, a low-supplemented diet containing 5 mg/kg Se, a medium-supplemented diet containing 10 mg/kg Se, or a high-supplemented diet containing 15 mg/kg Se for 15, 30, and 45 days, respectively. Over the entire experimental period, serum and thymus samples were collected and used for the detection of the experimental index. The results indicated that the antioxidative enzyme activities and messenger RNA (mRNA) levels of antioxidative enzymes, IFN-γ and IL-2 in the thymus, and the content of IFN-γ and IL-2 in the serum of excessive-Se-treated chickens at all time points (except for the 5 mg/kg Se supplement group at 15 days) were significantly decreased (P < 0.05) compared to the corresponding control groups. Interestingly, a significantly increase (P < 0.05) in the content of IFN-γ was observed in the serum and thymus in the 5 mg/kg Se supplement group at 15 and 30 days compared to the corresponding control groups. In histopathological examination, the thymus tissue from excessive-Se-treated chickens revealed different degrees of cortex drop, incrassation of the medulla, and degeneration of the reticular cells. These results suggested that the excessive Se could result in a decrease in immunity, an increase in oxidative damage, and a series of clinical pathology changes, such as cortex drop, incrassation of the medulla, and degeneration of the reticular cells.
authors.affiliation: School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.|Engineering Research Center of Biomass Materials, Ministry of Education, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.
authors.forename: Yachao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.affiliation: School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China.
authors.forename: Yuanfeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Engineering Research Center of Biomass Materials, Ministry of Education, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China. XuegangLuo@126.com.|School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China. XuegangLuo@126.com.
authors.forename: Xuegang
authors.initials: X
authors.lastname: Luo
authors.affiliation: School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China. hejiansichuan@163.com.
authors.forename: Jian
authors.initials: J
authors.lastname: He
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002645:Chickens / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D019587:Dietary Supplements; D007109:Immunity / Q000187:drug effects*; D066298:In Vitro Techniques; D018384:Oxidative Stress / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012643:Selenium / Q000008:administration & dosage / Q000494:pharmacology*; D013950:Thymus Gland / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology*
chemical_list: D000975:Antioxidants; D016207:Cytokines; D012333:RNA, Messenger; D012643:Selenium
keywords: Chicken; Cytokine; Immunotoxicity; Oxidative stress; Selenium