title: Preventive and reparative effects of isoleucine against copper-induced oxidative damage in primary fish enterocytes.
abstract: The present study aimed to assess the possible preventive and reparative effects of isoleucine (Ile) against copper (Cu)-induced oxidative stress in fish enterocytes in vitro. In experiment 1, enterocytes were preincubated with increasing concentrations of Ile (0, 50, 120, 190, 260, and 330 mg L-1) for 72 h followed by exposure to 6 mg L-1Cu for 24 h. In experiment 2, the enterocytes were pretreated with 6 mg L-1Cu for 24 h and then treated with 0-330 mg L-1Ile for 72 h to investigate its potential reparative role. The results of experiment 1 showed that Cu exposure increased lactate dehydrogenase (LDH) activity and malondialdehyde and protein carbonyl (PC) content; these changes were completely suppressed by pretreatment with Ile at optimum concentrations (P < 0.05). Moreover, Ile pretreatment prevented the decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in the enterocytes exposed to Cu (P < 0.05). Additionally, cells exposed to Cu exhibited adaptive increases in glutathione-S-transferase (GST) activity. In experiment 2, the LDH activity and protein oxidation induced by Cu were completely reversed by Ile posttreatment. Meanwhile, the Cu-induced decrease in SOD, GPx, and GST activity was completely reversed by subsequent Ile treatment, but the reduced glutathione content was not restored. Collectively, these results indicate that Ile suppresses Cu-induced oxidative damage via preventive and reparative pathways in primary enterocytes and thus protects the structural integrity of enterocytes in fish.
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.|Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.|Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Wu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.|Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.|Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.
authors.forename: Weidan
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.|Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.|Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.|Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.|Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
authors.forename: Yongan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China. zhouxq@sicau.edu.cn.|Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China. zhouxq@sicau.edu.cn.|Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China. zhouxq@sicau.edu.cn.|Animal Nutrition Institute, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China. zhouxq@sicau.edu.cn.
authors.forename: Xiaoqiu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.|Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.|Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
mesh_terms: D000818:Animals; D002347:Carps; D002478:Cells, Cultured; D003300:Copper / Q000633:toxicity*; D020895:Enterocytes / Q000187:drug effects*; D007532:Isoleucine / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D007532:Isoleucine; D003300:Copper
keywords: Antioxidant capacity; Copper; Cyprinus carpio var. Jian; Enterocyte; Isoleucine