title: The effects of emodin on cell viability, respiratory burst and gene expression of Nrf2-Keap1 signaling molecules in the peripheral blood leukocytes of blunt snout bream (Megalobrama amblycephala).
abstract: We determined the effects of emodin on the cell viability, respiratory burst activity, mRNA levels of antioxidative enzymes (Cu-Zn SOD, CAT and NOX2), and gene expressions of the Nrf2-Keap1 signaling molecules in the peripheral blood leukocytes of blunt snout bream. Triplicate groups of cultured cells were treated with different concentrations of emodin (0.04-25 μg/ml) for 24 h. Results showed that the emodin caused a dramatic loss in cell viability, and occurred in a dose-dependent manner. Emodin exposure (1-25 μg/ml) were significantly induced the ROS generation compared to the control. The respiratory burst and NADPH oxidase activities were significantly induced at a concentration of 0.20 μg/ml, and inhibited at 25 μg/ml. Besides, mRNA levels of antioxidant enzyme genes were dramatically regulated by emodin exposure for 24 h. During low concentrations of exposure, mRNA levels of Cu-Zn SOD in the cells treated with 0.04, 0.20 μg/ml, CAT, NOX2 and Nrf2 in the cells treated with 1 μg/ml were sharply increased, respectively. Whereas, high concentrations were dramatically down-regulated the gene expressions of CAT in the cells treated with 5, 25 μg/ml and NOX2 in the cells treated with 25 μg/ml. Furthermore, sharp increase in Keap1and Bach1 expression levels were observed a dose-dependent manner. In conclusion, this study demonstrated that emodin could induce antioxidant defenses which were involved in cytotoxic activities, respiratory burst and the transcriptional regulation levels of antioxidant enzymes and Nrf2-Keap1 signaling molecules.
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China. Electronic address: zhaozhenxin8@163.com.
authors.forename: Zhenxin
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xie
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China. Electronic address: liub@ffrc.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China. Electronic address: gexp@ffrc.cn.
authors.forename: Xianping
authors.initials: X
authors.lastname: Ge
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Changyou
authors.initials: C
authors.lastname: Song
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Mingchun
authors.initials: M
authors.lastname: Ren
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Qunlan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Linghong
authors.initials: L
authors.lastname: Miao
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Shan
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Zhenfei
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects*; D003530:Cyprinidae; D004642:Emodin / Q000008:administration & dosage / Q000494:pharmacology*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D000072019:Kelch-Like ECH-Associated Protein 1 / Q000235:genetics / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D016897:Respiratory Burst / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D029941:Fish Proteins; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; D004642:Emodin
keywords: Antioxidant defenses; Emodin; Gene expression; Megalobrama amblycephala; Nrf2 signaling pathway