title: Effects of dietary cholesterol on antioxidant capacity, non-specific immune response, and resistance to Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss) fed soybean meal-based diets.
abstract: This study evaluated the effects of dietary cholesterol on antioxidant capacity, non-specific immune response and resistance to Aeromonas hydrophila in rainbow trout (Oncorhynchus mykiss) fed soybean meal-based diets. Fish were fed diets supplemented with graded cholesterol levels (0 [control], 0.3, 0.6, 0.9, 1.2, and 1.5%) for nine weeks. The fish were then challenged by A. hydrophila and their survival rate recorded for the next week. Dietary cholesterol supplementation generally increased the serum and hepatic superoxide dismutase (SOD), glutathione-peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (TAC) activities, but decreased the serum and hepatic malondialdehyde (MDA) contents. Further, the hepatic CAT and serum SOD, CAT, and TAC activities were significantly higher in fish fed diets supplemented with 0.9 or 1.2% cholesterol compared to those fed the control diet, whereas the serum and hepatic MDA contents were significantly lower. The respiratory burst activity, alternative complement activity, and hepatic lysozyme activity increased steadily when the supplemental cholesterol was increased by up to 1.2% and then declined with further addition. The serum lysozyme activity and phagocytic activity increased steadily with increasing dietary supplemental cholesterol level up to 0.9% and then declined with further addition. Dietary cholesterol supplementation generally enhanced the protection against A. hydrophila infection, and fish fed diets supplemented with 0.9 or 1.2% cholesterol exhibited the highest post-challenge survival rate. The results indicated that cholesterol may be under-supplied in rainbow trout fed soybean meal-based diets, and dietary cholesterol supplementation (0.9-1.2%) contributed to improved immune response and disease resistance of rainbow trout against A. hydrophila.
authors.affiliation: College of Animal Science and Technology, Yunnan Agricultural University, Panlong District, Kunming 650201, PR China.
authors.forename: Junming
authors.initials: J
authors.lastname: Deng
authors.forename: Bin
authors.initials: B
authors.lastname: Kang
authors.forename: Linli
authors.initials: L
authors.lastname: Tao
authors.forename: Hua
authors.initials: H
authors.lastname: Rong
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017756:Aquaculture; D002784:Cholesterol / Q000008:administration & dosage*; D003170:Complement Pathway, Alternative; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis*; D060467:Disease Resistance / Q000187:drug effects; D005393:Fish Diseases / Q000276:immunology* / Q000401:mortality / Q000517:prevention & control; D029941:Fish Proteins / Q000378:metabolism; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000401:mortality / Q000517:prevention & control / Q000662:veterinary*; D007113:Immunity, Innate / Q000187:drug effects; D009113:Muramidase / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000254:growth & development / Q000276:immunology*; D010587:Phagocytosis / Q000187:drug effects; D016897:Respiratory Burst
chemical_list: D000975:Antioxidants; D029941:Fish Proteins; D002784:Cholesterol; D009113:Muramidase