Protective Effect of Dietary Yeast Cultures on Lipopolysaccharide-induced Oxidative Stress, Immune and Inflammatory Responses in Pseudobagrus ussuriensis

摘要

This study aimed to evaluate the effects of dietary yeast culture （YC） on lipopolysaccharide （LPS）-induced oxidative stress,immune and inflammatory response in P.ussuriensis.The fish were randomly assigned into three groups as the control group,LPS group and YC+LPS group.The fish in the control were fed diet with no YC supplementation and no LPS challenge,and the fish in the LPS group or YC+LPS group were fed diet supplemented with no YC or 20 g·kg^-1 YC,and with LPS challenge,respectively.The results showed that compared with the control group,intestinal total antioxidant capacity （T–AOC） level and superoxide dismutase （SOD） activity were significantly decreased,while intestinal malondialdehyde （MDA）,plasma aspartate transaminase （AST） and alanine transaminase （ALT） levels were significantly increased in the LPS group （P<0.05）.Besides,lower plasma alkaline phosphatase （ALP）,alternative complement pathway （ACH50） activity and the albumin （ALB） level,as well as higher lysozyme （LZM） activity,were also found in the LPS group.However,dietary 20 g·kg^-1 YC supplementation could relieve the above LPS-induced changes in Pseudobagrus ussuriensis.Furtherly,LPS challenge could significantly up-regulate gene expression of interleukin–8 （IL–8）,heat shock protein （HSP70） and NF–κBp65 except for toll-like receptors 2 （TLR2）,while dietary 20 g·kg^-1 YC supplementation suppressed the increased expression of NF–κBp65 and IL–8 induced by LPS in P.ussuriensis.In summary,LPS challenge could induce immune impairment,oxidative stress and hepatic damage,and the protective effect of dietary 20 g·kg^-1 YC supplementation on LPS-induced immune impairment and oxidative stress was observed in the present study,which was associated with the enhanced levels of antioxidant enzymes and immune parameters.Also,dietary 20 g·kg^-1 YC supplementation could suppress LPS-induced inflammatory response by down-regulating NF–κBp65,HSP70 and IL–8 gene expression.

关键词

yeast culture / lipopolysaccharide / NF–κBp65 / Pseudobagrus ussuriensis