| In aquaculture,fish often encounter pathogen infection caused overusing antibiotic and oxidative stress.Feeding trials were conducted in indoor culture system to investigate the expression of peroxiredoxin gene in the liver,kidney,spleen,heart,brain,gill,muscle,swim bladder,foregut and hindgut of juvenile Wuchang bream(Megalobrama amblycephala),the effects of different dietary curcumin supplementation and feeding patterns on the growth and non-specific immune,the effects of Aeromonas hydrophila injection with different dietary curcumin supplementations and feeding patterns on M.amblycephala.The main results are as follows:1 This study explored the expression of peroxiredoxin gene in liver,kidney,spleen,heart,brain,gill,muscle,maw,foregut and hindgut of juvenile Wuchang bream(Megalobrama amblycephala),showed the Prx ?,?,?,?,?,? expression in various tissues that we examine in M.amblycephala.And the order of expression quantity is as follows:Prx ?:heart,kidney>liver,spleen,gill>hindgut>foregut>brain,muscles,maw;Prx ?:liver>foredgut>hindgut>heart,brain,maw,spleen kidney,gill,muscle;Prx ?:muscle,maw>spleen>liver>heart>hindgut foregut>gill,brain,kidney;Prx ?liver>hindgut>foregut>heart,brain,muscle>kidney>spleen,gill,maw;Prx ?:brain,heart>muscle>hindgut>foregut>kidney,spleen,gill,liver,maw;Prx ?:liver>foregut>muscle>hindgut>kidney>spleen,heart>gill>maw,brain.The difference expression level of Peroxiredoxin gene on each organization showed the unique.Under Aeromonas hydrophila stress for 24 hours,the Prx ?,Prx ?,Prx ?,Prx ?,Prx ?,Prx ?expressions in various tissues that we examine in M.amblycephala got a higher expression level than before.Since the gene whenever showed a higher expression level in the liver,we infer that the liver is an important place for ROS metabolism,and it would be the main organs of antioxidant.2 The present study was aimed to evaluate the effects of the feed additive curcumin on the growth and non-specific immune responses in juvenile Wuchang bream(Megalobra,ma amblycephala).The fish were randomly divided into six groups:the control group fed with basal diet and five treatment groups fed with basal diet supplemented with 15,30,60,120 and 240 mg/kg of curcumin,respectively.After 60 days of feeding trial,fish of the 60 mg/kg curcumin group had significantly higher weight gain rate(WGR)and specific growth rate(SGR),but significantly lower feed conversion ratio(FCR)than that of the control group.In addition,the number of leucocytes(WBC),interleukin-1?(IL-1?),tumor necrosis factor-?(TNF-?),alternative pathway of complement(ACH50),and respiratory burst activity increased first and then decreased with the increasing curcumin.The fish fed with the diets supplemented with 60 mg/kg curcumin had significantly higher number of WBC than that of the control group(p<0.05).In addition,the fish fed with 60 mg/kg curcumin had significantly lower levels of alanine transaminase(ALT)and aspartate transaminase(AST)than that of the control group(p<0.05).Furthermore,the fish fed with the diets supplemented with 60 and 120 mg/kg curcumin had significantly higher TNF-?and ACH50 activity compared with the control group(p<0.05),and the fish fed with the diets supplemented with 60 and 240 mg/kg curcumin had significantly higher IL-1?activity than that of the control group(p<0.05).In the bacteria challenge experiment with A.hydrophila,fish fed diet supplemented with 60 mg/kg had lower cumulative mortality rate than control group on 96 hours.And the highest expression of Prx ?,Prx ?,Prx ?,Prx ? and Prx ? mRNA were observed in 60 mg/kg group.Our results suggest that appropriate dietary curcumin supplementation(especially 60 mg/kg curcumin diet)significantly improved the growth and non-specific immune responses in juvenile M.amblycephalain.3 The present study was conducted to evaluate the effect of various feeding patterns of curcumin on growth and non-specific immune response in juvenile Wuchang bream.Healthy Megalobrama amblycephala(initial weight:3.15±0.01g)were grown in a circulating water system for 8 weeks.Five groups were studied:one control group was fed with a basal diet for eight weeks(Pattern 1,P1),and three treatment groups were fed with a trial diet of 30 mg/kg curcumin at one-week(Pattern 2,P2),two-week(Pattern 3,P3),four-week(Pattern 4,P4)intervals.The final treatment group maintained the trial diet for?the entire eight week study duration(Pattern 5,P5).Results indicated that(1)fish in the P3 treatment group had significantly higher rates of weight gain(WG)and Specific growth rate(SGR)than that of P1 and P5 groups(p<0.05).However,the P3 group got a significantly lowest feed conversion ratios(FCR)compare to P1,P2 and P5 groups(p<0.05);(2)Compared to the control group,the respiratory burst activity and interleukin(IL-1?)activity of the P2,P3 and P4 groups were significantly increased(p<0.05);(3)Plasma alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activity were shown to decrease at first and then increase from P1 condition to P5 condition,while,tumor necrosis factor-?(TNF-?)activity and Alternative pathway of complement hemolysis(ACH50)activity showed the opposite trend.Fish under P3 treatment showed the most significant improvement of all tested parameters compared to control(p<0.05);(4)In a bacterial challenge experiment with A.hydrophila,fish under P3 treatment showed significant lower cumulative mortality than the control group after 96 hours(p<0.05);(5)the highest expression of Prx ?,Prx ?,Prx ?,Prx ? Prx ? and Prx ? mRNA were observed in P3 treatment.The results of this study suggest that an initial 2-week feeding interval is recommended for the economic and practical culture of Megalobrama amblycephala.4 This study was aimed to investigate the effects of dietary curcumin supplementation and feeding patterns on M.amblycephala physiological response,immune response and the expression of peroxiredoxin gene in liver.The results indicated that ALT and AST activities were significantly enhanced after 24 h A.hydrophila stress.Compared with the control group,fish fed diets supplemented with 60 mg/kg curcumin and P3 feeding pattern had significant(p<0.05)inhibition in AST activities.However,WBC,NO content,NOS,IL-1? and TNF-? activities showed negtive trends.The expression of peroxiredoxin gene increased after A.hydrophila stress than that of before,suggesting A.hydrophila could affect the ability of antioxidant in juvenile blunt snout bream.Fish fed diets supplemented with 60 mg/kg curcumin and P3 feeding pattern increased the expression of Prx ?,Prx ?,Prx ?,Prx ? and Prx ? mRNA in liver,which strengthen the ability of M.amblycephala against A.hydrophila and enhance the antioxidative ability. |
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