饲喂不同浓度黄曲霉毒素B_(1)饲料对花鳗鲡幼鱼生长、抗氧化能力和毒素积累的影响

EFFECTS OF DIETARY AFLATOXIN B_(1) ON GROWTH,ANTIOXIDANT CAPACITY AND TISSUE ACCUMULATION OF JUVENILE MARBLED EEL(ANGUILLA MARMORATA)

以含不同浓度黄曲霉毒素B_1(AFB_1)(0、10、100和1000μg/kg饲料)的4种饲料饲喂平均初始体重为(6.41±0.10) g的花鳗鲡(Anguilla marmorata)幼鱼56d,探讨AFB_1对花鳗鲡幼鱼生长性能、抗氧化能力、肝脏组织结构及鱼体肌肉中的毒素积累的影响。结果表明,各实验组幼鱼均未表现出行为及体色的异常。1000μg/kg毒素组幼鱼的存活率、终末体重、摄食率、特定生长率和饲料效率显著低于对照组, 10μg/kg毒素组和100μg/kg毒素组与对照组无显著差异。10μg/kg毒素组幼鱼肝脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、谷胱甘肽S转移酶(GST)活性和丙二醛(MDA)含量与对照组无显著差异。饲料AFB_1含量≥100μg/kg显著影响花鳗鲡幼鱼肝脏的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSHPx)和谷胱甘肽转移酶(GST)活性。对照组和10μg/kg毒素组幼鱼肝脏组织学观察未发现明显病理变化。1000μg/kg毒素组幼鱼的肝脏细胞表现出严重的空泡化。随着饲料AFB_1水平的升高,幼鱼肝脏和肌肉中AFB_1积累量均显著升高。1000μg/kg毒素组幼鱼肝脏和肌肉中AFB_1积累量分别为17.75和5.98μg/kg,均超过FDA食品安全限定标准(5μg/kg)。由此可见,饲料中AFB_1≤10μg/kg对花鳗鲡幼鱼是相对安全的浓度。

To evaluate the effects of dietary aflatoxin B1(AFB1)on growth performance,antioxidant capacity,histological changes and accumulation in juvenile marbled eel(Anguilla marmorata),triplicate groups of marbled eel with initial body weight of[(6.41±0.10)g]were fed with four diets containing 0,10,100 and 1000μg/kg AFB1 for a 56-day trial.No unusual behavior or external changes were observed in fish fed diets containing AFB1.Significant lower survival rate,Final Body Weight(FBW),Feeding Rate(FR),Specific Growth Rate(SGR)and Feed Efficiency(FE)were observed in 1000μg/kg AFB1 group,while no significant differences were found among other groups.There were no significant differences in activities of superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-Px),glutathione S-transferase(GST),and malondialdehyde(MDA)in liver between the control and 10μg/kg AFB1 diet group.AFB1 above 100μg/kg significantly impacted activities of liver SOD,GSH-Px and GST.No significant histological lesions in liver were identified under the microscope in the control and 10μg/kg AFB1 diet groups.Severe vacuolar degeneration of hepatocytes was found in 1000μg/kg AFB1 group.AFB1 accumulation in liver and muscle significantly increased with increased dietary AFB1 levels,with 17.75 and 5.98μg/kg in 1000μg/kg AFB1 group,respectively,which are above the safety limitation of 5μg/kg as proposed by FDA.These results indicate that 10μg/kg AFB1 is the safe level in juvenile marbled eel diet.