饲料添加剂叔丁基对羟基茴香醚和抗生素诺氟沙星对剑尾鱼的毒性效应

Toxicity of the food additive BHA (butylated hydroxyanisole) and antibiotic NFLX (norfloxacin) to swordtail fish (Xiphophorus helleri)

研究了叔丁基对羟基茴香醚(butylated hydroxyanisole,BHA)和诺氟沙星(norfloxacin,NFLX)对剑尾鱼的急性毒性及其肝脏谷胱甘肽硫转移酶(GST)、丙二醛(MDA)、过氧化氢酶(CAT)及7-乙氧基异吩恶唑酮-脱乙基酶(EROD)活性的影响.结果表明,BHA和NFLX对剑尾鱼毒性大小分别属于高毒和低毒.BHA的暴露浓度为0.20mg.L-1和0.04mg.L-1时,GST和CAT活性诱导分别达到最大值;NFLX的暴露浓度为5mg.L-1时,GST和CAT均受到最大程度的诱导.随着BHA和NFLX暴露浓度的增加,GST和CAT呈现出先诱导后抑制的典型"钟型曲线"变化规律,而MDA含量和EROD活性则逐渐增加.其中,MDA和EROD响应较为敏感,适合作为BHA和NFLX暴露的生物标记物.雌雄个体酶响应的敏感程度存在一定的差异,雄性个体比雌性个体敏感.

The effects of the food additive butylated hydroxyanisole （BHA） and the antibiotic Norfloxacin （NFLX） on swordtail fish （Xiphophorus helleri） were measured by considering a number of parameters, including glutathione S-transferase （GST）, catalase （CAT）, 7-ethoxyresorufin-o-dealkylases （EROD） and malondialdehyde （MDA） contents. Upon exposure to BHA or NFLX, both GST and CAT levels in swordtail fish first increased and then decreased after reaching a maximum. The highest level of GST was detected when the fish were exposed to BHA at a dose of 0.20 mg·L^-1. However, we detected the highest CAT level at an exposure level of 0.04 mg·L^-1 BHA. When exposed to NFLX, the highest levels of GST and CAT were found at a concentration of 5.00 mg·L^-1, suggesting that BHA is more toxic than NFLX. EROD activity and MAD contents exhibited a linear increase. Therefore, MDA and EROD were the more sensitive measured parameters and may be used as potential biomarkers for BHA and NFLX exposure. Moreover, male fish were more sensitive than females to exposure to BHA and NFLX.