Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin 300071, People's Republic of China.
Environ Toxicol. 2011 Aug;26(4):417-23. doi: 10.1002/tox.20567. Epub 2010 Mar 1.
Increasing attention has been paid to antibiotic contamination as an increasingly serious environmental issue. Tetracycline has been widely used for decades in human and veterinary medicines, with incremental residues in the environment and adverse influences on living organisms. In the present study, the genetic toxicity of tetracycline was investigated using a bioassay method with wheat (Triticum aestivum L.) root-meristem cells at a concentration range of 0.25-300 mg L(-1) and exposure times of 24, 48, and 72 h. The results indicated that tetracycline at lower concentrations (0.25-1 mg L(-1) ) stimulated cell mitotic division, whereas at 50-300 mg L(-1) concentration caused a concentration-related decrease in mitotic index (MI). The lower tetracycline concentrations induced a slight increase in the frequency of micronucleus (MN), chromosomal aberration (CA), and sister chromatid exchange (SCE) in wheat root tips. However, there were significant increases in these indices at higher concentrations in concentration- and time-dependent manners, including the frequencies of MN (25-200 mg L(-1) ), CA (10-200 mg L(-1) ), and SCE (5-200 mg L(-1) ), respectively. The inducement of MN, CA, and SCE decreased at 250 and 300 mg L(-1) due to acute cell toxicity for all tested times. Comparatively, SCE was the most sensitive, followed by CA, with MN the least sensitive to the genotoxicity of tetracycline in wheat. These results imply that tetracycline may be genotoxic to plant cells, and exposure to tetracycline may pose a genotoxic risk to living organisms. The results also suggest that the wheat bioassay was efficient, simple, and reproducible in monitoring the genotoxicity of tetracycline in the environment.
越来越多的人关注到抗生素污染是一个日益严重的环境问题。几十年来，四环素被广泛应用于人类和兽医药品，其在环境中的残留量不断增加，对生物产生不良影响。本研究采用生物测定方法，以小麦（Triticum aestivum L.）根尖细胞为材料，研究了四环素在 0.25-300mg/L 浓度范围和 24、48 和 72h 暴露时间下的遗传毒性。结果表明，较低浓度（0.25-1mg/L）的四环素刺激细胞有丝分裂分裂，而 50-300mg/L 的浓度则导致有丝分裂指数（MI）呈浓度相关下降。较低浓度的四环素略微增加了小麦根尖微核（MN）、染色体畸变（CA）和姐妹染色单体交换（SCE）的频率。然而，在较高浓度下，这些指数以浓度和时间依赖的方式显著增加，包括 MN（25-200mg/L）、CA（10-200mg/L）和 SCE（5-200mg/L）的频率。由于所有测试时间的细胞毒性急性增加，MN、CA 和 SCE 的频率在 250 和 300mg/L 时降低。相对而言，SCE 最敏感，CA 次之，MN 对小麦中四环素的遗传毒性最不敏感。这些结果表明，四环素可能对植物细胞具有遗传毒性，暴露于四环素可能对生物产生遗传毒性风险。结果还表明，小麦生物测定法在监测环境中四环素的遗传毒性方面是高效、简单和可重复的。
