DNA damage and biochemical toxicity of antibiotics in soil on the earthworm Eisenia fetida.
DNA damage and changes in enzyme activities were used as biomarkers to evaluate the genotoxicity and oxidative stress of tetracycline and chlortetracycline on the earthworm Eisenia fetida. The results showed that both antibiotics induced significant genotoxicity on earthworms in a dose-dependent manner (p<0.01) with chlortetracycline having a stronger effect than tetracycline in the short term. The tests on the activities of superoxide dismutase (SOD) and catalase (CAT) enzymes further indicated biochemical stresses induced by the antibiotics. An N-shaped activity pattern was noted with the enzyme activities being stimulated first, then inhibited, and stimulated again with increasing concentration. The induced activity of SOD or CAT could scavenge oxygen free radicals and protect the organisms against oxidative stress by alleviating the corresponding DNA damage. Compared to enzyme activities, DNA damage as a biomarker was more sensitive and is thus more suitable for detecting low concentration exposure and diagnosing the genotoxicity of contaminants in terrestrial environment.
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Luxi
L
Dong
Jie
J
Gao
Xiujie
X
Xie
Qixing
Q
Zhou
D000818:Animals; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D002751:Chlortetracycline / Q000633:toxicity; D004249:DNA Damage / Q000187:drug effects; D005609:Free Radicals / Q000378:metabolism; D009835:Oligochaeta / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D013752:Tetracycline / Q000633:toxicity
D000900:Anti-Bacterial Agents; D005609:Free Radicals; D012989:Soil Pollutants; D002374:Catalase; D013482:Superoxide Dismutase; D013752:Tetracycline; D002751:Chlortetracycline