Abstract
Triclosan (TCS) and trichlocarban (TCC) are used as antimicrobials in soaps and other household products, because of their antibacterial and anti-fungal properties. We assessed the potential toxicological effects associated with TCS and TCC using Caenorhabditis elegans (C. elegans) as a model soil organism. We examined changes in the test endpoints of growth and maturation such as body length,ratio (%) of gravid worms and fecundity. Growth tests showed that the lowest observed effective concentrations (LOEC) of TCS and TCC in C. elegans were 0.78 and <0.074 mg/L, respectively. The estimated LOEC values in maturation tests were 3.13 mg/L for TCS and 0.17 mg/L for TCC. The estimated LOEC for TCC in reproduction tests was 0.11 mg/L, but this could not be determined for TCS (>6.25 mg/L). We also investigated the suitability of the DNA microarray as an eco-toxicogenomic approach to determine the physiological function of TCS and TCC in C. elegans. Both TCS (5.0 mg/L) and TCC (0.166 mg/L) were examined mainly as cytochrome P450 (CYP) gene expression using a customized chip for C. elegans. Among 79 CYP genes, 19 and 10 were up-regulated upon exposure to TCS and TCC, respectively. Both TCS (5.0 mg/L) and TCC (0.166 mg/L) were common to indicate the induction ability of CYP35As, which function is related to mammalian CYP2 clade.
