Fragrance materials affect life history parameters and gene expression in Daphnia magna: An emerging issue for freshwater ecosystems

A chronic toxicity test (21 d exposure) with the model organism Daphnia magna was performed to study the single-compound and combined effects of four fragrance materials (FMs), including musk xylene (MX), CelestolideTM (ADBI), GalaxolideTM (HHCB), and ethylene brassylate (MT). Furthermore, the transcriptional responses of ten target genes related to detoxification, molting and reproduction (DHR96, P-gp, CYP360A8, GST, CYP314, EcRb, Vtg, CAT, GPX, and GCLC) were determined by performing a quantitative real-time polymerase chain reaction (qRT-PCR) after juvenile D. magna was exposed for 48 h. The results showed that MX, ADBI and HHCB affected development and reproduction after chronic exposure at a concentration of 10 mu g L-1. Conversely, MT did not affect reproduction, growth or molting during the 21 d exposure. In juvenile D. magna, gene expression was significantly altered by ADBI (DHR96, CYP260A8, and GCLC) and MX (DHR96, CYP360A8, EcRb, Vtg, CYP314, and GCLC) but not by HHCB. These results suggest that compared to biochemical measures, conventional biological endpoints provide more informative data regarding the effects of this FM. Compared to single substances in the chronic test, the mixture of the four FMs showed effects at lower concentrations and increased gene expression for EcRb and CYP314 during juvenile exposure, indicating a possible additive or synergistic effect of the four FMs compared to single compound exposure.

Automated summary

A chronic toxicity test was conducted using Daphnia magna as the model organism to investigate the effects of four fragrance materials (MX, ADBI, HHCB, and MT). The study found that MX, ADBI, and HHCB had adverse effects on development and reproduction, while MT had no effect. Gene expression analysis showed that ADBI and MX significantly altered gene expression in juvenile D. magna, but HHCB did not. The mixture of the four fragrance materials showed effects at lower concentrations and increased gene expression, suggesting a possible additive or synergistic effect.