Comparative Toxicokinetics and Biomarker Responses of Typical Psychiatric Pharmaceuticals in Daphnia magna

The widespread availability and pseudo-persistence of typical psychiatric pharmaceuticals (PDs) can have serious impacts on aquatic ecosystems and even human health. However, the toxicokinetics of typical PDs and the corresponding enzymatic biomarker responses are unclear. In this study, eight typical PDs [carbamazepine (CBZ), citalopram (CIT), sertraline (SER), venlafaxine (VLF), amitriptyline (AMT), chlorpromazine (CPM), quetiapine (QTP) and clozapine (CLZ)] were selected to study the uptake, depuration and biological effects of PDs in <i>Daphnia magna</i>. The results found that the uptake rates (<i>K</i>_u) were in the sequence of VLF < QTP < CBZ < CLZ < CIT < AMT < SER < CPM, while the depuration rates (<i>K</i>_d) were in the order of CLZ < AMT < CIT < SER < QTP < CBZ < CPM < VLF. Correspondingly, the bioconcentration factors (BCFs) followed on as VLF < QTP < CBZ < CIT < AMT < CLZ < SER < CPM. Both pH-dependent octanol-water partition coefficients (log <i>D</i>_ow) and liposome-water partition coefficients (log <i>D</i>_lip-w) exhibited positive correlations with the log BCF of PDs (<i>p</i> < 0.05), indicating the important roles of ionization degree and biological phospholipid contents on bioconcentration. Superoxide dismutase (SOD) activities were evidently induced in the SER and CPM groups, while ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST) activities were significantly induced only in the CBZ group. Acetylcholinesterase (AChE) activity was obviously induced by CBZ, SER and AMT, with levels 1.73, 1.62 and 2.44 times that of the control group (<i>p</i> < 0.05). The <i>K</i>_u of PDs, oxidative stress and metabolic level of <i>D. magna</i> combine to affect BCF levels together. In conclusion, this study contributes to a better understanding of the toxicokinetics and biochemical responses of PDs in <i>D. magna</i> and potential mechanisms of action, which may allow for a better assessment of their environmental health risks to aquatic ecosystems.