Triclocarban (TCC), an antimicrobial agent used in personal care products, has been widely detected in aquatic ecosystems and has raised significant concerns for aquatic organisms and human health. Th Show more
Triclocarban (TCC), an antimicrobial agent used in personal care products, has been widely detected in aquatic ecosystems and has raised significant concerns for aquatic organisms and human health. This study aimed to investigate the neurotoxic effects of TCC exposure, a broad-spectrum bactericide, through behavioral, molecular, pathological, and metabolomic analyses. For this purpose, adult zebrafish were exposed to TCC at doses of 3, 10, and 30 μg/L for 96 h, and their brain tissues were removed. Subsequently, behavioral (anxiety and circadian rhythm tests), molecular (qPCR), histopathological, and metabolomic analyses were performed on these fish. The data obtained showed that TCC treatment increased anxiety-like behaviors in zebrafish and caused disruptions in the circadian rhythm. Additionally, it was determined that the expression levels of both core clock genes (Bmal and Gnat2) and genes associated with neuroplasticity, stress response, and neurotransmission (Bdnf, Crhr, 5-ht4, Ache) changed significantly in a dose-dependent manner compared to the control group. Additionally, it was observed that TCC increased degeneration and necrosis in the brain in parallel with the dose increase, while raising 8-OHdG and BDNF protein levels and decreasing NRF2 and SIRT1 protein levels. When metabolomic analysis data were evaluated, it was determined that TCC, especially at the highest dose, significantly altered metabolite levels. These results reveal that TCC, beyond being an environmental pollutant, may cause behavioral disorders and neurotoxic effects. Show less
The transport of pharmaceutical compounds into aquatic ecosystems poses a significant environmental threat, particularly due to the presence of drugs that cannot be completely removed during wastewate Show more
The transport of pharmaceutical compounds into aquatic ecosystems poses a significant environmental threat, particularly due to the presence of drugs that cannot be completely removed during wastewater treatment processes. Diclofenac (DCF), one of the most widely used nonsteroidal anti-inflammatory drugs worldwide, is among the pharmaceuticals frequently detected in aquatic environments due to its high consumption levels and persistence in the environment. It is known that this compound causes neurotoxicity, behavioral disorders, and physiological stress responses in aquatic organisms even at low concentrations. This study aimed to determine the effects of diclofenac exposure on oxidative stress, circadian rhythm, and behavioral parameters in zebrafish larvae. For this purpose, zebrafish embryos and early-stage larvae were exposed to DCF at concentrations of 0.5, 2.5, and 12.5 μg/L for 120 h. Subsequently, to investigate the effect of DCF on oxidative stress, SOD, CAT, GPX, and AChE enzyme activities and gene expression levels were analyzed. To examine its effects on behavior and circadian rhythm, thigmotaxis and locomotor activity analyses were performed. Additionally, to determine the molecular-level effects of behavioral changes, the expression levels of the bdnf, 5ht4, crhr, bmal1, per, and gnat2 genes were analyzed. Overall, our findings indicate that DCF affects behavioral activity, neurotransmitter metabolism, oxidative stress response, circadian rhythm, and retina-related molecular regulators in zebrafish larvae in a multilevel manner. These results highlight the potential risks of pharmaceutical contaminants on neurodevelopmental processes in aquatic ecosystems and demonstrate that even environmental doses can produce complex responses in biological systems. Show less