Effect of Montmorillonite on 4-Nonylphenol Enrichment in Zebrafish

The aim of this study was to investigate the effect of montmorillonite on nonylphenol (4-nonylphenol, 4-NP) enrichment in a zebrafish model. The AB strain zebrafish were used as the animal subjects, and three concentration gradients were set for both nonylphenol and montmorillonite, according to their actual concentrations in aquaculture water in Huzhou City. A group treated with nonylphenol alone was also set, adding up to 12 experimental groups. Concentrations of nonylphenol enriched in the liver, muscle and gills of zebrafish were detected by solid phase microextraction–high performance liquid chromatography at Days 7, 15 and 30, respectively. Additionally, the relative enzymatic activity of superoxide dismutase (SOD) and the glutathione S-transferase (GST) were also detected, and the data were statistically analyzed. The results showed that the concentrations of nonylphenol in zebrafish peaked at Day 7 and gradually decreased afterwards for all the experimental groups. The montmorillonite reduces short-term accumulation of nonylphenol in gills, and the high concentration of nonylphenol facilitates its enrichment in liver and muscle, while the low concentration of nonylphenol does not. Meanwhile, the low concentration of nonylphenol in liver exerts an influence on the inductive effect of SOD and GST, while the high concentration of nonylphenol shows the inhibiting effect of SOD and GST.