Effects of glycosylation on the accumulation and transport of fipronil in earthworm (Eisenia feotida)

Abstract In this study, the differences in the accumulation of fipronil (F) and the glycosylated product glucose-fipronil (GTF) in earthworm within 48 hours were investigated, and the reason for these differences was explored. The accumulation concentrations of F and GTF for 48 hours in earthworm were determined and studied by HPLC after simple, rapid pretreatment; the mean recoveries were 84.79~95.83%, and the relative standard deviations were 3.39~9.21%, indicating that the method could accurately detect the accumulation concentrations of F and GTF in earthworm. Results showed that the accumulation of F and GTF in earthworm increased with the treatment time, the accumulation concentrations of F in earthworm were significantly higher than those of GTF, and the accumulation concentrations of F were 3.1~6.2 times those of GTF. In addition, the half-lives of GTF in soil (16.90~18.24 days) were significantly lower than those of F (24.75~26.65 days). After adding a hexose transport inhibitor phlorizin, the accumulation change of F in earthworm were not significant, but the accumulation of GTF in earthworm were significantly inhibited, and the accumulation concentrations of GTF in earthworm after adding phlorizin were 32.71~59.07% of those without phlorizin. Overall, our results indicated that the uptake and transport of F and GTF in earthworm were significantly different, the uptake and transport of GTF was relate to monosaccharide transporters, and glycosylation could reduce the toxicity of fipronil to earthworm and the environment, providing an important reference for the application of glucose-fipronil.