Reproductive toxicity of dibutyl phthalate adsorbed on carbon nanotubes in male Balb/C mice

Abstract

Dibutyl phthalate (DBP) is an environmental hormone disrupter. This study was designed to investigate whether DBP adsorbed in multi-walled carbon nanotubes (MWCNTs) can easily cross the blood-testis barrier and slow down the degradation of DBP in male mice, thereby prolonging the interference effect of DBP. The results showed that: in male Balb/C mice, the sperm density of the MWCNTs group and the DBP plus MWCNTs group decreased significantly (p < 0.05); and the sperm deformity rate increased significantly (p < 0.05). Testicular tissue sections from the combined exposure group showed that most of the seminiferous tubules were atrophied, there were more large gaps between the cells in the tubules, and the number of mature-sperm decreased. The reactive oxygen species (ROS) levels increased significantly in the combined exposure group (p < 0.01). Proteomics results showed that there were 231 differentially expressed proteins in the combined exposure group compared with the MWCNTs only group, and 69 differentially expressed proteins compared with the DBP group. GO enrichment analysis showed that the differentially expressed proteins mainly include: 60 s acid ribosomal protein P1; nuclear autoantigen sperm protein; centromere protein V; and other proteins related to cell division. These results indicate that MWCNTs with adsorbed DBP can increase oxidative damage in the testis of male mice, interfere with DNA replication and cell division in testicular tissue cells, induce cell apoptosis, and destroy the normal spermatogenic function of the testis.