Parental CuO nanoparticles exposure results in transgenerational toxicity in Caenorhabditis elegans associated with possible epigenetic regulation.

Environmental nanomaterials contamination is a great concern for organisms including human. Copper oxide nanoparticles (CuO NPs) are widely used in a huge range of applications which might pose potential risk to organisms. This study investigated the in vivo transgenerational toxicity on development and reproduction with parental CuO NPs exposure in the nematode Caenorhabditis elegans. The results showed that CuO NPs (150 mg/L) significantly reduced the body length of parental C. elegans (P0). Only about 1 mg/L Cu2+ (~0.73%) were detected from 150 mg/L CuO NPs in 0.5X K-medium after 48 h. In transgenerational assays, CuO NPs (150 mg/L) parental exposure significantly induced developmental and reproductive toxicity in non-exposed C. elegans progeny (CuO NPs free) on body length (F1) and brood size (F1 and F2), respectively. In contrast, parental exposure to Cu2+ (1 mg/L) did not cause transgenerational toxicity on growth and reproduction. This suggests that the transgenerational toxicity was mostly attributed to the particulate form of CuO NPs. Moreover, qRT-PCR results showed that the mRNA levels of met-2 and spr-5 genes were significantly decreased at P0 and F1 upon only maternal exposure to CuO NPs (150 mg/L), suggesting the observed transgenerational toxicity was associated with possible epigenetic regulation in C. elegans.

Di (2-ethylhexyl) phthalate effects on the growth, development, and reproduction of Moina macrocopa (Crustacea: Cladocera).

Di (2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in plastics. The effects of DEHP on terrestrial vertebrates have been extensively reported but the effects of DEHP contamination on aquatic ecosystems have not been thoroughly studied. Since water bodies are one of the main mediums through which DEHP is released worldwide, the impacts of DEHP contamination should be manifested in water fleas. Therefore, maternal Moina macrocopa were exposed to 1, 10, 100, and 1000 µg/L concentrations of DEHP. Changes in growth and reproduction were evaluated. The findings demonstrated that DEHP exposure did not have a negative impact on growth or the ability to reproduce. An analysis of the ovary yolk body (YB) demonstrated that the average size and number of yolk bodies (YBs) produced by M. macrocopa exposed to 1000 µg/L DEHP were not significantly different to the average size and number of YBs produced in blank control and solvent control conditions. These outcomes support the cellular pathology data gathered by other researchers. Nevertheless, when M. macrocopa was exposed to 1000 µg/L DEHP for five days, a significant increase in YB numbers was observed with changes in YB morphology. The critical cellular pathology of YB showed morphological abnormalities, including rod-shaped YBs, and YB density was higher than in the blank and solvent controls. Even though these results suggest that antioxidative stress can be induced by DEHP exposure, growth, and reproduction were not significantly different among exposed water fleas compared to fleas in the blank and solvent controls. The result was attributed to the antioxidant response of the water flea. In conclusion, the present study enhances our understanding of previous findings from risk assessments of DEHP contamination in aquatic ecosystems.