The widespread accumulation
of nanoplastics is a growing
concern
for the environmental and human health. However, studies on the mechanisms
of nanoplastic-induced developmental toxicity are still limited. Here,
we systematically investigated the potential biological roles of nanoplastic
exposure in zebrafish during the early developmental stage. The zebrafish
embryos were subjected to exposure to 100 nm polystyrene nanoplastics
with different concentrations (0, 100, 200, and 400 mg/L). The results
indicated that nanoplastic exposure could decrease the hatching and
survival rates of zebrafish embryos. In addition, the developmental
toxicity test indicated that nanoplastic exposure exhibits developmental
toxicity via the inhibition of the heart rate and body length in zebrafish
embryos. Besides, behavioral activity was also significantly suppressed
after 96 h of nanoplastic exposure in zebrafish larvae. Further biochemical
assays revealed that nanoplastic-induced activation of the oxidative
stress responses, including reactive oxygen species accumulation and
enhanced superoxide dismutase and catalase activities, might affect
developmental toxicity in zebrafish embryos. Furthermore, a quantitative
polymerase chain reaction assay demonstrated that the mRNA levels
of the base excision repair (BER) pathway-related genes, including
lig1
,
lig3
,
polb
,
parp1
,
pold
,
fen1
,
nthl1
,
apex
,
xrcc1
, and
ogg1
, were altered in zebrafish embryos for 24 h after nanoplastic
exposure, indicating that the activation of the BER pathway would
be stimulated after nanoplastic exposure in zebrafish embryos. Therefore,
our findings illustrated that nanoplastics could induce developmental
toxicity through activation of the oxidative stress response and BER
pathways in zebrafish.