An assessment of the reproductive toxicity of GONPs exposure to Bombyx mori.

This study aimed to explore the toxicity of environmental residues of graphene oxide nanoparticles (GONPs) to reproduction of Lepidopteron insects using both ovary cell line (BmN) and individual female Bombyx mori as the research subjects. The results showed that GONPs dose dependently affect BmN cells. At higher concentrations (>25 mg/L), GONPs led to oxidative stress, ROS accumulation and DNA damage in BmN cells and significantly reduced their survival rate (p ≤ 0.05). Moreover, feeding female B. mori larvae with mulberry leaves treated with 25 mg/L GONPs significantly decreased their gonadosomatic index (GSI) by 40.84%, and increased oxidation levels and antioxidant enzyme activity in silkworm ovary tissues. Pathological analysis found that exposure to GONPs decreased the numbers of both oogonia and oocytes in ovarian tissues, increased the formation of peroxisome and vacuoles in follicle cells, reduced the transcription of genes (Vg, Ovo, Sxl-s, Sxl-l, and Otu) related to ovarian development in B. mori by 0.61, 0.65, 0.75, 0.72, and 0.42-fold, respectively, and lowered the amount of spawning by 52.25%. Overall, these results revealed that GONPs exposure is toxic to the reproduction of B. mori. The underlying mechanism is that oxidative stress due to GONPs causes oxidative damage to DNA, damages ovarian tissues, as well as hinders B. mori development and spawning. Thus, this study provides important experimental data for safety evaluation of reproductive toxicity due to GONPs exposure.