Synergy of Arsenic and Graphene Oxide in Utero and Lactation Exacerbates Reproductive Disorders in Female Rat Offspring Undergoing Puberty and Maturity

Abstract

Notably, the widespread ubiquity of arsenic and graphene oxide in the environment validates the occurrence of their co-exposure, posing significant threats to target organisms, including humans. Herein, prepuberty, puberty, and maturity were investigated using anogenital distance, vaginal opening, first estrus, reproductive hormone profiles, cyclicity, sexual behaviour and pregnancy outcomes to assess the impact of exposure to arsenic and/or graphene oxide on the puberty of offspring female rats after maternal exposure during gestation and lactation periods. Zero-day pregnant Sprague Dawley females were randomly divided into four groups, each receiving a different treatment via drinking water from gestation day 0 to postnatal day 21: control group (CON, drinking water); arsenic group (ARS, 10 mg/L sodium arsenite); graphene oxide group (GOX, 0.5 mg/mL); and co-exposure group (ARS + GOX; 10 mg/L of arsenic combined with 0.5 mg/mL of graphene oxide). Individually or combined, arsenic and graphene oxide exposure increase the sexual retardation and female masculinization, as evidenced by a significant increase in anogenital distance, delay in the first estrus cycle, and prolongation in the timing of the vaginal opening. At maturity, the offspring exhibited a significant elevation of testosterone and a significant decrease in estradiol. Offspring females showed inhibited receptivity to their male mates, indicated by lower lordosis quotient and intensity. Additionally, there was an increase in the number of estrous cycles but a decrease in their duration. Moreover, an increase in implantation loss and the number of resorbed embryos, along with a reduction in viable fetuses. In conclusion, reproductive deterioration was more significant in the offspring exposed to combined arsenic and graphene oxide compared to those exposed to ARS or GOX alone, indicating that arsenic exposure is exacerbated when combined with graphene oxide during the experimental episode.