Chronic oral exposure to a glyphosate-base herbicide impairs female reproductive outcomes in Wistar rats

GASTIAZORO MP; DONÁ F; LORENZ V; VARAYOUD J; MILESI MM; DURANDO M

Modalidad Virtual

Congreso; Reunión de Sociedades de Biociencias 2021, LXVI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2021

SAIC

Glyphosate-based herbicides (GBHs) are the most globally used herbicide increasing the environmental exposure risk. The chronic effects on reproductive outcomes associated with long-term exposure to GBHs remain unexplored. In the present work, we investigated, in Wistar rats, the effects of chronic oral administration of a safe dose of a commercial GBH on: 1) body weight and food intake; 2) reproductive performance and feto-placental parameters. Female rats were exposed to GBH through food, in a dose of 2 mg of glyphosate/kg bw/day, from postnatal day 21 (PND21) and during 11 weeks. Control group (CON) was provided with a laboratory pellet chow-based paste. Body weight and food intake were registered along the exposure. Females at the proestrus stage were caged with males with proven fertility. We evaluated the pregnancy rate by assessing the number of pregnant females/number of females housed with a male x 100. In addition, we determined the reproductive performance by quantifying the number of corpora lutea, the implantation sites (IS) and the resorption sites on gestational day 19 (GD19). The fetuses and the placentas pairs were removed and weighted. The placental index was calculated as follows: placental weight/fetal body weight. Last, fetal length and litter size were determined. We detected an increase in body weight of the rats exposed to GBH 8 days after the beginning of treatment (PND30). However, not differences were found on food intake between CON and GBH-treated rats. Regarding reproductive performance, we detected a lower number of IS in GBH group compared to CON group. Fetal development was impaired, we detect a decrease in weight and length of the fetuses in GBH group. Neither placental weight nor placental index, were altered by GBH treatment. In conclusion, chronic exposure to GBH impaired female fertility and fetal development. We consider the importance of the evaluation of chronic oral exposure to GBH to showing additional evidence associated to GBH effects.