Evaluation of the Pre-, Peri-, and Postnatal Toxicity of Monoethanolamine in Rats Following Repeated Oral Administration during Organogenesis

Abstract

Pregnant Wistar rats (40/group) were administered monoethanolamine (MEA) as an aqueous solution by gavage at dose levels of 0, 40, 120, and 450 mg/kg/day on days 6 through 15 of gestation. On day 20 of gestation, 25 dams/group were euthanized and the fetuses were delivered by cesarean section, weighed, sexed, and examined for external, visceral, and skeletal alterations. The remaining dams (15/group) were allowed to litter and rear their pups to day 21 postpartum. The dams and pups were then euthanized and examined for gross pathologic changes. Gavage administration of 450 mg MEA/kg/day to pregnant rats resulted in maternal toxicity as evidenced by statistically significant (α = 0.05) decreases in feed consumption on gestation days 6–8 and 17–20 and on postpartum days 0–4. Additionally, statistically significant decreases in mean maternal body weights were observed on gestation days 15, 17, and 20 and on lactation days 0, 4, 7, and 21. Body weight gains of the 450 mg/kg/day dams were also significantly decreased (13% relative to controls) on gestation days 15–20. There was no evidence of maternal toxicity at 40 or 120 mg/kg/day of MEA. Despite the maternal effects observed at 450 mg/kg/day, no significant fetal effects were observed at this or any dose level tested, nor were there any indications of a treatment-related effect on postnatal growth or on the viability of offspring. Thus, it was concluded that MEA was not developmentally toxic to Wistar rats following repeated oral administration, even at maternally toxic dose levels as high as 450 mg/kg/day.