Prenatal toxicity of L-mimosine in Wistar rats.

L-Mimosine is the main active component of the plant Leucaena leucocephala. Due to its metal-chelating mechanism, it interacts with various metabolic pathways in living organisms, making it a potential pharmacological target, although it also leads to toxicity. The present study aimed to investigate the transplacental passage of L-mimosine and its effects on embryofetal development. Pregnant Wistar rats were divided into control groups (CO2; n = 8 or CO3; n = 6, according to experimental design 2 or 3) that received only the vehicle, and groups that received doses of 60 (n = 9), 100 (n = 8), 140 (n = 9), and 240 (n = 7) mg/kg of L-mimosine from gestational day (GD) 6-19. For the transplacental analysis, five rats were used: two as controls and three treated with a dose of 140 mg/kg L-mimosine from GD12 to 14. All the animals received food and water ad libitum. The parameters analyzed were body weight gain; water and food consumption; serum biochemistry; blood cell counts; reproductive indices; and histopathological, visceral and skeletal analyses of the fetuses. In the groups that received doses of 60, 100, and 140 mg/kg, alterations (P < 0.05) in the skeletal development of the fetuses were observed. In the 240 mg/kg group, a decrease (P < 0.05) in total food consumption; a decrease (P < 0.05) in absolute leukocyte and neutrophil counts; alterations (P < 0.05) in the levels of ALT, GGT, and creatinine enzymes; a decrease (P < 0.05) in the relative weight of the thymus along with a loss of the corticomedullary distinction; coalescence of lymphoid follicles in the spleen; and skeletal and visceral alterations and alopecia were observed. L-Mimosine was detected in the amniotic fluid of the rats. These results demonstrate the complex action of L-mimosine, leading to toxic effects on both dams and fetuses, highlighting the risk of exposure to this substance during the perinatal period, which negatively impacts embryo/fetal and neonatal growth and development.