The "toxic window" of amoxicillin exposure during pregnancy on long bone development in fetal mice.

AIMS: Amoxicillin is a broad-spectrum beta-lactam antibiotic used to treat infectious diseases in pregnant women. Studies have shown that prenatal amoxicillin exposure (PAmE) has developmental toxicity on fetal development. However, the effect of PAmE on long bone development has not been reported. This study aimed to investigate the "toxic window" of PAmE on long bone development and explore its possible mechanism in fetal mice.

MATERIALS AND

METHODS

Pregnant mice were administered amoxicillin by gavage at different stages (gestational day (GD)10-12 and GD16-18), different doses (150 and 300 mg/kg·d) and different courses (single and multiple courses). Fetal femurs were collected at GD18 and bone development related indicators were detected.

KEY FINDINGS: The results showed that PAmE significantly reduced the length of the femur and primary ossification center of fetal mice, and inhibited the development of fetal growth plate. Meanwhile, PAmE inhibited the development of bone marrow mesenchymal stem cells, osteoclasts and endothelial cells in fetal long bone. Further, we found the fetal long bone developmental toxicity induced by PAmE was most significant at late-pregnancy (GD16-18), high dose (300 mg/kg·d) and multiple-course group. Besides, PAmE inhibited the expression of Wnt/β-catenin signaling pathway in fetal long bone. The β-catenin mRNA expression was significantly positively correlated with the development indexes of fetal long bone.

SIGNIFICANCE: PAmE has toxic effects on long bone development, and there was an obvious "toxic window" of PAmE on the long bone development in fetal mice. The Wnt/β-catenin signaling pathway may mediate PAmE-induced fetal long bone development inhibition.