Exposure to excess phenobarbital negatively influences the osteogenesis of chick embryos

Abstract

Phenobarbital is an antiepileptic drug that is widely used to treat epilepsy in a clinical setting. However, a long term of phenobarbital administration in pregnant women may produce side effects on embryonic skeletogenesis. In this study, we aim to investigate the mechanism by which phenobarbital treatment induces developmental defects in long bones. We first determined that phenobarbital treatment decreased chondrogenesis and inhibited the proliferation of chondrocytes in chick embryos. Phenobarbital treatment also suppressed mineralization in both in vivo and in vitro long bone models. Next, we established that phenobarbital treatment delayed blood vessel invasion in a cartilage template, and this finding was supported by the down-regulation of vascular endothelial growth factor in the hypertrophic zone following phenobarbital treatment. Phenobarbital treatment inhibited tube formation and the migration of human umbilical vein endothelial cells. In addition, it impaired angiogenesis in chick yolk sac membrane model and chorioallantoic membrane model. In summary, phenobarbital exposure led to shortened lengths of long bones during embryogenesis, which might result from inhibiting mesenchyme differentiation, chondrocyte proliferation, and delaying mineralization by impairing vascular invasion.

Effects of Calcium Lactate on the Development of Chicken Embryos in a Shell-less Culture System up to Day Seventeen of Incubation

“…A delay in embryo development is considered to be one of the reasons for the smaller embryo size in SLCS (Ono and Tuan, 1986). Experimental treatment with phenobarbital, an antiepileptic drug, has been reported to shorten the fetal long bones by exerting inhibitory effects on chondrocyte proliferation and bone mineralization (Yan et al, 2016). Therefore, the development of a tibia with normal morphology and density associated with subnormal quantitative parameters observed in the present study, could be attributed to the effects of unidentified inhibitory factor(s) on chondrocyte proliferation in cSLCS.…”