Neurotoxic effects of phenytoin on primary culture of hippocampal neurons: Neural development retardation

Objectives

Ions are key regulators of the morphogenesis, dendritogenesis and development of neurons therefore drugs that perturb ion homeostasis are associated with high risk of mental retardation, intellectual disability and even abortion of fetus. Phenytoin (PHT) is an antiepileptic drug which regulates ion influx especially Ca²⁺ and Na⁺ and widely prescribed to pregnant women suffer from epilepsy. This study aimed to investigate neurodevelopmental features of primary culture of hippocampal cells such as morphology, dendritogenesis, cytotoxicity and cell death in the presence and absence of PHT.

Methods

Primary culture of hippocampal neurons from neonatal rat was treated by 25 and 50 μg/ml of PHT and morphological development was evaluated during the 14 days. Arborization of neurons during the time was monitored by light microscopy. MTT assay and lactate dehydrogenase (LDH) penetrating test also assessed PHT imposed cytotoxicity.

Results

Our results confirmed high dose of PHT could cause excessive cell death in neural cells. PHT exposing causes morphological abnormalities in hippocampal neurons such as shrieked cell body or thick and short dendrite. PHT also prevents branching of dendrites and induces LDH leakage that refers to cytotoxicity.

Discussion

By considering the Ca²⁺ and Na⁺ important roles in cell development process, PHT affect neural shape and arborization rate. It could retard neural development and lead neurons to the cell death. PHT is an anticonvulsant that prescribed to pregnant women so could disrupt brain development and increase the risk of mental retardation in newborn children.