Propylthiouracil Induced Neurotoxicity in Swiss Albino Mice Fetus

Abstract

Introduction: Anti-thyroid drugs are used to treat hyperthyroidism in pregnancy, as pregnancy-associated hyperthyroidism causes fetal and maternal complications. Propylthiouracil is recommended for the treatment of hyperthyroidism in the first trimester, though limited reports of congenital anomalies are associated with its antenatal usage.
Aim: The present study aims to reveal the teratogenicity of propylthiouracil by studying its neurotoxic effect in mice fetuses.
Material and Methods: Propylthiouracil was orally administered in a dose of 100 mg/kg body weight/day to pregnant Swiss albino mice during the period of organogenesis (treated group), while pregnant dams of control group were given distilled water orally (same volume and for same duration). The pregnancy was terminatedon the 18th day of conception after sacrificing the pregnant dams and fetuses were collected. The fetal brains (from both, control and treated groups) were dissected out, examined and processed for further histological study.
Results: The brains of the treated group shows hemorrhagic spots on gross examination, while microscopic examination shows degeneration in the hippocampal area, degenerated
choroid plexus and dilatation of lateral and fourth ventricles along with the destruction of ependymal lining of these ventricles. No such findings are present in brain of control
group.
Conclusion: The safety of propylthiouracil must be re-evaluated through large randomised clinical trials, as it is observed to have neurotoxic effect on mice fetus in the present study