The Possible Protective Role of Selenium Against Long-Term Phenytoin Administration Effects on Cerebellar Cortex of Adult Male Albino Rats: Histological and Immunohistochemical Study

Background: Phenytoin is a commonly prescribed antiepileptic drug. Chronic phenytoin treatment has been documented to be associated with cerebellar degeneration. Selenium is one of the main antioxidant coenzymes of glutathione peroxidase and it is a key component of seleno-proteins that play important roles in brain development and metabolism.
Aim: This work aimed to study the possible protective role of selenium against long-term phenytoin administration effects on cerebellar cortex of the adult male albino rats.
Material and Methods: Forty-five adult male albino rats were used in this study, aged from 6-8 months, weighting 180 -200 gm. Rats were equally divided into three groups: Group I: rats were further equally subdivided into: group IA: kept as negative control, group IB: each rat received 1ml of distilled water /day orally for 45 days and group IC: each rat received selenium at a dose of 0.5 mg/kg BW(body weight)/day orally for 45 days. Group II: each rat received phenytoin at a dose of 20mg/ Kg BW /day orally for 45 days. Group III: each rat received phenytoin as group II in addition to selenium at a dose of 0.5 mg/kg BW/day orally for 45 days.
Results: The present work revealed that long term phenytoin administration induced histological changes of rat’s cerebellar cortex in the form of decreased thickness, irregular deeply stained Purkinje cells and increased perineural space around Purkinje cells and granule cells. Selenium administration with phenytoin nearly preserved the histological structure of the cerebellar cortex.
Conclusion: Long term phenytoin administration led to histoarchitectural changes of rat’s cerebellar cortex. However, Selenium administration with phenytoin greatly protected the cerebellar cortex from such changes