Cerium oxide nanoparticles protect gastrointestinal epithelium from radiation-induced damage by reduction of reactive oxygen species and upregulation of superoxide dismutase 2

Abstract 

The ability of rare earth cerium oxide (CeO₂) nanoparticles to confer radioprotection against gastrointestinal epithelium was examined. The pretreatment of normal human colon cells (CRL 1541) with varying concentrations of CeO₂ nanoparticles 24 hours before single-dose radiation exposure conferred protection from radiation-induced cell death by reducing the amount of reactive oxygen species produced and increasing the expression of superoxide dismutase 2 (SOD2), in a dose-dependent manner. In subsequent experiments athymic nude mice were pretreated with intraperitoneal injections of CeO₂ nanoparticles before a single dose of radiation to the abdominal area. Immunohistochemical analysis show a decrease in TUNEL-and caspase 3–positive cells in the colonic crypt, 4 hours after radiation. In sharp contrast, a significant increase in SOD2 expression was observed. In the end, these studies suggest that CeO₂ nanoparticles protect the gastrointestinal epithelium against radiation-induced damage by (1) acting as free-radical scavengers and (2) increasing the production of SOD2 before radiation insult.

From the Clinical Editor

In this study, the ability of rare earth cerium oxide (CeO₂) nanoparticles to confer radioprotection was examined. The results suggest that CeO₂ nanoparticles protect the gastrointestinal epithelium against radiation-induced damage both by acting as free-radical scavengers and by increasing the production of SOD2 before radiation insult.

Key words: Cerium oxide nanoparticles, Radioprotection, SOD2, Gastrointestinal epithelium