The Possible Protective Effect of Cerium Oxide Nanoparticles on Colistin-Induced Injury in Renal Cortex of Adult Male Albino Rats: Light and Electron Microscopic Study.

INTRODUCTION Acute Kidney Injury (AKI) is a rapid decline in renal function. Colistin, a last resort antibiotic for multidrug-resistant infections, is associated with significant nephrotoxicity. Cerium oxide nanoparticles (CeONPs) are potent scavengers of reactive oxygen species (ROS), exhibiting antioxidant and anti-inflammatory properties. This study aimed to investigate the protective effects of CeONPs against colistin-induced renal damage in adult male albino rats.

METHODS Forty-eight adult male albino rats were equally divided into four groups: Group I (Control), Group II (CeONPs), Group III (Colistin), and Group IV (CeONPs + Colistin). At the end of the experiment, blood samples were collected to assess renal function by measuring serum urea and creatinine. Kidney tissue was processed for histological examination and immunohistochemical staining to evaluate the expression of the inflammatory marker for nuclear factor Kappa B (NF-κB).

RESULTS Colistin administration in Group III resulted in significant renal impairment, characterized by elevated serum urea and creatinine, severe histopathological damage (including tubular necrosis), and a marked increase in NF-κB expression. In contrast, rats pre-treated with CeONPs (Group IV) demonstrated significantly improved kidney function tests, a substantial reduction in histopathological lesions, and a notable decrease in NF-κB expression compared to the colistin group.

DISCUSSION Colistin induces AKI through increased membrane permeability, oxidative damage, and acute tubular necrosis. This oxidative stress upregulates inflammatory mediators like NF- κB, exacerbating tissue injury. The renoprotective effect of CeONPs is attributed to their unique ability to switch between Ce³⁷ and Ce³⁷ oxidation states, allowing continuous ROS scavenging. By reducing oxidative stress, CeONPs also suppress the NF-κB-mediated inflammatory pathway.

CONCLUSION CeONPs exhibit notable nephroprotective effects against colistin-induced AKI through their antioxidant and anti-inflammatory characteristics. These findings propose CeONPs as a potential therapeutic adjunct to reduce nephrotoxicity in patients requiring colistin treatment.