Effects of various types of cerium oxide nanoparticles on C. elegans healthspan

Abstract

Cerium oxide (CeO2) nanoparticles (nanoceria) are potent antioxidants that are being explored as a potential therapeutic for oxidative stress diseases. Nanoceria catalytically neutralize multiple types of reactive oxygen species. However, both therapeutic and toxic effects of CeNPs have been reported1-3. We hypothesize that these disparate reports are due to small chemical differences in each type of particle arising from the synthetic process4. Due to its short lifespan and easily observable behaviors which serve as robust indicators of health, we used the nematode C. elegans to examine, in parallel, the effects of differing types of cerium oxide nanoparticles on animal healthspan. We fed the animals the different types of nanoceria and analyzed fertility, egg-laying, defecation, and thrashing behaviors. We also assessed the ability of the worm to withstand thermal stress (thermotolerance). None of the nanoparticles tested had any significant effects on the behaviors analyzed, suggesting that nanoceria are not toxic at the doses tested. Interesting, all of the nanoparticles significantly improved worm thermotolerance, suggesting that the nanoceria may be protective under stressful conditions. Future studies will further assess the ability of nanoceria to be protective in worm models of oxidative stress.