Effects of a potent antioxidant, platinum nanoparticle, on the lifespan of Caenorhabditis elegans

We have shown that platinum nanoparticles (nano-Pt) are a superoxide dismutase (SOD)/catalase mimetic. Various data have shown extension of the Caenorhabditis elegans lifespan by antioxidant treatment. The present study was designed to elucidate the survival benefit conferred by nano-Pt, as compared to the well-known SOD/catalase mimetic EUK-8. At 0.5 mM, nano-Pt significantly extended the lifespan of wild-type N2 nematodes and at 0.25 and 0.5 mM, nano-Pt recovered the shortened lifespan of the mev-1(kn1) mutant,which is due to excessive oxidative stress. In both instances, EUK-8 at 0.05, 0.5, and 5 mM did not extend nematode lifespan. Even when 0.4 M paraquat was loaded exogenously, nano-Pt (0.1 and 0.5 mM) and EUK-8 (0.5 and 5 mM) were effective in rescuing worms. Moreover, 0.5 mM nano-Pt significantly reduced the accumulation of lipofuscin and ROS induced by paraquat. We measured the in vitro dose-dependent quenching of O-2(-) and H2O2, indicating that nano-Pt is a more potent SOD/catalase mimetic than EUK-8. Nano-Pt prolonged the worm lifespan, regardless of thermotolerance or dietary restriction. Taken together, nano-Pt has interesting anti-ageing properties. (C) 2008 Elsevier Ireland Ltd. All rights reserved.