Influence of platinum nanoparticles orally administered to rats evaluated by systemic gene expression profiling (CBX118). unidentified

Platinum is recognized as a harmless metal and is widely used in many industrial products. Recent studies have proposed that platinum in the form of nanoparticles has antioxidant properties, which promotes the utilization of platinum nanoparticles as supplements and cosmetics, which are directly exposed to humans. However, the influence of platinum nanoparticles in humans has not been sufficiently evaluated thus far. Therefore, to investigate the influence of platinum nanoparticles on a living body, we comprehensively examined the expression profiles of genes obtained from 25 organs and tissues of rats after oral administration of platinum nanoparticles by gavage. Comparative analysis revealed that the expression levels of 18 genes were altered in 12 organs and tissues after the administration (approximately 0.17% of the entire genes examined). Of the tissues examined, the glandular stomach was most directly exposed to orally administered nanoparticles showed altered expression levels of genes associated with inflammation. In the subcutaneous adipose tissue, the expression level of genes whose products exhibit ATPase activity was altered. Real-time polymerase chain reaction (RT-PCR) analysis confirmed the alteration in the expression levels of these genes in the 2 different tissues. Our findings indicate that orally administered platinum nanoparticles do not have a marked effect on systemic gene expression levels, except on a small number of genes expressed in rat tissues, including peripheral tissues indirectly exposed to the orally administered nanoparticles.