OBJECTIVE: Platinum nanoparticles (nano-Pt) have been reported to possess anti-oxidant and anti-tumor activities. However, the biological activity and mechanism of action of nano-Pt in inflammation are still unknown. The present study was designed to determine the in-vitro anti-inflammatory effects of nano-Pt on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.METHODS: RAW 264.7 macrophages were used for the study. The LPS-induced production of reactive oxygen species (ROS) was determined by flow cytometry. The prostaglandin E(2) (PGE(2)) concentration was measured using a PGE(2) assay kit. The protein levels and mRNA expression of the pro-inflammatory cytokines [tumor necrosis factor-á, interleukin (IL)-1â and IL-6], along with cyclooxygenase (COX-2) and inducible nitric oxide synthase, were analyzed by Western blotting and reverse transcription-polymerase chain reaction analysis. The phosphorylation of extracellular signal regulated kinase (ERK1/2) and Akt, and the phosphorylation and degradation of inhibitory kappa B-alpha (IêB-á) was determined by Western blot analysis.RESULTS: Nano-Pt significantly reduced the LPS-induced production of intracellular ROS and inflammatory mediators. In addition, nano-Pt suppressed the phosphorylation of ERK1/2 and Akt, and significantly inhibited the phosphorylation/degradation of IêB-á as well as nuclear factor kappa-B (NFêB) transcriptional activity.CONCLUSION: These results suggest that the anti-inflammatory properties of nano-Pt may be attributed to their downregulation of the NFêB signaling pathway in macrophages, thus supporting the use of nano-Pt as an anti-inflammatory agent.
Animals Anti-Inflammatory Agents