Evaluation of the anti-inflammatory effects of phloretin and phlorizin in lipopolysaccharide-stimulated mouse macrophages

Many reports suggest that phloretin and phlorizin have antioxidant properties and can inhibit glucose transportation, the anti-inflammatory effects and mechanism of phloretin and phlorizin remain unclear. This study aims to evaluate the anti-inflammatory effects of phloretin and phlorizin in LPS-stimulated murine RAW264.7 macrophages. RAW264.7 cells were pretreated with various concentrations of phloretin or phlorizin (3-100 mu M) and cell inflammatory responses were induced with LPS. Pretreated with 10 mu M phloretin significantly inhibited the levels of NO, PGE(2), IL-6, TNF-alpha, iNOS and COX-2. Furthermore, it was demonstrated that phloretin suppressed the nuclear translocation of NF-kappa B subunit p65 proteins, and decreased phosphorylation in MAPK pathways. Surprisingly, phlorizin did not suppress the inflammatory response in LPS-stimulated RAW264.7 cells. These results suggest that phloretin has an anti-inflammatory effect that reduces levels of proinflammatory cytokines and mediators in RAW264.7 cells. (C) 2012 Elsevier Ltd. All rights reserved.