Anti-Inflammatory Effect of Rosa rugosa Flower Extract in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

Rosa rugosa Thunb, a deciduous shrub of the genus Rosa, has been widely used to treat stomach aches, diarrhoea, pain, and chronic inflammatorydisease in eastern Asia. In recent years, our research team has extensively studied the Rosa rugosa flowerextract, and specificallyundertook pharmacological experiments which have optimized the extraction process. Our methods have yielded a standard extract enriched in phenolic compounds, named PRE. Herein, we expand our efforts and evaluated the antiinflammatoryactivity of PRE on lipopolysaccharide (LPS)-induced inflammationin RAW 264.7 macrophages. PRE significantlyinhibited production of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and interleukin 1β (IL-1β), as well as expression of their synthesizing enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase2 (COX-2). Furthermore, PRE inhibited activity of mitogen-activated protein kinases (MAPK) as well as nuclear factor-kappa B (NF-κB) signaling pathway. Our findingsare the firstto explain the anti-inflammatorymechanism by PRE in LPS-stimulated macrophages. Given these results, we propose that PRE has therapeutic potential in the prevention of inflammatory disorders.