Antioxidative and Anti-inflammatory Activities of Rosebud Extracts of Newly-Crossbred Roses

Oxidative stress and inflammation are basic pathogenic factors involved in tissue injury, pain, as well as acute and chronic diseases. Since long-term uses of steroids and non-steroidal anti-inflammatory drugs (NSAIDs) cause severe adverse effects, novel effective materials with minimal side effects are required. In this study, polyphenol content and antioxidative activity of rosebud extracts from 24 newly-crossbred Korean roses were analyzed. Among them, Pretty Velvet rosebud extract (PVRE) were found to contain high polyphenols and to show in vitro antioxidative and anti-inflammatory activities. In RAW 264.7 cells stimulated with lipopolysaccharide (LPS), PVRE down-regulated mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and thereby decreased nitric oxide (NO) and prostaglandin E2 (PGE2) production. In an air-pouch inflammation model, treatment with PVRE decreased λ-carrageenan-induced tissue exudation, infiltration of inflammatory cells including neutrophils, monocytes and lymphocytes, and tumor necrosis factor-α and interleukin-1β concentrations, as achieved with dexamethasone (a steroid). Notably, PVRE also inhibited PGE2, similar to dexamethasone and indomethacin (an NSAID). The anti-inflammatory effects of PVRE were confirmed by microscopic findings, attenuating tissue erythema, edema, and inflammatory cell infiltration. These results indicate that PVRE exhibits dual (steroid- and NSAID-like) anti-inflammatory activities by blocking both the iNOS ― NO and COX-2 ― PG pathways, and that PVRE could be a promising anti-inflammatory material for diverse issue injuries.