Pyrogallol Plays a Central Role in Anti-Allergic and Anti-Inflammatory Activities of Rosebud Extracts of Newly Crossbred Roses

Since chemical anti-allergic compounds have adverse effects, many investigators pay attention on relatively-safe natural products. In order to fulfill such a requirement, we investigated anti-allergic, anti-inflammatory, and antioxidative activities of the extracts of newly-crossbred rosebuds in vitro and in vivo. Twenty-four candidate rosebuds were extracted with 80% ethanol, and analyzed for polyphenols, flavonoids, tannins, proanthocyanidins, and pyrogallol (1,2,3-benzenetriol). The extracts’ in vitro antioxidative, anti-allergic, and anti-inflammatory activities were analyzed through 1,1-diphenyl-2-picrylhydrazyl radical-scavenging capacity as well as inhibitory effects on the β-hexosaminidase release from Compound 48/80-stimulated RBL-2H3 mast cells and nitric oxide production from lipopolysaccharide-activated RAW 264.7 macrophages, respectively. The in vivo activity was assessed via protection against lethality and itching (scratching) symptoms in mice challenged with Compound 48/80. Among candidates, Lover Shy, Pretty Velvet, Ice Wing, Red Perfume, Onnuri, Jaemina Red, and Hanggina were found to possess high concentrations of antioxidant components and antioxidative activity. By comparison, Pretty Velvet, Red Perfume, Jaemina Red, Hanggina, Onnuri, and Ice Wing were highly effective in anti-allergic and anti-inflammatory activities in vitro, in parallel with their concentrations of pyrogallol. Their anti-allergic effects were confirmed in mice: The 6 extracts protected against Compound 48/80-induced mortality and scratching behaviors in a dose-dependent manner. The allergen-induced increases in serum IgE and histamine as well as inflammatory cytokines, tumor-necrosis factor-α and interleukin-1β, were remarkably attenuated following treatment with the rosebud extracts. These findings demonstrate that the extracts and active ingredients from cross-bred rosebuds exert anti-allergic and anti-inflammatory activities through their high levels of antioxidants and pyrogallol, and that could be promising candidates to overcome allergic responses such as atopic dermatitis.