Screening of bioactive compounds from moutan cortex and their anti-inflammatory activities in rat synoviocytes

Moutan Cortex, a widely used traditional Chinese medicine for the treatment of various diseases, is the root bark of Paeonia suffruticosa Andrews (Paeoniaceae). Most of the pharmacological investigations of Moutan Cortex have been addressed to its central nervous system activities, anti-oxidative and sedative actions. Otherwise, there are few reports about the active compounds with anti-inflammatory activity of Moutan Cortex. The aim of the present study was to screen and identify bioactive compounds with anti-inflammatory effect from Moutan Cortex. With the aid of preparative high performance liquid chromatography (HPLC) technique, ethyl acetate and ethanol extract of Moutan Cortex were isolated into twenty-two fractions. Bioactivities of these fractions were evaluated by measuring expression of tumor necrosis factor-alpha (TNF-alpha) in rat synoviocytes subjected to interleukin-1beta (IL-1beta). Eight compounds were isolated from six active fractions and identified by HPLC/MS(n). Purified compounds, paeoniflorin, paeonol and pentagalloylglucose resulted in dose-dependent inhibition of TNF-alpha synthesis and IL-6 production in synoviocytes treated with proinflammatory mediator. These results suggested that paeonol, paeoniflorin, glycosides and pentagalloylglucose contribute to the anti-inflammatory effect of Moutan Cortex.