Anti-inflammatory activity of the methanol extract of Moutan Cortex in LPS-activated Raw264.7 cells

Moutan Cortex (MCE) has been used in traditional medicine to remove heat from the blood, promote blood circulation and alleviate blood stasis. This study was conducted to evaluate the effects of NICE on regulatory mechanisms of cytokines and nitric oxide (NO) involved in immunological activity of Raw264.7 cells. Cells were pretreated with methanolic extracts of NICE, and further cultured for an appropriate time after lipopolyssacharide (LPS) addition. During the entire experimental period, 0.1 and 0.3 mg ml(-1) of NICE had no cytotoxicity. In these concentrations, NICE inhibited the production of NO and prostaglandin E-2 (PGE(2)), the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and phosphorylated inhibitor of kappa B alpha (p-I kappa B alpha), and the activation of nuclear factor kappa B (NF-kappa B). MCE also reduced the concentration of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL- 1 beta) and interleukin-6 (IL-6) in the Raw264.7 cells that were activated by LPS. These results demonstrate that NICE has anti-inflammatory effects through the inhibition of iNOS and COX-2 expression by suppressing the phosphorylation of I-kappa B alpha and the activation of NF-kappa B.