Cynandione A from Cynanchum wilfordii Attenuates the Production of Inflammatory Mediators in LPS-Induced BV-2 Microglial Cells via NF-kappa B Inactivation

Abstract

Cynanchum wilfordii is one of most widely used medicinal plants in Oriental medicine for the treatment of various conditions. In the present study, we isolated cynandione A (CA) from an extract of Cynanchum wilfordii roots (CWE) and investigated the effects of CA on the expression of inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines in lipopolysaccharide (LPS)-induced BV-2 microglial cells. CWE and CA significantly decreased LPS-induced nitric oxide production and the expression of iNOS in a concentration-dependent manner, while they (CWE up to 500 mu g/mL and CA up to 80 mu M) did not exhibit cytotoxic activity. Results from reverse transcription-polymerase chain reaction (RT-PCR) analysis and enzyme-linked immunosorbent assay (ELISA) showed that CA significantly attenuated the expression of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 beta in LPS-stimulated BV-2 cells. Furthermore, CA inhibited the phosphorylation of inhibitor kappa B-alpha (I kappa B-alpha) and translocation of nuclear factor-kappa B (NF-kappa B) to the BV-2 cell nucleus, indicating that CWE and CA may have effective anti-inflammatory activities via NF-kappa B inactivation in stimulated microglial cells.