Anti-inflammatory effects of Hwang-Heuk-San, a traditional Korean herbal formulation, on lipopolysaccharide-stimulated murine macrophages

Background: Hwang-Heuk-San (HHS), a Korean traditional herbal formula comprising four medicinal herbs, has been used to treat patients with inflammation syndromes and digestive tract cancer for hundreds of years; however, its anti-inflammatory potential is poorly understood. The aim of the present study was to investigate the anti-inflammatory effects of HHS using a lipopolysaccharide (LPS)-activated RAW 264.7 macrophage model. Methods: The inhibitory effects of HHS on LPS-induced nitric oxide (NO), interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) production were examined using Griess reagent and enzyme-linked immunosorbent assay (ELISA) detection kits. The effects of HHS on the expression of inducible NO synthase (iNOS), IL-1 beta and TNF-alpha, their upstream signal proteins, including nuclear factor kappa B (NF-kappa B), mitogen-activated protein kinases (MAPKs), and activator protein (AP-1), were also investigated. Results: A noncytotoxic concentration of HHS significantly reduced the production of NO, IL-1 beta and TNF-alpha in LPS-stimulated RAW 264.7 cells, which was correlated with reduced expression of iNOS, IL-1 beta and TNF-alpha at the mRNA and protein levels. HHS efficiently blocked the phosphorylation of MAPKs, especially that of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) but not that of the p38 MAPK. The reduced production of inflammatory molecules by HHS was followed by decreased activity of NF-kappa B and AP-1. Conclusions: These results suggest that HHS may offer therapeutic potential for treating inflammatory diseases accompanied by macrophage activation.