The bark of Rhus verniciflua Stokes (RVS) is used as a food additive and herbal medicine for various inflammatory disorders and cancer in Eastern Asia. RVS exerted anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, but whether this effect occurs in macrophages after oral administration has not been determined. We used a thioglycollate-induced peritonitis model to obtain macrophages from mice given RVS. We examined the systemic inflammatory response to intraperitoneal LPS. RVS-treated mice had an increased population of peritoneal exudate cells expressing CD11b and SRA. Increased uptake of Alexa Fluor 488-labeled acetylated lipoprotein was observed in monocyte-derived macrophages from RVS-treated mice. When these cells from the RVS group were stimulated with LPS, the levels of tumor necrosis factor (TNF)- and interleukin (IL)-6 in the supernatant decreased, but the level of IL-12 increased. The surface expression of CD86 was reduced, but surface expression of class II MHC molecules was increased. RVS suppressed the serum levels of LPS-induced TNF- and IL-6. RVS enhanced monocyte differentiation in thioglycollate-induced peritonitis by increasing scavenger receptor expression and activity. Macrophages isolated from mice given RVS responded differently to LPS. These findings demonstrate that RVS confers selective anti-inflammatory activity without causing the overall inhibitory effects on immune cells.
