Protective effect of Asarum extract in rats with adjuvant arthritis.

The aim of the present study was to investigate the protective effect of Asarum extract on rats with adjuvant arthritis (AA) and to determine the underlying mechanism. An AA model was established by injecting Freund's complete adjuvant into the rats. The degree of toe swelling, arthritis index, spleen index, and the expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were measured. In addition, the underlying molecular mechanism was investigated using murine macrophage-derived RAW 264.7 cells. Asarum extract was found to significantly reduce the severity of arthritis by decreasing hind paw swelling, the arthritis index, the spleen index, and TNF-α, IL-1β and IL-6 expression levels in plasma. In vitro, Asarum extract inhibited the nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways. These results indicate that Asarum extract may be a therapeutic agent for AA and may exert an anti-inflammatory effect by mediating the NF-κB and MAPK signaling pathways.