Inhibitory effects of 87 species of traditional Chinese herbs on nitric oxide production in RAW264.7 macrophages, activated with lipopolysaccharide and interferon-γ

In the current study, effects of 87 species of traditional Chinese herbs on nitric oxide ( NO) production by a murine macrophage-like cell line, RAW 264.7, which was activated by lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) were investigated. NO production by macrophages preactivated with LPS and IFN-gamma for 16 h was also inhibited by the 19 species. The inhibitory rate of the 19 species was more than 80%. Among these species, Adina rubella Hance, Centipeda minima ( L.), and Gentiana loureirii (G. Don) Griseb. exhibited strong inhibitory activity toward NO production, exhibiting IC50 values of 3, 7.34, and 13.5 mu g/ml, respectively. However, Aristolochia kaempferi Wild var. heterophylla, Stephania tetrandra S. Moore, Ardisia japonica (Hornsted) Blume, and Helicteres angustifolia ( L.) also affected the cell viability. These results suggest that Adina rubella, Centipeda minima, and Gentiana loureirii have the pharmacological ability to suppress NO production by activated macrophages. The inhibitory mechanisms of NO production will need to be further studied in the future.