Studies on the anti-inflammatory action of Taraxacum officinale extract in central nervous system

Substance P(SP) can stimulate production of tumor necrosis factor-(TNF-) from astrocytes stimulated with lipopolysaccharide(LPS). The objective of the current study was to determine the effect of Taraxacum officinale(TO) on the production of TNF- from primary cultures of rat astrocytes. TO(100& 1000/ml) significantly inhibited the TNF- production by astrocytes stimulated with LPS and SP. Interleukin-1(IL-1) has been shown to elevate TNF- production from LPS-stimulated astrocytes while having no effect on astrocytes in the absence of LPS. We therefore examined whether IL-1 mediated inhibition of TNF- production from primary astrocytes by TO. Treatment of TO(100 and 1000/ml) to astrocytes stimulated with both LPS and substance P decreased IL-1 production significantly. Moreover, the production of TNF- by LPS and substance P in astrocytes was progressively inhibited with increasing amount of IL-1 neutralizing antibody. These results suggest that TO may inhibit TNF- production by inhibiting IL-1 production and that TO has an antiinflammatory activity in the central nervous system.