Taraxacum officinale inhibits tumor necrosis factor-alpha production from rat astrocytes

Substance P (SP) can stimulate production of tumor necrosis factor-alpha (T NF-alpha) from astrocytes stimulated with lipopolysaccharide (LPS). The obj ective of the current study was to determine the effect of Taraxacum offici nale (TO) on the production of TNF-alpha from primary cultures of rat astro cytes. TO (100 and 1000 mu g/ml) significantly inhibited the TNF-alpha prod uction by astrocytes stimulated with LPS and SP. Interleukin-1 (IL-1) has b een shown to elevate TNF-alpha production from LPS-stimulated astrocytes wh ile having no effect on astrocytes in the absence of LPS. We therefore exam ined whether IL-1 mediated inhibition of TNF-alpha production from primary astrocytes by TO. Treatment of TO (100 and 1000 mu g/ml) to astrocytes stim ulated with both LPS and SP decreased IL-1 production significantly. Moreov er, the production of TNF-alpha by LPS and SP in astrocytes was progressive ly inhibited with increasing amount of IL-1 neutralizing antibody. Our resu lts suggest that TO may inhibit TNF-alpha production by inhibiting IL-1 pro duction and that TO has an antiinflammatory activity in the central nervous system.