The ethyl acetate (EA) fraction obtained from a methanol extract of Spatholobi caulis (Leguminosae) has been investigated for anti-metastatic activities in vitro. The EA fraction of Spatholobi caulis inhibited platelet aggregation induced by B16BL6 melanoma cells with an IC(50) of 50 microgram/mL. The EA fraction significantly inhibited HT1080 cancer cell invasion through a matrigel-coated filter with an IC(50) of 25 microgram/mL. Messenger RNA expression of uPA was effectively decreased in HT1080 cells by the EA fraction of Spatholobi caulis with an IC(50) of 30 microgram/mL, but the expressions of MMP-2 (matrix metalloproteinase) and TIMPs (tissue inhibitors of metalloproteinases) were not changed. These findings indicated that the EA fraction suppressed tumour cell invasion by downregulation of uPA (urokinase-type plasminogen activator). Taken together, these results suggest that the EA fraction of Spatholobi caulis may have anti-metastatic activities by blocking tumour cell-induced platelet aggregation (TCIPA) and tumour cell invasion.
Copyright 2003 John Wiley & Sons, Ltd.