A crude ethanol extract of Kaemperia parviflora Wall. Ex Baker and a purified compound, 5,7,4-trimethoxyflavone (KP.8.10), were evaluated for pharmacological effects on human cholangiocarcinoma cell lines (HuCCA-1 and RMCCA-1). The cells were incubated with various concentrations of extract for various time periods and metabolic activity (MTT assay) was assessed for cell viability. The results showed a dose-dependent effect of both crude ethanol extract and the pure compound. CC50s for the crude extract on HuCCA-1 and RMCCA-1 cells were 46.1 microg/ml and 62.0 microg/ml, respectively. Values for the pure compound could not be determined because of solubility problems. Interestingly, K. parviflora ethanol extract and KP.8.10 at low concentrations (10-20 microg/ml and 2.5-5 microg/ml, respectively) markedly reduced rhHGF-induced invasion by HuCCA-1 and RMCCA-1 cells across matrix-coated transwell plates. Higher concentrations of K. parviflora ethanol extract (60 and 80 microg/ml) and KP.8.10 (20 microg /ml) dramatically changed the cellular morphology and caused death in both cell types. KP.8.10 further exhibited progressive action via caspase-3 mitochondrial enzyme activation, enhancing cellular toxicity in a time-dose dependent fashion. Therefore, 5,7,4-trimethoxyflavone appeared to be a bioactive component of K. parviflora extract capable of exerting anti-cancer action. The results suggested a benefit of this edible plant in prevention and treatment of cholangiocarcinoma.