To investigate anticancer effects of Kaempferia parviflora, rhizomes of K. parviflora were extracted with supercritical CO 2 fluid and ethanol under various extraction conditions. Antiproliferative activity of these extracts was evaluated against human cervical cancer HeLa and human gastric adenocarcinoma AGS cell lines. Supercritical CO 2 fluid extracts (SFEs) of K. parviflora showed more potent antiproliferative activity than the ethanol extracts against both cell lines, because SFEs contained higher concentration of polymethoxyflavones (PMFs) (72-89 wt%) than the ethanol extract (55-70 wt%). From the compositional analysis of the extracts, 5,7-dimethoxyflavone (1) in K. parviflora was proposed as a potent anticancer PMF. Furthermore, it was found that PMFs with more methoxy groups do not necessarily show better anticancer activity.Keywords antiproliferative, cancer, Kaempferia parviflora, polymethoxyflavone, supercritical Polymethoxyflavones (PMFs) found from various plant materials show a broad spectrum of biological activities (Li et al., 2006), including anti-carcinogenic property with low toxicity (Du and Chen, 2010). Most biological studies of PMFs were carried out with those found from Citrus fruits, and Li et al. ( 2007) suggested that anticancer activity of PMFs was proportional to the number of methoxy groups. For example, heptamethoxyflavone showed better anticancer activity than hexamethoxyflavone. Furthermore, Kaempferia parviflora was identified as an alternative PMF-rich resource. We previously reported that supercritical CO 2 fluid extraction of K. parviflora rhizome yielded the PMF-concentrated extract (Wongsrikaew et al., 2011). Whereas nobiletin (5,6,7,8,3', 4'-hexamethoxyflavone) and tangeritin (5,6,7,8,3'-pentamethoxyflavone) are the most abundant PMFs in Citrus plants, PMFs in K. parviflora are structurally different from those in Citrus plants in that only specific positions of flavone structure, such as C-3, C-5, C-7, C-3' and C-4', are methoxylated (Table 1).Because anticancer activity is an important biological activity of PMFs, Yenjai et al. ( 2004) tested cytotoxicity of nine PMFs isolated from K. parviflora against KB, BC, and NCI-H187 cell lines. However, none of PMFs were reported to show anticancer activity. However, Patanasethanont et al. (2007) reported that ethanol extract of K. parviflora rhizome significantly inhibited multidrug resistance associated-protein and therefore could improve cancer chemotherapy. Recently, antiproliferative activities of K. parviflora ethanol extract against human promyelocytic leukemic cells and human bile duct cancer cell lines were reported by independent research groups (Banjerdpongchai et al., 2008;Leardkamolkarn et al., 2010).In this note, antiproliferative activity of K. parviflora extracts was evaluated against human cervical cancer (HeLa) and human gastric adenocarcinoma (AGS) cancer cell lines to confirm the anticancer activity. The composition of PMFs in each extract was also analyzed to establish the relationship between PMF constituen...

To ensure polymethoxyflavone (PMF) extract from krachaidum, Kaempferia parviflora rhizome, supercritical CO 2 extraction was attempted as an efficient and nontoxic method. Extraction yields and composition of PMFs in the supercritical fluid extracts (SFEs) were obtained under the different extraction conditions of pressure and temperature. Nine PMFs, including 5,7-dimethoxyflavone (1), 5,7,4'-trimethoxyflavone (2), 5,7,3',4'-tetramethoxyflavone (3), 5-hydroxy-7-methoxyflavone (4), 5-hydroxy-3,7-dimethoxyflavone (5), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (6), 3,5,7-trimethoxyflavone (7), 3,5,7,4'-tetramethoxyflavone (8) and 3,5,7,3',4'-pentamethoxyflavone (9), were isolated by vacuum liquid chromatography and characterized using various spectroscopic methods. The extraction yield by supercritical CO 2 extraction was highest at 60 o C and 300 bar, and the content of PMFs reached up to 85% in the SFEs.

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