Inhibitory Activity of Extract, Fractions, and Compounds from Zingiber montanum Rhizomes on the Migration of Breast Cancer Cells

Zingiber montanum rhizomes are traditionally used for the treatment of numerous human ailments. The present study was carried out to investigate the inhibitory activity of the crude extract, chromatographic fractions, and purified compounds from Z. montanum rhizomes on the migration of MDA-MB-231 cells. The effect of the extract on cell migration was investigated by a scratch assay, which showed significant inhibition in a concentration-dependent manner. Vacuum liquid chromatography on silica gel afforded four fractions (Frs. 1 - 4), which were tested on cell migration in the scratch assay. Frs. 1 and 2 showed the most significant inhibition of MDA-MB-231 cell migration. The effect of the most potent fraction (Fr. 2) was further confirmed in a transwell migration assay. The study of Frs. 1 and 2 by gelatin zymography showed significant inhibition of MMP-9 enzyme activity. Chromatographic separation of Frs. 1 and 2 afforded buddledone A (1: ), zerumbone (2: ), (2E,9E)-6-methoxy-2,9-humuradien-8-one (3: ), zerumbone epoxide (4: ), stigmasterol (5: ), and daucosterol (6: ). In a cell viability assay, compounds 1:  - 4: inhibited the viability of MDA-MB-231 cells in a concentration-dependent manner. The study of buddledone A (1: ) and zerumbone epoxide (4: ) on cell migration revealed that 4: significantly inhibited the migration of MDA-MB-231 cells in both scratch and transwell migration assays. The results of the present study may lead to further molecular studies behind the inhibitory activity of zerumbone epoxide (4: ) on cell migration and support the traditional use of Z. montanum rhizomes for the treatment of cancer.