The antiproliferative effects of Zingiber zerumbet extracts and fractions on the growth of human breast carcinoma cell lines

Zingiber zerumbei, from Zingiberaceae family, is known for its medicinal properties. From the ethnopharmacologyand laboratory studies, extracts and active component of this plant, zerumbone, were reported to have the antiinflammatory, antioxidant, antimicrobial and antitumour properties. However, no studies have been done to verify the antiproliferative activity of this plant extracts on breast cancer cells. The present study investigated the effects of extracts and fractions of Z. zerumbet on the growth of human breast carcinoma (MCF-7) cell lines. The number of living cells was evaluated by methylene blue staining technique. Our data indicated that Z. zerumbet extracts and some fractions exhibited antiproliferative effect on MCF-7. Bioassay-guided fractionation of petroleum ether extract, the most active crude extract, with EC50 of 4.25 ± 0.05 pglmL resulted in the isolation of two active subfractions. One of them was found to contain 2,6,10-cycloundecatrien-1-one, 2,6,9,9,-tetramethyl with 94% similarity to zerumbone obtained from theGC-MS analysis. A comparative study between both subfractions and tamoxifen showed that the active subfractions of Z. zerumbet displayed a strong antiproliferative effect with ECsoof 2.81 ± 0.24 and 2.49 ± 0.13 μg/mL, respectively, on MCF-7 but less cytotoxic to normal cells