Cytotoxic Effects of the Extracts of Iranian Taxus baccata and Cupressus horizentalis on Cancer Cells

It has been reported that several conifers possess cytotoxic activities on some human tumor cell lines. Taxol as a natural cytotoxic compound has been extracted from this family. In a program to screen the cytotoxic effects of natural resources, male and female branchlets, fruit or bark of two different species of Iranian conifers were collected, identified and the cytotoxic effects of their hydroalcoholic extracts on three human tumor cell lines were determined. Different concentrations of extracts were added to cultured cells and incubated for 72 h. Cell survival was evaluated using MTT assay. Extracts from bark of female Taxus baccata showed inhibitory activities against Hela cells. The extracts of the branchlets of male and female T. baccata and branchlets of Cupressus horizentalis showed inhibitory activities against MDA-MB-468 cells, whereas the extracts of branchlets of female T. baccata showed inhibitory activities against KB cells. In conclusion, extract obtained from the bark of Iranian T. baccata showed a comparable cytotoxic effect to doxorubicin against Hela cells.