Paclitaxel, which isolated from Taxus brevifolia, is recently started to be used against prostate cancer treatment and it is a very effective compound against cancer. In this study, we aimed to test the synergistic effect of two plant active compounds (sulphoraphane (SFN) and silymarin (SILY)) and several endemic plant species from Turkey (such as Phlomis leucophracta, Rubia davisiana, Alkanna tinctoria), which are known to have anticarcinogenic effect on androgen-independent PC3 and DU145, and androgen-dependent VCaP prostate cancer cell lines, with paclitaxel on the expression of cell cycle signaling and apoptosis regulator genes.