Screening of medicinal plants from Iranian flora against human cancer cell-lines have shown that an hexane extract from roots of Salvia sahendica Boiss. & Buhse, Lamiaceae, is active against human cervical cancer (HeLa) and colorectal adenocarcinoma (Caco-2) cell-lines at the test concentration of 100μg/ml (100% inhibition). Cytotoxicity of the extract was localized with the aid of HPLC-time-based activity profiling adapted to the tetrazolium colorimetric bioassay. Four abietane-type diterpenoids in active time-windows were identified as cytotoxic compounds namely: sahandone (1), sahandol (2), 12-deoxy-salvipisone (3) and sahandinone (4). Compound 1 showed the highest toxicity against HeLa cells (IC50=5.6±0.1μg/ml), which was comparable with betulinic acid (IC50=4.3±1.2μg/ml), the positive control. Compound 2 was active against the HeLa cells (IC50=8.9±0.7μg/ml) but not the Caco-2 cell-line. Compounds 1, 3 and 4 exhibited moderate activity (IC50=22.9–41.4μg/ml) against the Caco-2 cells. This study reveals that the HeLa cells are more sensitive to all tested compounds than the Caco-2 cells. In silico molecular docking study showed a rigid binding of the compounds to tyrosine kinase pp60src, and proved their cytotoxic activity.