Comparison of cytotoxic activity of some Iranian Stachys spp. extracts on different cancer cell lines

The genus Stachys belongs to Lamiaceae family with about 300 species and worldwide distribution. In the present study, the cytotoxic activity of four fractions of different Satchys species (S. byzatina C. Koch., S. inflata Benth., S. setifera Ten. and S. persica Gmel.), has been investigated against HT-29 (colon carcinoma), Caco-2 (colorectal adenocarcinoma), T-47D (breast ductal carcinoma) and NIH-3T3 (Swiss mouse embryo fibroblast) cell lines by MTT test. The samples were extracted by percolation method with four solvents; petroleum ether (60-80 degrees C), chloroform, ethyl acetate and 80% aqueous methanol, susseccively. All cell lines were cultured in proper medium. Concentrations of 62.5-750 mu g/mL from partition fractions of all samples, dissolved in 1% (v/v) DMSO were tested on each cell line. Cells with no treatment and methotrexate were examined as negative and positive controls, respectively. Cell viability was determined by MTT assay. Some fractions showed good cell inhibitory activity with IC50<100 mu g/mL, but most of them were considered not potent compared to methotrexate. The chloroform fraction of S. setifera was the most cytotoxic sample with high selectivity toward cancerous cell lines, and it could be investigated for its pharmaceutical active components in future studies.