Antiproliferative Effect of Trifolium Pratens L. Extract in Human Breast Cancer Cells.

Breast cancer is currently the most common cancer in women worldwide. Tamoxifen is used for the treatment of both early and advanced estrogen receptor positive breast cancer. Trifolium pratense L. has been suggested for cancer treatment in traditional medicine. The effect of T. pratense extract on breast cell lines (MCF-7 and MDA-MB-231) was investigated here. The cells were treated with T. pratense extract and cell viability was evaluated using trypan blue staining, MTT assay and lactate dehydrogenase activity measurement. Apoptosis, autophagy cell death was detected using fluorescent dye staining. Griess assay was performed to nitric oxide (No) measurement. Change in expression level of some apoptotic and autophagic- related genes was detected using real-time PCR. The combination effect of exteract and tamoxifen was evaluated by calculating the combination index and dose reduction index (DRI) values. T. pratense extract reduced the cell viability in dose and time- dependent manner. Apoptosis and autophagy was increased after treatment with T. pratense extract. Nitric oxide production significantly reduced in cells and combination of tamoxifen and T. pratense extract had a synergistic cytotoxic effect on breast cancer cell lines. T. pratense as a dietary supplement can be beneficial for some patients with breast cancer who receive conventional chemotherapy.