Activity of schisandrin C isolated from Schisandra chinensis against human cancer cell lines

Schisandrin C, a dibenzocyclooctadiene lignan isolated from the fruits of Schisandra chinensis (Turcz.) Baill. (Schisandraceae), was investigated for cytotoxicity and influence on three human cancer cell lines. Among human hepatocelluar carcinoma cells (Bel-7402), human breast cancer cells (Bcap37) and human nasopharyngeal carcinoma cells (KB-3-1), Bel-7402 cells were most sensitive with IC50 equal to 81.58 +/- 1.06 mu M after treatment with schisandrin C for 48 h. Cytotoxicity of schisandrin C on tumor cells depends on cellular accumulation of the drug. The intracellular schisandrin C concentration was assayed by high-performance liquid chromatography (HPLC) and showed that schisandrin C could permeate the cell membrane. Staining with Hoechst 33258 showed fragmentation and condensation of chromatin in the cell treated with 75 AM schisandrin C for 24 h. Flow cytometric analysis was performed to determine hypodiploid cells. The results of flow cytometry indicated that the percentage of hypodiploid Bel-7402 cells was 40.61 +/- 1.43% after 24 h treatment with 100 AM schisandrin C. The treatment resulted in the appearance of a hypodiploid peak (sub-G(0)/G(1) region), probably due to the presence of apoptosing cells and apoptotic bodies with DNA content less than 2n. To our knowledge, this is the first report against human hepatocelluar carcinoma cells (Bel-7402) of schisandrin C.