Anti-tumor Activity and Cell Cycle Arrest of a New Diterpene Ester from Daphne mucronata Using K562 Cells

In our search for new anticancer medicinal plants, the antiproliferative activity of the methanol extract of Daphne mucronata (Thymelaeaceae) was evaluated using human myelogenous leukemia K562 cells. The cells responded to plant treatments in a dose dependent manner and the IC50 of the crude extract (equivalent to 1 g of plant leaves powder per ml) and the purified active component were found to be 42 µl and 1.3 µM, respectively. The antiproliferative activity of the plant was also evaluated using flow cytometry technique. The results indicated that the crude extract and the active purified component are capable of arresting the cells in G1 phase of the cell progression cycle. This data may provide a mechanism for the antiproliferative action of the plant.