Selective inhibition of the growth of cancer cells by diterpenes selected with embryonic cells of Xenopus.

We used Xenopus embryo cells with a cell cycle of 20-30 min to detect inhibitory effects on cell proliferation. Inhibition of proliferation was observed when isolated embryonic cells were incubated for 16 h in a simple salt solution containing the well-known anticancer drugs 5-fluorouracil and adriamycin. In addition, three diterpene compounds isolated from the anticancer herbal medicine kansui: kansuinin B, 20-OD-ingenol Z, and 20-OD-ingenol E specifically inhibited the proliferation of isolated embryonic cells. The inhibitory compounds selected using the embryonic cells also inhibited proliferation of certain mammalian cell types.