The effect of withaferin A, a natural steroidal lactone, on the fine structure of S-180 tumor cells.

Mouse sarcoma 180 (S-180) solid and ascites tumor cells were treated in vivo and in vitro with withaferin A and observed with the electron microscope. The compound was found to effect this spindle microtubules of cells in metaphase. An interesting finding was the double membranes surrounding the chromosomes in the treated cells; probably the nuclei were reconstructed directly from the metaphase stage in the in vivo withaferin A-treated cells. In addition the membranes of the cells in interphase were affected by in vivo or in vitro treatment with the compound.