Swedish scientists reported in the American Cancer Society
Journal of Natural Products that cardiac glycosides, which are a
family of naturally derived drugs which are used to treat
congestive heart failure and arrhythmia, show anti-tumor
activity against colon cancer cells. There is little known how
these drugs work as potential anti-cancer agents. These
scientists screened several of these glycosides in colon cancer
cell lines, and they found that the drugs were all effective, to
varying degrees, at killing the cancer cells. The sensitivity,
however, was rather low when compared to that of other cancer
cell types reported previously. Several of the drugs also showed
increased anticancer activity when combined with certain drugs
used for standard chemotherapy. The findings suggest that these
heart drugs may affect colon cancer outcome when used alone or
combination with conventional chemotherapy drugs. These drugs
are found in the leaves of the oriental foxglove plant and
contain digitoxin, a drug used to tr