This study used grape seeds

An extract from grape seeds forces laboratory leukemia cells to self destruct, or commit cell suicide, according to researchers from the University of Kentucky. Within 24 hours of exposure to the extract, three-quarters of leukemia cells die off.

The researchers say that this proves the value of natural compounds. In making their discovery, they teased apart the cell signaling pathway associated with use of grape seed extract that led to the cell-suicide. This self-destructive process, known as apoptosis, normally gets rid of damaged or aberrant cells.