The exposure of human lymphoid leukemia Molt 4B cells to honokiol led to bo
th growth inhibition and the induction of apoptosis. Morphological change s
howing apoptotic bodies was observed in the cells treated with honokiol. Th
e fragmentation by honokiol of DNA to oligonucleosomal-sized fragments that
are characteristics of apoptosis was observed to be concentration- and tim
e-dependent. These findings suggest that growth inhibition by honokiol of M
olt 4B cells results from the induction of apoptosis in the cells.