Flavonoids and the inhibition of PKC and PI 3-kinase

Flavonoids provide a large number of interesting natural compounds that are consumed daily and exhibit more or less potent and selective effects on so me signaling enzymes as well as on the growth and proliferation of certain malignant cells in vitro. Among the identified signal transducers, phosphoi nositide 3-kinase (PI 3-kinase) and protein kinase C (PKC) are now consider ed key players in many cellular responses including cell multiplication, ap optosis, and transformation. Despite their lack of strict specificity, some flavonoids provide valuable bases for the design of analogues that could b e used to specifically block particular isoforms of PI 3-kinase or PKC and their downstream-dependent cellular responses. (C) 1999 Elsevier Science In c. All rights reserved.