Fig. 7

Potential points of action of flavonoids within PI3K/Akt signalling pathway. Active PI3K catalyzes the production of phosphatidylinositol-3,4,5-triphosphate (PIP₃) which activates phosphoinositide-dependent protein kinase 1 (PDK1). PDK1 plays a central role in many signal transduction pathways, activating Akt and the PKC isoenzymes p70 S6 kinase and RSK. Through its effects on these kinases, PI3K is involved in the regulation of a wide variety of processes, including cell growth, cell proliferation, differentiation, cell cycle entry, cell migration and apoptosis. Flavonoids have been proposed to act on this pathway via direct modulation of PI3K activity via binding to its ATP binding pocket, in a similar manner to that of LY294002. Alternatively, they may act to modulate the activity of the tumour suppressor, PTEN