Biological activities of malvidin, a red wine anthocyanidin

Abstract

Abstract Malvidin (mv) has been identified as a potential inhibitor of 3′,5′‐cyclic adenosine monophosphate (cAMP) phosphodiesterases (PDE). This study was to investigate if, as a possible consequence of intracellular PDE inhibition, the activity of the mitogen‐activated protein kinase (MAPK) cascade is affected by mv treatment. At a concentration of 5 μM of mv a significant decrease of phosphorylated ERK1 and ERK2 (ERK, extracellular regulated kinase) in HT29 cells was observed. However, an increase in substance concentration led to a substantial recurrence of the phosphorylated enzymes. Cell cycle analysis underlined that indeed G 1 ‐relevant targets are only marginally affected by mv. The recurrence of phosphorylated ERK1/2 and the lack of effectiveness on the G 1 ‐passage up to 100 μM indicated that the inhibition of cAMP‐specific PDEs is of minor relevance for the growth‐inhibitory properties of mv in HT29 cells. In contrast, the release of cells, synchronised in the G 2 /M‐phase of the cell cycle by nocodazole treatment, was effectively blocked in the presence of 1 μM mv. These results suggest that mv interferes with cellular targets relevant for G 2 /M‐progression which have not been identified so far.