Neuroprotective effect of cocoa flavonids on in vitro oxidative stress

Background Cocoa is a rich source of flavonoids that, among other functions, can act as antioxidants. In living systems, the production of reactive oxygen species (ROS) activate an array of intracellular cascades, including mitogen-activated protein kinases (MAPK), that are closely associated with cell death or survival pathways. Aim of the study To ascertain the role of a cocoa extract and its main flavonoid, (-)-epicatechin, in an in vitro model of oxidative stress induced in a neuronal cell line. Methods We analyzed ROS production by fluorometry (dichlorofluorescein assay), and activation of MAPK pathways including extracellular signal-regulated kinases 1/2 (ERK 1/2), c-Jun N-terminal kinase (JNK), and p-38, by Western blot analysis. Results Cells incubated with cocoa extract or (-)-epicatechin, reduced ROS production in a dose-dependent manner, reaching 35% inhibition. pJNK and p38, involved in apoptosis, were down-modulated by cocoa extract and (-)-epicatechin with p38 inhibition reaching up to 70%. Conclusions Our results show that cocoa extract and (-)-epicatechin may exert a neuroprotective action by reducing ROS production and modulating MAPK activation.