Research Article

Dual Roles of Quercetin in Platelets: Phosphoinositide-3-Kinase and MAP Kinases Inhibition, and cAMP-Dependent Vasodilator-Stimulated Phosphoprotein Stimulation

Figure 5

Quercetin suppresses collagen-activated PI3K/Akt and MAP kinase phosphorylations. ((a) and (b)) Washed platelets were stirred in an aggregometer with quercetin or vehicle at the concentrations indicated for 3 min and stimulation with collagen for 5 min before termination of the reactions. Proteins were extracted, separated by SDS-PAGE transferred to PVDF membranes, and immunoblotted with antibodies. Blots were visualized by ECL. (a) Quercetin dose-dependent effect on p38, JNK1, and ERK2 phosphorylations. (b) Effects of quercetin on platelet PI3K and Akt phosphorylation. Immunoblots are representatives of 3 to 4 experiments.