Pomegranates are widely consumed either as fresh fruit or in beverage form as juice and wine.
Ellagic acid possesses potent antioxidative properties; it is known to be an effective phytotherapeutic agent with antimutagenic and anticarcinogenic qualities.
Ellagic acid (20 to 80 μ M) exhibited a potent activity in inhibiting platelet aggregation stimulated by
collagen; however, it did not inhibit platelet aggregation stimulated by
thrombin,
arachidonic acid, or
U46619. Treatment with
ellagic acid (50 and 80 μ M) significantly inhibited platelet activation stimulated by
collagen; this alteration was accompanied by the inhibition of relative [Ca(2+)] i mobilization, and the phosphorylation of
phospholipase C (PLC) γ 2,
protein kinase C (PKC),
mitogen-activated protein kinases (MAPKs), and Akt, as well as
hydroxyl radical (
OH(●)) formation. In addition,
ellagic acid also inhibited
p38 MAPK and Akt phosphorylation stimulated by
hydrogen peroxide. By contrast,
ellagic acid did not significantly affect PKC activation and platelet aggregation stimulated by PDBu. This study is the first to show that, in addition to being considered a possible agent for preventing
tumor growth,
ellagic acid possesses potent antiplatelet properties. It appears to initially inhibit the PLCγ2-PKC cascade and/or
hydroxyl radical formation, followed by decreased phosphorylation of MAPKs and Akt, ultimately inhibiting platelet aggregation.