Fruitflow inhibits platelet function by suppressing Akt/GSK3ß, Syk/PLCγ2 and p38 MAPK phosphorylation in collagen-stimulated platelets.

ABSTRACT

BACKGROUND: Platelets play an important role in the progression of atherosclerosis and cardiovascular events. The inhibition of platelet function is a main strategy to reduce risk of cardiovascular events. Some studies have shown that tomato extracts inhibit platelet function, but the molecular mechanisms remain unclear. Fruitflow is a water-solute tomato extract and the main ingredients including flavonoids, adenosine, chlorogenic acid, phytosterols, naringenin, and carotenoids. The present study investigated the effects of fruitflow on adenosine diphosphate (ADP)- and collagen- stimulated platelet aggregation, platelet adhesion, and levels of thromboxane B2 (TXB2), 6-keto-prostaglandin F1α (PGF1α), and platelet factor 4 (PF4) and explored the underlying molecular mechanisms. METHODS: Platelet-rich plasma (PRP) was used for measurement of platelet aggregation, TXB2, 6-keto- PGF1α, and PF4 levels. Platelet aggregation was analyzed using a Chrono-Log aggregometer. TXB2, 6-keto- PGF1α, and PF4 levels were determined using enzyme-linked immunosorbent assay kits. Immunoblotting was used to detect protein expression and phosphorylation on washed platelets. Platelet adhesion and spreading were determined by immunofluorescence. RESULTS: Fruitflow (1, 3, 10 and 100 µg/ml) dose-dependently inhibited platelet aggregation that was induced by ADP and collagen. Fruitflow (100 µg/ml) treatment completely suppressed ADP- and collagen-stimulated platelet aggregation. Fruitflow (100 µg/ml) significantly decreased TXB2 and 6-keto-PGF1α generation and PF4 release in ADP- and collagen-stimulated platelets. Treatment with fruitflow effectively blocked collagen-induced platelet spreading. To determine the potential molecule mechanism of action of fruitflow, we investigated the protein expression and phosphorylation of several signaling molecules in collagen-activated platelets. Fruitflow dose-dependently suppressed Akt, Glycogen synthase kinase-3ß (GSK-3ß), spleen tyrosine kinase (Syk) and phospholipase Cγ2 (PLCγ2) and p38 MAPK phosphorylation that was induced by collagen. CONCLUSION: Fruitflow inhibited platelet aggregation and reduced TXB2, 6-keto-PGF1α, and PF4 levels in ADP- and collagen-stimulated platelets. The mechanism of action of fruitflow may be associated with the suppression of Akt/GSK3ß, Syk/PLCγ2, and p38 MAPK phosphorylation in collagen-activated platelets. Fruitflow is a natural product derived from tomato and can be used as a health food for decreasing platelet activity.