The effect of ellagic acid on platelet activation as measured by the quantification of P-selectin using flow cytometry.

The purpose of this study was to investigate the effects of ellagic acid on platelet expression via the cyclooxygenase (COX) pathway by examining its effects on platelet activation and comparing them with known COX inhibitors in male Sprague-Dawley rats. Ellagic acid is a major compound found in certain fruits and nuts. It has been attributed as having anti-inflammatory, free radical scavenging, and coagulation properties as well as effects on tumor genesis in multiple forms of cancer. We assessed the similarities of ellagic acid to known COX-2 specific and nonspecific COX inhibitors by examining their effects on platelet activation via use of P-selectin flow cytometry. Compared with the vehicle group, both the ellagic acid (P = .035) and the ketorolac (P = .038) groups demonstrated a significant decrease in platelet activation (P = .026). Furthermore, compared with all other groups, ellagic acid plus ketorolac group showed a significant decrease in platelet activation (P = .01). Our findings suggest that ellagic acid is likely a nonspecific COX inhibitor. It also suggests that combining ellagic acid with a known nonspecific COX inhibitor such as ketorolac may cause a significant decrease in platelet activity and an increase in blood loss.