Evaluation of the anti-inflammatory effects of ellagic acid

Few studies have investigated the anti-inflammatory properties of ellagic acid and no published studies have examined the effects of ellagic acid in combination with anesthetic adjuvants. In this study, 54 Sprague-Dawley rats were assigned to one of six groups: (1) vehicle; (2) ketorolac and vehicle; (3) meloxicam and vehicle; (4) ellagic acid and vehicle; (5) ellagic acid, ketorolac, and vehicle; and (6) ellagic acid, meloxicam, and vehicle. Groups 5 and 6 investigated interactions between ellagic acid and cyclooxygenase inhibitors. Paw inflammation was induced with 3% carrageenan and was measured with a plethysmometer at 30 minutes and 4, 8, and 24 hours after intraperitoneal injection. All rats received one intraperitoneal injection of equivalent volumes according to group assignment. Analysis of covariance followed by post hoc analysis determined that ketorolac was the only compound to significantly reduce paw edema at 4 hours (P = .019); ellagic acid alone (P = .038) and the combination of ellagic acid and ketorolac (P = .038) were the only compounds to significantly reduce paw edema at 8 hours. At 24 hours, only ellagic acid was effective (P = .01). Our findings suggest that ellagic acid may be effective against inflammation, may have a prolonged onset and duration of action, and may interact with known cyclooxygenase inhibitors.