Evidence for an in vitro Anticoagulant Activity of Red Onion (Allium cepa L.)

Background: Haemostasis is the process that retains the blood within the vascular system during periods of injury, localizes the reactions involved to the site of injury, repairs and re-establishes blood flow through the injured vessel. Onion (Allium cepa) is a largely universal staple herb popular throughout history as both food and medicine and it has been consumed for prevention of cardiovascular disorders.Objectives: To study the possible anticoagulant effects of red onion in vitro, by using blood samples of normal individuals.Methods: In vitro anticoagulant effects of an aqueous extract (5%) of red onion in different volumes (25, 50 and 75 ìL) were examined on the blood samples of normal individuals by measuring prothrombin time (PT).Results: The aqueous extract of red onion was found to inhibit coagulation process in vitro and significantly prolonged prothrombin time in a dose-dependent manner.Conclusion: This study showed that red onion aqueous extract in different concentrations inhibits clot formation and increases prothrombin time. Red onion can be used as a supplementary anticoagulant agent to improve and/or prevent cardiovascular diseases