Antihaemostatic effect of combination of Allium sativum L. ethanol extract and warfarin in Wistar rats

Resumen

Background: concomitant use of herbal products with commonly prescribed conventional medications has been associated with higher risks of adverse effects. Allium sativum L. (garlic) has long been used both for flavoring and for medicinal purposes in many cultures but many serious concerns over surgery or contraindications with anticlotting medications such as warfarin are expressed in the medical arena.
Objectives: to evaluate the antihaemostatic effect resulting from the combination of Allium sativum and warfarin in Wistar rats.
Methods: 22.5 % A. sativum ethanol extract was obtained from fresh A. sativum cloves and the phytochemical screening was done. Twelve Wistar rats were divided into four groups, one control and three experimental. A single oral warfarin dose (3 mg/kg) was administered to one experimental group. The other two groups received orally A. sativum ethanol extract (10 mg/kg) once daily for 11 days, and a single dose of warfarin (3 mg/kg) was added to one of them the last day of the study. The clotting time and clot retraction were determined to assess the hemostatic functions on the study groups. The mean differences were calculated and P value less than 0.05 were considered significant.
Results: fats and oils, terpenoids, reducing sugars, and tannins were present in the A. sativum ethanol extract. The clotting time was significantly delayed in the experimental groups which received A. sativum and the combination of A. sativum and warfarin. The clot retraction was poor in the group treated with the combination of the drugs studied.
Conclusions: a. sativum oils may be responsible for the antihaemostatic effects found which can be potentiated by its additive interaction with warfarin increasing the risk of bleeding complications when both drugs are used concomitantly.