Garlic effect on fibrinolytic activity

Inhibition of fibrinolytic activity (FA) or deficiency of the factors involved might upset the hemostatic balance and allow excessive fibrin deposition. In diabetes, hypertension, hypercholesterolemia etc, it is possible that disturbance in the coagulation-fibrinolytic system may be an important factor leading to the development of thrombosis and ischemia. Accordingly, the greater the FA, the more favorable is the antithrombic effect. FA is generally determined by euglobulin lysis time. The patients who died with acute or old myocardial infarction showed the highest values of plasma fibrinogen, euglobulin lysis time and antiplasmin. This suggests that prognosis in myocardial infarction is partly influenced by the degree to which plasma fibrinolysis is impaired [45].

Animals studies

Marked rise in blood coagulability of rabbits that followed 3 months of cholesterol feeding (0.2 g/kg/day) was significantly reduced by the essential oils of garlic. Fibrinolytic activity was actually increased even above the normal control levels. The essential oils of garlic (equivalent to 1 g/kg/day of raw bulbs) proved effective in mediating fibrinolytic activity [10,46]. Experimental study also revealed that garlic juice (raw garlic; 250 mg/day) had significant effect in enhancing the fibrinolytic activity in rabbit after receiving a cholesterol rich diet for 13 weeks [47]. The plasma fibrinolytic activity in rabbit, which was decreased on cholesterol feeding, was considerably increased when this diet was supplemented with garlic [48].

Human studies

Almost all human studies on fibrinolytic activity of garlic have been found to have positive effect (Table- 2). Acute as well as chronic intake of garlic oil and raw garlic increased fibrinolytic activity (FA). In 1975, Bordia first demonstrated that garlic oil increased FA after 3 hours of administration. Bordia also reported that chronic (3 weeks to 3 months) administration of garlic oil (dose: equivalent to 1 gm/kg of fresh garlic) increased FA significantly ranging from 36% to 130% in healthy as well as acute myocardial infarction patients [49-52]. Some other investigators also found the same results [53-55]. Dried garlic powder has been also tested for its fribinolytic activity. While two studies [24,25] showed no difference in FA, one study [56] showed increased FA as well as tissue plasminogen activator activity after acute and chronic garlic powder intake. Chutani and Bordia (1981) designed one study to show that both raw and fried garlic significantly enhance FA [53]. Frying removes the strong acrid smell of garlic, but preserves it useful effects on FA. The rise in FA has been observed within 6 hours of garlic administration, which showed that garlic has a rapid onset of action and the effect is well maintained as long as garlic is being taken. Recently Bordia (1998) found that intake (3 months) of ethyl acetate extract of crushed raw garlic also increased FA [57].

References