Garlic thromboxane inhibition

Garlic (Allium sativum) is thought to have several beneficial cardiovascular effects, such as lowering blood pressure and serum lipid, and antithrombotic activity. Garlic oil has been reported to interrupt thromboxane synthesis, thereby inhibiting platelet function. 

Makheja AN, Vanderhoek JY, Bailey JM. Inhibition of platelet aggregation and thromboxane synthesis by onion and garlic. Lancet 1979 1 781. 

Other investigators have shown that oily garlic extracts, which contain ajoene, are able to inhibit enzymes necessary for arachidonic acid conversion to thromboxane (Srivastava anad Tyagi, 1993). Makheja et al. (1979) demonstrated the effect of garlic oil on platelet thromboxane synthesis. Human and rabbit platelets were incubated with garlic oil, resulting in almost complete... 

An in vitro study demonstrated that the concentrations of an aqueous extract of garlic required to inhibit ADP, epinephrine, and collagen-induced platelet aggregation were much less than those needed to inhibit thromboxane production (Srivastava, 1984). This finding suggests that inhibition of thromboxane synthesis is not the only mechanism by which garlic inhibits platelet aggregation. 

In blood samples taken from healthy volunteers orally administered 5 ml of aged garlic extract daily for 13 weeks, inhibition of the rate of ADP-induced aggregation was observed. Plasma levels of thromboxane Bj and 6-ketopros-taglandin Fi were unchanged (Rahman 2007). 

Among common foodstuffs, onion and garlic have been reported to contain a heat-stable, lipid soluble factor that inhibits platelet aggregation [183-186], This factor inhibits thromboxane synthesis in platelets from exogenous [ C]arachidonic acid. Along with the decreased thromboxane formation, a new metabolite of arachidonic acid appeared, 10-hydroxy-11,12-epoxy-5,8,14-eicosatrienoic acid, probably via the platelet lipoxygenase pathway [185],... 

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