Selective suppression of platelet thromboxane formation with sparing of vascular prostacyclin synthesis by aqueous extract of garlic in rabbits.

It has been suggested that a drug which selectively inhibits platelet thromboxane synthesis, sparing vascular synthesis of prostacyclin, would be more effective as an anti-thrombotic agent. We studied the effect of an aqueous extract of garlic on the production of thromboxane and prostacyclin by rabbit whole blood and aorta in vitro and ex vivo. A dose-dependent inhibition of thromboxane production was observed during blood clotting. Synthesis of prostacyclin was not affected by any concentration of garlic extract used in the experiment. A slight but insignificant reduction in the vascular synthesis of prostacyclin was observed at the highest concentration of garlic used in in vitro experiments. The synthesis of thromboxane by aorta was completely suppressed at all the concentrations of garlic tested. A similar pattern of results was observed after intraperitoneal administration of garlic (1 ml/kg) for one week on the enzymatic synthesis of thromboxane and prostacyclin of these tissues ex-vivo. Aortic synthesis of prostacyclin was significantly increased in the garlic treated rabbits compared to the controls. The data obtained from these rabbit experiments suggested that it may be possible to achieve a selective suppression of thromboxane formation by platelets with sparing of vascular synthesis of prostacyclin by garlic treatment.