POTENT ACTIVATION OF NITRIC-OXIDE SYNTHASE BY GARLIC - A BASIS FOR ITS THERAPEUTIC APPLICATIONS

Garlic (Allium sativum L.) is thought to have a variety of therapeutic applications including inhibition of platelet aggregation. Many of th e therapeutic actions of garlic parallel the physiological effects of nitric oxide and may be explained by its ability to increase nitric ox ide synthase activity intracellularly. Our studies showed that both wa ter and alcoholic extracts of garlic are very potent inhibitors of pla telet aggregation induced by epinephrine and ADP. Similar dilutions of garlic extract also activated nitric oxide synthase activity in isola ted platelets in vitro. The same extract was also very effective in ac tivating nitric oxide synthase activity in placental villous tissue. T he addition of garlic extracts increased nitric oxide synthase activit y in a dose-dependent manner. Nitrite levels in the supernatants of in cubated placental villous tissue were similarly increased. Activation of calcium-dependent nitric oxide synthase and the subsequent producti on of nitric oxide is probably the most novel mechanism yet claimed by which garlic can exert its therapeutic properties.