Fermented garlic extract decreases blood pressure through nitrite and sGC-cGMP-PKG pathway in spontaneously hypertensive rats

Garlic (Allium sativum L.) has long been used as an anti-hypertensive. The study investigated the effect of fermented garlic extract (Fgarlic) on systolic blood pressure (SBP) and its molecular basis using spontaneously hypertensive rats (SHRs). Fgarlic contained high content of stable nitrite (0.975 mg nitrite/ml). Acute feeding of different amounts (0.3, 0.6, and 0.9 ml) of concentrated Fgarlic (9.75 mg nitrite/ml) reduced SBP dose-dependently. Chronic feeding of Fgarlic (containing 27 mg nitrite/day) for 12 days reduced SBP with increased expressions of eNOS and PKG proteins in aortic tissues, which were attenuated by a soluble guanylyl cyclase (sGC) inhibitor. The relaxation responses of thoracic aorta to acetylcholine and sodium nitroprussside were improved in SHRs fed Fgarlic. These results suggest that nitrite in Fgarlic, which converts to NO in the body, functions as an anti-hypertensive molecule and its effect is mediated through sGC-cGMP-PKG pathway.