appears to exert numerous effects on the cardiovascular system, and
Atherosclerosis in particular, beyond the reduction of serum lipids.
There are possibly multiple protective effects of garlic, including
inhibition of platelet aggregation and enhancement of fibrinolysis.
Wild garlic (Allium ursinum) has been reported to contain similar
amounts of sulfur-containing compounds (thiosulfinates and ajoenes)
as garlic (Allium sativum), and to exert similar effects on
cyclooxygenase, 5-lipoxygenase, angiotensin converting enzyme, and
Lipid-lowering Effects; garlic's lipid lowering effects may occur via inhibition of HMG-CoA reductase or other enzymes, possibly by diallyl di- and trisulphide components of garlic. Other suggested mechanisms include increased loss of bile salts in feces and mobilization of tissue lipids into circulation, as garlic has a profound effect on post-prandial hyperlipidemia. Wild garlic (Allium ursinum) has shown similar efficacy to garlic (Allium sativum) in decreasing hepatocyte cholesterol synthesis In vitro. Aged garlic extract and its constituents have been shown to inhibit Cu2+-induced oxidative modification of low-density lipoprotein.38 Aged garlic extract and its constituent S-allylcysteine have been found to protect vascular endothelial cells from injury caused by oxidized LDL.
Vascular Effects; vasorelaxant properties of garlic have been noted in multiple pre-clinical studies. Cutaneous microperfusion is increased in humans following ingestion of 600mg of garlic, and vasodilation of conjunctival arterioles and venules occurs at 900mg. Garlic may act on the nitric oxide system and exert effects on the elastic properties of vasculature, yielding changes in systemic blood pressure. It has been suggested that allicin is the component of garlic responsible for nitric oxide-mediated effects. Prostaglandins have been identified in garlic extracts which may exert pharmacologic effects, although this has not been demonstrated in vivo.