Antithrombotic, garlic

Ajoene (Spanish, ajo, garlic), 4,5,9-trithiadodeca-l,6,ll-triene-9-oxide 35 (Scheme 12), an antithrombotic compound with other well-defined physiological properties, is formed from allicin.84 Like allicin, ajoene is a sulfoxide but has two further sulfur atoms in a disulfide linkage. E and Z isomeric forms are possible involving the C=C bond at positions 6 and 7. Ajoene is somewhat more stable than allicin. The formation of ajoene probably involves condensation of 2 molecules of allicin forming a sulfonium salt 33, with elimination of propenesulfenic acid. Elimination of a second molecule of propenesulfenic acid... 

Garlic clearly has antithrombotic properties. Ajoene (an allicin metabolite) and methyl allyl trisulfide inhibit platelet aggregation. Garlic may promote vasodilation by relaxing smooth muscle, and it may reduce low-density lipoprotein (LDL) oxidation. 

The parent compound, thioacrolein, affords similar cycloadducts which are present in garlic and show potent antithrombotic activity479 480. 

Garlic is used for a variety of reasons, and some of the attributes associated with it, e.g. for cancer prevention, or to reduce heart attacks, may not be substantiated. Other properties such as antimicrobial activity, effects on lipid metabolism, and platelet aggregation inhibitory action have been demonstrated. Ajoene has been shown to be a potent antithrombotic agent through inhibition of platelet aggregation. 

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. 

The constituents of garlic bulbs, in particular the sulphur derivatives such as alliin, ajoenes, vinyldithines etc., are known for their lipid and cholesterol effects as well as antithrombotic... 

Fukao, H., H. Yoshida, Y. Tazawa, and T. Hada. 2007. Antithrombotic effects of odorless garlic powder both in vitro and in vivo. Biosci. Biotechnol. Biochem. 71(l) 84-90. 

Garlic is known to have various pharmaceutical effects such as an antithrombotic effect, anticancer effect, antibiotic effect, and antioxidant effect (Reuter et al 1996 Lawson 1998), and it has been used as a medicine as well as a spice since the ancient times. 

The cardiovascular diseases and thrombotic diseases, which would be attributed more or less to the atherosclerosis, have been increased recently, and are the leading cause of death especially in the industrialized countries. The intake of garlic and onion is supposed to benefit in lowering the mortality and morbidity rates of these diseases by their antithrombotic, lipid-lowering, and hypoglycemic effects. In this section, antithrombotic and anticardiovascular effects of garlic and onion are described. 

Aqueous extracts of raw garlic also inhibited cyclooxygenase activity in rabbit platelets, again contributing to an antithrombotic effect. In addition, AGE and S-allyl cysteine and S-allyl mercapto-cysteine have antiplatelet adhesion effects. Platelet adhesion to the endothelial surface is involved in atherosclerosis initiation. Furthermore, S-allyl mercaptocysteine inhibits the proliferation of rat aortal smooth muscle cells, another important... 

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