Bioactive Organosulfur Compounds of Garlic and Garlic Products

Garlic ( Allium sativum L.) and some of its derived products have well-established biological activities as antibiotics and as agents in reducing the risk factors of cardiovascular disease, and have received growing support as potential anticancer agents. However, because garlic's organosulfur compound composition varies greatly with the method of processing and because analysis of most of these compounds has only been recently achieved, there has been considerable variation in the experimental conditions, and subsequent results, in the biological studies with garlic and garlic products. This chapter discusses the importance of garlic's organosulfur compounds and the many changes that occur in their chemistry when garlic is crushed, cooked, ingested, metabolized, or commercially processed. The large variation in composition of commercial garlic products necessitates standardization of these products, especially for use in biological studies. Rapid pre-hepatic physiological changes occur to as yet undetected compounds in the blood, thus making in vitro and organ perfusion studies of limited value. The clinical studies on the cardiovascular effects of garlic preparations are summarized, and evidence is presented that low doses of allicin (allyl 2-propenethiosulfinate) and the vinyl-dithiin oils are significant blood lipid-reducing agents.