Molecular mechanisms for the anti-cancer effects of diallyl disulfide

Considerable evidence in recent years suggests that garlic has anti-proliferative effects against various types of cancer. Garlic contains water-soluble and oil-soluble sulfur compounds. Oil-soluble compounds such as diallyl sulfide (DAS), diallyl disulfide (DADS), diallyl trisulfide (DATS) and ajoene are more effective than water-soluble compounds in protection against cancer. DADS, a major organosulfur compound derived from garlic, can decrease carcinogen-induced cancers in experimental animals and inhibit the proliferation of various types of cancer cells. Its mechanisms of action include: the activation of metabolizing enzymes that detoxify carcinogens; suppression of the formation of DNA adducts; antioxidant effects; regulation of cell-cycle arrest; induction of apoptosis and differentiation; histone modification; and inhibition of angiogenesis and invasion. These topics are discussed in depth in this review.