Cancer chemoprevention by garlic and its organosulfur compounds-panacea or promise?

Of late medicinal plants and functional foods rich in bioactive phytochemicals have received growing attention as potential agents for cancer chemoprevention. Accumulating evidence from epidemiological studies as well as laboratory data supports the anticancer properties of garlic widely used as a medicinal herb and spice. Garlic and its organosulfur compounds (OSCs) appear to exert their anticarcinogenic effects through multiple mechanisms that include modulation of carcinogen metabolism, inhibition of DNA adduct formation, upregulation of antioxidant defences and DNA repair systems, and suppression of cell proliferation by blocking cell cycle progression and/or inducing apoptosis. Since multiple signaling pathways are dysfunctional in cancer and new oncogenic mutations accumulate with carcinogenic progression, dietary agents such as garlic with its rich array of bioactive OSCs that modulate cancer cascades offer promise as potential chemopreventive and chemotherapeutic agents.