Garlic - A Natural Source of Cancer Preventive Compounds.

Several epidemiological observations and a number of laboratory studies have indicated anticarcinogenic potential of garlic, which has been traditionally used from time immemorial for varied human ailments in different parts of the globe. The anticarcinogenic properties of garlic have been attributed to a wide variety of chemical compounds identified to be present in garlic but most studies have focused on specific thioallyl constituents. Garlic components have been found to block covalent binding of carcinogens to DNA, enhance degradation of carcinogens, have antioxidative and free radical scavenging properties and to regulate cell proliferation, apoptosis and immune responses. In view of the variety of effects produced by garlic and its chemical constituents, renewed interest has been generated in investigating its medicinal properties, particularly with reference to cancer prevention and prophylaxis. There are a number of mechanisms at work which jointly are responsible for eliciting the anticarcinogenic effects noted in laboratory studies in a wide range of experimental systems. This has opened up a new avenue for researchers in the field of cancer chemoprevention and merits further scrutiny to establish the role of garlic in prevention of human cancers.