ACTIVE COMPONENTS: Alliin is an odorless sulfur-containing chemical derived from the amino acid cysteine. When garlic bulbs are crushed, alliin is converted into another compound called allicin. Allicin appears to be at least one of the primary active compounds

MODE OF ACTION:

Being a strongly oxidising compound, it protects garlic from attack by bacteria and insects by disabling the enzymes that are found in the substrate necessary for infections to occur, thus acting as a natural insecticide. It does so by attacking the SH groups found on their active sites. This is also the case for proteinases and alcohol dehydrogenases, enzymes that promote invasion and infection of bacteria in the human body. It is therefore believed that allicin is a good natural cure-all. The antimicrobial effect of allicin is due to its chemical reaction with thiol groups of various enzymes.
The incidence of gastric ulcers is lower in populations with high garlic intake. Studies have confirmed that allicin has inhibitory activity on Helicobacter pylori, a bacteria responsible for the development of gastric ulcers. The sensitivity of Helicobacter pylori to allicin might also explain the lower risk of stomach cancer in people with high garlic intake. A study by Ankri et al (1997) demonstrated that allicin inhibited the ability of the parasite Entamoeba histolytica to destroy monolayers of baby hamster kidney cells.
Allicin is not bioavailable and will not get absorbed in the blood, even after ingesting large amounts of allicin.