Antimicrobial properties of allicin from garlic

Allicin, one of the active principles of freshly crushed garlic homogenates , has a variety of antimicrobial activities. Allicin in its pure form was f ound to exhibit i) antibacterial activity against a wide range of Gram-nega tive and Gram-positive bacteria, including multidrug-resistant enterotoxico genic strains of Escherichia roll; ii) antifungal activity, particularly ag ainst Candida albicans; iii) antiparasitic activity, including some major h uman intestinal protozoan parasites such as Entamoeba histolytica and Giard ia lamblia; and iv) antiviral activity. The main antimicrobial effect of al licin is due to its chemical reaction with thiol groups of various enzymes, e.g. alcohol dehydrogenase, thioredoxin reductase, and RNA polymerase, whi ch can affect essential metabolism of cysteine proteinase activity involved in the virulence of E. histolytica. (C) Elsevier, Paris.