ABSTRACT – Allicin, one of the active principles of freshly crushed garlic homogenates, has a variety
of antimicrobial activities. Allicin in its pure form was found to exhibit i) antibacterial activity against
a wide range of Gram-negative and Gram-positive bacteria, including multidrug-resistant
enterotoxicogenic strains of Escherichia coli; ii) antifungal activity, particularly against Candida albicans;
iii) antiparasitic activity, including some major human intestinal protozoan parasites such as Entamoeba
histolytica and Giardia lamblia; and iv) antiviral activity. The main antimicrobial effect of allicin is due
to its chemical reaction with thiol groups of various enzymes, e.g. alcohol dehydrogenase, thioredoxin
reductase, and RNA polymerase, which can affect essential metabolism of cysteine proteinase activity
involved in the virulence of E. histolytica. © Elsevier, Paris