Allicin, in garlic

Bocchini, P., Andalo, C., Pozzi, R., Galletti, G.C. and Antonelli, A. (2001) Determination of diallyl thiosulfinate (allicin) in garlic (Allium sativum L.) by high performance liquid chromatography with a post-column photochemical reactor, Anal. Chim. Acta, 441(1), 37-43. 

Sun X, Ku DD (2006) Allicin in garlic protects against coronary endothelial dysfunction and right heart hypertrophy in pulmonary hypertensive rats. Am J Physiol Heart Circ Physiol 291(5) H2431-H2438. doi 10.1152/ajpheart.00384.2006... 

Garlic supplements - powder tablets or capsules, steam-distilled oil, vegetable oil macerate extract, or extract aged in dilute alcohol - are widely available and are taken by millions. Since the active principle, allicin, is not present in garlic bulb, the supplements rely on the presence of precursor alliin and enzyme alliinase. In tests on 24 commercial brands of enteric-coated tablets, all except one gave low dissolution allicin release 83% of the brands released less than 15% of their potential allicin.78,79 Relevant factors were impaired enzyme activity caused by excipients and slow tablet disintegration. Caveat emptor ... 

Constituents that have some known pharmacological activity that contributes to some extent to the efficacy of the product have been identified. These are known as active markers. An example of this category is alliin, which is converted to allicin in presence of allinase enzyme, and is present in garlic. These active markers may or may not have clinically proven efficacy in their own right. A minimum content or range for active markers is usually specified in pharmacopeial articles. A quantitative determination of active marker(s) during... 

Human clinical studies Allicin is well absorbed, as indicated by a persistent garlicky odor on the breath, skin, and amniotic fluid of persons after consumption of fresh garlic (83). Because oral comsumption of pure allicin has been shown to significantly increase overall body catabolism of triglycerides, a substantial absorption of allicin is assumed to occur (84). However, the metabolic fate of allicin in the body is not well understood. 

A number of studies have focused on identifying the active antimicrobial principles in fresh garlic extract. Allicin has been identified as the active agent in garlic extracts. The antifungal activity of allicin has been shown to depend on the sulfhydryl moiety because activity is destroyed by thiols such as L-cysteine, glutathione, and mercaptoethanol. Ajoene, a compound found in oil-macerated garlic, has also been shown to have antimicrobial activity (Ali et al., 2000). 

Prasad, K. et ah, Antioxidant activity of allicin, an active principle in garlic, Mol. Cell. Biochem., 148,183-189, 1995. 

The exact compounds in garlic responsible for its antioxidant effects are undetermined. Some believe allicin to be the primary antioxidant compound in garlic and... 

Freeman, F. and Kodera, Y. (1997) Rebuttal on garlic chemistry Stability of 5-(2-propenyl) 2-propene-l-sulfinothioate (allicin) in blood, solvents, and simulated physiological fluids. J. Agric. Food Chem. 45 3709-3710. 

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