A Comprehensive Survey of Garlic Functionality

Garlic (Allium sativum L.) is the edible bulb from a plant of the Allium genus, commonly used for flavouring in cooking and for its beneficial effects for human health. Although garlic cloves are usually eaten raw or cooked, different garlic dietary supplements including dried or powdered formulations, oils and liquid extracts have being recently incorporated into the market to satisfy the demand of consumer for garlic bio-active compounds. Despite the numerous therapeutic effects attributed to garlic, the chemistry behind its health-promoting effects is still poorly understood. Garlic is a major source of sulfurcontaining compounds, particularly S-alk-(en)yl-L-cysteine sulphoxides (Cs), being alliin the major one. Volatiles such as allicin, and lipid-soluble sulphur compounds such as diallyl sulphide, diallyl disulphide, diallyl trisulphide, dithiins, ajoene and others, are originated from ACSOs by different metabolic pathways after tissue damage of garlic by cutting, crushing or bitting. These compounds provide to garlic its characteristic odour and flavour, as well as most of its biological properties. The effect of garlic on cardiovascular diseases, including hypocholesterolemic, anti-hypertensive, antithrombotic, and antihyperglycaemic activities, is one of its most extensively studied benefits. Garlic intake has also been described to reduce the risk for developing several types of cancer, especially those of the gastrointestinal tract (colon and stomach). Other bioactivities previously described in garlic include antimicrobial, antioxidant, antiasthmatic, immunomodulatory and prebiotic effects. Recently, it has been demonstrated that additional garlic constituents such as organo-selenium compounds, steroid saponins and sapogenins (e.g. β-chlorogenin), * Corresponding author: e-mail: mvillamiel@ifi.csic. es , Tel: +34 915622900, Fax: +34 915644853 The exclusive license for this PDF is limited to personal printing only. No part of this digital document may be reproduced, stored in a retrieval system or transmitted commercially in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services. Alejandra Cardelle-Cobas, Ana Cristina Soria, Marta Corzo-Martinez et al. 2 vitamins B6 and B12, flavonoids (e.g. allixin), lectins and N-fructosyl-aminoacids, may contribute, along with organo-sulphur compounds, to the above mentioned biological effects of this vegetable. Despite garlic can cause side effects, including gastrointestinal distress, allergic and asthmatic reactions, and interfere with a few medications, its use as therapeutic agent seems to be safe, since these adverse effects appear with an excessive and prolonged consumption. Thus, the efforts of research should be directed to determine the effective intake to note the beneficial properties as well as the most suitable preparation to avoid undesirable effects.