Vol. 5(9), pp. 401-408, September, 2013 DOI: 10.5897/IJMMS2013.0960 ISSN 2006-9723 ©2013 Academic Journals http://www.academicjournals.org/IJMMS International Journal of Medicine and Medical Sciences Review Medicinal values of garlic: A review Gebreselema Gebreyohannes 1 * and Mebrahtu Gebreyohannes 2 1 Department of Biology, Faculty of Natural and Computational Sciences, University of Gondar, Ethiopia. 2 Faculty of Veterinary Medicine, University of Gondar, Ethiopia. Accepted 12 August, 2013 Garlic products are used as sources of medicine in many ways in human beings in their day today life. As a result, researchers from various disciplines are now directing their efforts towards discovering the medicinal values of garlic on human health. The main interest of researchers in the medicinal values of garlic is its broad-spectrum therapeutic effect with minimal toxicity. Garlic extract has antimicrobial activity against many genera of bacteria, fungi and viruses. Garlic contains a higher concentration of sulfur compounds which are responsible for its medicinal effects. The chemical constituents of garlic have also been investigated for treatment of cardiovascular disease, cancer, diabetes, blood pressure, atherosclerosis and hyperlipidaemia and highly praised by several authors. Therefore, this paper is reviewed to inspire and impress the young researchers about the medicinal values of garlic. Key words: Allium sativum, immunity booster, antibacterial, antifungal, antiviral, anticancer INTRODUCTION Natural products of animals, plants and microbial sources have been used by man for thousands of years either in the pure forms or crude extracts to treat many diseases (Parekh and Chanda, 2007). Garlic (Allium sativum L.) is one of those plants that were seriously investigated over several years and used for centuries to fight infectious diseases (Onyeagba et al., 2004). The taxonomic posi- tion of garlic and related genera had been a matter of controversy for long period of time. The most recent classification scheme of garlic was class Liliopsida, subclass Liliidae, superorder Liliianae, order Amary- llidales, family Alliaceae, subfamily Allioideae, tribe Allieae and genus Allium which is mainly based on the sequences of nuclear ribosomal DNA (Friesen et al., 2006). The early Egyptians used garlic to treat diarrhea and its medical power was described on the walls of ancient temples and on papyrus dating to 1500 BC (Bradley, 1992). It was used by Greek physicians Hippocrates and Galen to treat intestinal and extra-intestinal diseases; ancient Japanese and Chinese used it to treat headache, flu, sore throat and fever. In Africa, particularly in Nigeria, it is used to treat abdominal discomfort, diarrhea, otitis media and respiratory tract infections (Jaber and Al- Mossawi, 2007). In Europe and India, it was used to treat common colds, hay fever and asthma. Garlic is nicknamed as Russian penicillin for its widespread use as a topical and systemic antimicrobial agent; it is commonly used in many cultures as an excitement and reputation of healing power (Timbo et al., 2006). POTENTIALLY ACTIVE CHEMICAL CONSTITUENTS OF GARLIC Garlic contains at least 33 sulfur compounds, several enzymes and the minerals germanium, calcium, copper, iron, potassium, magnesium, selenium and zinc; vitamins A, B1 and C, fiber and water. It also contains 17 amino acids to be found in garlic: lysine, histidine, arginine, aspartic acid threonine, swine, glutamine, proline, glycine, alanine, cysteine, valine, methionine, isoleucine, leucine, tryptophan and phenylalanine (Josling, 2005). It has a higher concentration of sulfur compounds than any other Allium species which are responsible both for garlic’s pungent odor and many of its medicinal *Corresponding author. E-mail: ggebreselema@yahoo.com.