Sulfur compounds namely allicine substance seems to be the active ingredients of garlic. The available data reveal that garlic is used for about 5000 years, and for 3000 years in China is used in medicine. 
Historically, garlic has been used around the world to address a variety of diseases, including hypertension, infections and cholesterol. It has been suggested that patients taking anticoagulants should show caution when eating garlic, and displays anticoagulant properties.