Ancient Greece was a key contributor to the rational development of herbalism in the ancient West. As tradition credits, it was Hippocrates (460-377 BC) and Aristotle (384-322 BC) who inherited this tradition—initial beliefs from India and Egypt—that were essentially their own. The philosopher-natural scientist, Theophratus (~300 BC), explained the medicinal properties of herbs in his History of Plants, as well as the ability to transform them by cultivation. In 100 AD, Dioscorides, a Greek physician, recorded and described the collection, storage, and use of medicinal herbs through travel with Roman armies, and Galen (130-200 AD), who also practiced and taught pharmacy and medicine in Rome, published more than 30 books on it. They gained fame through the formulas they used in their complex prescriptions and compound medicines, sometimes containing dozens of ingredients, ("galenicals") (Wehr et al., 1999).
Greek and Roman medicine was based on the belief that the world was made up of four elements—earth, air, fire and water. Each of these corresponded to what were called humors—the four vital fluids in the body. Blood, phlegm, black bile and yellow bile made up these four disorders that were believed to affect health and temperament according to the following classification—sanguineous, phlegmatic, melancholic and choleric. Restoring balance was achieved through blood circulation (removal of excess blood) and purification (removal of excess black bile). The four humors were composed as follows: cold, heat, dampness and dryness, and each type had its own series of cold, hot, damp or dry herbs that were supposed to restore the imbalance. The European tradition also had many regional influences that inspired local folk practices.
Perhaps the most powerful influence was Dioscorides' De Materia Medica, a famous book written by a Greek physician during the first century AD. It is generally considered the first herbal for Europe, and gave rise to most herbals that followed it as the reference standard in Europe for over 1,000 years. This was reached in 800 AD when the standard layout for medicinal plants was cultivated in the monasteries of central Europe. One of the famous physicians of this period was Hildegard of Bingen (1098-1179). In later years, a Swiss alchemist known as Paracelsus (1493-1541) emphasized the importance of correct dosage in medical treatment (Guraib-Fakim, 2006). Herbal medicine used to be a common way of life in many countries of Europe and, even today, remains a popular way of managing illnesses – although it is often considered more supportive than curative. It is still very popular in many countries of Europe. Besides these, 'natural products' consumed in raw format (unprocessed) - as teas or decoctions, the more refined phytomedicines (standardized and formulated extracts of plants and subjected to rigorous testing in humans) still remain popular alternatives to medicinal products derived from pure synthetic chemicals. (Wicker and Zollman, 1999).
With the advent of commercialization, knowledge about therapeutic traditional herbal remedies has reached a wider public and many active compounds isolated from medicinal plants are today exploited for their properties as single chemical entities (Pieroni, 2000).
