Medicinal knowledge followed the growth and fading of great civilizations that enriched its flow with their traditional experiences as evident from the fact that there has been a cycle in the evolution of ideas where ancient medicine never died, it kept evolving in forms.
Early man transferred his knowledge orally hence, there is a paucity of records.
The first well-preserved documentation of medicinal practices discovered, was in the form of clay tablets and cuneiform writings of the Mesopotamians highlighting the richness of the medicinal practices of that era.
India's medicinal practices are just as rich as its culture.
Its two medicinal systems i.e Ayurveda, that evolved in the north and Siddha, that evolved in the south are among the oldest and are still prevalent all over the world.
According to tradition, Chinese emperor Chi'en Nung, over 4,000 years ago, put together a book of medicinal plants called Pen Tsao.
It contained descriptions of more than 300 plants, several of which are still used in medicine.
The hieratic writings of the Egyptian papyri reveal an unusually extensive material medica. The Greeks were critical in their scientific observations that enriched the system.
The Romans inherited the medicinal knowledge from the Greeks and built further on its edifices.
Downfall of Roman Empire gave rise to the Arabian world.
The Arabs further enriched medicinal knowledge that has been passed through civilizations.
Monks in Europe who studied and grew medicinal plants and translated the Arabic works further nurtured this knowledge.
The present work traces the journey followed, giving a brief account of the contribution of all the major civilizations to the development of medicinal systems.
The book further speaks about several prominent personalities of each medicinal system who helped in shaping the system.
Each civilization recorded their medicinal knowledge in some or the other form that are called the 'Herbals'.
This work gives a compilation of herbals from the Mesopotamians until Renaissance period.
Thus provides an insight into medicinal practices of each period.
These herbals were the source of medicinal knowledge and were relied upon by medicinal practitioners until the nineteenth century. Nineteenth century led to the discovery of substances such as alkaloids, glycosides, resins, volatile oils, gums, tannins, etc collectively called secondary metabolites.
A small fraction of these constituents have been isolated and explored for their medicinal properties.
Secondary metabolites is very vast topic hence, selected categories of secondary metabolites have been discussed.
This book also discusses in brief, their biosynthesis along with their role as pharmaceuticals.
Though Allopathy remains as the mainstream in health care, herbal medicines have been main source of primary healthcare in many nations.
These herbal medicines are the synthesis of therapeutic experiences of generations of practicing physicians of indigenous systems of medicine for over hundreds of yeaEach country, each region, each tribe has their own traditional health care system.
The practice, the belief and the basis of a few traditional systems, prevalent in each continent are discussed providing a brief insight into these traditional systems of medicine.
This book also includes monograph of 120 plants. Scientific data along with traditional uses are included in these monographs to highlight their usage as mainstream pharmaceuticals.
In order to facilitate better understanding, a glossary of various terms used through out this work has been provided in the end.