History of pharmacognosy can be regarded as the history of pharmacy and medicine because pharmacognosy had its origin in the health-related activities of the most primitive human race of the remote past. The early man must have sought to alleviate his sufferings from injury, pain or disease by utilizing the plants that were growing in his environment. The processes that contributed to the early man’s search for cures and selection of the medicament include the following:
- Guesswork, that is, application of intelligence or natural intuition.
- Trial and error, that is, try and then discard, if not useful or repeatedly use if found beneficial.
- Curiosity and search for food contributed considerably to his knowledge about the medicinal and edible plants and their virtues.
- ‘Signature of Nature’, that is, superficial resemblance between the plant parts and the affected organs or some symptoms of the ailment also guided the ancient man in the selection of his drugs.
- Observations on the animals’ instinctive discrimination between toxic and palatable plants might also have helped the primitive man to choose those plants that were beneficial from nutritive and medicinal standpoints.
- The healing powers of some plants were undoubtedly discovered by accident.
It is probable that by a combination of these various methods, the ancient people were able to build up a considerable knowledge of medicinal and food plants. Once such properties of any plant were discovered they were too important for him to forget. The acquired knowledge was transmitted from generation to generation and new information was added to it by the next generation. This way the volume of knowledge about natural drugs also increased with time. Gradually a group of people in each generation started specializing in collecting and processing medicinal plants and using them against various diseases.
This group of people later emerged as the ‘Medicine men‘ of the ear her civilizations and they monopolized the knowledge of drug plants. They used to hide the knowledge of various drugs in some mysterious incantations, which they also used as charms. Before people could learn to read and write, the knowledge of drugs was passed from one generation to another either orally or by the use of some signs and symbols. As civilization progressed, the method of documentation of human knowledge about drugs and diseases also changed from signs and symbols to written language.
As far as historical records are available, the Chinese pharmacopoeia, the Pen Tsao, attributed to the legendary Emperor Shen Nung (written between 3000 and 2730 BC ~d appeared around 1122 BC), appears to be the oldest pharmacopoeia on earth. This treatise includes recipes and therapeutic uses of many Chinese traditional medicines. Babylonians (about 3000 BC) appear to have been aware of a large number of medicinal plants and their medicinal properties. Some of the plants they used are still used almost in the same manner and for the same purpose.
As evident from Ebers Papyrus (written in 1550 BC), the ancient Egyptians possessed an understanding of the human anatomy and a good knowledge of the medicinal uses of hundreds of plants and animals. Many of the present day important drugs like Henbane, Mandrake, Opium, Pomegranate, Castor Oil, Aloe, Onion, many essential oils, bile, lard and many others were in common use in Egypt about 4500 years ago. The earliest plant medicines used in the Ayurvedic system were described around 1200 BC with a list of 127 plants.
The practice of medicine using medicinal plants flourished most during the Greek civilization when many historical personalities practiced herbal medicine. Some, of the early naturalists, scientists and physicians who contributed enormously to the development of human knowledge about medicinal plants include Hippocrates (460-370 BC), Aristotle (384-322 BC), Theophrastus (370-287 BC), Dioscorides (First Century AD), Pliny the Elder (23-70 AD) and Galen (131-200 AD). Hippocrates, a physician, is regarded as the father of medicine for this contribution to human anatomy and physiology. He is also known to have collected and identified a number of medicinal plants and practiced herbal medicine. His Materia Medica consists of some 300 to 400 medicinal plants. Aristotle, a philosopher, recorded the properties of more than 500 plants of medicinal importance. Dioscorides, a physician, published five volumes of a book, entitled ‘De Materia Medica’ in 78 AD This encyclopedic work described more than 600 medicinal plants including their collection, storage and uses.
Galen was a Greek pharmacist-physician, who, for the first time in history, described hundreds of recipes and formulations of medicinal preparations containing both plant and animal ingredients. These recipes and their methods of preparation and his other observations on medicinal plants have been recorded very accurately in as many as twenty books. The present-day ‘Galenical pharmacy’ is a manifestation of his methods and recipes and the term is used as a tribute to him. The present-day allopathic and homeopathic systems of medicine are based on the doctrines expatiated by Galen. Ancient Arabian physicians and emperors possessed a vast knowledge of medicinal plants. They contributed enormously to the development of modern medicine based on the Greek system.
In earlier days the apothecary (pharmacist-physician) used to handle the works of both the pharmacist and the physician. That is, he himself used to collect, identify and process the collected drug for compounding and dispensing them to the patient, in addition to his job of diagnosing the disease and prescribing the remedy for him. As the volume of knowledge of disease, therapeutic uses of medicinal plants and technology of preparation of medicaments increased gradually over the years, it became impossible for a single person to manage these two different aspects of health management.
Thus, the specialization of the people involved in the health management profession started developing on two different aspects. As a result, medicine and pharmacy started emerging along two separate paths, one group of people specializing in diagnosing the ailment and prescribing the remedy for the patient and another group specializing in collecting, compounding and dispensing the medicament. The former group became known as physicians and the latter apothecaries or pharmacists. Thus it can be commented safely that pharmacognosy was the beginning of both pharmacy and medicine.