Pharmacognosy is a scientific discipline, which is primarily concerned with the study of crude drugs obtained from natural sources, such as plants, animals, and minerals.
The term ‘Pharmacognosy’ was first coined and used by German Scientist Seydler in 1815 in a book he wrote on crude drugs, entitled ―Analecta Pharmacognostica.
It was derived from two Greek words: pharmakon, which means ‘a drug’, and gnosis, which means knowledge of’.
Thus Pharmacognosy may be defined as the objective study of crude drugs and related substances of natural origin (Plants, Animals and minerals) to acquire knowledge about their nature and properties.
History of Pharmacognosy
The history of Pharmacognosy is as old as civilization. Plants were used medicinally in
• Greece before beginning of the Christian era.
Chinese pharmacy, according to legend, stems from Shen Nung (about 2700 B.C.), emperor who sought out and investigated the medicinal value of several hundred herbs.
He reputed to have tested many of them on himself, and to have written the first Pen T-Sao, or Native Herbal, recording 365 drugs.
These were subdivided as follows: 120 emperor herbs of high, food grade quality which are non-toxic and can be taken in large quantities to maintain health over a long period of time, 120 minister herbs, some mildly toxic and some not, having stronger therapeutic action to heal diseases and finally 125 servant herbs that having specific action to treat disease and eliminate stagnation.
Most of those in the last group, being toxic, are not intended to be used daily over a prolonged period of weeks and months.
Shen Nung conceivably examined many herbs, barks and roots brought in from the fields, swamps and woods that are still recognized in pharmacy (podophyllum, rhubarb, ginseng, stramonium, cinnamon bark and ephedra).
The most complete medical documents existing are the Ebers Papyrus (1550 B.C.), a collection of 800 prescriptions, mentioning 700 drugs and the Edwin Smith Papyrus (1600 B.C.), which contains surgical instructions and formulas for cosmetics.
The Kahun Medical Papyrus is the oldest it comes from 1900 B.C. and deals with the health of women, including birthing instructions.
However, it is believed that the Smith Papyrus was copied by a scribe from an older document that may have dated back as far as 3000 B.C.
In India knowledge of medicinal plants is very old, and medicinal properties of plants are described in Rigveda and in Atharvaveda (3500–1500 B.C.) from which Ayurveda has developed.
The Ayurvedic writings can be divided in three main ones (Charaka Samhita, Susruta Samhita, Astanga Hrdayam Samhita) and three minor ones (Sarngadhara Samhita, Bhava Prakasa Samhita, Madhava Nidanam Samhita).
Ayurveda is the term for the traditional medicine of ancient India.
Ayur means life and veda means the study of which is the origin of the term.
The oldest writing –
Charaka Samhita—is believed to date back six to seven centuries before Christ. It is assumed to be the most important ancient authoritative writing on Ayurveda.
The Susruta Samhita is thought to have arisen about the same time period as the Charaka Samhita, but slightly after it Astanga Hrdayam and the Astanga Sangraha have been dated about the same time and are thought to date after the Charaka and Susruta Samhitas.
Most of mentioned medicines origin from plants and animals, e.g. ricinus, pepper, lilly, valerian, etc.
Ancient Greece and Rome
Greek scientists contributed much to the knowledge of natural history. Hippocrates (460–370 B.C.) is referred to as father of medicine and is remembered for his famous oath which is even now administered to doctors.
Aristotle (384–322 B.C.), a student of Plato was a philosopher and is known for his writing on animal kingdom which is considered authoritative even in twentieth century.
Theophrastus (370–287 B.C.), a student of Aristotle, wrote about plant kingdom.
Dioscorides, a physician who lived in the first century A.D., described medicinal plants, some of which like belladonna, ergot, opium, and colchicum are used even today.
Pliny wrote 37 volumes of natural history and Galen (131 – A.D. 200) devised methods of preparations of plant and animal drugs, known as ‘galenicals’ in his honour.