Historical Development Of Pharmacognosy

HISTORICAL DEVELOPMENT OF PHARMACOGNOSY Pharmacognosy is regarded as the mother of all science. History of pharmacognosy represents the history of pharmacy & medicine. Pharmacognosy had its origin in the health-related activities of the most primitive human race of the remote past. The early man sought to alleviate his sufferings of illness & injuries by using plants. They acquired knowledge of medicinal properties of plants in the following way: a) By guesswork or trial & error b) While searching for food c) By superficial resemblance between the plant parts & the affected organs, that is, by examining the “Signature of Nature” d) By observing other animals instinctive discrimination between toxic & palatable plants e) By accidental discovery By a combination of all these means the ancient people acquired a considerable volume of knowledge about drugs. In course of time a group of people emerged in each community who acquired expertise in collecting, testing & using medicinal plants for treating diseases. These people later became known as `Medicine Men'. The Medicine Men monopolized the knowledge of drugs and hide that knowledge in some mysterious incantations. They transferred this secret knowledge only to their trusted predecessors of the successive generations, who gradually increased the volume of knowledge about drugs and their uses. Initially the transfer of the acquired knowledge from generation to generation used to be done verbally by the use of signs & symbols. As civilization progressed, transfer and recording of the knowledge were done in writing. According to recorded history: The history of herbal medicine is as old as human civilization. In the past, almost all medicines used were from the plants. Many ancient documents revealed that plants were used medicinally in China, India, Egypt and Greece long before the beginning of Christian era. In China, medicinal plants had been in use since 5000BC. The oldest known herbal document ‘Pentaso’ written by Shen nung came out around 3000BC. During the same period, meticulous efforts had been progressing in India also, to examine and classify herbs. Charaka made 50 groups of 10 herbs each of which was meant for a particular illness. Sushrutha arranged 760 herbs in 7 groups based on their common properties. Thus, the well known treatises in Ayurveda,

‘ Charaka Samhita’ and ‘ Sushruta samhita’ were formed. The earliest plant medicines used in the Ayurvedic system originated in india were described around 1200 BC ago with a list of 127 plants. Ebers Papurus, written in 1550 BC, recorded that Egyptians possessed a good knowledge of human anatomy & medicinal uses of hundreds of plants which made them capable of embalming dead bodies for making mummies. Many of the present day drugs, such as Henbane, Mandrake, opium, Pomegranate, Caster oil, Aloe, Onion, many fixed oils & fats, were in common use in Egypt about 4500 years ago. Babylonians (about 3000 BC) had knowledge of large number of medicinal plants and their properties.Some of the plants used are still used almost in the same way and for the same purposes. The Greek civilization witnessed a highly developed system of medicine which used medicinal plants and minerals. Arab Muslims further enriched this system and developed the Greco-Arabic or Unani system, which formed the basis of modern Allopathic system of medicine. In the 19 th century, the term ‘materia medica’ was used for the subject pharmacognosy. Seydler, a German scientist coined the term

‘pharmacognosy’

in

1815

in

the

title

of

his

work

‘Analecta

pharmacognostica’. The term ‘pharmacognosy’ is derived from two Greek words – ‘Pharmakon’ which means ‘drug’ and ‘Gignosco’ which means ‘ to aquire knowledge of’. The progress achieved during 19 th century in the field of botanical sciences had a direct influence in Pharmacognosy. The binomial classification of plants, introduced by Swede in the 18th century was further developed by Bentham or Hooker. Griger Mendel’s important observations on plant hybrids came in 1865. Soon, microscope was introduced as an simportant analytical tool, techniques like clearing, staining, mounting etc came in to use. Thus, anatomical atlas of crude drugs was published in 1865. In the 20 th century, tremendous work has been done in this field and phytochemistry as a distinct branch in science was evolved. Constituents isolated from the plants were not only used as such, but they were also used for semisynthesis and also as model for the synthetic drugs. The following people contributed development of Pharmacognosy:

significantly

to

the

gradual

Hippocrates (460-370 BC). He is regarded as the `Father of medicine' for his contribution to human anatomy and physiology. He collected, identified and used a large number of medicinal plants. Aristotle (384-322 BC). A student of great philosopher Plato listed more than 500 plants of medicinal importance with their description & uses. Theophrastus (370-287 BC) collected, identified a large number of medicinal plants and recorded their medicinal properties. Dioscorides (1st Century AD), a Greek Physician, published five volumes of a book, entitled `De Materia Medica' in 78 AD, which described more than 600 medicinal plants with their collection, storage & uses. Pliny de Elder (23-70 AD), a Greek botanist, collected and described a large number of medicinal plants with their uses. Galen (131-200 AD), a Greek pharmacist-physician, described methods of preparing pharmaceutical formulations containing plant and animal drugs. These methods & his other observations on medicinal plants have been recorded in as many as 20 volumes of books. The present day Galenical preparations or Galenicals are prepared according to those methods. So long the same person, the apothecary (pharmacist-physician), used to do all the works of collection, processing, preparation and dispensing of the medicaments (the works of the pharmacist) and also diagnosing the disease and prescribing the drug (the works of the physician). With the increase of knowledge of drugs, the volume of work also increased a lot and it become impossible for one person to manage them properly. Thus at this point pharmacy & medicine started developing along two separate paths: a) One group specialized in diagnosing the disease and prescribing the drug and became known as the physicians or doctors; b) The other group specialized in collecting, processing, preparing & dispensing the drug and became known as the apothecaries or pharmacist. In this way, Pharmacognosy progressed gradually and formed the basis and beginning of both pharmacy & medicine.