Nature has provided all the needs of human including medicines for better health. It includes complete cure for almost all type of ailments of mankind. The knowledge and experience accumulated over thousands of years has given birth to today’s modern medicine system. More than sixty percent of world population, directly or indirectly still uses natural products for their primary healthcare needs.
Definition:
Pharmacognosy is systematic study of these crude drugs obtained from natural origin like plant, animal and minerals. Pharmacognosy can be defined as branch of science which involves detail study of drugs obtained from natural origin including name, habitat, collection, cultivation, macroscopy, microscopy, physical properties, chemical constituents, therapeutic actions, uses and adulterants. The word pharmacognosy is derived from two words, pharmakon means medicine (drug) and gignosco means to acquire knowledge of something.
Prof. John Schimidt coined the term pharmacognosy in his book Lehrbuch der Materia Medica. Earlier subject was known as ‘Materia medica’. It includes systematic study of crude drugs from nature. Study of pharmacognosy includes the history, distribution, cultivation, collection, processing and preservation. It also includes the study of physical, chemical and structural characters and the safe uses of crude drugs. In short, pharmacognosy is study of drugs from natural origin. Drugs from natural origin can be obtained by plants, animals (terrestrial as well as marine) and minerals.
The word phytopharmaceutical is derived from Greek word ‘phyton’ means plant. Phytopharmaceuticals are drugs whose active constituents are exclusively plant based and are used in rational phytotherapy. Isolated plant constituents like taxol, morphine, quinine, digoxin, caffeine as well as drugs which are based on homoeopathic are not considered as phytopharmaceuticals.
History and development of pharmacognosy:
The history of
pharmacognosy is as old as human existence. To know the future one should know
the past. The word ‘drug’ is derived from
Latin term Droog means dried, when dried
plants were commonly used as medicine. Broadly, history of pharmacognosy can be
classified into three major stages. First stage before eighteenth century, very
few documents and recorded evidences are available showing use of natural
products by human. Second stage involves nineteenth century, which is the time
when basic subject has evolved. In this century, the name pharmacognosy came
into practice. Initially the subject was more likely to descriptive botany of
medicinal plants. But as the time progress, it changes the course and
encompasses extraction, isolation and other advances techniques. In twentieth century, which may be considered
as third stage of development, series of discoveries resulted in complete
metamorphosis of the subject. From last
two decades, pharmacognosy is studied in more systematic manner. As herbal wave
continue to sweep the world, importance of natural product is at the pinnacle.
People are expecting natural products to fit in modern framework. As a result
of this there are series of new herbal formulations in the market.
The ancient Egyptians
documented their knowledge about medicine on paper made from Cyperus aquaticus commonly called
acquatic sage or papyrus. Papyrus Ebers
(around 1500 BC), Berlin Egypt
and Mesopotamia clay tablets were used to
document knowledge of drugs which are dating back to 3000 BC. Ancient India
In eighteenth century,
pharmacognosy was much closely related to botany. In old days, drugs from
natural origin were used in crude form as powder or decoction. Later in
nineteenth century, development in science has expanded arena of pharmacognosy.
Now a day’s pharmacognosy has become a kind of multidisciplinary subject which embarrasses
phytochemistry, analytical pharmacognosy, pharmacotherapy, medicinal plant
biotechnology, herbal formulations and nutraceuticals. Zoopharmacognosy is branch of pharmacognosy which involves
observation of animal behavior for discovery and development of new drugs. Now
a day’s drug from natural origin are studied, formulated and regulated in the
framework of modern medicine. More detailed record and history of medicine can
be studied from the website of US National Library of medicine on following
website www.nlm.nih.gov/hmd/medieval/arabic.html
Scope of pharmacognosy:
Pharmacognosy is
critical in development of different disciplines of science. A pharmacognosist
should possess a sound knowledge of the terms used to describe the vegetable
and animal drugs as covered under botany and zoology, respectively. The
knowledge of plant taxonomy, plant breeding, plant pathology and plant genetics
is helpful in the development of cultivation technology for medicinal and
aromatic plants. Plant - chemistry (phytochemistry) has undergone significant
development in recent years as a distinct discipline. It is concerned with the
enormous variety of substances that are synthesized and accumulated by plants
and the structural elucidation of these substances. Extraction, isolation,
purification and characterization of phytochemicals from natural sources are
important for advancement of medicine system. The knowledge of chemotaxonomy,
biogenetic pathways for formation of medicinally active primary and secondary
metabolites, plant tissue culture and other related fields is essential for
complete understanding of Pharmacognosy. One should have the basic knowledge of
biochemistry and chemical engineering is essential for development of
collection, processing and storage technology of crude drugs.
- Pharmacognosy is important branch of pharmacy which is playing key role in new drug discovery and development by using natural products. Pharmacognosy has given many leads for new drug discovery and development.
- It is an important link between modern medicine systems (allopathy) and traditional system of medicine. It is part medicinal system which is affordable as well as accessible to common man. As part of integrative system of medicine, pharmacognosy can help to increase effectiveness of modern medicine system.
- It is acting as bridge between pharmacology, medicinal chemistry and pharmacotherapeutics and also pharmaceutics. It also bridges pharmaceutics with other pharmacy subjects.
- More than 60 percent of world population is still using natural product for their primary healthcare needs. Pharmacognosy can provide safe and effective drugs in combination with modern medicine system.
- Pharmacognosy includes knowledge about safe use of herbal drugs including toxicity, side effects, drug interaction thereby increasing effectiveness of modern medicine.
- Pharmacognosy is an important link between pharmacology and medicinal chemistry. As a result of rapid development of phytochemistry and pharmacological testing methods in recent years, new plant drugs are finding their way into medicine as purified phytochemicals, rather than in the form of traditional galenical preparations.
- Pharmacognosy is the base for development of novel medicines. Most of the compounds obtained from natural product serve as prototype or base for development of new drug which are more active and less toxic.
- By means of pharmacognosy, natural products can be dispensed, formulated and manufactured in dosage forms acceptable to modern system of medicine.
- There are vast number of plant and animal species which are not studied systematically.
- Development of pharmacognosy also leads to development of botany, taxonomy, plant biotechnology, plant genetics, plant pathology, pharmaceutics, pharmacology, phytochemistry and other branches of science.
