Pharmacognosy-1
PHG 222
Taghreed Abdou Ibrahim
Associate Professor of
Pharmacognosy
Nasir Ali Siddiqui
Associate Professor of
Pharmacognosy
Topics of the Course
Topic
Introduction to Pharmacognosy
No. of
hours
2
Medicinal plants in selected health care systems
4
Production and Preparation of crude drugs
4
Plant metabolites & biosynthetic pathway
2
Medicinal plants (botanical and chemical characters)
9
Basic Principles and Application of Chromatography
7
Introduction to Pharmacognosy
Lecture 1
Learning outcomes of the lecture
By the end of the lecture, the students should be able
to:
1- Define terms related to pharmacognosy and natural
products.
2- Recognize the history of natural products.
What is Pharmacognosy
The word Pharmacognosy is derived from the
Greek "Pharmakon", meaning a drug or
poison. and,
“Gignosko" meaning to acquire a knowledge of,
and literally meaning "the entire knowledge
of drug".
Pharmacognosy, is an applied science that deals with the
biological, biochemical and economic features of natural
crude drugs and their constituents.
It is a study of drugs from plant, animal and mineral
sources and their natural constituents.
e.g.: Digitalis leaf & its glycosides (digitoxin)
Thyroid gland & its extracted hormone (thyroxin)
Kaolin and Talc powder
Pharmacognosy
• The scientific study of the structural, physical,
chemical and sensory characters of crude drugs of
vegetable, animal and mineral origin.
• It also includes their history, cultivation of the
medicinal plants producing them and methods
involved for their collection and other particulars
related to the treatment they received during their
passage from the producer to the distributor or
pharmacist and Storage.
Recently Pharmacognosy includes:
1- Modern isolation techniques.
2-Pharmacological testing procedures to prepare
purified substances.
3- Cultivation and propagation by tissue culture.
4- Marine Pharmacognosy.
What Do Pharmacognosists “Do”?
1- Extraction of selected plant material.
2- Isolation & characterization of “active constituents”.
3- Characterization of the pharmacology of crude
extracts & active constituents.
4- Evaluation of quality of natural medicines.
5- Interdisciplinary relationship with ethnobotany &
ethnopharmacology.
Definitions
Ethnobotany is the study of the relationship between people and
plants, field includes studying plants as medicines, alternative
methods for healing, as wild foods, as agricultural crops; modes of
transportation; as clothing and in the religious ceremonies.
Ethnopharmacology is the scientific study correlating ethnic groups,
their health, and how it relates to their physical habits and
methodology in creating and using medicines.
Ethnomedicine: It refers to the use of local plants as medicine by
the population surrounding the vegetation.
Traditional medicine: It is the sum total of all non-mainstream
medical practices, usually excluding so called “western” medicine.
History of Pharmacognosy
1- Ancient Egyptian period
• The ancient Egyptians 3000 B.C. were experts in using
drugs for curing diseases.
• The healing of the sick was undertaken by priest doctor
and pharmacist "Son" who prescribed and prepared
medicines.
• Crude drugs of vegetable origin used included Aloes,
Gum, Myrrh, Poppy, Pomegranate, Colocynth, Linseed,
Squill, Coriander, Onion, Anise, Melon, Castor, etc...
The first recorded prescriptions were found in Egyptian
tombs. These were the Hieratic papyri, Ebers
papyrus, the Gynecologic papyrus.
2- The Babylonians Period
2- The Babylonians Period
• The Babylonian medicine was
known (Laws of Hamorabi 772
B.C.).
•
The drugs used were mainly of
vegetable origin.
•
The drugs used include 250
materials of plant, and 180
materials of animal source. Many
of these drugs were known to the
ancient Egyptians.
3- Old Indian Medicine
3- Old Indian Medicine
• The "Riveda" and Ayurveda (Acoko 2000 B.C.), contained the
sacred medicinal plants.
•
The collection of plant materials was done only by an
innocent, pure, religious person.
•
The fresh plants were considered to be the most effective.
• The most celebrated Indian drugs were; Sandal wood, Clove,
Pepper, Cardamom, Caraway, Ginger, Benzoin, Cannabis,
Castor oil, Sesame oil, Aloes, etc...
4- The old Chinese Medicine
4- The old Chinese Medicine
• Beside the famous acupuncture, the Chinese medicine is very
acknowledged for the herbal medicine.
•
The Pen Ts'ao Kang Moa 1000 B.C. contained an incredible
number of medicinal plants and drugs of animal origin.
• Their book includes many recipes for every disease. Among
the plants and minerals highly esteemed for its magic health
including power were; Ginseng, Rhubarb, Ephedra, Star Anise,
Pomegranate, Aconite.... Opium is a very old Chinese drug for
diarrhea and dysentery.
5- The Greek and Romans
a- Authors of antiquity Hippocrates (460-377 BC)
“The
Father
of
Medicine”,
was familiar with numerous drugs, and wrote "Corpus
Hipocraticum 460 B.C.".
b- The Greek Empire was followed by that of the Romans
Dioscorides who was a Greek by birth he was the first to
describe drugs and his work "Greek Herbal of Dioscorides"
included 5000 medicinal plants in addition to animal and
mineral drugs.
c- Pliny who lived about the same time as Dioscorides, was
also an eminent author of natural history.
d- Galen (134- 200 A.C.) was a physician and to him is
ascribed the use of "Galenical preparations".
6- Islamic Contributions
• In Islamic writings were found the first beginnings of
chemistry, the name of which is derived from an Arabic word
"Kemia"; as were also such familiar words alcohol and alkali.
•
The Arabs added numerous new plants and medicaments to
those already known to the Greeks and Romans.
•
In their days, pharmacy attained its highest reputation and
became an independent branch of medicine.
• It is interesting to note that the first dispensary was opened in
Baghdad, the center of trade in those days.
• The dispensary was made of Sandal wood and named
"Sandalia".
• Rhazey (850-932 A.C.) who was born at Rai in Persia was
the director of Baghdad hospital in the days of ElMansour.
• He published a famous book "Alhawi Kabeer".
• Abu Al Hosayn Ibn-Sina (980-1037 A.C.) whose name was latinised
to Avicenna. He was one of the most eminent and gifted Arabian
physicians.
• His "Canoon Fi Elteb" has been described as the most famous
medical text ever written and as having dominated the medical
schools of Europe and Asia and served as the chief source of
medical knowledge for 5 centuries, till the 15th century.
Ibn Al-Baitar (1197-1248 A.C.) was the best Arabian
pharmacognosist and botanist and ranked with Dioscorides
in that respect. His book "Jame-ul-Muffradat" contains
description of 2000 drugs.
• Sheikh Dawood El-Antaki wrote a book named "Tazkaret
Uli Al-Albab", now known as "Tazkaret Dawood
Alantaki" which describes several hundred herbs besides
drugs of animal and mineral origin.
The 18th Century, Pharmacognosy
• Johann Adam Schmidt (1759-1809): In 1811 his Lehrbuch
der Materia Medica was published, which was a work on
medicinal plants and their properties. In this book the term
"pharmacognosy" is originally coined.
• Carle Linnaeus (naming and classifying plants).
• At the end of the 18th century, crude drugs were still being
used as powders, simple extracts, or tinctures.
The Era of Pure Compounds
(In 1803, a new era in the history of medicine)
• Isolation of morphine from opium
• Strychnine (1817) from nux vomica seeds.
• Quinine and caffeine (1820) from cinchona bark
and coffee beans, respectively.
• Nicotine (1828) from tobacco leaves.
• Atropine (1833) from belladonna leaves.
• Cocaine (1855) from coca leaves.
• In the 19th century, the chemical structures of
many of the isolated compounds were
determined
• In the 20th century, the discovery of
important drugs from the animal kingdom,
particularly hormones and vitamins.
Microorganisms have become a very
important source of drugs