chapter one introduction of pharmacognosy.pptx

TIMA ADDE UNIVERSITY
FACULTY OF HEALTH SCIENCE
DEPARTMENT OF PHARMACY
COURSE: pharmacognosy
LECTURER: ABDIRAHMAN M. ELMI
DVM , B. pharm and MSc candidate of HSM

Course chapters
Chapter one: Introduction
Chapter two: alternative system of medicine
Chapter three: classification of drugs in natural origin.
Chapter four: drugs containing alkaloids.
Chapter five: drugs containing glycosides.
Chapter six: evaluation of drugs in natural origin.
Chapter seven: drug adulteration.

Chapter one: Introduction
At the end of this chapter students should be able
to understand:-
 The meaning of pharmacognosy
 History of pharmacognosy
 The scope and practice of pharmacognosy
 Importance of natural drug substances
 Sources of natural drugs
 Terminology

1.1: Definition of pharmacognosy
• What is The meaning of word Pharmacognosy?
Pharmacognosy derived from two Greek words which
ae "Pharmakon: meaning a “drug
or poison”
“gignosco" meaning “to acquire a knowledge”

Meaning of pharmacognosy
Pharmacognosy, known as initially as materica
medica, may defined as the “It is the study of
natural substances(drugs) i.e. plants, animals,
microorganisms or drug derived from soil used in
the treatment and prevention of the diseases or
having biological activity on different living
organisms.

Pharmacognosy is a multidisciplinary
subject
 The American Society of Pharmacognosy
defines pharmacognosy as "the study of the physical,
chemical, biochemical and biological properties of drugs,
drug substances or potential drugs or drug substances of
natural origin as well as the search for new drugs from
natural sources.
It is also defined as the study of crude drugs and their
natural derivatives.

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• Pharmacognosy is the study of medicines
derived from natural sources.
• Pharmacognosy covers general aspects of
medicinal plants such as
• A ) industrial applications
• B ) Research
• C ) Gene technology e.t.c

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• Today many people are purchase medicinal plants
and herbal products to prevent and cure disease .
Therefore pharmacists and physicians should be
familiar with medicinal plants and drugs that are
used in pharmacotherapy .
• Medicines or products containing medicinal plants
should only be taken under medical supervision or
according to the manufacturer’s indication .

Why are plants and their extracts still
important in pharmacy and medicine?
• Historically, plants have yielded some
of our most important drugs, but, with the
great advances in medicinal chemistry of the
last century, synthetic drugs have superseded
them as the main focus of research.

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• However, the development of drugs using natural
products as ‘lead’ molecules continues, and many
plant-derived pure
compounds(or natural products)are used in
modern,conventional medicine; other
compounds are potentially useful to humans or
are of toxicological relevance.

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• There has also been a huge rise in the use of
phytopharmaceuticals and herbal medicines in
recent years. Traditional medicine, which uses
many plant remedies, remains an important (and
in some cases, the only) form of treatment in
many developing countries, but it is now used
increasingly worldwide.

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• People in many countries now want to cure minor health
problems with something ‘natural’ and
ageing populations have an increasing demand for medicines
and foods (‘nutraceuticals’) to help combat the symptoms
and problems of ageing. This public demand is an enormous
challenge for all health professionals, many of whom have
little specialist knowledge of natural medicines.

HISTORY OF PHARMACOGNOSY
• In the early period, primitive man went in search of food
and ate at random, plants or their parts like tubers, fruits,
leaves, etc. As no harmful effects were observed he
considered them as edible materials and used them as food.
If he observed other effects by their eating they were
considered inedible, and according to the actions he used
them in treating symptoms or diseases.

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 If it caused diarrhea it was used as purgative, if vomiting it was
used as memtic and if it was found poisonous and death was
caused, he used it as arrow poison .
 Their knowledge was empirical and was obtained by trial and
error
 The results were passed on from one generation to the other, and
new knowledge was added in the same way.

A: Ancient China
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 of native herbal
• 1: 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,
• 2: 120 minister herbs, some mildly toxic
and some not, having stronger therapeutic action to heal
diseases and finally
• 3: 125 servant herbs that having specific action to treat
disease and eliminate stagnation .

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• Most of those in the last group, being toxic, are not intended to be
used daily over a prolonged period of weeks and months.
• Examples of native herbal include: podophyllum (removal of
warts, plantar warts and white patches on th tongue), rhubarb(
antitumor, antispasmodic, diuretic, laxative and purgative),
gin seng,( boost the immune system, improve physical and mental
performance) stramonium, cinnamon bark and ephedra).

B: Ancient Egypt
• 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,

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• 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.
• Commonly used herbs included: senna, honey, thyme, juniper, cumin,
(all for digestion); pomegranate root, henbane (for worms) as well as
flax, oakgall, pinetar, manna, bayberry, ammi, alkanet, aloe, caraway,
cedar, coriander, cyperus, elderberry, fennel, garlic, wild lettuce,
nasturtium, onion, peppermint,
papyrus, poppy-plant, saffron, watermelon, wheat and zizyphus-lotus.
Myrrh, turpentine and acacia gum were also used.

C: Ancient India
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 basic medicinal texts in this world region— The
Ayurvedic writings

Ayurveda
• 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
.

D: 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.

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• 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 19 century
A.D., described medicinal plants, some of which like
belladonna, ergot, opium, are used even today.

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• 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.

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• Even up to the beginning of twentieth century,
pharmacognosy was more of a descriptive subject akin
mainly to botanical science, and it consisted of
identification of drugs both in entire and powdered
conditions and concerned with their history, commerce,
collection, preparation and storage.

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• The development of modern pharmacognosy took place later
during the period 1934–1960 by simultaneous application of
disciplines like organic chemistry, biochemistry, biosynthesis,
pharmacology and modern methods and techniques of
analytic chemistry, including paper, thin layer, and gas
chromatography and spectophotometry ( is a method to
measure how much a chemical substance absorbs light by
measuring the intensity of light as a beam of light passes
through sample solution. )

1.4. SCOPE OF PHARMACOGNOSY
• Crude drugs of natural origin that is obtained from plants,
animals and mineral sources, their active chemical
constituents, pharmaceuticals aids(adjuvant or excipients)
and nutraceuticals or functional foods are the core subject
matter of pharmacognosy.
• These are also used for the treatment of various diseases
besides being used in cosmetic, textile and food
industries.

1. Crude drugs
 Artetmisia annula ( Artemisinin containg plant)
used as antimalarial.
 Camellia sinensis ( Tea leaves): used as antioxidants for the treatment
of cancer, antihypertensive, for migraine and fasten metabolism for
weight loss.
 Taverniera abyssinica: used for the treatment of sudden illness for
relief of fever ( antipyretic) and anti pain ( analgesics).
 Ginkgo biloba leaves: used fot the treatment fo brain disorders,
bronchitis, improves brain, treatment of senile dementia and
Alzheimer’s disease.

Cont. …
 Morphine from opium poppy: Analgesics
 Digoxin from foxgloves leaves: treatment of heart
failure.
 Vincrystine from aerial parts of vinca rosea: anticancer.

2. Pharmaceutical aids ( adjuvant or
excipients)
• Starch: from cereals: binder and disintegrant.
• glucose: from sugarcane: sweetener.
• peppermint oil: from menthe pipperita leaves:
flavouring agents.

Nutraceuticals or functional foods
 Foods having additional health benefits.
Allium sativum (Garlic): antiviral, antibacterial,
anticholesterol and antibiotic activity.
Ginger: for treating nausea and vomiting and inflammatory
responses of motion sickness.
Carotenoid containing plants: carrot:- vitamin and
antioxidant.

Importance of natural drug substances
• In general, natural drug substances offer four vital and
appreciable roles in modern system of medicines
1. Serve as extremely useful natural drugs.
2. provide basic compounds.
3. exploration of biologically active prototypes towards
newer and better synthetic drugs.
4. modification of inactive products by suitable
biological/chemical means into potent drug.

Natural/biological sources of drugs
1. Plants
2. Animals: gelatin from the skin (collagen) or bones of
cows and pigs.
3. Microorganisms
4. Minerals
A. Fungi
Pharmaceutical important drugs.
 Ergot alkaloids ( claviceps purpurea) ergotamine and
antibiotics such as penicillins from penicillinium notatum.

Cont. ……
B. Bacteria
 Production of antibiotics e.g. Tetracyclines, Aminoglycosides
and clavulanic acid from Streptomyces.
 Facility the conversion of certain substances into
pharmaceutically important product e.g. E. coli ( insulin
production).
4. Minerals: iron for anaemia and magnesium sulfate for
purgative

Terminology:
• Ethno pharmacology (1967) is defined as ‘the
scientific exploration of biologically active agents
traditionally employed or observed by man
• Ethno medicine: it refers to use of plants by humans as
medicine.
• Ethno botany: it is a broad term referring to the study
of plants by humans.
• Phytotherapy: Scientific study of plant & plant
extracts used in medicine or health promoting agents.

Cont. ………
- Natural (biological) origin: is the scientific name (generic
and specific names) of the plant or animal yielding the drug.
In the case of vegetable drugs the natural origin is spoken of
as the botanical origin.
- Geographic source and Habitat of plants is the region where
they grow.
- Plants growing in their native countries are said to be
indiginous plants e.g. Cassia senna is indigenous to
Somaliland. Plants are said to be naturalized when they grow
in foreign land or in another locality than their native home.

Cont. ……
- commercial origin: indicates their commercial source,
which may be either the country where the plant yielding
the drug is grown, or the port from which the drug is sent
into the marts of the world.
- official drug: is a drug that is listed and described in the
pharmacopoeias.

Cont. …..
Crude drugs: These are vegetable or animal drugs that
consist of natural substances which undergone only the
processing of collection and drying.

Cont. ………
- organized drugs: drugs, which consist of the cellular
organization in the form of anatomical features.
- unorganized drugs: have no morphological or
anatomical organization as such. Vegetable exudates,
extracts, secretions and other constituents.
- Cultivation and preparation: including details of
cultivation of the medicinal plants, methods of
collection, drying, packing and other treatment of the
drug during its preparation for the market.

Cont. …..
Uses: Biological activity and application of the drugs in
medicine.
Adulteration: is a practice of substituting the original drug
completely or partially with other similar looking substances
- Adulterants: including materials added fraudulently and
matter which has become associated with the drug owing to
carelessness in handling during collection, preparation,
packing or transport.

chapter one introduction of pharmacognosy.pptx

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