1. Natural Products and Evidence based Herbal medicines I
Department of Natural Products and Alternative Medicine
Natural Products and Evidence based Herbal medicines I

2. Introduction
Plants have universal role in the treatment of diseases in the major systems of medicine.
As examples: Western medicine:
In Mesopotamia and Egypt, Unani-Islamic, and Ayruvedic (Hindu) systems centered in Western Asia and the Indian and those of the Orient (China, Japan, Tibet,…etc).
Medical information transferred by:
ORAL from generation to generation (In tropical Africa, North & South America and Pacific countries)
Or by WRITING (e.g. the Egyptian Papyrus Ebers c BC)

3. Found in Egypt in the 1870s, the Ebers Papyrus contains prescriptions written in hieroglyphics for over seven hundred remedies. This prescription for an asthma remedy is to be prepared as a mixture of herbs heated on a brick so that the sufferer could inhale their fumes.
Georg Ebers (1837­1898), Papyros Ebers (Ebers Papyrus), Leipzig, 1875

4. What is Pharmacognosy?
Medicinal plants involves a number of disciplines including: commerce, botany, horticulture, chemistry, enzymology, genetics, quality control and pharmacology.
But Pharmacognosy is not any one of these, It is unified of whole of them.
Recently, monographs on crude drugs in a modern pharmacopoeia illustrate this multidisciplinary approach.
Accordingly, no one person can now expect to be an expert in all of these areas.

5. The word "Pharmacognosy" derived from the Greek word
What is Pharmacognosy?
The word "Pharmacognosy" derived from the Greek word
"Pharmakon“ means a drug, or medicine.
"gignosco“ means to acquire knowledge of
Pharmacognosy is “an applied science that deals with the biological, biochemical and economic features of natural crude drugs and their active constituents”.

6. What is Pharmacognosy?
Pharmacognosy is closely related to botany and plant chemistry (originate scientific studies on medicinal plants)
From botanical side, it concerned with the description & identification of drugs, both in whole state & in powder & with their history, commerce, collection, preparation and storage, which are of fundamental importance particularly for pharmacopoeial identification and quality control purposes.

7. Pharmacognosy does not include the study of synthetic drugs.
What is Pharmacognosy?
Pharmacognosy does not include the study of synthetic drugs.
Pharmacognosy is NOT identical to Medicinal Chemistry and/or Pharmacology but utilizes their methods.
Pharmacognosy is a study of drugs from plant and animal kingdoms and their natural derivs.

8. Pharmacognosy
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 and animal kingdoms and their natural derivs.
E.g.: Digitalis leaf & its glycosides (digitoxin)
Rauwolfia root & its alklaoids (reserpine)
Thyroid gland & its extracted hormone (thyroxin)

9. What is Pharmacognosy?
Pharmacognosy is not confined to plants BUT
also investigates biodynamic compounds in animals, marine organisms, fungi, and micro-organisms
NOTE: Natural drug constituents which have been prepared synthetically (e.g. ephedrine, vanillin, caffeine, codeine, menthol, penicillin) BOTH natural and synthetic substances are considered a definite part of pharmacognosy.

10. What is Pharmacognosy?
Many species of plants containing substances of medicinal value which have yet to be discovered.
Now, large numbers of plants are constantly being screened for their possible pharmacological values e.g. hypoglycemic, …
Pharmacognosist with a multidisciplinary background are able to make valuable contributions to these rapidly developing fields of study.

11. Monographs on a large number of crude drugs, giving written descriptions, tests of identity, purity and assays of active constituents:
British Herbal Pharmacopoeia
American Herbal Pharmacopoeia.
Chinese Herbal Pharmacopoeia (Materia medica)

12. WHAT DO PHARMACOGNOSISTS “DO”?
Isolation & characterization of “active constituents”
Characterization of the pharmacology of crude extracts & active constituents
Evaluation of quality of natural medicines
Interdisciplinary relationship with ethnobotany & ethnopharmacology
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.

13. Crude Drugs
They are vegetable or animal drugs that consist of natural substances that have undergone only the processes of collection and drying.
The term natural substances refers to those substances found in nature, SUCH AS
Whole plants or organs of plants, e.g. leaves, flowers, seeds, and barks,
OR vegetable saps, extracts and secretions
Whole animals; glands or other animal organs, extracts, secretions; that have not had changes made in their molecular structure (as found in nature)

14. Crude Drugs
Also, means any product that has not been advanced in value or improved in condition by grinding, chipping, crushing, distilling, evaporating, extracting, artificial mixing with other substance OR by any other process or treatment beyond what is essential to its proper packing and the prevention of decay or deterioration pending manufacture.

15. Sources of Crude Drugs:
Crude drugs are used infrequently as therapeutic agents; more often their chief principles (derivatives or extractives which contains active constituents) are separated by various means.
Sources of Crude Drugs:
Plant sources, e.g. Senna, Digitalis, Datura, Cascara, Cinchona, Clove, Opium, etc.
Animal sources, e.g. cochineal, cantharidin, honey, cod liver oil, musk, thyroxin, etc.
Marine sources, e.g. sponges, red algae, agar, etc.
Mineral sources, e.g. talc, kaolin, kieselguhr, etc.

16. What is a Natural Product?
A natural product is a substance obtained from a natural source.
1. A crude drug , e.g. Senna, Cascara,
Cinchona, etc..
2. A galenical preparation of a crude drug,
e.g. extracts and tinctures, etc..
3. A pure compound, e.g. morphine,
atropine, digoxin, etc..
4. A semithynthetic product, e.g. etoposide,
teniposide, hyoscine butyl bromide etc..

17. Uses of Natural products:
As drugs for the treatment of a wide range of diseases, e.g. morphine, atropine, digoxin, hormones, antibiotics, etc..
As pharm. aids in pharm. industry, e.g. suspending & emulsifying agents, suppository bases, binders, excipients, sweetening & colouring agents, etc..

18. Uses of Natural products:
In cosmetics as flavouring & colouring agents, etc.
In culture media for the propagation of M.O. in microbiology laboratories & biotechnology.
General uses e.g. in food industries: as dusting powders, as indicators and in perfumery.

19. Classification of Medicinal Plants:
A- Alphabetical: Either Latin or Vernacular عاميnames may be used. Although they are simple and suitable for quick references, It gives no indication of interrelationships between drugs e.g. Pharmacopoeias.

20. Classification of Medicinal Plants: (cont..)
B- Taxonomic: Based on botanical classification, drugs are arranged according to the plants from which they are obtained, into: Classes, orders, families, genera and species.

21. Classification of Medicinal Plants:
C- Morphological:
Drugs are divided into groups such as : leaves, flowers, fruits, seeds, herbs and entire organisms, wood, barks, rhizomes & roots (known as organized drugs).
Dried lattices, extracts, gums, resins, oils, fats and waxes (known as unorganized drugs).

22. Classification of Medicinal Plants:
D- Pharmacological or therapeutic:
This involves the grouping of drugs according to the pharmacological action of their most important constituents or their therapeutic uses, e.g cardiotonic drugs.

23. E- Chemical or Biogenetic:
Classification of Medicinal Plants: (cont..)
E- Chemical or Biogenetic:
Acc. To the important constituents e.g. alkaloids, glycosides, volatile oils, etc..,
OR based on their biosynthetic pathways,. This is a popular approach when the teaching of pharmacognosy is phytochemically biased.

24. References Containing Monographs on Medicinal Plants:
Government is aiming to standardized of: Quality, Efficacy and Safety of drugs in order that the many traditional herbs meet legal requirements of diff countries.
Pharmacopoeia is a book recognized by the government as legal authority for standardization of drugs, e.g.
British Herbal Pharmacopoeia, 1996.
The British Herbal Compendium Vol. 1& 2, 1993.
The United States Herbal Pharmacopoeia.
German Commission Monographs.
The Chinese Herbal Pharmacopoeia.

25. Monograph
The descriptive material pertaining to any of the drugs in the Pharmacopoeia is known as the monograph.
In the monograph of a crude drug, the following information are generally covered:
English, Arabic, Latin, French names, definition, description, special condition for collection or prepn for the market, identity tests, tests for adulterants, method of assay, special storage requirements, dose , natural or biological origin.

26. Official and Unofficial Drugs:
OFFICIAL DRUG is one that is listed and described as being a definite therapeutic agent in the pharmacopoeia.
UNOFFICIAL DRUG is that one that are not recognized in the pharmacopoeia and is used as therapeutic agent.

27. Origin of Crude Drugs: Botanical origin is used for a plant and
The natural or biological origin:
Botanical origin is used for a plant and
Zoological origin is used for of animal.

28. Benefit of Botanical Origin of the Crude Drugs
Knowledge of the biological origin enables one to indicate the proper right material and precise the source .
E.g. one year the drug is active, even poisonous and in other cases it is inactive, e.g. Strophanthus seeds

29. Benefit of Botanical Origin of the Crude Drugs
This is due to the fact that the drug is gathered from any species which collectors may find.
If the drug is obtained from one and the same species, the supply of the drug will be always of the same potency, this required authentic sample or genuine sample to comparison.

30. Nomenclature: The binomial system was founded by the Swedish biologist Linnaeus.
In this system,
The first name: Start with a capital letter
denotes the genus,
-Second name
denotes the species.
Carolus Linnaeus ( ) Swedish botanist and explorer. He studied botany at Uppsala university and explored Swedish Lapland. He is the first to develop principles for defining genera and species of organisms and to create a uniform system for naming them, binomial nomenclature.

31. -Genus and species name is followed by author’s name who first described the species or variety. e.g Artemisia cina Berg., Caryophyllos aromaticus L
Sometimes, species name is derived from author’s name, e.g. the species of Cinchona named after Charles Ledger, who brought its seeds from Brazil in 1865, is known as Cinchona Ledergiana.

32. The species name is usually chosen to indicate certain characteristics of the plant:
A. Striking characteristic of the plant:
Cassia acutifolia (sharp pointed leaflets)
Conium maculatum (maculate = spotted)
Cassia angustifolia (narrow leaflets)
Glycyrrhiza glabra (glabrous = smooth)
Atropa belladonna (bella= beautiful, donna=lady)
Hyoscyamus muticus (muticus = short)
Brosma serratifolia (serrat = margin)

33. B. Characteristic colour: - Piper nigrum (black) - Digitalis purpurea (purple) - Digitalis lutea (yellow) - Brassica nigra (black) - Brassica alba ( white)
C. An aromatic plant (certain aroma)
- Myristica fragrans (nice aroma)
- Caryophyllus aromaticus (refers to aroma)

34. D-Geographical source:
- Cinnamoum zeylanicum ( growing in Ceylon)
- Hydrastis Canadensis (growing in Canada)
- Tamarindus indica (growing in India)
- Uriginia maritima (near the coast)
E. Pharmacological activity:
- Papaver sominferum (inducing sleep)
- Lytta vesicatoriam (causing blistering)
- Strychnos nux-vomica (causing vomiting)
- Ipomoea purge (purgative action)

35. F. General meaning: - Allium sativum (cultivated)
- Riticum vulgare (wild).
- Linum usitatissimum (most useful).
The generic name may indicate certain characters of the plant:
e.g. Atropa means fate who cuts the thread of life
Glycyrrhiza means gluco = sweet, riza = root,
Linum, Linea = thread)

36. Production of Crude drugs
Collection, drying and storage of drugs:
The preparation of each drug for the market depends on its morphological nature, constituents, geographical source and other factors.
A. Collection of Crude Drugs:
1. Effect of Time of the Year (Seasonal var.):
It has been found that active constituents in plants vary in amount and nature throughout the year.
- Rhubarb is collected in summer (anthranol in wintrer→anthraquinones in summer).

37. - Colchicum corm: collected in spring (alkaloids).
Hyoscyamous muticus collected in summer (alkaloids).
2. Time of the Day 
- Digitalis is collected in the afternoon.
- Solanaceous leaves collected in the morning.
- Salix collected at night.
3. Stage of maturity and age:
- Clove: collected in bud form.
- Santonica fl & tea leaves: in as unexpanded flower buds.
- Solanaceous leaves: at flowering stage.
- Pyrethrum flower: in fully expanded.

38. 4. General factors: - Flowers are collected in dry weather.
- Leaves are collected when plant is flowering.
- Fruits and seeds when fully mature but unripe.
- Underground organs when aerial parts die down.
- Barks in spring (when they are easily separated).
- Unorganized drugs in dry weather (not rainy).

39. B. Drying of Crude Drugs Reasons of Drying:
- To decrease size and weight (facilitate packing, transport and storage).
- Facilitate powdering.
- Prevent enzyme action, microbial growth and
degradation of active constituents.
Enzyme action
Desirable: e.g. Vanilla pods, required slow drying.
Undesirable: e.g. Digitalis leaves, required fast drying.

40. Methods of drying:
1. Drying in open air: in sun and under cover sheds at night or during wet weather, e.g. clove, cinnamon,...
2. Artificial oven drying (Oven-drying is more rapid than air- drying, controlled temp. and more suitable for use in the wet weather countries. Leaves, herbs & flowers: 20-40oC, barks & roots: 40-65oC.
3. Vacuum drying: in oven, rapid and at low temp.
4. Lyophilization used for biological fluids, enzymes, proteins and royal jelly.

41. C. Storage of Crude Drugs:
During storage, Drugs are affected by light, moisture, temp., air oxygen (physicochemical) and by fungi, bacteria, worms, insects and mites (biological)
Long storage is not recommended, due to deterioration.
Therefore, drugs should be stored in sealed containers in cool dark places.

42. Evaluation of Crude Drugs Means to identify and to determine quality,
safety and purity.
It has to be certain of identity of the
collected plant from proper source by matching to authentic plant sample
2. Preparation by proper cleaning, drying and
garbling.
3. Proper preservation of cleaned, dried, pure
drug against contamination.

43. Evaluation of drugs involves the following methods:
1. Organoleptic
2. Microscopic
3. Chemical
4. Physical

44. I- ORGANOLEPTIC EVALUATION
Organoleptic refers to evaluation by means of the organs of sense which includes:
- The macroscopic appearance of the drug,
- Its odour and taste and the feel of the drug to the touch.
Description of the macroscopic characteristics of a drug include:
Shape and size.
Colour and external markings
Fracture and internal colour.
Odour and taste.

45. II-MICROSCOPIC EVALUATION:
The microscope is essential in the identification of
powdered drug and in the detection of the
adulterants in powdered plant OR animal drugs.
Microscopical description of the drug in sectional
view and powdered form is listed in official
monograph .

46. Histology refers to the character & arrangement of the tissues in a drug.
Some drugs have no cellular structure (gums, resin).
Some are composed of microscopic units, such as diatoms (kieselguhr) or hairs (Lupulin, kamala).
Histological studies on very thin transverse (TS) or longitudinal (LS) sections properly mounted in suitable stains, reagents or mounting media.

47. In the powdered drugs the cells are mostly broken, except those with lignified walls, but the cell contents (starch, calcium oxalate, aleurone grains …etc) are scattered in the powder and become very evident in the mounted specimen.
Microscope can be used for a quantitative microanalysis of admixed or adulterated powders.
This study is done by counting a specific histological feature (stomatal index, palisade ratio) in a measured quantity of the unknown powder and comparing the count with that obtained for the same feature in a known standard sample.

48. III-CHEMICAL EVALUATION:
Chemical tests are employed to identify crude
plant drugs.
E.g. characteristic red colour developed in
Cascara on addition of NH3 test solution.
To ascertain the purity of certain drugs
E.g. to detect the presence of inorg. iodine in thyroid tablets by adding a starch test solution.

49. III-CHEMICAL EVALUATION:
Chemical assays are dependent on the pharm. extractive processes with subsequent purification of the main constituent.
In many drugs the chemical assays represents the only method of determining the official potency.

50. IV-PHYSICAL EVALUATION
Typical physical constants is very rare.
The specific gravity is used with nutgalls,
where the galls that will not sink in H2O are
considered to be of inferior quality,
In jalap and clove, the specific gravity should
be higher than that of water.
The elasticity of certain fibers, such as
cotton, is a physical constant of importance.

51. IV-PHYSICAL EVALUATION
Alkaloids aconitine (light blue), berberine (yellow), emetine (orange).
Alkaloid quinine has blue fluroscence in acid solution in UV or even in daylight.
The use of physical constants on active constituents.:
Solubility, specific gravity, optical rotation, melting point… etc

52. IV-PHYSICAL EVALUATION
The response of some drugs in powdered form or in their smooth section surface to the UV , e.g. in detecting of adulteration of genuine of rhubarb from rhapontic rhubarb (blue fluroscence)

53. CHROMATOIGRAPHIC STUDY OF CRUDE DRUGS:
The morphological and anatomical evaluation are not sufficient but nature or the amount of the active substances are the most important
Chromatography (TLC, PC and GC) is really a finger print technique, where the individual substances to which the activity is due, can be tested rapidly.