Herbal Drug Technology

1. HERBS AS RAW MATERIALS

2. 1. Herb:-
“A plant of which the stem does not become woody or persistent (as in
a shrub or tree), but remains more or less soft and succulent, and dies
down to the ground (or entirely) after flowering.”
This applies to plants of which the leaves or stem and leaves are used
for food or medicine, or in some way for their scent or flavour.
As per WHO, “Herbs include crude plant material such as leaves,
flowers, fruit, seed, stems, wood, bark, roots, rhizomes or other plant
parts, which may be entire, fragmented or powdered”.
Definitions:-

3. 2. Herbal drug preparations:-
It includes powdered herbal materials, extracts, or tinctures and fatty
oils of herbal materials.
Preparations, derived from herbal drugs which are prepared by various
techniques like extraction, infusion, decoction, maceration, distillation,
expression, fractionation, purification, concentration and fermentation are
known as herbal drug preparations.
It may also consists of preparations made by steeping or heating herbal
materials in alcoholic beverages and/or honey, or in other materials.

4. 3. Herbal medicine:-
“Herbs and herbal preparations that are used either to maintain health or to
prevent, alleviate or cure a disease.”
Example: Tincture made from ginger to relieve an upset stomach.
As per WHO, “Herbal medicine include herbs, herbal materials, herbal
preparations and finished herbal products. ”
Note:- Medicines possessing crude material mixed with chemically distinct substances
including isolated phytoconstituents are not termed as herbal medicines.

5. 4. Herbal medicinal products:-
According to WHO “Herbal medicinal products consist of herbal
preparations made from one or more herbs. Herbal medicinal products
may contain excipients in addition to the active ingredients.”
In herbal medicinal products the active ingredient consists exclusively
of herbal substances or herbal preparations.
Hence, herbal medicinal product may contain, one or more herbal
substances or one or more herbal preparations, or one or more such herbal
substances in combination with one or more such herbal preparations as
active ingredients.

6. Sources of herbs
Herbs or medicinal plants can be obtained from three sources viz:
A. Wild source
B. Cultivated source
C. Modern scientific techniques like tissue culture, polyploidy,
mutation, hybridization, genetic engineering, germplasm etc. on
cultivated plants.

7. A. Wild source:
• Grow themselves without any type of care,
• Obtained from unutilized land such as forests, plains, river banks, etc.
• The wild plants also have reasonable active constituents and
sometimes new variety is produced.
Advantages:
• Economical; No cost of land, caring, fertilizers, irrigation etc.
• Less time consuming.

8. Disadvantages:
• The quality of the plants cannot be predicted due to various environmental
changes.
• They are sparsely distributed, so chances of adulteration and substitution are
more.
• If the plants are obtained continuously from wild source for prolonged
period, may lead to depletion of raw material.
• They cannot fulfil the demand when required.
• Sometimes genetically different plants are developed.

9. B. Cultivated source:
Grown in fields under controlled environmental conditions such as soil, climate,
rainfall, irrigation, time of sowing and collection, altitude, temperature, fertilizers,
manures, pesticides, weeds etc.
Advantages:
• Better yield and therapeutic quality, and give more profit.
• It ensures regular supply of raw materials due to planned cultivation.
• Cultivation of medicinal and aromatic plants leads to industrialization and has
given rise to several cottage and small scale industries.
• Rapid growth of phytopharmaceuticals, perfumery and allied industries is possible
due to cultivation of medicinal and aromatic plants.

10. C. Modern scientific techniques:
a. Plant tissue culture:
In vitro cultivation technique of plant cell or tissue under aseptic and
controlled environmental conditions, in liquid or on semisolid well-defined
nutrient medium for the production of primary and secondary metabolites or
to regenerate plant.
Advantages:
• Extinction and decimation problems of medicinal plants can be minimized.
• Genetic modification is possible.

11. Disadvantages:
• Requires a well-equipped culture laboratory.
• Involves various steps, viz. preparation, of nutrient medium containing
inorganic and organic salts, supplemented with vitamins, plant growth
hormone(s) and amino acid as well as sterilization of explant (source
of plant tissue), glassware and other accessories inoculation and
incubation.

12. b. Polyploidy:
An increase in number of chromosome in certain tissues or entire plant in
multiples of the basic or haploid number is known as polyploidy.
Polyploidy is common in nature and provides a major mechanism for
adaptation and speciation.
Polyploidy in plants is caused by cell generations, physical agents like X-
rays, centrifugation, temperature, shock and chemical agent like colchicine.
Advantages:
• Polyploidy plant is usually healthier, stronger and larger.
• Phytoconstituents of some plants can be increased.

13. c. Mutation:
Mutation is the change in nucleotide sequence of a gene. This give rise to a new genetic trait
or changed genotype.
A cell or organism which shows the effect of mutation is called mutant and the agent which
causes mutation is known as mutagenic agent.
The types involve: natural and artificial (physical, chemical, radiation) mutation.
Advantages:
• Phytoconstituents of some plants can be increased.
• Chemical mutagens have a successful use in increasing morphine content of Papaver
somniferum.
• Radiation mutagen has increased the yield and diosgenin content of Dioscorea bulbifera.

14. d. Hybridization:
The process of formation of offspring as a result of interbreeding between two
plants of the same or different taxa that differ in one or more heritable traits is called
hybridization. The plant produced as a result of interbreeding is called hybrid plant.
The types involve: Intervarietal (simple & complex) hybridization and Distant
hybridization.
Advantages:
• Phytoconstituents of some plants can be increased.
• Desirable characters of two different plants can be obtained in a single hybrid
plant.

15. Selection of herbal materials
The species or botanical variety selected for cultivation should be the same as
specified in the official Pharmacopoeia or official document.
In case of newly introduced medicinal plants, the variety selected for
cultivation should be identified and documented.
Methods of herbal materials selection-
A. Randomized approach
B. Ecological approach
C. Chemosystematics' approach
D. Ethno-guided approach

16. Identification of herbal materials
Identification tests should be specific for the herbal material and are
usually a combination of three or more of the following:
• Macroscopic identification
• Microscopic identification
• Physical identification
• Chemical reactions
• Chromatographic procedures.

17. Authentication of herbal materials
Contd…
Herbal materials
Taxonomic
Authentication
Chemical
markers
Molecular
markers
Single locus
probes
Multi locus
probes
New repetitive
DNA markers
Arbitrary
sequence
markers

18. Molecular
markers
Single locus
probes
Multi locus
probes
New repetitive
DNA markers
Arbitrary
sequence markers
• RFLP
• STS
• ASAPs
• EST
• SSCP
• RLGS
• Repititive DNA
• Micro and mini
satellites
• STMS
• DAMD-PCR
• ISSR
• Transposable
elements
• Alu- repeats
• Repeat
complementary
primers
• RAPD
• AP-PCR
• SCAR
• AFLP
• RAMPD
CAPs

19. Processing of herbal raw materials
Primary processing
1. Garbling (Sorting)
2. Washing
3. Parboiling
4. Leaching
5. Drying
Secondary Processing
1. Cutting/sectioning
2. Aging/sweating
3. Baking/roasting
4. Boiling/steaming
5. Stir frying
6. Fumigation
7. Extraction