Conservation of Medicinal Plants

Conservation of Medicinal Plants
By
Dr Gana Manjusha Kondepudi
Associate Professor
Vignan Institute of Pharmaceutical Technology
VIGNAN INSTITUTE OF PHARMACEUTICAL TECHNOLOGY

Medicinal plants and traditional medicine play an important
role in the health care system of most developing countries.
The traditional health care practice is mainly dependent on
medicinal plants collected from the wild.
In spite of this, the medicinal plant biodiversity is being
depleted due to man-made and natural calamities.
Moreover, the indigenous knowledge associated with the
conservation and use of medicinal plants is also disappearing
at an alarming rate

NEED FOR CONSERVATION
The goal of conservation is to support sustainable development by
protecting and using biological resources in ways that do not diminish
the world’s variety of genes and species or destroy important habitats
and ecosystems.
In general, it involves activities such as collection, propagation,
characterization, evaluation, disease indexing and elimination, storage
and distribution.
The conservation of plant genetic resources has long been realized
as an integral part of biodiversity conservation.
There are two methods for the conservation of plant genetic
resources, namely In-Situ & Ex-Situ conservation.

To Conserve Medicinal Plant Species In Situ –
In-situ method of conservation deals with the “on-site
conservation” of the wild genetic diversity in natural habitat.
In India, the conservation of forest areas pre-serves through
Protected Areas like National Parks, Wildlife Sanctuaries and
Biosphere Reserves.
The Government should prepare a policy at national level on
the conservation and utilization of medicinal plants in protected
areas.

This type of conservation is achieved both by setting away
areas as nature reserves and wild nurseries and by ensuring
that as many wild species as possible can still survive in
managed habitats, like farms and plantation forests.
The Government should assess the extent to which the
protected areas system covers the medicinal plants of the
country.
Species that are heavily depleted by over-collection should
be re-introduced into areas where they originally grew in wild.

Natural Parks - Natural Parks are protected areas of important
wild resources created to preserve and re-store biodiversity.
Around the world, more than 12,700 protected areas have been
established. Conserving medicinal plants in their natural habitat
requires evaluating the contributions and ecosystem roles of in-
dividual habitats.
E.g. Velavadar National Park in Gujarat, Ranthambore National
Park in Rajasthan, Corbett National Park in Uttarakhand.

Wild nurseries - The populations of medicinal plants are under
hefty burden because of overexploitation, habitat degradation
and invasive species, wild nurseries can provide an effective
approach for in situ conservation of medicinal plants that are
endemic, threatened, and in-demand.
E.g. Periyar Wildlife Sanctuary, Bandipur Wildlife Sanctuary in
Karnataka and the Dandeli Wildlife Sanctuary in south India.

Biosphere Reserves – Out of the 34 biodiversity rich spots in the
world, three lies in India; they are the Western Ghats, the Eastern
Himalayas and Indo-Burma region.
There are 18 biosphere reserves in India.
These aim at securing the ecosystem by stopping irresponsible
interference of humans with the ecosystem and also to conserve
the endemic and endangered species.
Out of these 18, 4 are part of the World Network of Biosphere
Reserves.
E.g. Nilgiri 2000, Sunderban, 2001, Nanda Devi, 2004, Pachmarhi,
2009, Great Nicobar, 2013, Agasthyamala, 2016 and
Khangchendzonga, 2018.

To Conserve Medicinal Plant Species Ex Situ –
Ex-situ conservation deals with the “off-site conservation” of
the wild genetic resources in natural habitat.
It includes the collection, preservation and maintenance of
certain genetic resources from wild.
Ex-situ method of conservation is a complementary action to
conserve the genetic diversity, thereby reducing pressure on
wild environments and enhancing raw material availability.

For many species of medicinal plants their wild population is on
life-threatening level and it is not suitable for dealing in-situ
conservation action.
It can be served as field gene banks and also help to engaging
the number of stakeholders in production and regeneration of
medicinal plants

Botanic gardens – should set up seed banks for the medicinal
plants native and cultivated in the country.
Botanic gardens should set up alternative means of ex situ
conservation for those species which cannot be stored in seed
banks.
Botanical Survey of India is actively engaged in the ex-situ
conservation through its chain of Botanic gardens established in
different regional circles.
E.g. Government Botanical Gardens in Tamil Nadu, Garden of
Medicinal Plants in west Bengal and Empress Garden in
Maharashtra

Seed banks – Seed banks proposed a better way of storing the
genetic diversity of many medicinal plant’s ex situ than through
botanic gardens.
They are recommended to help preserve the genetic diversity
of wild medicinal plant species.
Seed banks allow quick access to plant samples for the
evaluation of their properties.
The challenging tasks of seed banking are how to introduce
again the plant species back into the wild and how to actively
assist in the restoration of wild populations.

Field Gene Banks - Field gene banks conserve plants by using
tools of biotechnology.
These include – - In vitro conservation : - In vitro propagation and
re-introduction of plants to their natural habitats.
Molecular masker technology : Various In-vitro techniques have
been developed to store vegetatively propagated seed producing
species.
These can be categorised as –
• slow growth procedures, where germplasm is kept as sterile
plant tissue, or as plantlet on nutrient gel.
• Cryopreservation, where plant materials are stored in liquid
nitrogen.

Traditional Methods of Conserving Medicinal Plants
Major steps have been taken towards conserving the medicinal
plants. They include:
discouraging cutting down indigenous trees
encouraging the local people to plant fast-growing exotic and
indigenous trees for domestic use,
the inauguration of a national tree planting day
the creation of nature reserves

GERMPLASM TECHNIQUE FOR CONSERVATION
Germplasm conservation of vegetatively propagated crops, forest species
especially those with recalcitrant seeds in live gene banks in fields poses
tremendous problems in terms of required land space and labour input
during annual or perennial replanting, testing and documentation.
The advantage of in vitro or reduced growth storage include little space
necessary in growth rooms for maintaining thousands of genotypes and the
absence of diseases and pest attack in culture vessels.
Furthermore, in vitro storage eliminates the need for long and frustrating
quarantine procedures during movement and exchange of germplasm

Although the most economical means of germplasm storage for seed
propagated species is in the form of seeds, this is not always feasible
because of the following reasons:
Some crops do not produce viable seeds
Some seeds remain viable for a limited duration only and are recalcitrant
to storage
Seeds of certain species deteriorate rapidly due to seed borne pathogen
Some seeds are very heterozygous not suitable for maintaining true to
type genotypes.
Disadvantages of Germplasm

Effective approach to circumvent the above problems may be
application of cryopreservation technology

“Cryopreservation” is defined as the viable freezing of
biological material and their subsequent storage at ultra low
temperatures (- 196C)”using liquid nitrogen.
The use of liquid nitrogen, either by itself or as a source of
nitrogen gas, is based on the following unique combination of
features:
•Chemically inert
• Relatively low cost
• Non-toxic
• Non-flammable
• Readily available
CRYOPRESERVATION TECHNIQUE FOR CONSERVATION OF PLANTS

Encapsulation and dehydration
Vitrification,
Encapsulation and vitrification
Desiccation,
Pregrowth,
Pregrowth and desiccation,
Droplet freezing
New cryopreservation techniques

Cryopreservation procedures
Three different procedures have been used for
cryopreservation of plant cells:
two-step freezing, vitrification and encapsulationdehydration.
Two-step freezing: This procedure includes an incubation of
cells in a mixture of cryoprotectants (total concentration of 1–
2M), which causes moderate dehydration of the cells, followed
by a slow freezing step (for example, 1°C/min down to app –
35°C).

Vitrification: This procedure is based on severe dehydration at
non-freezing temperatures by direct exposure to concentrated
cryoprotectants (total concentration ranging from 5–8M),
followed by rapid freezing.
Encapsulation-dehydration: Cells are encapsulated in alginate
beads, cultured on medium with increased sucrose
concentration, air-dried using silica gel or the airflow of a flow
cabinet and directly transferred to liquid nitrogen.

TISSUE CULTURE TECHNIQUES USED FOR CONSERVATION
Plant tissue culture is a practice used to propagate plants under
sterile conditions, often to produce clones of a plant.

Cultivation Practice - In order to meet the increasing demand,
conservation and cultivation of medicinal plants has become
important.
Conservation involves imposing certain regulations on their
collection from the wild.
If such irrational collection continues, many plant species
which are widely available today will become endangered.
Some may even become extinct.
For their conservation, the proper cultivation methods must
be encouraged.

Cell suspensions:
a. Pre-treatment: The cell suspension is inoculated at high density into
standard medium containing 6% mannitol and cultured under standard
conditions.
b. The suspension is harvested when the cell will be dividing rapidly and
chilled on ice.
c. Cryopreservation: A double strength cryoprotectants solution(1M
dimethylsulfoxide (DMSO) + 1M glycerol + 2M sucrose)was prepared and
one volume of cryoprotectants solution is added to one volume of cell
suspension and the mixture is incubated on ice for 1hr. d. The mixture is
dispensed as 1 ml aliquots and the ampoules are cooled at 1oC min-1
until they reach -35oC

d. Storage: The ampoules are stored in or over liquid nitrogen. f.
e. Thawing: The ampoules are dropped into sterile water at about
40oC with a ratio of 4 ampoules to 150 ml water.
f. Re growth: The cells in suspension are transferred to several
layers of 5 cm filter paper on the surface of a 9 cm agar plate
containing a growth medium and are incubated under standard
conditions. The cells and upper layers of filter paper are then
transferred to fresh medium, until after 5 – 6 days, the cells alone
are transferred to agar medium

Medicinal plants collected from the wild normally vary in
composition and quality, due to the environmental and genetic
differences.
This variation and the uncertainty in their therapeutic benefit
can be much reduced by their proper cultivation. The possibility
of misidentification and adulteration also greatly reduces due to
cultivation.
Thus, medicinal plant cultivation can help in the conservation
of the wild stocks and can fulfill the global health needs.

THANK YOU

Conservation of Medicinal Plants

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