Preparing Medicinal Plants
Harvesting Medicinal Plants
Main Preparations :
Plants in Powder, Infusion,
Decoction and Maceration,
Alcohol Tincture and Mother Tincture, Essential
Around the World :
Creole Medicine, Medicine
with the Amerindian of the Guyanas
Plants in Polynesia,
Indigenous Australian Medicine
In tropico-equatorial areas, when people
need medicinal plants, they mostly use those around without stocking or
On the contrary, in very cold or very hot
must use medicinal plants as they are flowering. We also try to
preserve them in order to be able to reuse them later in the bad
In developped countries, even though it is
not necessary to
prepare remedies for oneself, people are fairly satisfied to heal
themselves using "natural" methods. They are cheap and enable not to
synthetic medicines whose effects are much too powerful or
improper. Medicinal plants often are the only one way to heal in many
countries where health services are disorganized and synthetic
|Harvesting Medicinal Plants
Traditionally medicinal plants are preferably harvested in
their natural environment. Nevertheless in many regions, plants become
harder and harder to harvest because of:
- the permanent increase of agricultural areas treated with pesticides -including pastures, hedges and fallows
- the critical disappearance of some
wild medicinal plants since they are either overexploited -to respond
to the increasing demand from traders and merchants in medicinal plants
of the pharmaceutical industry on a global scale- or weakened by the
modifications of natural surroundings such as pollution, industrial
agriculture, agroforestry, desertification and overgrazing.
Nowadays, most of the medicinal plants in great demand are cultivated in a reasonably
organic manner. But sometimes fertilizers and pesticides are used
In any case, when harvesting wild plants, only the necessary amount of plant has to be deducted the
amount of plants necessary; if possible, away from busy roads and
agricultural areas; and finally we should ask a botanical guide, a
pharmacist or a traditional practitioner to verify the identity of the medicinal plant needed.
When is it Time to Harvest?
- full plants: when flowering;
- leaves: after complete development and if possible, before flowering;
- flowers and sprays: right before total flowering;
- roots of annual plants: at the end of the vegetative period, i.e. at the end of growth;
- roots of bisannual plants: at the end of the
vegetative dormancy of the first year and before the resumption of
vegetative growth of the second year;
- roots of perennial plants: during their second
or third year; before becoming too rough and fibrous namely before the
- fruits and seeds: mature or very slightly before -if fruits are to be dried-;
- tree bark: in winter or at the beginning of
spring -during the dry season-; shrub bark after the hot season -at the
end of the wet season.
Thanks to cold preservation or immersion of roots into water, medicinal
plants are preserved for 24 to 48 hours. If they are not
meant to be used, plants have to be desiccated (or transformed into
After dehydration, plants are set into bunches when they
are meant to be used or sold soon. Otherwise plants are preserved
-in their full form, in snippets, in powder- in water and air-tight containers for 6
to 12 months.
- drying in the shade if possible, in an open and ventilated space: e.g. barn, solar furnace or drying terrace;
- sometimes kiln drying -soft heat- in regions
very sensitive to humidity and most of the time, for big fleshy roots
after being cut into slides or into pieces.
|Main Preparations of Herbal Remedies
|Plants in Powder
Properly desiccated plants are ground and used unprepared.
They may be blended with a little water or food. The taste is often
outrightly unpleasant: it is mainly due to the bitterness that is much
too strong for humans. That is why pills and capsules of dry powder
ready to pop are prepared. They will dissolve into the stomach and/or
|Infusion, Decoction and Maceration
The easiest way to extract the active principles from medicinal plants is by water.
Some components are sensitive to heat; others are difficult to combine
in solution. Therefore water temperature and duration of water
containment may be varied to extract specifically interesting
- Infusion or Tea or Tisane
the dry or fresh plant -sometimes in powder or in pieces- is covered
with very hot or boiling water for 3 to 6 minutes. Then softly agitated
To be drunk warm or cold immediately. Infusion may be preserved in a cold place 6 to 12 hours.
- Decoction or Concentrated Tea
the dry or fresh plant -sometimes in powder- hashed or mashed is put
into a container of cold water. Boil; let the mixture simmer 10 to 20
minutes; and filter.
Decoction may be preserved 2 to 3 days in a cold place.
- Aqueous Maceration
maintain the fragmented medicinal plant in cold water, in a cool place
for 12 to 24 hours; stir the mixture from time to time; and filter. To
be drunk within 6 hours.
|Alcohol Tincture and Mother Tincture
By definition mother tincture is "a liquid preparation
resulting from the solvent action of an alcoholic vehicle on fresh
Mother tincture is obtained by maceration of fresh or stabilized
plants in ethyl alcohol. If the plant is dry, the mixture is called
Even if the alcohol component may be unacceptable for some people,
alcohol tincture and mother tincture are very interesting. They are
easy to prepare; the product is fairly regular; the concentration in
an active substance controllable: a good point for an easy prescription.
Its preservation is really satisfying.
How to Prepare a Mother Tincture?
- Screen and trim medicinal plants or fragments -defined beforehand with care-
- Grind and let immediately macerate in ethyl
alcohol 95°; add to the blend the amount of distilled water
necessary to get a degree of about 60 to 70 alcohol;
- At the same time, put aside a part of the fresh
medicinal plant -which after being weighed- is dried out to the autoclave at
50°C for 12 to 24 hours. Weigh the mixture again to get its dry
weight, that generally corresponds to 20-30% of the fresh weight;
- The macerate is preserved in a cool and dark place in a water and air-tight container for 3 weeks; shake from time to time;
- At the end of the 3 weeks, filter and also retrieve
the liquid from pressing strongly out the residue of the macerated
plant; blend the whole mixture;
- Measure the liquid obtained; adjust the alcohol
degree (60°) and the volume of tincture to get the requested ratio
-compared with the theoretical weigh of the dry matter.
In a tincture to 1/10 -the most common in France-: 1 litre of tincture
corresponds either to 100 grammes of dehydrated medicinal plant or to
250-300 grammes of fresh plant.
The other current ratios are 1/5 and 1/20.
For private and non-commercial uses, there is an easier method to prepare a tincture.
100 grammes of dry plant in 1 litre of alcohol 60° or 250 grammes
of fresh plant in 1 litre of alcohol 70° produce -after fews weeks
of maceration; filtration and expression of residue- an alcohol tincture
about to 1/10 in alcohol 50°-60°. For a good preservation,
tincture must not contain less than alcohol 45°.
If an alcohol tincture is concentrated by evaporation, the
product is called fluid extract. The ratio -1/1- corresponds to 100
grammes of dry plant in 100 grammes of fluid extract, that is much more
concentrated in active principles.
If evaporation is prolonged, the material is called soft extract. Its syrupy texture is similar to consistency of honey.
Alcohol tincture is very convenient: it may be used
internally or externally. Alcohol tincture keeps several years in a
cool and dark place (e.g. coloured or opaque glass), in a waterproof
Alcohol tincture may be mixed with a lotion, a pomade, a cataplasm and
an enema. Various herbal tinctures may be blended together.
By definition, essentials oils are "products that contain volatile principles from plant species".
How to Obtain and Condense Volatile Substances?
- hot steam distillates volatile
substances and then condenses them. With the difference of gravity essential
oil gets separated from water;
- when plant have secretory cavities their content is presssed out (e.g. in the citrus family);
There are other ways to prepare essential oils: extraction by volatile
solvents, supercritical carbon dioxide extraction, extraction by a
fatty solvent. All these techniques require very specialised tools and a specialist knowledge.
Nevertheless, volatile principles of essential oils may be retrieved with alcohol maceration such as alcohol tincture.
Besides the components of essential oils become volatile to heat. Therefore it is possible to:
- heat leafy branches, aromatic wood,
bark and seeds, resin (frankincense) and thus breathe the components of
essential oils. They will be absorbed by airway.
- dip aromatic leaves into very hot
water and obtain an aromatic bath, remembering that the components of
essential oils easily penetrate skin when bathing.
The components of essential oils are soluble
in glycerids: glycerids may be used in a dissolved form but the process is
easier with vegetable oils like those of coconut, olive, sweet almond,
etc.. The preparation finally offers an aromatic oil. The oil contains
a major part of essential oil but also other liposoluble components.
(which is not always interesting)
PREPARATION: fill in half a container with the aromatic dry medicinal
plant roughly ground; complete with the oil; let macerate for 2 to 4 weeks
at room temperature and shake from time to time. Let oil settle,
otherwise filter it with a clean cloth. Preserve this aromatic oil in
tinted glass in a dark and cool place. Examples: monoï coconut
oil, aromatic (or infused) oil of flowers (rose, St John's worth) or of
labiates (thyme, rosemary, sage, etc.) .
These aromatic oils will be used as massage oils or in local skin
application (St John's worth) or quite simply when cooking (thyme,
The pharmaceutical industry mainly offers:
preparations that correspond more or less to the whole plants:
- packed fresh plant juice;
- split or ground dry plants;
- micronised dry powder;
- dry powder of plant after cryogrinding;
- full suspension of dry plant ground and stabilized.
Moreover pharmaceutical laboratories extract useful active
substances; purify them; at times modify or use them to synthetize new
molecules more or less toxic for the organism.
- hydro-alcoholic extracts, similar to tincture, fluid extract or soft extract;
- aqueous extracts, similar to infusions, decoctions, syrups;
- dry and sometimes atomized extracts -in general called nebulisate-;
- special: intrait, a fresh plant
extract beforehand stabilized chemically; glycero-alcoholic macerate
-at the heart of gemmotherapy- a little similar to mother tincture but
with addition of glycerin to better extract some active principles of
buds and very small branches; essential oil, that is at the base of
At the drugstore, there is a wide range of preparations that associate sometimes several plants, several modes of preparation.
|Medicinal Plants around the World
|Creole Medicine in the Antilles
In the Antilles the
advocates for infusion and decoction. Several plants may be blended
together. People differentiate between tisane that refreshes and tea
up. Tea is less profuse in quantity than tisane. In the Creole
the opposition between hot and cold, between inflammation and cooling
balances health. This notion also exists in Europe and in other countries.
If infusion and decoction are common, there is another preparation less
common: thelooch. It is an aqueous extract
concentrated by evaporation.
Alcoholic maceration -into rum of course, but also into cognac, brandy or cooked wines is a common process. Leaves, roots,
wood and/or bark fragments, at times animals (e.g. heads of snake) may be added.
Juice of plants is harvested by expression or after searing it lightly.
Traditionally in Africa but also in the Antilles-Guyanas, vegetable
ashes treat skin lesions.Parents put easily their children into a bath of plants or spray them
with it. Plasters and cataplasms of fresh plants are frequently used. People
blend on a lesser scale dry plant and animal fat.
|Medicine with the Amerindian of the Guyanas
Amerindian of the Guyanas, plants
are generally harvested, prepared and used during the day. Around
villages, forests are omnipresent.
Every vegetable parts of plants are usable: leaf, bud, fruit, seed,
flower, bark, wood, root, sap, latex and exudate.
Plants are macerating into cold water or prepared in decoction.
At times leaves are slowly cooked at a low temperature above embers.
Afterwards the material is ground or transformed into a medicinal smoke.
Juice of leaves and buds is gathered. Bark is softened by more or less
The Amerindian absorb healer's preparations through the mouth.
Nevertheless people currently pour a calabash containing medicinal preparation on
their heads and shoulders as an external washing.
use also the preparation as a gargle.
Steam bath with plants is rather reserved to shamans or healers so as
to favour their visions.
Bodily friction with leaves or bark -sometimes seared lightly to soften
them or to make them sweat-; plasters of plants and of sap are common.
|Medicinal Plants in Polynesia
Polynesian people do
not drink any infusion or decoction.
Medicinal plants -which include full plants, leaves, flowers, fruits,
roots, wood, bark- are generally ground with a stone pestle and blended
The preparation is carefully filtered with
- green coconut water -to degres of maturation that depend on
- or with coconut milk -prepared in a special manner, at times
with green walnuts-
- or with coconut oil. Brown sugar is sometimes added
to reduce bitterness.
In some cases the plant ground or its pure juice is directly
administered on the affected and/or painful part.
Plaster -kept on the harm- and the liminent are well-known by the
Most of the recipes associate various plants.
|Indigenous Australian Medicine
First colonialists considered Indigenous Australians as an healthy
people even though they lived in very difficult conditions. Indigenous
people resort to plants from the Australian bush to heal wounds and
ulcers, to fight against fairly common diarrhoea, muscular pains,
eye infections and ophtalmias; and wounds due to venomous stings,
As often in folk medicine plants have a symbolic clan value. This
healing power is expected by Indigenous people but leaves modern pharmacologists
As opposed to Polynesian they were regular drinkers of infusions and
As many populations living close to nature, Indigenous Australians
often employed fresh plants: sap, latex, leaves as well as young shoots
and bark ground as plaster or in temporary application. For instance
to cure mouth disorders and dental pains, people chewed leaves and
spat the juice.
Indigenous Australians discovered the powerful physiological effect
There are indeed in Australian bushes some genera of Solanaceae, Duboisia
and Nicotiana. The leaves of the small tree Duboisia hopwoodii were
the most wanted leaves (to be differenciated from D. myoporoides and
D. leichardtii containing rather other alcaloids, scopolamine or hyoscyamine,
(see Datura)). People chewed leaves and later smoked them, as European
Leaves and sprays were dried, ground and preserved with care in a
very small bag (because good Duboisia is rare), or dried on fire and
moistened and rolled like a cigar but after being blended with vegetable
ash of special trees and sometimes with natural wax to better stick
Chewing basic components of ash released nicotine of quid, thus increasing
the sensation felt. The lime of betel quid in Asia or of coca in South
America also helps release alcaloids.
Copyright 2006: Dr Jean-Michel Hurtel. All Reproduction Prohibited