Medicinal Plants
Ancient archaeological records of
medicinal plants
3500 BCE - India had an extensive pharmacopoeia.
Much of that knowledge is still used as part of the
Ayurveda medical system
2250 BCE – Egypt and Babylon were trading
medicinal plants
900 BCE - Archaeological records demonstrate the
use of medicinal and psychoactive plants in the
New World
330 BCE - One of the Theophrastus’s students,
Alexander the Great, sent medicinal plants from
Asia back to Greece for cultivation
2000 YA - The first written Chinese records
although use is probably as ancient as India’s
Use of Medicinal Plants
• Use of medicinal plants developed from
informal experimentation and based on a
general familiarity with medicinal plants.
This knowledge was amassed via
experimentation over many generations and
was handed down orally from person to
person – often woman to woman in
traditional cultures.
Theophrastus
370-285 BCE
History of Herbals
• Dioscorides, in the 1st Century AD, was a Greek
physician who described the medicinal properties
of plants - he described the use of 500 species of
plants in his book De Materia Medica
• The first herbal written in the Anglo-Saxon world
was an 11th Century book known as the
Herbarium of Apuleius Platonicus
• The first herbal to break from Dioscorides and
print descriptions of local flora, with accurate
drawings of the plants was by Leonhart Fuchs, his
extremely well illustrated herbal De Historia
Stirpium was published in 1543
Page from “Vienna Dioscorides”
Arabic – 6th Century
Page from Arabic edition of
Dioscorides herbal 1334
Title page from Fuchs
herbal –1543
Page from Fuchs Herbal 1543
Papaver or Poppy
More from Fuchs Herbal 1543
Nicotiana - Tobacco
English Herbals
• The earliest printed English herbal was anonymous volume
from 1525 published by Richard Banckes
• In 1526, Peter Treversi published an English translation of
a French herbal
• In 1538, William Turner published an herbal entitled
Libelluls de re Herbaria Novus
• In 1551, Henry F. Lyte published an English translation of
Rembert Dodoen’s herbal Stirpium Historiae Pemptades
Sex which was valued because of its all inclusive treatment
of many plants and excellent plates illustrating flowers
Best English Herbals
• In 1597, John Gerard published his outstanding
book The Herball, Or Generall Historie of Plantes
- it is a huge volume of 1392 pages and 2200
woodcut illustrations of plants - it was widely used
by physicians and became widely quoted and
referenced - the book has remained in print for
400 years
• The last major herbal published in English was
John Ray’s herbal, published in 1688 - it is also a
major taxonomic work and Ray was the first
person to divide the flowering plants into two
main groups - the dicots and monocots
Cover of
Gerard’s
Herbal –
1597
Page from Gerard’s Herbal - 1597
Title Page of John Ray’s
Herbal - 1688
Page from John Ray’s Herbal - 1688
Ginseng root – Panax
pseudoginseng
Foxglove –
Digitalis purpurea
• Foxglove may be
useful as a way to
cure people of
“grosse and slimie
flegme and
naughtie humors” –
from Gerard’s
Herbal - 1597
William Withering
- holding a foxglove
Withering’s work on Foxglove
• Began experiments with foxglove in 1775 Withering had heard about an old family cure for
dropsy
• Reported his findings in a paper published in
1785, “An Account of the Foxglove and Some of
its Medical Uses”
• Powdered foxglove leaf is still prescribed in
tablets or capsules to treat congestive heart failure
• The somewhat crude powdered drug is called
Digitalis after the plant
• Foxglove produces more than 30 different cardiac
glycosides - two in particular - Digoxin and
Digitoxin are produced from foxglove and
prescribed to heart patients around the world today
Foxglove - Digitalis purpurea
Willow Bark – inspiration for Aspirin
Urgent need to study medicinal plants
The utility of plants in current therapy
There has been a rush to develop synthetic
medicines based on plant medicines, but
often the synthetic medicines don’t work
as well as the original plant medicines.
For example – quinine and malaria
Efficacy of Quinine
• Quinine is traditional and effective preventative of
malaria
• Synthetic preventatives such as chloroquine,
maloprim, and fansidar have largely replaced the
use of quinine
• Many strains of Plasmodium have developed
resistances to the synthetics and the synthetics are
more toxic. It is recommended that people do not
take fansidar for more than 3 months due to
potential liver damage.
Malaria Cycle
Anopheles freeborni mosquito – intermediate
host and vector for Plasmodium sp.
Historical distribution of Malaria
Red areas show countries with malaria today
One of the sources of Quinine –
Cinchona succirubra
Cinchona pubescens
Timeline of Quinine Use
• 1633, a Jesuit priest named Father Calancha described how
to use quinine bark to cure fevers
• 1645 Father Bartolome Tafur took some bark to Rome and
many of the clergy used it
• Cardinal John de Lugo wrote a pamphlet to be distributed
with the bark - use of the bark became so widespread that
in the papal conclave of 1655 no one died of malaria
• 1654 – English aware of use of quinine bark
• 1735, a French botanist named Joseph de Jussieu
journeyed to South America and found and described the
tree that is the source of the bark - he sent samples to
Sweden where in 1739, Carl Linneaus named the tree
genus Cinchona
Timeline of Quinine Use
• 20 to 40 species of Cinchona - the species are very
hard to tell apart and the species will hybridize, so
the exact number of species is unknown – mostly
understorey trees
• 1820 the French chemists Joseph Pelletier and
Joseph Caventou isolated the alkaloid quinine
from the bark and identified it was the active
ingredient in Peruvian bark
• 1861, an Australian named Charles Ledger
obtained seeds from an Aymara Indian named
Manuel Incra
• by 1930, the Dutch orchards in Java produced 22
million pounds of quinine, 97% of the world’s
market
Charles Ledger – 1818-1906
Chemical structure of quinine
Properties of Quinine
• Quinine itself is an odorless white powder with an
extremely bitter taste
• It can be used to treat cardiac arrhythmias as well
as malaria - it is also used as a flavoring agent
• Quinine prevents malaria by suppressing
reproduction of the Plasmodium protozoan and
also helps prevent some of the fevers and pain
associated with malaria
Quinine fluoresces under UV light
Raymond Fosberg in the
field in 1948
Cinchona bark drying in the sun in
Ecuador, 1944
Arrow Poisons
Documented use of arrow poisons
around the world
Monkshood – Aconitum ferox –
source of Acontine
Monkshood –
Aconitum ferox in the wild
Uses of Aconitum
• In Europe the plant has been used as a liniment or tincture
in the treatment of neuralgia, sciatica, and rheumatism, and
taken internally to alleviate fevers.
• In India and China the plant is still used in treatment. In
the raw state, tubers are applied to the skin as a surface
anaesthetic and to treat lumbar and leg pains, neuralgia and
rheumatoid arthritis. After much processing it is used for
cardiotonic and diuretic properties.
• Acontine is an alkaloid derived from monkshood - used in
heart medicines, common cough medicines, and used in fly
control in Europe since 1240
First Ethnobotanical Chemical
Isolation - Strychine
• 1805 – Leschenault describes the preparation of
the Javanese dart poison Upas Tieute.
• 1809 – Magendie and Delile publish accounts of
experiments on mechanism of action of the
poison.
• 1819 – Pelletier and Caventou isolate strychine
from other sources. Magendie uses strychine in
clinical medicine.
• 1824 – Pelletier and Caventou isolate strychine
from upas tieute
• 1963 – total synthesis of strychine by Woodward
et al.
Strychnos nux-vomica - source of
Strychine
Strychnos nux-vomica
leaves and seeds
Strychnos
• Interestingly there are about 200 species in
the genus Strychnos but only 6 actually
contain strychine – in particular S. nuxvomica, S. ignatii (St. Ignatius’ bean), S.
colubrina (snake wood) and S. guianensis.
Strychine is commonly used in rat poison.
It has been used to stimulate circulation, but
that cannot be recommended because it
frequently poisons the patient.
Curares
Calabash curare from Strychnos
guianensis – carried in gourd
Crescentia cujete – source
of calabash gourd
Tube Curares – made from members of
Chondrodendron and other moonseeds Menispermaceae
Chondrodendron tomentosum leaves and vine
Tube and Calabash Curares
• The bamboo tube curare yielded
tubocurarine and the calabash gourd curare
yielded toxiferine - both are useful as an
anaesthetic in open-heart surgery - these are
muscle relaxants which kill by relaxing
muscles which allow breathing
Bark being scraped to start
preparation of curare
Liquid dripped through shavings to
extract Curare
Curare added to arrow/dart tips
Waorani man
Toxicities of several arrow poisons
Anti-tumor medicines from
Arrow Poisons?
• There is a possibility that plants producing arrow
poisons may also have value in producing antitumor medicines. Spjut and Perdue (1976)
surveyed 76 species from 63 genera in 29 families
and found that 46 of the species had been screened
for anti-tumor activity. Of these 52% of the
species and 75% of the genera had been found to
have anti-tumor activity. This high anti-tumor
activity probably comes from the fact that arrow
poison plants almost all produce cardenolide
glycosides that are cytotoxic (kill cells).
Herbal Medicines Today
• Though many modern cultures make extensive use
of herbal remedies, most notably in India and
China, much of Western medicine has moved
away from herbal medicines. In Great Britain
there is still a tradition of homeopathic doctors and
herbal Culpeper Shops. Homeopathy is based on
using minute quantities of substances that in
massive doses produce effects similar to those of
the disease being treated.
Nicholas Culpeper
1616-1654
Culpeper’s Influence on
Homeopathy
Grave’s patent medicine – a
Laudanum product
Medicines from Plants
• About 25% of the prescription drugs used in the
western world have active ingredients that are
derived from plants – often the only way to
acquire these drugs is through growing and
harvesting the plants because synthetic substitutes
are not as effective.
• 89 plant derived drugs that are currently used in
western medicine as prescription medicines were
discovered by studying folk knowledge of the
plant’s properties
Strychnos toxifera
– source of D-tubocurarine
Mexican yam – Dioscorea villosa
Source of cortisone
Indian snakeroot – Rauwolfia
serpentina –Source of reserpine
Madagascar periwinkle Catharanthus
roseus –Source of vincristine
White Hellebore – Veratrum album
Source of hypotensive alkaloids
Medicinal Plants in
the Amazonian Basin
• 3 million square miles in size, supports the
world’s largest rainforest with an estimated
80,000 species of plants, about 15% of the
world’s species
• The northwest section of the Colombian
Amazon is home to 70,000 Indians in 50
ethnic groups that speak many languages
from 12 linguistic families. They have been
recorded to use medicines made from
almost 1600 plants from 596 genera in 145
families
Cannabis sativa and C. indica
Cannabis sativa and C. indica
Cannabis sativa x indica hybrid
High tech Cannabis growing
in the Netherlands
UK Police Bust of High-Tech Growth
World Cannabis Laws - 2011