Medicinal Plants

ASTE 2900Unit 12

Overview Over 40% of medicines now prescribed in

the U.S. contain chemicals derived from plants.

Before the synthetic revolution of mid-1960s, it was as high as 75%.

Advantage to modern drugs:Less resistance (i.e. malaria)Complements conventional treatmentNot as acutely harmful

Overview

Historically, plant medicines were discovered by trial and error.

For example, our ancestors noticed that aches and pains went away when they drank tea made from the bark of a willow tree.

Later, scientists found that willow bark contains salicylic acid, the active ingredient in aspirin.

Contemporary Example For years, the native Pacific yew (Taxus

brevifolia) was burned as trash generated by logging operations in the Pacific Northwest.

In 1975, a substance in its bark, taxol, was found to reduce the production of cancerous tumors.

It is most commonly used as a chemotherapy drug to treat ovarian, breast and non-small cell lung cancer.

Non-prescription drugso At least 175 plants native to North America are

for sale in the non-prescription medicinal market in the U.S.

o Most are collected from the wild in large quantities (hundreds of thousands of plants) for commercial markets in the U.S. and abroad.

o For example, during the last few years, about 34 million ginseng plants have been harvested from the wild in the forests of the eastern United States on an annual basis.

Impacts and implicationso In the United States, the market for

medicinal herbs is worth more than $3 billion.

o Many of the plants supplying this industry are wild collected in vast quantities because techniques to cultivate them on a commercial scale have not been developed.

o Consider the implications of such popularity for these plants.

Doctrine of Signatures The “doctrine” has been an idea of

herbalists for centuries. Yet, it did not become part of the medical

thinking until the middle of the seventeenth century.

In simple terms, the "Doctrine of Signatures" is the idea that God has marked everything He created with a sign (signature).

The sign was an indication of the purpose for the creation of the item.

Doctrine of Signatures

Part of a plant had the shape of a part of the human body, it would be useful in treating a disease of the human part it most closely resembled.

Walnuts treat brain disorders Hepatica with its kidney-shaped leaves for kidney

diseases Lousewort, Pedicularis - thought to be useful in

repelling lice Spleenwort, Asplenium - thought to be useful in

treating the spleen Liverwort - thought to be useful in treating the

liver

Ethnobotany: MYRRH

Myrrh is mainly found in Ethiopia, Somalia, Saudi-Arabia, Iran and Thailand.

Myrrh has been used in perfumes, incense and embalming. Its astringent, antimicrobial and antiseptic properties have been used to treat acne and boils as well as mild inflammatory conditions.

It finds specific use in the treatment of infections in the mouth such as ulcers, gingivitis, and pyorrhea.

Ethnobotany: GINSENG

Ginseng is the most famous Chinese herb of all. It is native to north-eastern China, eastern Russia and Korea.

The related species occurs in the eastern United States and Canada.

Ginseng has been praised for its remarkable therapeutic benefits for about 7,000 years. Its value was so great that wars were fought for control of the forests in which it thrived.

Ginseng increases mental and physical efficiency and resistance to stress and disease. It often shows a dual response like sedating or stimulating the central nervous system.

Ethnobotany: CHAMOMILE

Chamomile grows wild in Europe and west Asia. Related species are found in North America and Africa.

Its flowers help to ease indigestion, nervousness, depressions and headaches, being ideal for emotion related problems such as peptic ulcers, colitis, spastic colon and nervous indigestion.

It is an excellent herb for many digestive disorders and for nervous tension and irritability.

Ethnobotany: WORMWOOD

Native to Europe, wormwood was called absintium by the Romans, what means "bitter".

Wormwood leave's primary uses is to stimulate the gallbladder, help prevent and release stones, and to adjust digestive malfunctions.

It also increases bile secretion and is useful in expelling intestinal worms.

It is taken in small doses and sipped, the intensely bitter taste playing an important part in its therapeutic effect.

In the past, wormwood was one of the main flavorings of vermouth (whose name derives from the German for wormwood).

Ethnobotany: DANDELION

Occurring naturally in Asia, Dandelion is now a common plant everywhere.

Its medicinal virtues were probably introduced in Europe by the Arabs in the 10th Century.

Both the Persians and the East Indians used it for liver complaints.

The leaves, which can be eaten in salads, are a powerful diuretic. The roots act as a "blood purifier" that helps both kidneys and the liver to remove impurities from the blood.

This effect seems to be due to its potassium content. It also acts like a mild laxative and improves appetite and digestion

Ethnobotany: ST JOHN'S WORT

The plant is native to Europe but is widely cultivated elsewhere.

St. John's wort flowers at the time of the summer solstice, and in medieval Europe it was considered to have powerful magical properties that enabled it to repel evil.

The most well-known action of St. John's wort is in repairing nerve damage and reducing pain and inflammation.

It is taken to relieve the pain of menstrual cramps, sciatica and arthritis. The oils is applied to inflammations, sprains, bruises and varicose veins.

St. John's wort is also used to treat circulation problems, bronchitis and gout.

Ethnobotany: GINKGO

Ginkgo is thought to be the oldest tree on the planet, first growing about 190 million years ago.

Traditionally known as an anti-microbial and anti-tubercular action, it has now been shown that ginkgo as a profound activity on brain function and cerebral circulation.

This action is useful to prevent dizziness, tinnitus, short-term memory loss, depression and other symptoms related to poor brain circulation.

Its effect on poor circulation also used to treat other related disorders like diabetes, hemorrhoids, varicose veins, and asthma.

Ethnobotany: Common Foxglove

1775 Dr. William Withering, an English physician, discovered the efficacy of Foxglove in the treatment of severe congestive heart failure.

He attributed its efficacy to a diuretic effect and published his findings based on clinical observations in 1785.

The pharmacological properties of regulating the heart rate and rhythm and strengthening of the heart muscle were discovered later.

Ethnobotany: Hoodia Long known by the indigenous populations of Southern

Africa for treating indigestion and small infections. In 1977, the South African Council for Scientific and

Industrial Research (CSIR) isolated the ingredient in hoodia - which is responsible for its appetite-suppressant effect, and patented it in 1996.

The CSIR then granted United Kingdom-based Phytopharm a license, and they collaborated with the pharmaceutical company Pfizer to isolate active ingredients from the extracts and look into synthesizing them for use as an appetite suppressant.

Pfizer released the rights to the primary ingredient in 2002 stating there were indications of unwanted effects on the liver caused by other components, which could not be easily removed from the supplement.

Ethnobotany: POPPY

Opium is the name for the latex produced within the seed pods of the poppy, Papaver somniferum.

Psychological effects of opium may have been known to the ancient Sumerians (circa 4,000 B.C.) whose symbol for poppy was hul, "joy" and gil, "plant".

In 1805, the German pharmacist Friedrich W. Serturner isolated and described the principal alkaloid and powerful active ingredient in opium.

He named it morphium after Morpheus, the Greek god of dreams. We know it today as morphine.

Medicine Man (1992 film)

How many medicines have we already lost?

How many more remain to be found?