Science in the Service of Folk Medicine

C. E. Seaforth Ph.D.at the Caribbean Yard Campus

September 2014

The Evidence.

• “We live here by courtesy of the Earth’s green cover. Without plants man could not survive”.

……………………………………• Caribbean folk medicine has not been codified.

Therefore we could lose this folk knowledge, because of the lack of inter-generational transfer and the disinterest shown by people exposed to modern biomedical scientific systems.

For example, review the page “A” in theWorksheets.What do we know about the plant called • COCOA ONION or • SPIDER LILY or • WILD ONION?

Plant names and the plant extracts

The TOPICS

1. Introduction2. Selecting a plant name3. Collecting the medicinal plants…………………………………4. The “strategic” plant constituents5. The teas, decoctions, (safe?)dosages, etc.6. About TRAMIL and TRADIF7. Some herbs that work8. A Bibliography

1. Introduction

“Modern science and ancient wisdom should treat each other with mutual respect”.

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• Caribbean medicinal plants are amongst the least systematically evaluated for safety and for their reputed efficacies. They are found growing mainly as “weeds” in tropical places.

2. Local plant namesThe most popular plants we meet are best known by

their common or vernacular names.…………………………………………………………. But mis-identification and confusion can arise when

either(a) a common name (e.g. Sage) is shared

between two or more different plants; or(b) the same plant has 2 or more common

names (e.g. Bitter bush is also called Christmas bush, and Baby bush, and several other common names).

3. Why scientific plant names?

In order to avoid confusion, and the mis-identification of a plant and its special usefulness, we need to use its scientific name (e.g. Aloe vera) in our communications.

………………………..In assigning the correct scientific name to any plant, comparisons are made by an expert (taxonomist) between this plant and a “voucher specimen” lodged at a Herbarium.

4. The voucher specimen

• This is a pressed, dried plant specimen, attached to a sheet of paper deposited, preserved and stored for further reference, inside the Herbarium.

• The herbarium voucher specimen is used to verify the identity of another properly collected plant specimen.

5. The label

• The label for each correctly identified plant specimen should include –

• Scientific name…………………………………….• Common name…………………………• Location/Habitat…………………………….• Collector……………………………………………• Collection Date and No…………………………• Identified by……………………………………………..

6. Where is the herbarium?

• It is a place where a collection is kept of dried, pressed plant materials, correctly identified, labelled and mounted on sheets of paper, and filed systematically, together with books and related information products in plant taxonomy.

7. Plant classification

• In doing so, we use the hierarchical classification system for groups of organisms, which is approved by the International Code of Botanical Nomenclature (ICBN), and in which the basic unit is known as the species.

8. The rank of species

The species is described as a very closely related group of individuals (organisms) possessing

(a) numerous structural features (of the flowers, etc.) NOT present in other

species; and, especially (b) the capacity to inter-breed freely in nature.

9. The genus and other ranks1. Let’s look at the “box-within-box” diagram shown on page “B” in the Worksheets.

2. N.B. Any particular species can be identified as being part of a larger group called the genus, (e.g. the genus Hibiscus).3. The genus forms part of yet a larger group

of organisms called the family, and so on….through to the division, and so on to the largest group possible in the kingdom.

10. The scientific plant name (1)

1. Every plant can be given a scientific name, which is made up of 2 parts. It is binomial.

2. Each scientific plant name consists of the name of the genus to which the species belongs, together with a second word called the specific epithet.

3. In this name, only the generic name starts with a capital letter.

11. The scientific plant name (2)

1. The correct scientific name must always be underlined, or written in italics, because it is written in the dead language called Latin.

…………………………………………2. This name can also be written, followed by

the (usually abbreviated) name of the person first responsible for the scientific name. For example, “L”. is used for Linnaeus.

12. Regarding Linnaeus and others

N.B. The Sweet broom plant belongs to the family Scrophulariaceae; and its scientific name is Scoparia dulcis L.

……………………………………………Sometimes a plant is correctly given 2 or more

scientific names called synonyms; e.g. Bitter bush is Chromolaena odorata King & Robinson = Eupatorium odoratum L.

13. The Angiosperms

Over 250, 000 species of flowering plants are known on Earth, and over 2, 000 of them grow in T&T alone, including several species introduced here from Africa, India, Europe etc.

Roughly 150 plant species growing in T&T are still used today to make the home remedies as herbal preparations (“bush-teas”) for local folk medicine.

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• To collect good plant specimens in the field or garden, there is a special role for the plant press.

• To learn about how it is used, let us look at the second page “B” among the worksheets.

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• Let’s look at the 6 multiple-choice questions (MCQs) which are listed on page “C” in the worksheets.

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14. The plant constituents (1)

Every growing plant makes a vast array of chemical constituents (“metabolites”), such as glucose, and including its own “strategic” metabolites (like caffeine, morphine or nicotine) within its tissues.

………………………………………… A “strategic” plant constituent/metabolite (like

nicotine or even caffeine) is produced by the organism, so as to promote its own survival in a threatening/ hostile environment.

15. The plant constituents (2)

When we withdraw/separate any desired constituent(s) (whether acid, oil, alkaloid or glycoside) from within a plant material, the process employed is called “extraction”.

…………………………………………………Every raw herbal preparation (extract) consists

of a complex mixture of several different chemical components from the plant. (Note those items located within the “triangle” in the Diagram, on page “D” in the worksheets).

16. Teas, decoctions, etc.

“Home remedies” are the raw/”crude” extracts removed from within the plant material (whether leaf, flower, fruit, seed, stem, wood, bark, root or rhizome). (Review page “D”).

……………………………..N.B. The differences between a

“phytochemical” (like quinine) and a “raw extract” are shown on both pages “D” and “E” in the worksheets.

17. (Safe?) Dosages• N.B. The contents of the Glossary on page “E”.

The herbal extracts made “in the kitchen” may vary in composition according to their specific traditional usage as “bush-teas”.

Often a decoction or an infusion is made of 3 or 5 leaves per teacup of water. The “tea” may then be consumed thrice daily, for one week.

18. Herb-drug interactions

• This is a modern-day public health issue.The concern is that adverse interactions might

occur, when a conventional/prescription chemical drug is taken concomitantly with a herbal extract/preparation, because the latter also might contain bio-active ingredients.

See page “F” in the worksheetsSafety is of prime importance.

19. About TRAMIL and TRADIF (1)

• The Traditional Medicine in the Islands (TRAMIL) network of scientists has been researching folk medicinal plant usage in the Caribbean, since 1982.

TRAMIL is working towards scientific validation of the most used medicinal plant species, and also the “public diffusion” of this research work in books, statements, manuals, CDs, etc.

• But TRAMIL does not conduct clinical trials.

20. TRAMIL and TRADIF (2)A major publication of TRAMIL is the “Caribbean Herbal Pharmacopoeia” (2007)** an e-book which provides the profiles (as monographs) of the 99 most used folk medicinal plants and their extracts/preparations.

In this book, each plant is categorized as being either A – toxic (e.g. Lantana camara herb), or B – studies incomplete (e.g. Soursop leaf), orC -- validated as safe (e.g. Guava fruit).

21. (Safe?) TRAMIL dosages

According to the Caribbean Herbal Pharmacopoeia the usual dosage of a herbal extract (“bush tea”), for adults, consists of roughly 30 grams fresh plant part(s) per litre of water, taken 1 to 3 times per day, either as a 10-minute infusion for soft tissues (e.g. leaf), or as a 10-minute decoction for hard parts (e.g. bark). (See the Glossary on page “E”.).

22. The herbal pharmacopoeias

• The plant profiles (“monographs”) in the Caribbean Herbal Pharmacopoeia (of 2007) correspond to those published in the Indian Herbal Pharmacopoeia (from the 1960’s), in the British Herbal Pharmacopoeia (from the 1980’s), in the American Herbal Pharmacopoeia (from 1995), or in the African Herbal Pharmacopoeia (of 2010).

In each case, the objective/mission is to promote responsible use of the traditional herbal medicines in the particular country or region concerned.

In the “Table 1: Uses of medicinal plants supported by clinical data in WHO Monographs”, only 28 plant species are listed including the extracts from:- Aloe (for constipation), Ginger (for motion sickness), Turmeric (for flatulence), Senna (for constipation) and Valerian (as sedative). (HerbalGram. 1999. volume 47. pp. 41- 42).

23. Some herbs that work

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• A Bibliography is posted among the worksheets.

THANK YOU.