The “greening” of modern medicine

New categories of food and drug products

have entered the international market place.

Some are called “health foods”, and others

“botanicals”. Some are called nutraceuticals,

and are the refined food extracts or prepara-

tions designed to provide specific health

benefits. The use of herbal preparations has

also increased worldwide.

As a result of these actions today there is

increasing attention being paid to promoting

the responsible use of herbs and of herbal

medicinal products. For example, spreading

sound information about herbal products is a

major activity of the American Herbal Phar-

macopoeia (AHP). This body was formed in

1995 to produce documents called mono-

graphs, containing complete and critical re-

views of the traditional medicine and mod-

ern scientific literature describing the iden-

tity, quality, efficacy and safety of “the most

widely used” herbal medicinal agents. Docu-

ments of this kind are also published in other

countries, such as the British Herbal Com-

pendium, the German Commission E Mono-

graphs and the Indian Herbal Pharmaco-

poeia.

An article is written below on the sorrel as a

medicinal plant, which is partially based on

the German Commission E Monographs.

Such activities provide an indication of the

current “greening” of modern conventional

medicine.

Writing in a 2009 issue of the journal known

as Drugs, Professors Izzo and Ernst stated

that “the efficacy and safety of herbal me-

dicinal products can be tested in clinical tri-

als much like synthetic drugs, yet numerous

methodological and logistical problems ex-

ist. The therapeutic value of several herbal

medicines has been established; for many

others this is not the case, often because the

research has not been done”.

But there is dire need for more monographs

concerned with medicinal and food plants

which grow in the Tropics. This situation is

reflected in the book “Herbal Products:

Toxicology and Clinical Pharmacology”,

edited by Tracy, T.S. and Kingston, R.L.,

which was published by Springer in 2007.

This book is described as, “a comprehensive

resource for objective clinical information

about the potential uses, efficacy, and safety

of herbal medicines”; but its contents are

focused on the products of no more than

eighteen medicinal plants.

Inside this issue:

April, 2010 Volume 2, Issue2

C A R I B B E A N H E R B A L M E D I C I N E R E S E A R C H I N S T I T U T E

CaHMRI News

THE “GREENING” OF MOD-

ERN MEDICINE 1

THE SORREL AS A MEDICINAL

PLANT? 2

THE INTERACTIONS BETWEEN

HERBAL MEDICINES AND CONVENTIONAL (CHEMICAL) DRUGS

3

www.pharmainfo.net/pratyesh/ayurvedic-medicin...

taken in large amounts, because the acids are

difficult to be resorbed. The wine red colour

of the sorrel is due to its anthocyanin con-

stituents, which reach about one percent con-

tent in the calyx.

Anthocyanins are the coloured glycosides of

polyphenols of the flavonoid class. The an-

thocyanins in sorrel are mainly cyanidin gly-

cosides and delphinidin glycosides.

The safety of sorrel as a widely consumed

beverage is well-established.

Its medicinal properties may be separated

into three distinct categories. The first cate-

gory defines those of its therapeutic uses

which specifically are supported by good data

derived from clinical trials with human vol-

unteers. The second category describes those

uses supported in traditional systems of medi-

cine and sometimes documented in pharma-

copoeias and compendia. Those uses de-

scribed in the practices of folk medicine, but

which are not supported by experimental or

clinical data fall into the third category.

We shall describe some of the attributes of

sorrel which belong to the first category.

There is some good data derived from good

clinical trials which have been conducted

with human volunteers taking sorrel teas.

Recent scientific reports suggest that daily

consumption of sorrel tea, in an amount read-

ily incorporated into the diet, lowers blood

pressure in pre- and mildly hypertensive

adults (McKay D.L. et al. 2010).Two antho-

cyanin constituents of the sorrel calyx have

been shown to inhibit angiotensin converting

enzyme (ACE) activity (Ojeda D. et al.

2010); and such an effect can be correlated

with the hypotensive outcome.

Among the German Commission E Mono-

graphs (Bisset, N.G. 1994), the sorrel plant is

listed under the name as Hibisci flos. It is

included as a drug (or the nutraceutical) prod-

uct which comes from the calyx of Hibiscus

sabdariffa L. The calyx is the protective

layer that forms around the developing flower

of the plant, and Hibiscus sabdariffa is the

scientific name of the plant.

Other botanical names or synonyms some-

times are used for the plant, such as Abelmo-

schus cruentus Bertol, and Sabdariffa rubra

Kostel; and it belongs to the family known as

Malvaceae. A botanist would describe it as a

shrubby annual growing up to two metres

high, with or without hairs on the stems, its

leaves being deeply lobed, flowers solitary,

and the calyx up to two centimetres long in

flower, and increasing to become bright red

in fruit.

Sorrel is most probably of African origin, but

nowadays it is very widely distributed and

cultivated in many tropical countries around

the world, and not surprisingly, is known by

several local names. Some of these common

names are - Sour tea, Roselle, Red Sorrel,

Lozey, Lal-ambari, Karkade, Jamaica Sorrel,

Hibiscus, Guinea Sorrel and Florida Cran-

berry.

Numerous chemical constituents of the plant

are known. It contains organic acids (15-

30% in the calyx) including citric acid, malic

acid, and tartaric acid. Together with the

pectins and flavonoids and other polypheno-

lic glycosides in the calyx, these acids give

a pleasant and refreshing taste to sorrel

drinks. Sorrel tea is a mild laxative when

The Sorrel as a medicinal plant?

Page 2

Newsletter Title

SORREL TEA IS A

MILD LAXATIVE

WHEN TAKEN IN

LARGE AMOUNTS,

BECAUSE THE

ACIDS ARE

DIFFICULT TO BE

RESORBED.

No Caribbean herbal medicines seem to have been included in the book, except for those de-

rived from garlic and ginger.

Sorrel (Hibiscus sabdariffa)

www.rastaseed.com/…/2008/02/

rosella_sorrel.jpg

cont’d from page 1

The following introductory statements were

made by Professors Izzo and Ernst in their

2009 paper in the journal Drugs, -- which

was discussed above. “Approximately 38 million adults in the US (18.9% of the popu-

lation) use herbs or other natural supplements,

but only one-third tell their physician about

this use. This lack of information, combined

with the fact that herbal medicines are usually

a mixture of many active ingredients, in-

creases the likelihood of harm.”

In the journal article, the possible interactions

were critically reviewed between each of

seven popular herbal medicines (ginkgo, St. Johns Wort, ginseng, garlic, echinacea, saw

palmetto and kava) and conventional drugs.

The authors found that “numerous interac-

tions between herbal medicines and conven-

tional drugs have been documented” in the

biomedical literature. Garlic oil (of Allium

sativum) can cause prolonged bleeding when

taken with anti-coagulant (blood-thinning)

drugs, like warfarin. No interactions were

reported for saw palmetto (Serenoa repens).

Older adults have the highest per capita use of

prescription (chemical) medications, and therefore are at the greatest risk of harmful

herb-drug interactions.

In their paper, Izzo and Ernst noted that “the

study of herb-drug interactions is hindered by

the nature of herbal medicines. Invariably

(and by definition) these are not drugs with

only one pharmacologically active constituent.

Typically we are dealing with complex mix-

tures of dozens of potentially active princi-

ples. It seems obvious that this renders inves-tigations of herb-drug interactions more com-

plex than drug-drug interactions.”

The authors noted that current research into

herb-drug interactions is intense, and that it is

important that healthcare professionals are

well informed about this fast-expanding field.

The interactions between herbal medicines and conventional (chemical) drugs.

Page 3

Volume 2, Issue2

“APPROXIMATELY

38 MILLION ADULTS

IN THE US (18.9%

OF THE

POPULATION) USE

HERBS OR OTHER

NATURAL

SUPPLEMENTS, BUT

ONLY ONE-THIRD

TELL THEIR

PHYSICIAN ABOUT

THIS USE.

As so often stated, further research is warranted related to the bioavailability and potential

mechanism of action of sorrel teas as anti-hypertensive agents.

(REFERENCES: 1. Bisset NG (Editor). 1994. Max Wichtl Herbal Drugs and Phyto-

pharmaceuticals. (CRC Press, Boca Raton, Florida, USA); 2. McKay DL et al. 2010. Journal

of Nutrition, 140 (2): 298-303; 3. Ojeda D et al. 2010. Journal of Ethnopharmacology, 127:

7-10).

FUTURE ISSUES will include:

*News from the TRAMIL network

*Herbs for the cold season

*Natural and Traditional medicine in Cuba

*Legendary herbal aphrodisiacs

*Poisonous plants

To send us your comments

about this newsletter,

please contact;- The Herbal Institute at UTT at Tel: 1 (868) 640 0641 or compton.seaforth@utt.edu.tt or jennifer.paul@utt.edu.tt

cont’d from page 2