Medicinal plants. 'jamu' real or myth?

Medicinal plants. 'jamu' real or myth?

Bambang Kiranadi, Contributor, Bkiranadi@centrin.net.id

Experts have estimated that over 25 percent of the
prescriptions in the U.S. contain active ingredients from plants.
In Indonesia, medicinal plants have been widely used to remedy
some diseases.

Unfortunately, the efficacy of some plants and herbs have not
been documented. Pharmaceutical or biological tests on the drugs
have not been conducted, and details on the properties of
medicinal plants or herbs have yet to be understood.

Many plants have the potential to be made into drugs after
careful and sophisticated investigation. Digitalis is one such
example. It has been on the market since 1785 when William
Withering, a British physician, reported that taking dried leaves
from foxglove plants eased dropsy, an accumulation of fluid now
known to be caused by the heart's failure to function adequately.

The drug is known as digoxin or digitoxin, and is still widely
prescribed by doctors. The drug works by causing a blockage in a
sodium-potassium pump, which makes biologists Jens Skou and T.D.
Boyer earn the Nobel prize.

Similarly aspirin, made from the bark of the Filinpendula
ulmaria tree and then later synthesized by Hoffman has been
widely used since World War I for reducing pain and inflammation.
The drug's properties inhibit the formation of prostaglandin, the
culprit that causes pain and inflammation. Inhibiting
prostaglandin also has an effect on stopping blood from clotting,
thus preventing stroke.

By opening Pandora's box on how aspirin works also earned John
R. Vane Nobel prize. Another example is the shrub of the
Rauvolvia serpentina or Indian snakeroots, a traditional
treatment used by the people of India. It was discovered to be
reserpine, and it is still occasionally prescribed by doctors for
lowering blood pressure.

We can add more discoveries to the list of drugs that come
from plants, such as opiates for painkillers, quinine for
malaria, theopylline for opening bronchial passages and taxol for
cancer.

Basically, plants produce a chemical compound to be used for
an anti-predator or disease, which is also used for medicine.
Thanks to the development of analytical chemistry and organic
synthesis, scientists are capable of analyzing the compounds and
synthesizing some of them.

With the advent of modern biology some of the mechanisms of
how these components work in the body have been elucidated.

In tropical forests, such as in Indonesia, many plants with
potentially potent compounds for drugs are widespread but with
limited financial resources, it is impossible to screen their
biological activities extensively.

Since we understand the efficacy of medicinal plants from
tribes who have used them for generations, we have to start the
investigation of a potential drug through studying the belief of
what it can cure and interviewing the local healers, who can
choose the plants for pharmacological studies. The local healer
will be able to give clues to the biological activity of the
compound in the plants.

One notable result in using an ethnobotanical approach was the
hunt for a cancer drug compound from the plant Taxus brevifolia,
which produces taxol, and is used for the treatment of ovarian
cancer. It was approved by the U.S. Food and Drug Administration
(FDA) in 1994 for treating the metastasis of breast cancer.

Taxol worked in a different way than any other drug known at
that time. It bound the microtubules that played a crucial role
in cell division thereby curbing the process of cancer by
inhibiting uncontrollable cell division.

However, the plant that produces taxol grows very slowly and
scientists are hunting for a synthesis of the compound. The
ethnobotanical approach is also being used to search for a drug
to treat HIV. Special attention has been given to a plant called
Homalanthus mutants from Samoa, which contains a compound called
prostratin.

We can also approach the investigation through an ecological
survey, when plants survive in a very severe habitat or produce
molecules capable of affecting animals, then the toxic compound
might be capable of achieving a therapeutic effect.

What about Indonesian medicinal plants? Many have been widely
used by people in herbal remedies, such as jamu (herbal
medicine). Experts claim that plants such as bratawali (Tinaspora
crispa) could be a drug used to treat type two diabetes.
Unfortunately, we have not done enough to investigate the
medicinal properties of this compound to reduce the blood glucose
level.

The drug's properties that lower the blood glucose level do so
by either blocking the potassium channel or increasing the
sensitivity of the insulin receptor.

The belief that a mixture of kunyit (turmeric) and asam
(tamarind) aids in weight loss has attracted the attention of
many people. Based on the belief that losing weight is related to
a reduction in fat, this mixture is actually a potential drug
that can stop the absorption of lipids if we understand how it
works.

We understand that there is a drug that is isolated from
fungus called strepmyce toxytrini capable of reducing fat
absorption by up to 30 percent. It works by inhibiting the enzyme
lipase in the intestine.

Fat, which has a structure as a triglyceride, will not be
broken down into free fatty acids in the intestine, thereby
inhibiting the absorption of it. This drug is being used for
treating people with a high level of lipids and cholesterol in
the blood.

The arteries narrow as fatty acids and cholesterol accumulate
on the walls inside, and this is a major cause of stroke. To be
confident in using herbal medicine, we have to have information
on how this drug works in the body.

Traditional medicines are based on beliefs and healers, so to
utilize herbal remedies by using them in modern medicine and
synthesizing new drugs based on medicinal plants, there has to be
a good relationship between the healer and the scientist.

To locate the plants, healers should be treated as colleagues
and partners and not only as a source of information. The
partnership will have a greater impact on discovering the
medicinal plants needed for modern medicine.

Unfortunately, the traditional healer as a profession is not
attracting younger people. Healers do not have apprentices, and
when the healer dies, their knowledge is lost as well.

In the era of globalization, when the philosophy is to
maximize profit, the extraction of medicinal plants and their
extinction will be inevitable. Some western universities with a
good infrastructure, pharmaceutical companies and stockbrokers
could earn a lot of money from the knowledge given by traditional
healers.

Communities that have a history of using plants in traditional
medicine are a very good source of information as well as a
source for further studies on the effects of those medicinal
plants.

-- The writer is a senior lecturer at the Bogor Institute of
Agriculture (IPB) and a researcher at Unisosdem Jakarta.