Hoodia Gordonii
Common Name: Hoodia
Scientific Name: Hoodia Gordonii (Masson) Sweet ex Decne
Plant Family: Apocynaceae
Sub-Family: Asclepiadoideae
Other Common Names: Ghaap, Hoodia “cactus”, South African “desert cactus”,Xhoba
Native: Africa - Southern Africa (Namibia), South Africa (Cape Province, Orange Free State)
Temperature Zone: USDA: 10-11
Frost Tolerance: Hardy to 28°F (-2°C)
Sun Exposure: Light shade, morning sun
Growth Habits: Succulent, forming clumps of 12 inches tall, 12 inches wide (30 by 30 cm)
Propagation: Cuttings
Flowering: Large disk shaped flowers, with a very unpleasant smell.
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The term “cactus” is a misnomer to Hoodia Gordonii species by many individuals, as well as by some commercial herbal and nutritional supplement companies. Hoodia Gordonii is a succulent and not a cactus. Several species of spiny, succulent plants belonging to the genus Hoodia are found
in the arid parts of Southern Africa. The species of Hoodia resembles cacti, but
belong to a different sub family, the Asclepiadoideae, commonly known as the dogbane
or milkweed family.
Hoodia Gordonii is a succulent that is well known to the indigenous populations of
Southern Africa, who often use this plant for treatment of common ailments like
indigestion and minor infections. The San bushmen of the Kalahari desert have used
Hoodia plants for variety of foods for many centuries. However, the species Hoodia
Gordonii is used less often because it has a bitter lingering taste, which is a bit
unpleasant. In times of hardship and during long expeditions away from home, it is
sometimes eaten by the Bushmen.
The South African Council for Scientific and Industrial Research (CSIR) included
certain species of Hoodia plants in a research project to study a large number of
bush foods. As a part of the study, extracts of plants were made and tested for their
toxic effects. It was discovered that, quite surprisingly, Hoodia Gordonii extracts
caused a decrease in appetite and body weight in animals and this did not appear to
be the result of the toxic nature of the plants. CSIR identified the ingredient in
Hoodia that is responsible for the appetite-suppressant effects. This substance is
now known as P57.
Phytopharm, a United Kingdom based company, acquired a license from CSIR and
collaborated with one of the leading pharmaceutical companies in the world, Pfizer,
to isolate the active ingredient (P57) in Hoodia Gordonii responsible for appetite
suppressant effect. However, in 2002, Pfizer released the rights to the primary
ingredient indicating the difficulty in synthesizing P57 as the reason.
On 24th March 2003, the CSIR and South African San Council announced that they
reached an agreement where they officially recognised San people’s rights over
Hoodia. Under the agreement, “the CSIR will pay the San eight percent of all
milestone payments it receives from its licensee, UK-based Phytopharm plc, as well
as six percent of all royalties that the CSIR receives once the drug is commercially
available. Milestone payments are subject to agreed technical performance targets of
P57 during its clinical development over the next three to four years, and royalties
are based on sales, which are not set to commence before 2008. This benefitsharing
model ensures that the San will receive equitable benefits if the drug is
successfully commercialised, and is based on established international benefitsharing
models for the pharmaceutical industry. Factors such as the size of the
global anti-obesity market and the percentage of total market that the potential new
drug could capture, are typically factors which determine the translation of the royalty
percentage into monetary value.
Hoodia Gordonii is a now protected plant and can only be harvested by individuals
and companies who have been granted a license. In October 2004, following a
review at a Conference of Parties in Bangkok it was decided to include Hoodia onto
Appendix II of CITES. This will help ensure that all harvest operations and trade of
Hoodia plant material are controlled at an international level in order to conserve
indigenous plant populations within the range states (South Africa, Namibia and
Botswana). CITES (Convention on International Trade in Endangered Species of
Wild Fauna and Flora) is an international agreement between governments to ensure
that international trade in specimens of wild animals and plants does not threaten
their survival. There are 166 Parties (States bound by the Convention). Species
covered by CITES are listed in three appendices. Appendix II includes species not
necessarily threatened with extinction, but for which trade must be controlled in order
to avoid utilisation incompatible with their survival.
In the last 2-3 years, there has been immense press on Hoodia Gordonii and
supplements created from the plant. Not all the news has been positive and several
press articles have tried warn people on not the plant itself, but on the authenticity of
the products created from Hoodia.
Hoodia P57 is the ingredient in Hoodia plant identified by Council for Scientific and Industrial Research (CSIR) that is responsible for appetitie suppressant effects. Phytopharm, a United Kingdom based company, acquired a license from CSIR and
collaborated with one of the leading pharmaceutical companies in the world, Pfizer,
to isolate the active ingredient (P57) in Hoodia Gordonii responsible for appetite
suppressant effect. However, in 2002, Pfizer released the rights to the primary
ingredient indicating the difficulty in synthesizing P57 as the reason.
Some researchers believe they have pinpointed the active constituent(s) responsible
for hoodia’s appetite-suppressant actions, without much investigation into the plant’s
other potential mechanisms of biological action. However, hoodia’s active
constituent(s) may have only been partially identified. Government researchers in
South Africa have focused attention on the sterol glycosides. Part of a group of
naturally occurring substances called cardenolides; glycosides are best known for
their effects on cardiac function. However, measurable effects on Na/KATPase, the
target of action of cardiac glycosides, are not believed to be associated with the
administration of Hoodia.
One prevailing hypothesis implies steroidal glycosides act directly upon the
hypothalamus, triggering a message that blood glucose is high. This is an effect
related to the glucostatic mechanism of weight control. Animal experiments found
intracerebroventricular injection of Hoodia extracts (termed “P57AS3” by Phytopharm
PLC) resulted in increased ATP content or production in the hypothalamus, which
may be a signal for the energy sensing of satiety. Specific receptors for the steroidal
glycoside (P57) have not been identified in the rat brain, but administration of these
compounds into the brain reduces food intake by a factor of up to 60 percent and
increases the content of ATP hypothalamic neurons of the rat by up to 150 percent.
The sensing of energy input by the hypothalamus may be signalled by increases in
intracellular neuronal energy, in the form of ATP. One such study was carried out in
2004 at Division of Endocrinology at Brown Medical School, RI, USA, proving the
above hypothesis.
These animal experiments suggest one potential mechanism of action of Hoodia
components on brain signals that may regulate appetite, hunger or thirst; but there
are many complex factors that control feeding behaviors operating through many
messenger molecules.
As of 2007 there are four independent labs which are conducting tests to verify
Hoodia gordonii in consumer products. They are: Advanced Laboratories, Inc. in
Smithfield, NC, Alkemist Pharmaceuticals, Chromadex Labs of Costa Mesa, CA. and
The University of Mississippi. The American Herbal Products Association (AHPA) is
also working on a Hoodia Standard which is believed to be available in the industry in
late 2007 in response to scrutiny by the Federal Trade Commission of the Hoodia
industry and complaints by consumers of fraudulent Hoodia products being
marketed.
Clinical Trials on Humans
There have been no published peer-review double-blind clinical trials on humans
to investigate the safety of Hoodia Gordonii in the form of pills as a natural
supplement.
A clinical trial conducted by Phytopharm demonstrated that taking large doses of
Hoodia Gordonii extract repeatedly caused a significant decrease in daily calorie
intake. Phytopharm claims that the calorie intake decreased by approximately
1000 cal per day, by day 15 of the trial. However, the quantity of Hoodia Gordonii
extract taken has not been published by Phytopharm.
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