Hoodia is a genus of 13 species in the flowering plant family Apocynaceae, under the subfamily Asclepiadoideae. They are stem succulents, described as "cactiform" because of their remarkable similarity to the unrelated cactus family. They can reach up to 1m high and have large flowers, often with flesh colour and strong smell.

Many Hoodia species are protected plants, typical of the Namib Desert, ranging from Central Namibia to southern Angola, especially in plains and rocky areas. Common names include "Bushman's Hat" and "Queen of the Namib".

Several species are grown as garden plants, and one species, Hoodia gordonii, is being investigated for use as an appetite suppressant.

On January 18, 2008, the Botanic Gardens Conservation International (representing botanic gardens in 120 countries) stated that "400 medicinal plants are at risk of extinction, from over-collection and deforestation, threatening the discovery of future cures for disease." These included Yew trees (the bark was used for cancer drugs, paclitaxel, although current licensed syntheses do not); half of Magnolias (used as Chinese medicine for 5,000 years to fight cancer, dementia and heart disease); and Autumn crocus (for gout) and Hoodia. The group was said to have found that five billion people rely upon traditional plant-based medicine for health care.

Hoodia is currently listed in Appendix II to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which includes species not currently considered endangered but are at risk if trade is not controlled.

History

The use of Hoodia has long been known by the indigenous populations of Southern Africa, who infrequently use these plants for treating indigestion and small infections. However, it is their centuries old use of the meat of the plant to suppress appetite when making long hunting trips in the Kalahari Desert that has stimulated the most interest.

In 1977, the South African Council for Scientific and Industrial Research (CSIR) isolated the ingredient in hoodia?now known as P57?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. Paul Hutson, associate professor in the University of Wisconsin-Madison School of Pharmacy, told the Wisconsin State Journal, "For Pfizer to release something dealing with obesity suggests to me that they felt there was no merit to its oral use". Pfizer states that development on P57, the active ingredient of Hoodia, was stopped due to the difficulty of synthesizing P57. Jasjit Bindra, lead researcher for hoodia at Pfizer, states there were indications of unwanted effects on the liver caused by other components, which could not be easily removed from the supplement, adding "Clearly, hoodia has a long way to go before it can earn approval from the Food and Drug Administration (FDA). Until safer formulations are developed, dieters should be wary of using it."

In 2002, CSIR officially recognized the San tribespeople's rights over Hoodia, allowing them to take a percentage of the profits and any spin-offs resulting from the marketing of Hoodia.[5] Hoodia gordonii is a protected plant which may only be wild-harvested by individuals and the few companies who have been granted a license.

Scientific study

There is no published scientific evidence that Hoodia works as an appetite suppressant in humans. The safety and/or effectiveness of Hoodia Gordonii as a dietary supplement must thus be considered as unsubstantiated.

Animal research on hoodia includes one published scientific study in which a purified extract of Hoodia Gordonii, known as P57, was injected directly into the brains of rats. The author of the rat study said that P57 was easily broken down by the liver, so it might be hard to take in enough of it to ensure that it had an effect. MacLean cautioned that currently available supplements might be inadequate, stating "I question whether there is really enough of the active ingredient in there to do much."

Richard M. Goldfarb, MD, a doctor and medical director of Bucks County Clinical Research in Morrisville, Pennsylvania, claims to have conducted a preliminary efficacy study of Hoodia gordonii on seven people and reports to have found it effective. This very small trial was reportedly sponsored by a Hoodia manufacturer and none of the findings were ever published in any peer-reviewed journal. Such information cannot be considered as evidence that hoodia is effective as a weight loss product.

Other medical weight loss experts remain skeptical and do not recommend hoodia to obese patients. Adrienne Youdim, MD, medical director of the Comprehensive Weight Loss Program at Cedars-Sinai Medical Center and Michael Steelman, MD, chairman of the board of trustees for the American Society of Bariatric Physicians says "There is no [published scientific] data to support its use." In addition, the FTC recommends against the use of such diet products marketed with exaggerated claims.

Authentication

As Hoodia gordonii is a species threatened with extinction if international trade is not monitored, it is listed under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) and is illegal to export from Africa without a CITES certificate being issued by proper authorities.

In the USA, the Fish and Wildlife Service (FWS), United States Department of Agriculture (USDA) and United States Customs Service (part of the Department of Homeland Security) regulate the importation and re-exportation of species such as Hoodia gordonii. Current U.S. laws stipulate that not only must a CITES certificate accompany shipments of Hoodia gordonii but that the importers must possess a permit issued by the USDA to import Terrestrial Plants. In order to re-export H. gordonii, you must apply for a CITES re-export certificate.

In addition to looking for a copy of a CITES and USDA permit from a manufacturer of "Hoodia" products a consumer should also look for a report from an independent testing lab which has conducted scientific analysis on the product in question, testifying that they have been able to authenticate the presence of Hoodia gordonii.

The primary testing methods for authenticating Hoodia gordonii are:

?HPTLC

?HPLC

?Microscopy /DPI

?P57

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, North Carolina, Alkemist Pharmaceuticals, Chromadex Labs of Costa Mesa, California, 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.