Hoodia gordonii

From Wikipedia, the free encyclopedia - View original article

Hoodia gordonii
Hoodia gordonii
Scientific classification
Kingdom:Plantae
(unranked):Angiosperms
(unranked):Eudicots
(unranked):Asterids
Order:Gentianales
Family:Apocynaceae
Subfamily:Asclepiadoideae
Tribe:Stapeliae
Genus:Hoodia
Species:H. gordonii
Binomial name
Hoodia gordonii
(Masson) Sweet ex Decne., 1844
 
Jump to: navigation, search
Hoodia gordonii
Hoodia gordonii
Scientific classification
Kingdom:Plantae
(unranked):Angiosperms
(unranked):Eudicots
(unranked):Asterids
Order:Gentianales
Family:Apocynaceae
Subfamily:Asclepiadoideae
Tribe:Stapeliae
Genus:Hoodia
Species:H. gordonii
Binomial name
Hoodia gordonii
(Masson) Sweet ex Decne., 1844

Hoodia gordonii is a leafless spiny succulent plant with medicinal properties. It grows naturally in South Africa and Namibia. The flowers smell like rotten meat and are pollinated mainly by flies. The indigenous Bushmen[which?] call this plant ǁhoba (pronounced [kǁʰɔbɑ] - the initial sound is a lateral click) - and the Afrikaans Ghaap.

Hoodia gordonii was discovered and painted by col. Robert Jacob Gordon in the vicinity of the Orange River in about 1779, and identified as a Stapelia, a closely related genus.

Contents

Medicinal properties

The use of Hoodia spp. has long been known by the indigenous populations of Southern Africa, who infrequently use these plants for treating indigestion and small infections. But it is their centuries-old use of the meat of the plant to suppress appetite on 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.[1] 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".[2] Pfizer states that development on P57, the active ingredient of hoodia, was stopped due to the difficulty of synthesizing P57.[3] 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."[4]

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.[6]

Painting of Hoodia gordonii by Robert Jacob Gordon

Scientific study

Appetite Suppression

There is no published scientific evidence that hoodia works as an appetite suppressant in humans. 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.[7] 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."[8] However, upon further review and in vitro experimentation it was found that P57AS3 was generally not inhibited metabolically by human liver enzymes and has a relatively high secretion rate.[9]

Given standardization techniques and the likely passage of the active ingredient into the blood stream and relatively stable metabolism by the liver,[9] one can estimate the oral dosage required to achieve the amount of active ingredient which will likely to be passed to the brain where it is thought the ATP availability in the hypothalamus regulates appetite.[7]

Other medical weight loss experts remain skeptical. 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."[10] In addition, the FTC recommends against the use of such diet products marketed with exaggerated claims.[11]

Gastric Acid Reduction

Gastric acid production is inhibited by P57, the active molecule found in Hoodia gordonii,.[12] The study found that standardized extract P57SD at 50 mg/kg reduced gastric acid output in the stomach by 40-60%. The experiments were in vivo with control populations of rats, as well as in vitro.

Authentication

As Hoodia gordonii and the whole genus Hoodia are threatened with extinction if international trade is not monitored, the genus is listed under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), at Appendix II, and it is illegal to export plant material in any form 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 and Border Protection (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. a CITES re-export certificate is needed to re-export H. gordonii.

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:

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 Irvine, California, and the University of Mississippi. The American Herbal Products Association (AHPA) completed work in 2009 establishing the defacto industry standard for Hoodia authentication in response to scrutiny by the Federal Trade Commission of the hoodia industry and complaints by consumers of fraudulent hoodia products being marketed.

Media coverage

The BBC reported on the Hoodia gordonii plant in 2003.[13] On November 21, 2004, 60 Minutes aired a report on the effectiveness of the Hoodia gordonii plant as a natural appetite suppressant.[14]

Prior to this 60 Minutes report, there were a total of three hoodia products on the U.S. market and Hoodia gordonii was being sold by African farmers at US$13 per kilogram. In 2007, there were an estimated 300 products being sold worldwide being touted as "authentic Hoodia gordonii" with a street rate for Hoodia gordonii at $250 per kilogram on average. As of November 2008, the street price of Hoodia gordonii has dropped to $130/kg for wildcrafted Hoodia gordoni and an estimated $85 for cultivated Hoodia gordoni material.

The media coverage and heavy marketing by nutritional supplement companies that followed those reports have created such a demand for Hoodia spp. plants that a protected status was imposed in several countries like Namibia. Many products claiming to contain Hoodia spp. do not actually contain the active ingredient alleged to suppress appetite. An ongoing review of hoodia pills by Alkemists Pharmaceuticals found that at least half of the products advertised as containing hoodia contained none.[15]

In March 2006, Consumer Reports investigated the dietary supplement and concluded, "This weight loss drug lacks the clinical evidence for the Consumer Reports experts to recommend this product."[16]

Marketing and spam

Lack of scientific evidence or regulatory approval have not stopped dietary supplement companies from marketing Hoodia gordonii supplements with claims that it can lower blood pressure and reduce the appetite. Goen Technologies Corporation's TrimSpa unit began marketing Hoodia gordonii under the brand name X32 with celebrity spokesperson Anna Nicole Smith, even though the FDA has notified Trimspa in a Warning Letter that it has not demonstrated that claims for their product are scientifically supportable.[17] Health Canada has not approved any hoodia products for sale.[18] However, they are sold in natural health stores. Goen Technologies has also been sued by the state of New Jersey for misleading consumers.[19] The Trimspa brand is currently the subject of a lawsuit in California which claims that it does not contain any of Hoodia's active ingredient.[15]

In December 2004, Unilever entered into an agreement with Phytopharm to start marketing Hoodia gordonii commercially in the form of shakes and diet bars although as of April 2007 no products have yet surfaced on the consumer market from that venture.[20]

Between March and June 2006, millions of E-mail spam and forum messages were sent out concerning hoodia, ostensibly offering hoodia extracts for weight control purposes. The Federal Trade Commission has logged numerous complaints of consumer fraud associated with hoodia and the number is expected to continue to rise.[15]

On July 1, 2006, it was reported on entertainment news show Extra that a company is now marketing hoodia-enhanced lollipops called PowerPops.[21]

On November 14, 2008, Unilever pulled out of deal with Phytopharm to continue commercial development of Hoodia. A document on Unilever's website entitled "Sustainable Development 2008: An Overview," and signed by Paul Polman, CEO, contains the following statement: "Innovation also carries uncertainties and does not always lead to a positive outcome. During 2008, having invested 20 million [pounds] in R&D, Unilever abandoned plans to use the slimming extract hoodia in a range of diet products. We stopped the project because our clinical studies revealed that products using hoodia would not meet our strict standards of safety and efficacy." Page 12.

Hoodia gordonii products are currently being marketed in a variety of formats to include: capsules, tablets, liquid tinctures, tea, coffee, syrups, protein shakes and even diet fruit bars.

In October 2009, Santa Cruz County District Attorney Bob Lee joined colleagues from several other counties in a lawsuit against three companies who allegedly make false claims that their diet supplements contain extract from the African hoodia plant. The lawsuit filed in Solano County, states that Dex L-10 by Delmar Labs, Breakthrough Engineered Nutrition and Geopharma produce products with packaging and advertising that claim to contain Hoodia Gordonii when they contain little or none of it.[22]

References

  1. ^ Dixon, Robyn (December 26, 2006). Hoodia fever takes a toll on rare plant. Los Angeles Times.
  2. ^ Rath, Jay. "New Drug Tempting Dieters, But Experts Debate Hoodia's Merits". Wisconsin State Journal, September 5, 2005, D1.
  3. ^ Morris, Joan. "Little research behind claims that hoodia is safe, effective for losing weight". Seattle Times, March 9, 2006.
  4. ^ Bindra, Jasjit. "A Popular Pill's Hidden Danger", The New York Times, April 26, 2005.
  5. ^ Council for Scientific and Industrial Research (24 March 2003) The San and the CSIR announce a benefit-sharing agreement for potential anti-obesity drug.
  6. ^ Thompson, Ginger (April 1, 2003). "Twee Rivieren Journal; Bushmen Squeeze Money From a Humble Cactus". The New York Times.
  7. ^ a b MacLean DB, Luo LG (September 2004). "Increased ATP content/production in the hypothalamus may be a signal for energy-sensing of satiety: studies of the anorectic mechanism of a plant steroidal glycoside". Brain Research 1020 (1–2): 1–11. doi:10.1016/j.brainres.2004.04.041. PMID 15312781. 
  8. ^ Duenwald, Mary (April 19, 2005) "An Appetite Killer for a Killer Appetite? Not Yet." The New York Times.
  9. ^ a b Madgula VL, Avula B, Pawar RS, et al. (August 2008). "In vitro metabolic stability and intestinal transport of P57AS3 (P57) from Hoodia gordonii and its interaction with drug metabolizing enzymes". Planta Medica 74 (10): 1269–75. doi:10.1055/s-2008-1074580. PMID 18612942. 
  10. ^ Kathleen Doheney, "Hoodia: Lots of Hoopla, Little Science; Few studies support the promise of the South African appetite suppressant, but believers abound", WebMD, September 6, 2006, Reviewed by Louise Chang, MD (last accessed March 24, 2007).
  11. ^ Weighing the Evidence in Diet Ads, US Federal Trade Commission
  12. ^ [1], Patent # 6808723, Gastric acid secretion, John Hakkinen et al
  13. ^ Mangold, Tom. "Sampling the Kalahari Hoodia diet". BBC Correspondent, May 30, 2003.
  14. ^ Stahl, Lesley. "African Plant May Help Fight Fat". CBS News 60 Minutes, November 21, 2004.
  15. ^ a b c Engelhaupt, Erika (July 9, 2006). "But do Hoodia diet pills actually work? Diet miracle from an African plant is a spam special". The Philadelphia Inquirer.
  16. ^ "Hoodia: lose weight without feeling hungry?" (Subscription required) Consumer Reports 2006 Mar; 71(3):49.
  17. ^ US Food and Drug Administration (March 26, 2004). "Warning Letter for Weight Loss Products 'TrimSpa Carb Blocker' and 'TrimSpa Fat Blocker'"
  18. ^ Hawaleshka, Danylo. "Hoodia love: An appetite suppressant used by Bushmen is the diet world's newest fad". Macleans, August 3, 2005.
  19. ^ New Jersey Office of the Attorney General (October 16, 2003). New Jersey Sues Founder of Goen Seminars.
  20. ^ Tomlinson, Heather, "Prickly solution to obesity?", The Guardian Weekly, (undated).
  21. ^ "Lick Away Weight with Power Pops", ExtraTV.com, May 30, 2006.
  22. ^ Santa Cruz, other DAs sue manufacturers of weight loss products, Santa Cruz Sentinel, October 1, 2009

External links