Botanicals to Promote Weight Loss

References

Hoodia, Coleus and green tea may help reduce appetite, increase energy and promote thermogenesis and lipolysis, according to both research studies and history of traditional use.

As a succulent, Hoodia species have long been used as thirst quenchers and appetite suppressants, and are themselves adept at storing moisture during long dry spells in their native habitats. One of the earliest recorded accounts of Hoodia’s effectiveness noted, “When on one occasion thirst compelled me to follow the example of my Hottentot guide, it saved further suffering and removed the pangs of hunger so efficiently that I could not eat anything for a day after having reached the camp.”¹

The most popular species currently used in dietary supplements is Hoodia gordonii. Hoodia’s rise to fame in Western culture is a result of stories about how the San tribe of Southern Africa Bushmen would consume this plant when they went on hunts and how the Hoodia was able to suppress their appetite and give them energy. According to one study, the San hunters find Hoodia, “when eaten even in small quantities, causes the sensation of hunger to cease.”²

The stories led South Africa’s Council for Scientific and Industrial Research (CSIR) to investigate the plant’s effects.³ Subsequent animal research demonstrated that an extract from the plant was highly effective in reducing weight; and in 1997, CSIR approached the British firm Phytopharm to collaborate in developing the active ingredient, P57, into a prescription drug. Global marketing of P57 is not expected until 2008.⁴ Meanwhile, CSIR holds a U.S. patent on the process for obtaining the Hoodia extract, a process for synthesizing the P57 compound, and the use of the extracts and compound as a medicine for appetite suppressant activity.⁵

Naturally, with all of the Hoodia excitement being generated, it wasn’t long before consumers started asking for Hoodia products. Unfortunately quality and supply issues are vexing the market. Information supplied by ChromaDex suggested up to half of “Hoodia” dietary supplements may not contain any actual Hoodia. In fact, if the price seems too good to be true, it probably is, as Hoodia can be a very expensive ingredient.

An interesting aspect of Hoodia’s popularity is that there is actually little published in vivo research on this botanical, and no published human clinical research, although there is some unpublished data. For example, in a company-sponsored, unpublished study of lean and obese rats, the animals fed Hoodia voluntarily decreased their food intake by almost half within 48 hours, and there was a 15-percent decline in blood glucose, compared to control animals.⁶ After three weeks of Hoodia intake, the obese rats—which at baseline had been twice as large as lean rats—were near normal weight; lean rats had a 29-percent weight reduction.

Phytopharm conducted a proof-of-principle study of P57 in humans, which has been discussed, but not published.⁷ During this double blind, placebo-controlled trial, 60 patients participated in an assessment of safety, tolerability and pharmacokinetics of both ascending single doses and repeated dosing in healthy overweight volunteers, as well as the effects of calorie intake in overweight men who took the compound or placebo twice daily for 15 days. The reported results were that men in the treatment group achieved a 30- percent reduction in calorie intake, accompanied by a significant reduction in body fat content by 1 kg. And in a case study report from Pennsylvania, seven overweight subjects given 400 mg of Hoodia twice daily (one hour prior to lunchtime and one hour prior to dinner) had a median weight loss of 10 pounds over a period of one month.⁸

Since Hoodia is not a stimulant like caffeine or ephedrine, how does it exert its appetite suppression properties? It appears that P57 increases the content of ATP (the “energy currency” of the body) by 50 to 150 percent in the hypothalamus region of the brain, which may, in turn, trigger the appropriate neural, endocrine and appetite control responses.⁹ The increase in ATP may also help explain Hoodia’s endurance-enhancing effects in San tribesman during traditional hunts.

Coleus (Coleus forskohlii) is an herb used in Ayurvedic medicine. Its active principle is a diterpene known as forskolin. The medicinal uses of Coleus include various types of cardiovascular disease, glaucoma, asthma and digestive insufficiency.¹⁰ With regard to weight loss, coleus has been shown to promote lipolysis (the breakdown of fat in the fat cells) and weight loss.

In one study, six obese women were given 250 mg Coleus, standardized for 10 percent forskolin (as ForsLean®, from Sabinsa Corp.), twice daily for eight weeks.¹¹ The women maintained previous daily physical exercise and eating habits, and showed an average weight loss of 9 pounds, almost an 8-percent reduction in percentage body fat, and a 4.23-percent increase in percentage of lean mass. Similar results were reported in a larger, double blind, randomized study, in which 30 overweight and obese men were given the same dose of coleus as in the previous study, or a placebo, for 12 weeks.¹² At the end of the study, men taking coleus showed a significant 11-percent decrease in body fat percentage, an almost 6-percent increase in lean mass, and a 17-percent increase in total testosterone.

In a third 12-week, double blind study, 19 mildly overweight women were give the same dose of coleus as in the previously cited studies.¹³ However, in this study, neither the coleus group nor the placebo group lost weight, although the coleus group did experience less hunger and less fatigue. In addition, subjects taking coleus were successful at preventing weight gain.

Considering the science, it appears 250 mg of Coleus given twice daily is effective in treating overweight and obese individuals, but not in mildly overweight individuals.

Much has been written elsewhere about the value of green tea (Camellia sinensis) from a health perspective; therefore, this article will only briefly review its weight loss properties. The active principles in green tea are its catechins and caffeine. Research has demonstrated green tea is capable of stimulating thermogenesis and promoting fat oxidation; in other words, it helps burn body fat.

In one three-day study, subjects given green tea providing 270 mg catechins and 150 mg caffeine daily experienced a significant increase in energy expenditure (i.e., calories burned).¹⁴ During the course of another three-month study, subjects given the same dose of green tea decreased their body weight by 4.6 percent and their waist circumference by 4.48 percent.¹⁵ And another three-month study found subjects given the same dose of green tea were better able to maintain their weight loss and continue losing weight after intervention.¹⁶

"Botanicals to Promote Weight Loss" References

1. Wynberg R. "Rhetoric, Realism and Benefit Sharing: Use of Traditional Knowledge of Hoodia Species in the Development of an Appetite Suppressant." J World Intell Prop. 7, 6:851-876, 2004.

2. Cairns E. "Obesity: The fat lady sings?" Drug Discovery Today. 10, 5:305-307, 2005.

3. Habeck M. "A succulent cure to end obesity." Drug Discovery Today. 7, 5:280-281. 2002.

4. Archer RH, Victor JE. "Hoodia pilifera subsp. pillansii: Apocynaceae: Asclepiadoideae." Curtis's Botanical Magazine. 20, 4:219-224, 2003.

5. Van Heerden FR et al. "Pharmaceutical compositions having appetite suppressant activity." Official Gazette of the United States Patent and Trademark Office. 1257(4), 2002. U.S. Patent No. 6376657.

6. Tulp OL, Harbi NA, DerMarderosian A. "Effect of Hoodia plant on weight loss in congenic obese LA/Ntul//-cp rats." FASEB J. 16, 4:pA648, 2002.

7. Habeck M. Op cit.

8. Goldfarb RM, Miller DJ. "Hoodia Gordonii (DEX-L10 Certified) an Appetite Suppressant: Positive Effects on Weight Loss – A Case Study Report of 7 Participants." Bucks County Clinical Research Inc. July 25, 2004; 3 pages.

9. MacLean DB, Luo LG." 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 Res. 1020, 1-2:1-11, 2004.

10. Bone K. Clinical Applications of Ayurvedic and Chinese Herbs: Monographs for the Western Herbal Practitioner. Warwick, Australia: Phytotherapy Press; p. 103-107.

11. Badmaev V et al. "Diterpene Forskolin (Coleus forskohlii, Benth.): A possible new compound for reduction of body weight by increasing lean body mass." NutraCos. March/April: 6-7, 2002.

12. Godard M, Johnson B, Richmond S. "Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men." Obesity Res. 13, 8:1335-1343, 2005.

13. Henderson S et al. "Effects of Coleus Forskohlii Supplementation on Body Composition and Hematological Profiles in Mildly Overweight Women." J Intl Soc Sports Nutr. 2, 2:54-62, 2005.

14. Dulloo A et al. "Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-hour energy expenditure and fat oxidation in humans." Am J Clin Nutr. 70:1040-5. 1999.

15. Chantre P, Lairon D. "Recent findings of green tea extract AR25 (Exolise) and its activity for the treatment of obesity." Phytomedicine. 9:3-8, 2002.

16. Westerterp-Plantenga MS, Lejeune MPGM, Kovacs EMR. "Body Weight Loss and Weight Maintenance in Relation to Habitual Caffeine Intake and Green Tea Supplementation." Obes Res. 13, 7:1195-1205, 2005.

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