Essiac
Flor•Essence
The Individual Herbs of Essiac and Flor•Essence

Essiac

In 2004, a mixture of the Essiac herbs showed a decreased proliferation in a prostate cancer cell line.[1] No other results of laboratory ( in vitro ) or animal ( in vivo ) studies of Essiac have been reported in the peer-reviewed scientific literature. Brief descriptions of three series of animal experiments, however, are available. Reviewed in [2]

In the mid-1970s, the developer submitted both dried and liquid samples of Essiac to the Memorial Sloan-Kettering Cancer Center in New York City for evaluation of its immunotherapeutic and chemotherapeutic potential. Reviewed in [2] No immunostimulatory or chemotherapeutic activity was detected in eight animal experiments that utilized the S-180 mouse sarcoma tumor model.

In the early 1980s, the corporation that acquired the four-herb recipe for Essiac from the developer submitted another sample to the Memorial Sloan-Kettering Cancer Center for evaluation in additional animal studies. No anticancer activity was detected in 17 separate experiments that utilized a variety of animal leukemia and tumor models. Reviewed in [2]

In 1983, the National Cancer Institute tested a liquid sample of Essiac that was provided by the manufacturer after the Canadian Department of National Health and Welfare (Health Protection Branch) requested that it be tested in animals. Reviewed in [2] These studies revealed no anticancer activity in the mouse P388 lymphocytic leukemia tumor system and found lethal toxicity at the highest concentrations of Essiac administered to test animals. It is not known, however, how the concentrations used in these animal tests compare with those achieved in humans after the consumption of the manufacturer's recommended doses.

There are conflicting results in the peer-reviewed literature. One study suggests that Flor•Essence enhances tumor growth in vitro, a finding that is contradictory to the widely available anecdotal evidence that this product suppresses or inhibits tumor development.[3] Another study suggests that the growth of human breast cancer cells is stimulated through estrogen receptor (ER)–mediated as well as ER–independent mechanisms of action from Flor•Essence and Essiac herbal tonics.[4] A third study demonstrated antiproliferative and differentiation-inducing properties in vitro only in high concentrations of Essiac and Flor•Essence herbal teas.[5]

The 2004 in vivo study of Flor•Essence in a rat model looked at mammary tumor development following administration of the herbal compound. Sprague-Dawley rats (N = 112) were assigned to one of three groups. The control group (n = 35) received water only. The second group (n = 40) received 3% Flor•Essence in their drinking water in an attempt to provide a dose equivalent to that recommended in the popular literature. The third group (n = 37) received 6% Flor•Essence in their drinking water to investigate the dose-response relationship. Mammary tumors were induced by a 40 mg/kg/bw dose of 7,12-dimethylbenz(a)anthracene. At 19 weeks, palpable mammary tumor incidence was greater (65% and 59.4%) in both Flor•Essence groups compared with controls (51%). Terminal necropsy was performed at age 23 weeks or when tumor burden became too great. Results showed mammary tumor incidence was 82.5% for controls compared with 90% and 97.3%, respectively, for rats consuming 3% and 6% Flor•Essence.[3]

Laboratory and animal experiments have shown that some of the chemicals in the herbs used to make Essiac and Flor•Essence have antioxidant, anti-inflammatory, estrogenic, or anticancer activity. Reviewed in [6-14]

Among the herbs used in both mixtures, burdock root (Arctium lappa L.) contains several flavonoids and polyphenols that have shown antioxidant activity; Indian rhubarb root (Rheum palmatum L.) contains several anthraquinones, including emodin and aloe-emodin, which have demonstrated anti-inflammatory and cytotoxic effects; sheep sorrel (Rumex acetosella L.) contains several types of anthraquinones, including emodin and aloe-emodin, as well as phytoestrogens, which may possess both procancer and anticancer activity; and slippery elm bark (Ulmus fulva Michx.) has been shown to contain antioxidants. Reviewed in [6-12]

Among the herbs found in Flor•Essence alone, watercress (Nasturtium officinale R.Br.)contains phenethyl isothiocyanate (PEITC), which has shown cytotoxic and antitumor activities; blessed thistle (Cnicus benedictus L.) contains cnicin, which is a sesquiterpene lactone that has demonstrated cytotoxic, antitumor, and anti-inflammatory effects, and arctiin and arctigenin, which are lignans that have shown anticancer activity; red clover (Trifolium pratense L.) contains a complex mixture of phytoestrogens including genistein, which has demonstrated antiangiogenic, estrogenic, and procancer and anticancer effects (depending on the dose); and extracts of kelp (Laminaria digitata [Hudson] Lamx.) have shown immunostimulatory and antitumor activities. Reviewed in [6,7,10,11,14]

Whether equivalent concentrations of relevant molecules can be achieved in the bloodstream of individuals who consume Essiac or Flor•Essence in the amounts recommended by their manufacturers has not been determined. An uncharacterized Flor•Essence commercial product was dosed at amounts less than those recommended by the manufacturers for humans, and there was an increase in tumor incidence in this model.[3]

References

1. Ottenweller J, Putt K, Blumenthal EJ, et al.: Inhibition of prostate cancer-cell proliferation by Essiac. J Altern Complement Med 10 (4): 687-91, 2004.  [PUBMED Abstract]
   
   
2. Herbal treatments. In: US Congress, Office of Technology Assessment.: Unconventional Cancer Treatments. Washington, DC: U.S. Government Printing Office, 1990. OTA-H-405, pp 71-5. Also available online. ¹ Last accessed March 07, 2008. 
   
   
3. Bennett LM, Montgomery JL, Steinberg SM, et al.: Flor-Essence herbal tonic does not inhibit mammary tumor development in Sprague Dawley rats. Breast Cancer Res Treat 88 (1): 87-93, 2004.  [PUBMED Abstract]
   
   
4. Kulp KS, Montgomery JL, Nelson DO, et al.: Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells. Breast Cancer Res Treat 98 (3): 249-59, 2006.  [PUBMED Abstract]
   
   
5. Tai J, Cheung S, Wong S, et al.: In vitro comparison of Essiac and Flor-Essence on human tumor cell lines. Oncol Rep 11 (2): 471-6, 2004.  [PUBMED Abstract]
   
   
6. Tamayo C, Richardson MA, Diamond S, et al.: The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac. Phytother Res 14 (1): 1-14, 2000.  [PUBMED Abstract]
   
   
7. Tamayo C: Essiac for cancer. Alternative Therapies in Women's Health 2 (3): 19-23, 2000. 
   
   
8. Kaegi E: Unconventional therapies for cancer: 1. Essiac. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ 158 (7): 897-902, 1998.  [PUBMED Abstract]
   
   
9. Essiac. Toronto, Canada: Canadian Breast Cancer Research Alliance, 1996. 
   
   
10. Franke AA, Cooney RV, Custer LJ, et al.: Inhibition of neoplastic transformation and bioavailability of dietary flavonoid agents. In: Manthey JA, Buslig BS, eds.: Flavonoids in the Living System. New York, NY: Plenum Press, 1998. Advances in Experimental Medicine and Biology, 439, pp 237-48. 
    
    
11. Waladkhani AR, Clemens MR: Effect of dietary phytochemicals on cancer development (review) Int J Mol Med 1 (4): 747-53, 1998.  [PUBMED Abstract]
    
    
12. de Witte P: Metabolism and pharmacokinetics of anthranoids. Pharmacology 47 (Suppl 1): 86-97, 1993.  [PUBMED Abstract]
    
    
13. Campbell MJ, Hamilton B, Shoemaker M, et al.: Antiproliferative activity of Chinese medicinal herbs on breast cancer cells in vitro. Anticancer Res 22 (6C): 3843-52, 2002 Nov-Dec.  [PUBMED Abstract]
    
    
14. Boué SM, Wiese TE, Nehls S, et al.: Evaluation of the estrogenic effects of legume extracts containing phytoestrogens. J Agric Food Chem 51 (8): 2193-9, 2003.  [PUBMED Abstract]
    
    

Glossary Terms

A substance found in certain plants, including aloe vera. It belongs to a family of compounds called anthraquinones, which have shown anti-inflammatory and anticancer effects.

An incomplete description of the medical and treatment history of one or more patients. Anecdotal reports may be published in places other than peer-reviewed, scientific journals.

A type of anticancer drug.

Having to do with reducing inflammation.

Having to do with reducing the growth of new blood vessels.

A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism). Free radicals may play a part in cancer, heart disease, stroke, and other diseases of aging. Antioxidants include beta-carotene, lycopene, vitamins A, C, and E, and other natural and manufactured substances.

A substance found in certain plants, including burdock. It has shown antiviral and anticancer effects. Arctigenin belongs to a group of substances called lignans.

A substance found in certain plants, including burdock. It has shown anticancer effects. Arctiin belongs to a group of substances called lignans.

A plant whose leaves, stems, and flowers have been used in some cultures to treat certain medical problems. Blessed thistle may have anti-inflammatory and anticancer effects. The scientific name is Cnicus benedictus. Also called cardin, holy thistle, spotted thistle, and St. Benedict's thistle.

A plant whose seeds and root have been used in some cultures to treat certain medical problems. It may have antioxidant effects. The scientific name is Arctium lappa. Also called happy major and lappa.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

A substance found in certain plants, including blessed thistle. It has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. Cnicin is a type of sesquiterpene lactone.

Cell-killing.

The amount of medicine taken, or radiation given, at one time.

A substance found in certain plants, including rhubarb. It belongs to a family of compounds called anthraquinones, which have shown anti-inflammatory and anticancer effects.

An herbal tea mixture that contains burdock root, Indian rhubarb root, sheep sorrel, and slippery elm bark. It has been claimed to remove toxins from the body, make the immune system stronger, relieve pain, control diabetes, treat AIDS, reduce tumor size, increase cancer survival, and improve quality of life. No clinical trial using Essiac in humans has been reported in a peer-reviewed, scientific journal, and the FDA has not approved the use of Essiac for the treatment of any medical conditions.

A member of a group of substances found in many plants and plant-based foods. Flavonoids have shown antioxidant effects.

An isoflavone found in soy products. Soy isoflavones are being studied to see if they help prevent cancer.

A substance that increases the ability of the immune system to fight infection and disease.

Treatment to boost or restore the ability of the immune system to fight cancer, infections, and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Agents used in immunotherapy include monoclonal antibodies, growth factors, and vaccines. These agents may also have a direct antitumor effect. Also called biological response modifier therapy, biological therapy, biotherapy, and BRM therapy.

In the laboratory (outside the body). The opposite of in vivo (in the body).

In the body. The opposite of in vitro (outside the body or in the laboratory).

The root of this plant has been used in some cultures to treat certain medical problems. It may have anti-inflammatory and anticancer effects. The scientific name is Rheum palmatum or Rheum officinale. Also called Chinese rhubarb, da-huang, rhubarb, and Turkish rhubarb.

A type of seaweed. The stem-like parts of this plant have been used in some cultures to treat certain medical problems. It may have immunostimulatory and anticancer effects. The scientific name is Laminaria digitata.

Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

A member of a group of substances found in plants that have shown estrogenic and anticancer effects. Lignans have been used in some cultures to treat certain medical problems.

A type of cancer in which the bone marrow makes too many lymphocytes (white blood cells).

Having to do with the breast.

The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms. If they contain more than one atom, the atoms can be the same (an oxygen molecule has two oxygen atoms) or different (a water molecule has two hydrogen atoms and one oxygen atom). Biological molecules, such as proteins and DNA, can be made up of many thousands of atoms.

A substance being studied in the prevention of cancer. It is a naturally occurring compound found in some cruciferous vegetables. Also called PEITC.

An estrogen-like substance found in some plants and plant products. Phytoestrogens may have anticancer effects.

A substance that is found in many plants and gives some flowers, fruits, and vegetables their color. Polyphenols have antioxidant activity.

Research using animals to find out if a drug, procedure, or treatment is likely to be useful. Preclinical studies take place before any testing in humans is done.

Cancer that forms in tissues of the prostate (a gland in the male reproductive system found below the bladder and in front of the rectum). Prostate cancer usually occurs in older men.

Trifolium pratense. A plant with flowers that has been used in some cultures to treat certain medical problems. It is being studied in the relief of menopausal symptoms and may have anticancer effects. Also called purple clover, Trifolium pratense, and wild clover.

A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

A substance found in some plants. Sesquiterpene lactones may have anti-inflammatory and anticancer effects. Plants containing sesquiterpene lactones have been used in some cultures to treat certain medical problems.

A plant that has been used in some cultures to treat certain medical problems. It may have anticancer effects. The scientific name is Rumex acetosella. Also called dock and sorrel.

The inner bark of this plant has been used in some cultures to treat certain medical problems. It may have antioxidant effects. Also called gray elm, Indian elm, red elm, sweet elm, Ulmus fulva, and Ulmus rubra.

Having to do with poison or something harmful to the body. Toxic substances usually cause unwanted side effects.

Cells, tissues, or animals used to study the development and progression of cancer, and to test new treatments before they are given to humans. Animals with transplanted human tumors or other tissues are called xenograft models.

Parts of the flowering plant have been used in some cultures to treat certain medical problems. It may have anticancer effects. The scientific name is Nasturtium officinale. Also called Indian cress.