Ellagic acid

Chembox new
Name = Ellagic acid
ImageFile = Ellagic acid.png ImageName = Ellagic acid
IUPACName = 2,3,7,8-Tetrahydroxy-chromeno [5,4,3-cde] chromene-5,10-dione
Section1 = Chembox Identifiers
CASNo = 476-66-4
PubChem = 5281855
SMILES = C1=C2C3=C(C(=C1O)O)OC(=O)C4=CC(=C(C(=C43)OC2=O)O)O
Section2 = Chembox Properties
Formula = C₁₄H₆O₈
MolarMass = 302.197 g/mol
Density = 1.67 g/cm³
MeltingPt =
BoilingPt =

Ellagic acid is a polyphenol antioxidant found in numerous fruits and vegetables including raspberries, strawberries, cranberries, walnuts, pecans, pomegranates and other plant foods. The antiproliferative and antioxidant properties of ellagic acid have spurred preliminary research into the potential health benefits of ellagic acid consumption.

Natural occurrence

Plants produce ellagic acid and convert it to a form of tannin known as ellagotannins. These are glucosides which are readily hydrolyzed by water to regenerate ellagic acid when the plants are eaten.

Ellagic acid is also a primary constituent of several tannin bearing plants which produce the category of tannins known as gallotannins.cite journal | author = D. A. Vattem and K. Shetty | title = Biological Function of Ellagic Acid: A Review | journal = Journal of Biological Food Chemistry | year = 2005 | volume = 29 | pages = 234–266] These, when hydrolized by water give rise to ellagic acid and gallic acid. Many such plants include "Terminalia chebula", "Terminalia belerica", two related species which are ingredients of the Ayurvedic medicine known as Triphala.

The highest levels of ellagic acid are found in strawberries, cranberries, and grapes.

Proposed health benefits

Ellagic acid has antiproliferative and antioxidant properties in a number of "in vitro" and small-animal models. [cite journal |author=Seeram NP, Adams LS, Henning SM, "et al" |title=In vitro antiproliferative, apoptotic and antioxidant activities of punicalagin, ellagic acid and a total pomegranate tannin extract are enhanced in combination with other polyphenols as found in pomegranate juice |journal=J. Nutr. Biochem. |volume=16 |issue=6 |pages=360–7 |year=2005 |month=June |pmid=15936648 |doi=10.1016/j.jnutbio.2005.01.006 |url=] The antiproliferative properties of ellagic acid are due to its ability to directly inhibit the DNA binding of certain carcinogens, including nitrosamines [cite journal | author = Madal, Shivappurkar, Galati, and Stoner | title = Inhibition of N-nitrosobenzymethylamine metabolism and DNA binding in cultured rat esophagus by ellagic acid | journal = Carcinogenesis | year = 1988 | volume = 9 | pages = 1313–1316 | doi = 10.1093/carcin/9.7.1313 | pmid = 3383347] [cite journal | author = Mandal and Stoner | title = Inhibition of N-nitrosobenzymethylamine-induced esophageal tumorigenesis in rats by ellagic acid | journal = Carcinogenesis | year = 1990 | volume = 11 | pages = 55–61 | doi = 10.1093/carcin/11.1.55 | pmid = 2295128] and polycyclic aromatic hydrocarbons. [cite journal | author = Teel, Babcock, Dixit, and Stoner | title = Ellagic acid toxicity and interaction with benzo [a] pyrene and benzo [a] pyrene 7,8-dihydrodiol in human bronchial epithelial cells | journal = Cell Biol. Toxicol. | year = 1986 | volume = 2 | pages = 53–62 | doi = 10.1007/BF00117707] As with other polyphenol antioxidants, ellagic acid has a chemoprotective effect in cellular models by reducing oxidative stress.

These properties have generated interest in potential human health benefits from the consumption of ellagic acid. However, very little study of these proposed benefits has been reported as of 2008. A small randomized controlled trial involving 19 patients with carotid artery stenosis found that pomegranate juice, which is high in ellagic acid, appeared to reduce blood pressure and carotid artery wall thickness. [cite journal |author=Aviram M, Rosenblat M, Gaitini D, "et al" |title=Pomegranate juice consumption for 3 years by patients with carotid artery stenosis reduces common carotid intima-media thickness, blood pressure and LDL oxidation |journal=Clin Nutr |volume=23 |issue=3 |pages=423–33 |year=2004 |month=June |pmid=15158307 |doi=10.1016/j.clnu.2003.10.002 |url=] A 2005 controlled study of 48 patients undergoing chemotherapy for prostate cancer found that ellagic acid supplementation reduced the rate of chemotherapy-associated neutropenia (though there were no cases of severe neutropenia in either the ellagic acid or control group). Ellagic acid supplementation did not improve overall or progression-free survival of patients with prostate cancer in this trial. [cite journal |author=Falsaperla M, Morgia G, Tartarone A, Ardito R, Romano G |title=Support ellagic acid therapy in patients with hormone refractory prostate cancer (HRPC) on standard chemotherapy using vinorelbine and estramustine phosphate |journal=Eur. Urol. |volume=47 |issue=4 |pages=449–54; discussion 454–5 |year=2005 |month=April |pmid=15774240 |doi=10.1016/j.eururo.2004.12.001 |url=]

Despite the very preliminary state of evidence supporting health benefits in humans, ellagic acid has been marketed as a dietary supplement with a range of claimed benefits against cancer, heart disease, and other medical problems. Ellagic acid has been identified by the U.S. Food and Drug Administration as a "Fake Cancer Cure Consumers Should Avoid". [ [http://www.fda.gov/bbs/topics/factsheets/fakecancercures.html 125 Fake Cancer 'Cures' Consumers Should Avoid] , from the U.S. Food and Drug Administration. Accessed June 17 2008.] A number of U.S.-based sellers of dietary supplements have been warned by the Food and Drug Administration for promoting ellagic acid with claims that violate the Federal Food, Drug, and Cosmetic Act. [ [http://www.fda.gov/foi/warning_letters/s6800c.htm Warning Letter] sent to Millennium Health by the United States Food and Drug Administration, dated May 21 2008.] [ [http://www.fda.gov/cder/warn/cyber/2007/UL1.pdf Warning Letter] sent to Kenton Campbell by the United States Food and Drug Administration. Accessed June 17 2008.]

References

External links

* [http://videocast.nih.gov/Summary.asp?File=13742 A Food-Based Approach to the Prevention of Gastrointestinal Tract Cancers] - video lecture dedicated mainly to ellagic acid. Read by Dr. Gary D. Stoner from the Ohio State University Comprehensive Cancer Center.
* [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=8538195 Polyphenols as cancer chemopreventive agents] , J. Cell Biochem Suppl. 1995'22:169-80