ellagic acid

Ellagic acid
IUPAC name	2,3,7,8-Tetrahydroxy-chromeno[5,4,3-cde]chromene-5,10-dione
Identifiers
CAS number	476-66-4 Y
PubChem	5281855
SMILES	C1=C2C3=C(C(=C1O)O)OC(=O)C4=CC(=C(C(=C43)OC2=O)O)O
Properties
Molecular formula	C14H6O8
Molar mass	302.197 g/mol
Density	1.67 g/cm³
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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 ellagitannins. 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.^[1] These, when hydrolyzed 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, raspberries, cranberries, and grapes.^[1]

Proposed health benefits

Ellagic acid has antiproliferative and antioxidant properties in a number of in vitro and small-animal models.^[2] The antiproliferative properties of ellagic acid are due to its ability to directly inhibit the DNA binding of certain carcinogens, including nitrosamines^[3][4] and polycyclic aromatic hydrocarbons.^[5] As with other polyphenol antioxidants, ellagic acid has a chemoprotective effect in cellular models by reducing oxidative stress.^[1]

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.^[6] 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.^[7]

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".^[8] 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.^[9][10]

References

External links

• 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.
• Polyphenols as cancer chemopreventive agents, J. Cell Biochem Suppl. 1995'22:169-80