OCHRATOXIN A

'Ochratoxin A', a toxin produced by ''Aspergillus ochraceus'' and ''Penicillium verrucosum'', is one of the most abundant food-contaminating mycotoxins in the world.^[1] Human exposure occurs mainly through consumption of improperly stored food products,^[2] particularly contaminated grain and pork products, as well as coffee and wine grapes.^[3] The toxin has been found in the tissues and organs of animals, including human blood and breast milk.^[4] Ochratoxin A toxicity has large species- and sex-specific differences.^[5]
Synonyms:

★ (''R'')-''N''-[(5-Chloro-3,4-dihydro-8-hydroxy-3-methyl-1-oxo-1H-2-benzopyran-7-yl)-carbonyl]-
''L''-phenylalanine

★ (-)-''N''-[(5-Chloro-8-hydroxy-3-methyl-1-oxo-7-isochromanyl)carbonyl]-3-phenylalanine

Contents

Impact on human and animal health

Carcinogenicity

Immuno suppression and immunotoxicity

Potential link to Balkan endemic nephropathy

Food animal industry impact

See also

References

Impact on human and animal health

Carcinogenicity

Ochratoxin A is potentially carcinogenic to humans (Group 2B). Ochratoxin A has been shown to be weakly mutagenic, possibly by induction of oxidative DNA damage.^[6]
There is sufficient evidence in experimental animals for the carcinogenicity of ochratoxin A. Ochratoxin A was tested for carcinogenicity by oral administration in mice and rats. It increased the incidence of hepato-cellular tumours in mice of each sex and produced renal-cell adenomas and carcinomas in male mice and in rats of each sex.

Immuno suppression and immunotoxicity

Ochratoxin A can cause immunosuppression and immunotoxicity in animals. The toxin's immunosuppressant activity in animals may include depressed antibody responses, reduced size of immune organs (such as the thymus, spleen, and lymph nodes), changes in immune cell number and function, and altered cytokine production. Immunotoxicity probably results from cell death following apoptosis and necrosis, in combination with slow replacement of affected immune cells due to inhibition of protein synthesis.

Potential link to Balkan endemic nephropathy

A number of descriptive studies have suggested a correlation between exposure to ochratoxin A and Balkan endemic nephropathy, and have found a correlation between the geographical distribution of Balkan endemic nephropathy and a high incidence of, and mortality from, urothelial urinary tract tumours.^[7] However, there is currently insufficient information to conclusively link ochratoxin A to Balkan endemic nephropathy.^[8] The toxin may require synergistic interactions with predisposing genotypes or other environmental toxicants to induce Balkan endemic nephropathy.^[9]

Food animal industry impact

Ochratoxin-contaminated feed has its major economic impact on the poultry industry. Chickens, turkeys and ducklings are susceptible to this toxin. Clinical signs of avian ochratoxicosis are similar to other toxins and generally involve reduction in weight gains, poor feed conversion, reduced egg production, poor egg shell quality and kidney poisoning.
Acute toxicity does not seem to constitute a problem in cattle.

See also

★ Ochratoxin

References

1. Immunotoxic activity of ochratoxin A, Al-Anati L, Petzinger E, , , J. Vet. Pharmacol. Ther., 2006
2. Ochratoxin A: An overview on toxicity and carcinogenicity in animals and humans, Pfohl-Leszkowicz A, Manderville RA, , , Mol Nutr Food Res, 2007
3. Factors affecting the presence of ochratoxin A in wines, Blesa J, Soriano JM, Moltó JC, Mañes J, , , Critical reviews in food science and nutrition, 2006
4. Ochratoxin a: its cancer risk and potential for exposure, Clark HA, Snedeker SM, , , Journal of toxicology and environmental health. Part B, Critical reviews, 2006
5. Ochratoxin A: the continuing enigma, O'Brien E, Dietrich DR, , , Crit. Rev. Toxicol., 2005
6. Ochratoxin A-Induced Mutagenesis in Mammalian Cells Is Consistent with the Production of Oxidative Stress, Palma N, Cinelli S, Sapora O, Wilson SH, Dogliotti E, , , , 2007
7. Balkan endemic nephropathy: role of ochratoxins A through biomarkers, Castegnaro M, Canadas D, Vrabcheva T, Petkova-Bocharova T, Chernozemsky IN, Pfohl-Leszkowicz A, , , Mol Nutr Food Res, 2006
8. Role of exposure analysis in solving the mystery of Balkan endemic nephropathy, Long DT, Voice TC, , , Croat. Med. J., 2007
9. Ochratoxin A concentrations in food and feed from a region with Balkan Endemic Nephropathy, Abouzied MM, Horvath AD, Podlesny PM, ''et al'', , , Food additives and contaminants, 2002