Conference paper
Exposure to Mycotoxins and Malignant Tumours
Maja Peraica
; Institut za medicinska istraživanja i medicinu rada
Radovan Pleština
; Institut za medicinska istraživanja i medicinu rada
Abstract
Mycotoxins are secondary metabolites of a variety of moulds having toxic properties in human, animal and plant organisms. Some of them have proven or suspected carcinogenic potential. Thus aflatoxin B1 and M1, ochratoxin A, and fumonisin B1 are proven carcinogens in some experimental animals. Aflatoxins are produced by moulds which are common for the tropical climate, whereas fungi-producing ochratoxins and fumonisins are present everywhere. Among numerous aflatoxins, aflatoxin B1 is the most toxic and so is ochratoxin A among ochratoxins and fumonisin B1 among fumonisins. Aflatoxins form DNA adducts, which may serve as good biological markers for the exposure to aflatoxins. Aflatoxins primarily affect liver and kidney, causing cirrhosis which ends with liver cancer. Ochratoxin A is a potent nephrotoxic agent, affecting primary tubules and leading to functional impairment and development of fibrosis. Results of many experiments have shown strong resemblance to human kidney disease, known as endemic nephropathy. It is rather common that endemic nephropathy is associated with otherwise rare urothelial tumours. Ochratoxin A is found in many samples of human food and animal feed, but also in human blood. While it is frequent in urban population, but in low concentrations, in rural areas with endemic nephropathy both the frequency and the level are significantly higher. Fumonisins disturb some essential physiological processes by inhibiting the sphingomyelin metabolism, which leads to detectable changes in the sfinganine-sfingosine ratio. This finding may be useful in assessing exposure to fumonisins. Taking into account the potential long-term effect of fumonisins, there are valid indications that fumonisin B1 may be associated with an excessive incidence of oesophageal cancer in several regions in the world.
Keywords
aflatoxins; fumonisins; lipid metabolism; liver cancer; nephropathy; ochratoxins; oesophageal cancer; urothelial tumours
Hrčak ID:
65685
URI
Publication date:
26.7.2000.
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