Dietary fumonisin exposure in a rural population of South Africa

ArticleA validated culturally specific dietary assessment method was used to determine the habitual maize intakes of black Xhosa-speaking Africans living in the Centane region of the Eastern Cape Province to assess their exposure to the carcinogenic fumonisin mycotoxins. The mean total dry weight maize intakes of home-grown, commercial or combined (both maize sources) were 474, 344, 462 g day(-1), respectively. When considering the total mean levels of fumonisin in home-grown maize (1142 microg kg(-1)) and commercial maize (222 microg kg(-1)), the probable daily intakes (PDI's), expressed as microg kg(-1) body weight day(-1) were 12.1 (95%CI: 0.3-4926.5) and 1.3 (95%CI: 1.0-1.8) for men and 6.7 (95%CI: 1.0-457.8) and 1.1 (95%CI: 0.9-1.3) for women, consuming home-grown and commercial maize, respectively. Based on the different maize-based beer drinking frequencies the PDI's varied between 6.9 and 12.0 microg kg(-1)/drinking event. Depending on the maize intake patterns an exposure "window" exists where fumonisin exposure is below the recommended group provisional maximum tolerable daily intake (PMTDI) for fumonisins of 2 microg kg(-1)bw day(-1). The assessment of fumonisin exposure and development of preventative strategies depend, not only the accurate determination of total fumonisin levels in maize, but also on the distinct dietary patterns of a specific population.Cancer Association of South Africa (CANSA)Medical Research Council (MRC

A potential mechanism for fumonisin B(1)-mediated hepatocarcinogenisis: cyclin D1 stabilization associated with activation of Akt and inhibition of GSK-3beta activity.

GesondheidswetenskappeMolekul�re Biologie & MensgenetikaPlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Structure and natural occurrence of stereoisomers of the fumonisin B series mycotoxins

Article1H and 13C NMR spectroscopy of both fumonisin B3 and B4, as well as high-performance liquid chromatography (HPLC) analysis of samples of fumonisin B3 used as standards, showed in each case the presence of two stereoisomers, which could not be separated by preparative chromatography. The 2,3-anti relative configuration for the two minor stereoisomers of fumonisin B3 and B4 was deduced from the NMR data, and their 2S,3R absolute configurations were established by application of Mosher's method using the fumonisin B3 sample. Samples of fumonisin B3 and B4 can contain between 10 and 40% of fumonisin B compounds of the 3-epi series. The 3-epi-FB3, determined by HPLC with fluorescence detection of the o-phthaldialdehyde derivative and confirmed by liquid chromatography-tandem mass spectrometry, was found to occur naturally in a range of maize samples at levels much lower than FB3 (< 20%). The identification of members of the 3-epi-fumonisin B series provides insight into the order and selectivity of steps in fumonisin biosynthesis.University of PretoriaNational Research Foundation, PretoriaWellcome Trus

Role of fumonisin B1 on DNA methylation changes in rat kidney and liver cells

Context: Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium verticillioides (Sacc.) Nirenberg (Nectriaceae) mold that contaminates maize and other agricultural products. Although the effects of FB1 on sphingolipid metabolism are clear, little is known about early molecular changes associated with FB1 carcinogenicity

Hepatotoxicity and -carcinogenicity of the fumonisins in rats. A review regarding mechanistic implications for establishing risk in humans

ArticleCancer induction by the non-genotoxic mycotoxin, fumonisin B1, has been investigated by studying the mechanisms involved during cancer initiation and promotion in rat liver. Cancer initiation is effected through a toxic-proliferative response while the inhibitory effect on hepatocyte cell proliferation appears to be a key aspect determining cancer promotion. Dose-response effects of the fumonisins on the induction of early neoplastic lesions in both long- and short-term animal experiments have been established. The biphasic response of FB1 on hepatocyte proliferation will be discussed in relation to the known mechanisms of cancer induction by the genotoxic hepatocarcinogens. Recent investigations regarding the effect of the fumonisins on lipid biosynthesis and its inhibitory effect on hepatocyte growth stimulatory responses in vitro will be highlighted. Integration of our current knowledge regarding the carcinogenic potential of the fumonisins in setting a realistic and applicable risk assessment model for this non-genotoxic carcinogen will finally be addressed