Aflatoxin M-1 (AFM(1)) is a hydroxylated metabolite of aflatoxin B-1 and its presence in milk is considered to be a potential health risk for humans. Due to the important role of milk in humans, especially in infant nutrition, this study is intended to evaluate the quality of milk consumed on daily basis in South Africa by both rural and urban population in regard to AFM(1) contamination. To achieve this, samples were collected from rural subsistence (RSFs) and commercial dairy farms (CDFs) in selected areas of South Africa and samples were extracted using two clean-up procedures, C-18 cartridges and immunoaffinity columns (IAC) and analysed using thin layer chromatography (TLC) or by fluorometry (VICAM) (VF) and high pressure liquid chromatography (HPLC) coupled with a fluorescence detector and a coring cell (CoBrA cell) for AFM(1) derivatisation. Results obtained showed a frequency of contamination with AFM(1) of RSFs milk samples at 22.8% by TLC, 93.9% by VF 86% by HPLC and in CDFs of 17.8% (TLC) 96.5% (VF) and 100% (HPLC). No significant differences were obtained between milk from rural subsistence and commercial farms with mean varying between 0.15 and 0.17 mu g kg(-1) (C) 2013 Elsevier Ltd. All rights reserved.
Bio-monitoring of human exposure to mycotoxin has mostly been limited to a few individually measured mycotoxin biomarkers. This study aimed to determine the frequency and level of exposure to multiple mycotoxins in human urine from Cameroonian adults. 175 Urine samples (83% from HIV-positive individuals) and food frequency questionnaire responses were collected from consenting Cameroonians, and analyzed for 15 mycotoxins and relevant metabolites using LC-ESI-MS/MS. In total, eleven analytes were detected individually or in combinations in 110/175 (63%) samples including the biomarkers aflatoxin M-1, fumonisin B-1, ochratoxin A and total deoxynivalenol. Additionally, important mycotoxins and metabolites thereof, such as fumonisin B-2, nivalenol and zearalenone, were determined, some for the first time in urine following dietary exposures. Multi-mycotoxin contamination was common with one HIV-positive individual exposed to five mycotoxins, a severe case of co-exposure that has never been reported in adults before. For the first time in Africa or elsewhere, this study quantified eleven mycotoxin biomarkers and bio-measures in urine from adults. For several mycotoxins estimates indicate that the tolerable daily intake is being exceeded in this study population. Given that many mycotoxins adversely affect the immune system, future studies will examine whether combinations of mycotoxins negatively impact Cameroonian population particularly immune-suppressed individuals. (C) 2013 Elsevier Ltd. All rights reserved.
T-2 toxin is the most acutely toxic trichothecene mycotoxin: it inhibits protein, DNA and RNA synthesis. The main goal of this study was to evaluate the rate of DNA damage caused by T-2 toxin in porcine mononuclear cells in increasing concentrations (0.1, 0.5 and 1.0 μmol) and after two different incubation periods (24 and 42 h). The lowest concentration caused DNA damage and about 50% of the treated cells could be categorised as having 1 to 4 scores in comet assay. In parallel with the increase of T-2 toxin concentration, the frequency of intact lymphocytes decreased from 50.2% (0.1 μM) to 36.3% (1.0 μM) in the first 24 h. In case of score 3, the highest concentration of T-2 toxin resulted in a 5-fold change, as compared to the lowest dose. Cells with score 4 were found only after exposure to 1.0 μM T-2 toxin. The exposure time did not have a significant effect on the results, while concentration did (P < 0.0001). However, a significant interaction between concentration and time as fixed factors (P < 0.0001) was found. When these were combined as a single factor, the results showed a significant toxin treatment effect on the results. It was concluded that a time- and dose-dependent DNA damaging effect of T-2 toxin could be demonstrated using peripheral blood mononuclear cells from healthy pigs by comet assay.
Mycotoxic nephropathy was induced in eighteen young pigs by mouldy diets containing 0.5 ppm ochratoxin A (OTA) and/or 10 ppm fumonisin B1 (FB1) for three months. While the most obvious damages provoked by OTA were seen in the kidneys as expressed by the strong degenerative changes in proximal tubules and fibrosis in kidneys, FB1 was found to induce an increase in permeability of vessels mainly in lung, brain, cerebellum or kidneys and slight to moderate degenerative changes in kidneys. Pathomorphological damages in pigs exposed to both mycotoxins simultaneously present a combination of the main lesions provoked by each mycotoxin alone being stronger in their expression. Biochemical investigations as expressed by the increase of serum creatinine, urea and enzyme activity of ASAT/ALAT and by the decrease of serum cholesterol, total protein, albumin and glucose were strongest in pigs exposed to both mycotoxins simultaneously as can be anticipated form the strongest lesions in the kidneys. Both mycotoxins and their combination were found to disturb powerfully humoral immune response in all experimental pigs as expressed by the strong decrease in antibody titer against Morbus Aujesky at days 21 and 35 after vaccination. Having in mind that the feed levels of the both mycotoxins as well as the exposure time and the pathological findings corresponded to those in some spontaneous cases of porcine nephropathy in Bulgaria and South Africa, it can be concluded that the same mycotoxins are involved in the observed field cases of that nephropathy.
Aim of the study: This study investigated effect of a crude extract of Dodonaea viscosa on the proteinase and phospholipase production and adherence to epithelial cells by Candida albicans isolated from HIV positive and HIV negative patients.Materials and methods: Twenty Candida albicans strains isolated from HIV positive and 20 from HIV negative patients were investigated. The isolates were exposed to subinhibitory concentration of crude plant extract and adherence, proteinase and phospholipase production were assessed. The results were analysed using Student's t-test and a two-way ANOVA.Results: Dodonaea viscosa var. angustifolia inhibited the adherence of Candida albicans to oral epithelial cells (p = <0.01) but no significant effect of the plant extract on proteinase and phospholipase production was observed. Results from Candida albicans strains isolated from HIV positive and HIV negative patients were similar.Conclusions: Dodonaea viscosa var. angustifolia inhibited the adherence of Candida albicans to oral epithelial cells, which is the initial step of colonization in the infection process. This plant has a therapeutic potential at subinhibitory concentration. (C) 2009 Elsevier Ireland Ltd. All rights reserved.