Haematopoiesis radioprotection in Balb/c mice by an aqueous mycelium extract from the Basidiomycete Pleurotus ostreatus mushroom.

The study examined the radioprotective activity of an aqueous extract from Pleurotus ostreatus mycelium administered to Balb/c mice. Male mice were whole-body irradiated on day 0 ((60)Co, at 0.43 Gy/min) and divided into two groups. The extract was administered intraperitoneally to one group (100 mg/kg) on days - 10 to - 6 and - 2 to +1 with respect to the irradiation. The irradiated-control group was injected with saline solution; non-irradiated mice were used as negative controls. The radioprotective effect was evident by increases in bone marrow cellularity (5.1 × 10(6)/femur vs. 1.1 × 10(6)/femur in saline-control mice, p < 0.05), leucocyte counts (10.5 × 10(9)/L vs. 4.5 × 10(9)/L, p < 0.05), and spleen cellularity (11.2 × 10(7)/spleen vs. 6.2 × 10(7)/spleen, p < 0.05). The extract stimulated macrophage phagocytic activity as judged by a faster rate of carbon clearance in terms of absorbance ratios (1.62 vs. 2.01, p < 0.05). Therefore, this extract may be a candidate therapeutic agent with radioprotective activity for haematopoiesis damage, particularly to cells involved in immune function.

Sanitary Risks Connected to the Consumption of Infusion from Senna rotundifolia L. Contaminated with Lead and Cadmium in Cotonou (Benin).

This study carried out an assessment of sanitary risks connected to the consumption of Senna rotundifolia Linn. contaminated with lead and cadmium. This plant was collected and analyzed by atomic absorption spectrophotometry. The results revealed a contamination of plants from markets of Dantokpa, Vossa, and Godomey with heavy metals. Senna from Vossa was higher in cadmium and lead levels (Pb: 2.733 mg/kg ± 0.356 mg/kg; Cd: 0.58 mg/kg ± 0.044 mg/kg) compared to the two other places (Pb: 1.825 mg/kg ± 0.133 mg/kg, Cd: 0.062 mg/kg ± 0.015 mg/kg and Pb: 1.902 mg/kg ± 0.265 mg/kg, Cd: 0.328 mg/kg ± 0.024 mg/kg), respectively, for Dantokpa and Godomey. In terms of risk assessment through the consumption of Senna, the values recorded for lead were nine times higher with children and six times higher with adults than the daily permissive intake (Pb: 3.376 × 10(-2) mg/kg/day for children and 2.105 × 10(-2) mg/kg/day for adults versus 3.6 × 10(-3) mg/kg/day for DPI). With respect to cadmium, there was no significant difference between the recorded values and the DPI (Cd: 1 × 14 10(-3) mg/ kg/day for children and Cd: 0.71 × 10(-3) mg/ kg/day for adults versus Cd: 1 × 10(-3) mg/kg/day for adults). This exposure of the population to lead and cadmium through the consumption of antimalarial healing plants could pose public health problems.

Bacterial-based additives for the production of artificial snow: what are the risks to human health?

For around two decades, artificial snow has been used by numerous winter sports resorts to ensure good snow cover at low altitude areas or more generally, to lengthen the skiing season. Biological additives derived from certain bacteria are regularly used to make artificial snow. However, the use of these additives has raised doubts concerning the potential impact on human health and the environment. In this context, the French health authorities have requested the French Agency for Environmental and Occupational Health Safety (Afsset) to assess the health risks resulting from the use of such additives. The health risk assessment was based on a review of the scientific literature, supplemented by professional consultations and expertise. Biological or chemical hazards from additives derived from the ice nucleation active bacterium Pseudomonas syringae were characterised. Potential health hazards to humans were considered in terms of infectious, toxic and allergenic capacities with respect to human populations liable to be exposed and the means of possible exposure. Taking into account these data, a qualitative risk assessment was carried out, according to four exposure scenarios, involving the different populations exposed, and the conditions and routes of exposure. It was concluded that certain health risks can exist for specific categories of professional workers (mainly snowmakers during additive mixing and dilution tank cleaning steps, with risks estimated to be negligible to low if workers comply with safety precautions). P. syringae does not present any pathogenic capacity to humans and that the level of its endotoxins found in artificial snow do not represent a danger beyond that of exposure to P. syringae endotoxins naturally present in snow. However, the risk of possible allergy in some particularly sensitive individuals cannot be excluded. Another important conclusion of this study concerns use of poor microbiological water quality to make artificial snow.

Domoic acid induces direct DNA damage and apoptosis in Caco-2 cells: recent advances.

Domoic acid (DA) is a neurotoxin produced by sea-water phytoplankton. Shellfish feeding on the phytoplankton can bioconcentrate DA, leading to a potentially serious health hazard for people consuming the contaminated shellfish. DA is the principal toxin responsible for amnesic shellfish poisoning (ASP). The toxic mechanism of DA is believed to be mediated at the level of the mitochondria, where uncoupling of oxidative phosphorylation decreases membrane permeability, causing cell swelling and ultimately lysis. Literature is poor concerning data on the possible genotoxicity and cytotoxicity of DA. In the present study, we have evaluated the cytotoxicity and genotoxicity of DA on a human colorectal adenocarcinoma cell line (Caco-2). Our results clearly demonstrate that DA decreased cell viability (IC(50) about 70 ng/mL), induced direct DNA damage from 15 ng/mL, and apoptosis in Caco-2 cells at 100 ng/mL. This apoptosis is likely bax-dependent and occurred only at high concentrations of DA, while lower concentrations upregulated both bax and bcl-2 at an apparent constant ratio until a sudden decrease of bcl-2 at 100 ng/mL and increase of bax.

Cytogenetic analysis of tannery workers in Morocco.

This study investigated the possible genetic effects in blood lymphocytes of tannery workers from Morocco being professionally exposed to multiple chemical agents. It was shown that the frequencies of cells with chromosome aberrations and micronuclei were significantly increased in the lymphocytes of the workers compared with the frequencies found in an unexposed control population.

Anticancer effect of a new benzophenanthridine isolated from Zanthoxylum madagascariense (Rutaceline).

Fractionation of the cyclohexane extract from the stem bark powder of Zanthoxylum madagascariense led to the isolation of a new benzophenanthridine-type alkaloid, hydrochloride of 2,3-methylendioxy-8-hydroxy- 7-methoxy-benzo[C]phenanthridine (Rutaceline), characterized on the basis of its spectral data. Rutaceline was evaluated for its antiproliferative capacity on the human colorectal adenocarcinoma (Caco-2) and the African green monkey kidney (Vero) cell lines. The 50% inhibition of cell growth (IC50) obtained after 24 h incubation was similar for both cells lines (110-115 microg/ml, i.e. 269-281 microM), but at 48 h the IC50 value for the Caco-2 cells was lower than for the Vero cells (20 microg/lml, i.e. 49 microM versus 90 microg/ml, i.e. 220 microM) indicating a higher cell growth inhibitory effect on the colon adenocarcinoma cells. At the respective IC50 concentrations, Rutaceline did not significantly induce apoptosis but induced cell cycle arrest in the GO/G1 phase, as well as a decrease of cells in S phase. Rutaceline also induced DNA fragmentation in both cell lines, as revealed by agarose gel electrophoresis, and a dose-dependent clastogenic effect in both cell lines as revealed by the Comet assay.

Preliminary survey of ochratoxin A in millet, maize, rice and peanuts in Côte d'Ivoire from 1998 to 2002.

In a preliminary study, samples of millet (n =33) maize (n=41), rice (n=10) and peanuts (n=10) from Côte d'Ivoire were analysed for ochratoxin A (OTA) by HPLC with fluorimetric detection, followed by confirmation by cleavage of the OTA molecule using carboxypeptidase with HPLC separation and fluorimetric quantification of the released ochratoxin alpha (OTh). With the exception of four samples of peanuts, all samples showed OTA contamination, ranging from 3 to 1738 microg/kg. All cereals were contaminated and the OTA concentrations were in the range of 17-204 microg/kg for millet, 3-1738 microg/kg for maize, 9-92 microg/kg for rice and 0.6-64 microg/kg for peanuts, depending on the year of harvest. Most of the samples would not be accepted according to the EU regulatory limits for this mycotoxin. Following this survey, research for other mycotoxins and the evaluation of the exposure of the population is underway.

Micronucleus test in mussels Perna perna fed with the toxic dinoflagellate Prorocentrum lima.

Micronucleus (MN) and other nuclear abnormalities have been measured in the hemocytes of mussels Perna perna to verify whether feeding mussels with different concentrations of Prorocentrum lima results in accumulation of levels of okadaic acid (OA) capable of inducing genotoxic effects at the chromosome level, as evidenced by micronuclei and nuclear abnormalities. Four groups of 12 mussels housed individually in aquaria containing filtered seawater were fed with different concentrations of P. lima. Another group collected directly from the production area served as outdoor control. A significantly higher frequency of MN and nuclear lesions was observed in hemocytes from the groups fed P. lima.

Zearalenone induces chromosome aberrations in mouse bone marrow: preventive effect of 17beta-estradiol, progesterone and Vitamin E.

The cytogenetic effect of zearalenone (ZEN), a non-steroidal estrogenic mycotoxin, was evaluated in vivo, in mouse bone marrow cells, by assessing the percentage of cells bearing different chromosome aberrations. The studies included different conditions for animal treatment, as follows: (1) single intraperitoneal (ip) injection, (2) repeated ip injections, (3) pre-treatment for 24h with Vitamin E (Vit E), and (4) pre-treatment for 4h with 17beta-estradiol (17beta-Est) or progesterone (Prog). ZEN induced different types of chromosome aberrations, which was concentration-dependent (2-20 mg/kg bw). These doses corresponded to 0.4-4% of the LD50 in the mouse. Interestingly, when the dose of ZEN (40 mg/kg) was fractionated into four equivalent doses (4 x 10 mg/kg bw), into three doses (15 + 10 + 15 mg/kg bw), or into two equivalent doses (2 x 20 mg/kg bw), given every 24 h, the percentage of chromosome aberrations increased significantly. This finding suggests that ZEN proceeds by reversible binding on receptors that could become saturated, and that it damages the chromosomes in a 'hit and go' manner. Furthermore, pre-treatment of animals with 17beta-estradiol or progesterone significantly decreased the percentage of chromosome aberrations, suggesting that (i) these hormones bind to the same cytoplasmic receptors transported into the nucleus to elicit DNA damage, (ii) they may play a role in preventing chromosome aberrations induced by ZEN. Similarly, Vit E prevented these chromosome aberrations indicating that Vit E, previously reported to prevent most of the toxic effects induced by ZEN, may also bind to the same receptors.

Monitoring of mycotoxin biomarkers in the Czech Republic.

AFM1 was determined in 72 (72%) samples of human urine, range 19-6064 pg/g creatinine, mean 367 pg/g creatinine, median 158 pg/g creatinine and 90% percentile 755 pg/g creatinine in 1997. AFM1 was determined in 46 (43.8%) samples of human urine, range 21-19219 pg/g creatinine, mean 414 pg/g creatinine, median 96 pg/g creatinine and 90% percentile 415 pg/g creatinine in 1998. OTA was determined in 2077 (94.2%) samples of human serum, range 0.1-13.7 µg/L, mean 0.28 µg/L, median 0.2 µg/L and 90% percentile 0.5 µg/L in 1994-2002. OTA was determined in 12 (40%) samples of human kidneys, range 0.1-0.2 µg/kg, mean 0.07 µg/kg, and median 0.05 µg/kg in 2001.

Magnesium content in seminal fluid as an indicator of chronic prostatitis.

Magnesium and zinc are both involved in a high number of enzymic activities vital for mammals. They are found in prostate in remarkably high concentrations and released into seminal fluid. Furthermore, drastic reduction of Zn and Mg concentrations in the semen fluid may lead to disorders in male fertility. We aimed to analyse the differences in Mg and Zn levels in the seminal plasma of 213 males including 48 normozoospermic, 30 azoospermic, 28 oligoasthenozoospermic, 22 asthenozoospermic and 85 chronic prostatitis. Mg and Zn concentrations were measured using an atomic absorption spectrophotometer. While zinc levels did not show correlation either with the volume of the sperm or the percentage of pathological forms, magnesium concentrations in seminal plasma were significantly decreased in chronic prostatitis patients as compared to other groups or normozoospermic patients (p<0.001). We propose therefore magnesium as a marker of prostatitis.

Micronucleus induction in mussels exposed to okadaic acid.

Some toxins present in the marine environment are capable of inducing mutagenicity and/or carcinogenicity. Among these toxins, okadaic acid (OA) is gaining considerable interest since it induces DNA based modifications at low concentrations and accumulates in filter-feeding marine animals, including those used for human consumption. This study aims to evaluate the genotoxicity of OA in the haemocytes of the mussel Perna perna, using the micronucleus assay. Fifty-four mussels were separated into three groups of 18 animals. One group received 0.3 microg of OA diluted in 10 microl of ethanol and ultrapure water while the other groups were considered as controls and were exposed to a solvent plus seawater mixture. A significantly higher frequency of micronuclei was observed in haemocytes from the OA-exposed group. There were no statistical differences between the two control groups.

Ochratoxin A in human plasma in Morocco: a preliminary survey.

Available epidemiological information seems to indicate that Balkan endemic nephropathy is associated with consumption patterns involving foodstuffs contaminated with ochratoxin A (OTA) and with a higher frequency of OTA-positive blood samples. The aim of this preliminary study was to assess OTA concentrations in human plasma in Morocco. Therefore, samples from 309 healthy volunteers (213 males, 96 females) were analysed. The analyses revealed that 60% of the human plasma sampled was positive for OTA (61.5% in the male and 56% in the female population), and an average concentration of 0.29 ng/mL (0.31 ng/mL in males, 0.26 ng/mL in females). The highest concentration found was 6.59 ng/mL. The results suggest that the Moroccan population is exposed to OTA, even though the OTA plasma levels are lower than that reported in some North African countries.

Toxicokinetics of ochratoxin A in vervet monkeys (Cercopithecus aethiops).

The toxicokinetics of ochratoxin A were investigated in vervet monkeys (Cercopithecus aethiops). Three female monkeys were treated intravenously with ochratoxin A at doses, respectively, of 0.8, 1.5 and 2 mg/ kg body weight (BW). Blood and urine samples were collected over a period of 21 days. Plasma and urine extracts were analysed by high-performance liquid chromatography (HPLC) with either fluorescence or negative ion electrospray ionization mass spectrometric detection. The clearance of ochratoxin A from plasma followed a two-compartment model. The elimination half-life of ochratoxin A in the monkeys was determined to be 19-21 days and the average total body clearance was 0.22 +/- 0.07 ml/h per kg and the average apparent distribution volume of the central compartment was 59 +/- 9 ml/kg and the peripheral compartment was 59 +/- 20 ml/kg. No evidence was found for any metabolic conversion of ochratoxin A.

Ochratoxin A in beverages from Morocco: a preliminary survey.

In a preliminary study, samples of Moroccan wines (n = 30), beers (n = 5) and fruit juices (n = 14) were assayed for ochratoxin A (OTA) by HPLC with fluorimetric detection, followed by confirmation by cleavage of the OTA molecule using carboxypeptidase with HPLC-fluorimetric determination of ochratoxin alpha (OT alpha). All the wine samples were contaminated, and the overall median OTA concentration was 0.65 microg/l (range 0.028-3.24 microg/l). One of the 14 samples of fruit juices was contaminated with a concentration of 1.16 microg/l, whereas none of the five beer samples was contaminated. This is the first report on the occurrence of OTA in various beverages from Morocco.

Aspartame prevents the karyomegaly induced by ochratoxin A in rat kidney.

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus as well as other moulds. This mycotoxin contaminates animal feed and food. OTA is immunosuppressive, genotoxic, teratogenic, carcinogenic and is nephrotoxic in all animal species studied so far. OTA inhibits protein synthesis and induces lipid peroxidation. Since it seems impossible to avoid completely contamination of foodstuffs by toxigenic fungi, it is necessary to investigate the possible ways of limiting such toxicity. An attempt to prevent OTA-induced nephrotoxic and genotoxic effects, mainly the karyomegaly, has been made in vivo using aspartame (L-aspartyl-L-phenylalanine methyl ester), a structural analogue of both OTA and phenylalanine. Aspartame (25 mg/kg body weight) prevented most of the nephrotoxic effects induced by OTA (289 microg/kg body weight). It also showed some utility in preventing morphological and histological damage, mainly the karyomegaly. The protective effects of aspartame on OTA-induced nephrotoxicity could be based on several mechanisms related to competitive binding to plasma proteins, to transport or tissue distribution in the kidney or to the elimination of the toxin in the urine.

DNA breaks and cell cycle arrest induced by okadaic acid in Caco-2 cells, a human colonic epithelial cell line.

Okadaic acid (OA) is a shellfish toxin produced by dinoflagellates, in mussels. It is a potent tumour promoter and represents a potential threat to human health even at low concentrations. OA targets mainly the gastrointestinal tract in acute poisoning, causing diarrhoea. Therefore the present investigations were designed to study the ability of okadaic acid to induce cytotoxicity and DNA lesions in a human colonic cell line (Caco-2). Incubation of Caco-2 cells with OA (3.75-60 ng/ml, i.e. 4.6 x 10(-3)-7.5 x 10(-2) microM) causes a significant reduction in cell viability. Moreover, okadaic acid inhibits protein and DNA synthesis with, respectively, IC50 of 16 and 6.5 ng/ml after 24 h incubation. It also provokes cell cycle arrest, characterised by an increase in the number of S phase cells, correlated with a significant decrease in G0/G1 phase cells at high concentration. One of the main results obtained in these investigations is the apoptosis induced by OA in Caco-2 cells of intestinal origin, shown by DNA laddering in agarose gel electrophoresis (250-1000 base pairs). OA also induces clastogenic effects evaluated by DNA fragmentation analysis using the method of Higuchi and Aggarwal (52% for 60 ng/ml) and comet assay (increase of the frequency of comets and their tails length). Therefore, the cell death induced by OA seems clearly to be concentration-dependent after 24 h of incubation. The cytotoxic properties of okadaic acid and its ability to damage DNA result in cell death, mainly by apoptosis. Since consumption of shellfish contaminated with acceptable okadaic acid concentrations exposes colonic cells to harmful concentrations of this toxin, the possibility that OA would display its toxic effects on intestinal cells in vivo should be evaluated in human primary intestinal cells and human intestinal slices for cytotoxic effects, DNA fragmentation and apoptosis.

Experimental mycotoxic nephropathy in pigs provoked by a diet containing ochratoxin A and penicillic acid.

Mycotoxic nephropathy was induced in 18 young pigs by diets contaminated with strains of Aspergillus ochraceus containing ochratoxin A (OTA) and penicillic acid (PA) at levels corresponding to those naturally encountered in animal feeds in Bulgaria. Haematological and biochemical parameters, as well as the morphological and ultrastructural changes in various internal organs, and especially in the kidneys, were examined at different stages of development of the disease. A mottled surface of the kidneys was only seen in pigs exposed to a mouldy diet containing 180 ppb OTA for 3 months, but microscopic lesions, as well as changes in various haematological and biochemical parameters, were observed in all groups exposed to the same mouldy diet containing only 90 or 180 ppb OTA. Histological examination showed two types of change: degenerative changes affecting the epithelial cells of the proximal tubules, which predominated at the initial stage, and proliferative changes in the interstitium, which predominated at the later stage of the disease. Telangiectasis and lymph stasis were also seen, as well as degenerative changes in the capillary endothelium. The characteristic renal lesions were similar to those observed in spontaneous cases of mycotoxic porcine nephropathy in Bulgaria, but they were a little different from the classic Danish porcine nephropathy. The enhanced toxicity of OTA in our study may be due to a synergistic effect between OTA and PA or to some other unknown metabolites produced by the same ochratoxinogenic strains of A. ochraceus.

Lipid peroxidation as pathway of aluminium cytotoxicity in human skin fibroblast cultures: prevention by superoxide dismutase+catalase and vitamins E and C.

Lipid peroxidation is one of the main manifestations of oxidative damage and has been found to play an important role in the toxicity and carcinogenicity of many xenobiotics. In the present study, we investigated the possible induction of lipid peroxidation by aluminium in human foreskin fibroblast cultures by assaying the malondialdehyde (MDA) produced inside the cells. The MDA-thiobarbituric acid (TBA) adduct was assayed by HPLC using fluorometric quantification after extraction in n-butanol. Lactate dehydrogenase (LDH) release was used as a marker of aluminium toxicity. MDA production was significantly increased after 24 h incubation with aluminium and paralleled LDH release. Superoxide dismutase (SOD)+catalase and vitamins C and E added in the culture medium as oxygen radical and free radical scavengers were efficient in preventing MDA production by aluminium, indicating that oxidative processes are one of the main pathways whereby this metal induces cytotoxicity. The latter is also largely prevented, thus confirming the link between oxidative stress induced by aluminium and its cytotoxicity in human skin fibroblasts.