Apoptotic effects of satratoxin H is mediated through DNA double-stranded break in PC12 cells

Satratoxin H is an important air- and food-borne mycotoxin, which has been implicated in human health damage. Satratoxin H is known to induce apoptosis as well as genotoxicity in PC12 cells. In the present study, we further investigated the mechanism of apoptotic effects of satratoxin H with focus on caspase-3 and poly-ADP-ribose polymerase (PARP) pathway. We also examined whether it induces DNA damage in PC12 cells. In the cells treated with satratoxin H, caspase-3 was cleaved in a time-dependent manner. Furthermore, satratoxin H induced cleavage of PARP, one of the downstream molecules of caspase-3. The cleavage was inhibited by SB203580, a p38 MAPK inhibitor, or SP600125, a JNK inhibitor. Satratoxin H, however, had no effect on expression levels of Bax and Bcl-2. Furthermore, the micronucleus assay revealed that satratoxin H induced chromosome break. Also, satratoxin H increased the level of phosphorylation of histone H2A, indicating that it caused DNA double-stranded breaks in PC12 cells. Meanwhile, no genotoxicity was detected with any of treatments carried out in the alkaline comet assay. These results imply that satratoxin H induces genotoxicity by DNA double-stranded break. Our results suggest a considerable potential for the genotoxic risk associated with the presence of satratoxin H.

Fumonisins, trichothecenes and zearalenone in cereals

Fumonisins are phytotoxic mycotoxins which are synthesized by various species of the fungal genus Fusarium such as Fusarium verticillioides (Sacc.) Nirenberg (ex F.moniliforme Sheldon) and Fusarium proliferatum. The trichothecene (TC) mycotoxins are secondary metabolites produce by species that belong to several fungal genera, especially Fusarium, Stachybotrys, Trichothecium, Trichoderma, Memnoniella and Myrothecium. Fusarium mycotoxins are widely dispersed in cereals and their products. Zearalenone (ZEA) is an estrogenic compound produced by Fusarium spp. such as F. graminearum and F. culmorum. Fumonisins, the TCs and ZEA are hazardous for human and animal health. Contamination with TCs causes a number of illnesses in human and animal such as decrease in food consumption (anorexia), depression or inhibition on immune system function and haematoxicity. The purpose of this paper is to give a review of the papers published on the field of fumonisin, TC and ZEA mycotoxins in cereals consumed in the world.

Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on small intestinal morphology of turkeys

An experiment was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on morphometric indices of duodenum, jejunum, and ileum in turkeys. The possible preventative effect of a polymeric glucomannan mycotoxin adsorbent (GMA) was also determined. Three hundred 1-d-old male turkey poults were fed wheat, corn, and soybean meal-based starter (0 to 3 wk), grower (4 to 6 wk), developer (7 to 9 wk), and finisher (10 to 12 wk) diets formulated with control grains, contaminated grains, and contaminated grains + 0.2% GMA. Morphometric indices were measured at the end of each growth phase and included villus height (VH), crypt depth, villus width, thicknesses of submucosa and muscularis, villus-to-crypt ratio, and apparent villus surface area (AVSA). At the end of the starter phase, feedborne mycotoxins significantly decreased the VH in the duodenum, and supplementation of the contaminated diet with GMA prevented this effect. The feeding of contaminated grains also reduced (P < 0.05) VH and AVSA in jejunum, whereas none of the variables were affected in the ileum. Villus width and AVSA of duodenum, VH, and AVSA of jejunum and submucosa thickness of ileum were significantly reduced when birds were fed contaminated grains at the end of the grower phase, and supplementation with GMA prevented these effects in jejunum and ileum. No effects of diets were seen on morphometric variables at the end of the developer and finisher phases. It was concluded that consumption of grains naturally contaminated with Fusarium mycotoxins results in adverse effects on intestinal morphology during early growth phases of turkeys, and GMA can prevent many of these effects.

Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance, hematology, metabolism, and immunocompetence of turkeys

An experiment was conducted to investigate the effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on performance, hematology, metabolism, and immunological parameters of turkeys. The efficacy of polymeric glucomannan mycotoxin adsorbent (GMA) in preventing these adverse effects was also evaluated. Three hundred 1-d-old male turkey poults were fed wheat-, corn-, and soybean meal-based starter (0 to 3 wk), grower (4 to 6 wk), developer (7 to 9 wk), and finisher (10 to 12 wk) diets formulated with uncontaminated grains, contaminated grains, and contaminated grains + 0.2% GMA. Feeding contaminated grains significantly decreased BW gains during the grower and developer phases, and GMA supplementation prevented these effects. There was no effect of diet, however, on feed intake or feed efficiency. The feeding of contaminated grains reduced total lymphocyte counts at wk 3 (P < 0.05). Dietary supplementation with GMA increased plasma total protein concentrations compared with controls and birds fed the contaminated diet. Plasma uric acid concentrations in birds fed contaminated grains were increased at the end of the experiment compared with controls, and the feeding of GMA prevented this effect. Feeding contaminated grains significantly increased the percentage of CD4(+) lymphocyte populations during wk 6; however, there was no change in the percentage of CD8(+) and B-lymphocyte populations. Contact hypersensitivity to dinitrochlorobenzene, which is a CD8(+) T cell-mediated delayed-type hypersensitivity response, was significantly decreased after 24 and 72 h by feedborne mycotoxins compared with controls. Supplementation of the contaminated diet with GMA prevented the decrease in response after 24 h. Secondary antibody (IgG titer) response against SRBC antigens (CD4(+) T cell-dependent) was significantly decreased after feeding contaminated grains compared with controls. It was concluded that turkey performance and some blood and immunological parameters were adversely affected by feedborne Fusarium mycotoxins, and GMA prevented many of these effects.

Fumonisin production by Fusarium verticillioides strains isolated from maize in Mexico and development of a polymerase chain reaction to detect potential toxigenic strains in grains

Fumonisins are mycotoxins produced by Fusarium verticillioides (Sacc. Nirenberg) in maize (Zea mays L.), a staple crop in Mexico. In this study, we report the isolation and identification of 67 Fusarium strains isolated from maize kernels collected in Northwest and Central Mexico. The strains were characterized regarding fumonisin B(1) production and the presence of the FUM1 gene. F. verticillioides was the predominant species isolated in both geographic regions, but the isolates from Northwest Mexico produced higher levels of fumonisin. A polymerase chain reaction (PCR)-based method, to detect a region of the FUM1 gene involved in fumonisin biosynthesis, was developed and employed to detect mycotoxigenic fungi in pure culture and in contaminated maize. The presence of the FUM1 gene was associated with fumonisin production in most isolates, except seven that did not synthesize fumonisin but contained the gene in their genome. The PCR method allowed the direct detection of fungal contamination in ground corn and could be employed to screen for the presence of potential mycotoxigenic fusaria.

Mechanism of action of sphingolipids and their metabolites in the toxicity of fumonisin B1

Fumonisins are a group of mycotoxins produced primarily by Fusarium moniliforme. Several fumonisins have been isolated through out the years but only fumonisin B1, B2 and B3 are the ones present in naturally contaminated foods, with B1 being the most toxic between them. The structural similarity between sphinganine and fumonisin B1 suggests that the mechanism of action of this mycotoxin is mainly via disruption of sphingolipid metabolism, this is an important step in the cascade of events leading to altered cell growth, differentiation and cell injury. Sphingolipids are a second type of lipid found in cell membranes, particularly nerve cells and brain tissues. Toxicity of fumonisin B1 is given via inhibition of ceramide synthase that catalyzes the formation of dihydroceramide from sphingosine. This mechanism of action may explain the wide variety of health effects observed when this mycotoxin is ingested like high rate of human oesophageal cancer and promotion of primary liver cancer.

Evaluation of reduced toxicity of zearalenone by extrusion processing as measured by the MTT cell proliferation assay

The objective of this study was to determine loss of toxicity of zearalenone in extruded cereal-based products by the MTT (tetrazolium salt) cell proliferation assay using a sensitive MCF-7 human breast cancer cell line and to compare the results to chemical (high-performance liquid chromatography, HPLC) and biochemical (enzyme-linked immunosorbent assay, ELISA) methods of analysis. A split-split plot design was used for the extrusion process experiments at temperatures of 150, 175, and 200 degrees C and screw speeds of 70 and 140 rpm. The initial zearalenone concentration in the artificially contaminated corn grits with Fusarium graminearum was found at a mean concentration of 37.88 microg/g as measured by HPLC. The percent reductions of zearalenone in the contaminated corn grits upon extrusion processing were in the ranges of 67-81, 60-72, and 66-78% as measured by HPLC, ELISA, and the MTT cell proliferation assay, respectively. The MTT cell proliferation assay results were more closely correlated with HPLC results (r = 0.96) than ELISA results (r = 0.83). The MTT cell proliferation assay was demonstrated to be a useful method for quantification of zearalenone as well as a potential toxicity screening method for contaminated extruded cereal-based products.

Occurrence of fumonisins B1and B2in asparagus from Shandong province, P.R. China

Thirty samples of asparagus spears were collected from the fields in Shandong province, China, in July 2004, and were analysed for the occurrence of fumonisins B1 and B2 (FB1 and FB2) by HPLC coupled with electrospray ionization tandem mass spectrometry. Twenty-four samples (80%) contained fumonisins, ranging from 24 to 670 ng g(-1) (average 123 ng g(-1)) and 17 to 138 ng g(-1)(average 35 ng g(-1)) for FB1 and FB2, respectively. The total amount of fumonisins (FB1 and FB2) in all samples ranged from 47 to 714 ng g(-1) (average 158 ng g(-1)) (based on dry weight). This is the first report on the natural occurrence of FB1 and FB2 in asparagus spears in China.

Genetic polymorphisms of CYP2E1, GSTT1, GSTP1, GSTM1, ALDH2, and ODC and the risk of advanced precancerous gastric lesions in a Chinese population

There have been few studies of the associations of genetic polymorphisms with precancerous gastric lesions. We conducted a cross-sectional study to compare the prevalences of several genetic polymorphisms in 302 subjects with mild chronic atrophic gastritis with prevalences in 606 subjects with deep intestinal metaplasia or dysplasia. This stratified random sample of 908 subjects was selected and analyzed for genetic polymorphisms from 2,628 individuals who had gastric biopsies with histopathology in 1989 in Linqu County, Shandong Province, China. In subjects with mild chronic atrophic gastritis, the frequencies of the variant (less common) alleles of CYP2E1 RsaI, CYP2E1 DraI, GSTP1, ALDH2, and ODC were, respectively, 0.156, 0.201, 0.189, 0.190, and 0.428. The frequencies of the null genotypes of GSTM1 and GSTT1 in the mild chronic atrophic gastritis group were 0.509 and 0.565, respectively. Comparing mild chronic atrophic gastritis with deep intestinal metaplasia or any degree of dysplasia, we found no statistically significant associations with any genotype from these loci for dominant, additive, or recessive inheritance models. There was no statistically significant evidence of multiplicative interactions between any pair of genotypes based on CYP2E1 RsaI, CYP2E1 DraI, GSTP1, GSTM1, or GSTT1; nor between Helicobacter pylori status and any of these five loci; nor between smoking status and GSTP1, GSTM1, or GSTT1; nor between alcohol consumption and ALDH2. Statistically significant interactions were noted between salt consumption and GSTP1 and between sour pancake consumption and CYP2E1 RsaI. There was, moreover, a statistically significant interaction (odds ratio, 1.78; 95% confidence interval, 1.03-3.08) between CYP2E1 DraI and smoking at least one cigarette per day. A positive but not statistically significant interaction was also seen between CYP2E1 RsaI and smoking status. These polymorphisms do not seem to govern progression from mild chronic atrophic gastritis to advanced precancerous gastric lesions, but the effects of smoking may be accentuated in individuals carrying variants of CYP2E1.

Chronic effects of fumonisin B1 on ducks

Partially purified fumonisin B1 (FB1) was orally administrated for 77 d to 5 groups of 8 mule ducks starting at 7 d of age; the concentrations corresponded to 5 diets containing 0, 2, 8, 32, and 128 mg of FB1/kg of feed. No mortality was observed, and no effects on feed consumption and body weight gain were observed at the end of the treatment period. But, surprisingly, FB1 ingested at 32 and 128 mg/kg led to decreased body weight from d 28 to 63 and from d 7 to 63, respectively. FB1 had no effect on the relative weight of heart and breast muscle, whereas a significant increases in the relative weights of gizzard, spleen, and liver were measured in ducks receiving 32 and 128 mg of FB1/kg of feed without evidence of detectable microscopic modification of these organs. FB1 had no significant effect of the serum aspartate aminotransferase and gamma-glutamyltransferase levels but increased serum total protein, cholesterol, alanine aminotransferase, lactate dehydrogenase, alkaline phosphatase levels when 128 mg of FB1/kg of feed was given. Serum, liver, and kidney sphinganine to sphingosine ratio was significantly increased in ducks fed 8 to 128 mg of FB1/kg of feed. The biggest increase was observed in kidneys, suggesting that this organ is the most sensitive to detect FB1-induced disruption of sphingolipid metabolism.

Toxicity of maize containing known levels of fumonisin B1 during force-feeding of ducks

The toxicity of maize containing known doses of fumonisin B1 (FB1) was investigated in mallard ducks during force-feeding. Seventy-five ducks at 12 wk of age were randomly divided into 3 groups of 25, and received control maize, naturally contaminated maize containing 20 mg/kg of FB1, or a mixture of control and contaminated maize (50/50, vol/vol). Force-feeding was performed during 12 d that correspond to a final average feed intake of approximately 10 kg of maize per duck. At the end of the study, 8% mortality was observed in ducks fed 20 mg of FB1/kg of feed, whereas no mortality occurred in the other groups. Liver weight, and plasma concentrations of protein, cholesterol, alanine aminotransferase (ALAT), and lactate dehydrogenase (LDH) were increased by force-feeding, whereas feed conversion ratio appeared decreased by the toxin. Microscopic examination of the liver showed that steatosis was mostly macrovacuolar in control ducks, whereas it was microvacuolar in ducks fed 20 mg of FB1/kg of feed. Free sphingolipid concentrations were measured in liver and plasma. Sphinganine (Sa) and sphinganine to sphingosine (Sa/So) ratio were increased in all treatment groups. These parameters were not affected by force-feeding and all individual values obtained in the treated ducks were higher than those obtained in control ducks. Our results suggest that free Sa level and Sa/So ratio can be used to reveal exposure of ducks to FB1 at doses of 10 mg/kg or greater in feed.

Sphinganine to sphingosine ratio and predictive biochemical markers of fumonisin B1 exposure in ducks

The kinetics of free sphinganine (Sa), sphinganine to sphingosine ratio (Sa/So), proteins, cholesterol, alanine aminotransferase (ALAT) and lactate dehydrogenase (LDH) were investigated in the course of fumonisin B1 (FB1) exposure in ducks (20 growing males divided into four groups of 5 receiving, respectively, a daily dose of 0, 5, 15 or 45 mg/kg FB1 via oral administration over 12 days). Descriptive statistics of these parameters were also studied in a large number of ducks not exposed to mycotoxins and free of known pathology. Although the toxin at the end of the treatment affected all the parameters investigated, only 2 days of treatment appeared necessary to increase free Sa concentrations in serum, whereas 6 days were necessary to detect a significant effect on Sa/So ratio. Significant differences between control and treated ducks were observed after 4 days of treatment for ALAT and LDH and after 6 and 8 days for cholesterol and proteins concentrations. The minimum doses of FB1 required to determine an effect were assessed using three different methods. This approach reveals that FB1 has greater effects when it is ingested at a low dose for a long time than when ingested at a high dose for a short time. Although the minimum toxic dose of FB1 in ducks remains to be determined, this result must be considered in the context of chronic exposure to the toxin, not only in avian populations.

Indoor mold, toxigenic fungi, and Stachybotrys chartarum: infectious disease perspective

Damp buildings often have a moldy smell or obvious mold growth; some molds are human pathogens. This has caused concern regarding health effects of moldy indoor environments and has resulted in many studies of moisture- and mold-damaged buildings. Recently, there have been reports of severe illness as a result of indoor mold exposure, particularly due to Stachybotrys chartarum. While many authors describe a direct relationship between fungal contamination and illness, close examination of the literature reveals a confusing picture. Here, we review the evidence regarding indoor mold exposure and mycotoxicosis, with an emphasis on S. chartarum. We also examine possible end-organ effects, including pulmonary, immunologic, neurologic, and oncologic disorders. We discuss the Cleveland infant idiopathic pulmonary hemorrhage reports in detail, since they provided important impetus for concerns about Stachybotrys. Some valid concerns exist regarding the relationship between indoor mold exposure and human disease. Review of the literature reveals certain fungus-disease associations in humans, including ergotism (Claviceps species), alimentary toxic aleukia (Fusarium), and liver disease (Aspergillys). While many papers suggest a similar relationship between Stachybotrys and human disease, the studies nearly uniformly suffer from significant methodological flaws, making their findings inconclusive. As a result, we have not found well-substantiated supportive evidence of serious illness due to Stachybotrys exposure in the contemporary environment. To address issues of indoor mold-related illness, there is an urgent need for studies using objective markers of illness, relevant animal models, proper epidemiologic techniques, and examination of confounding factors.

Identification of enterococci isolated from cow's milk cheese: comparison of the classical methods and the API 20 STREP system (technical note)

A comparison of the results obtained using the classical methods with those of the API 20 Strep system was carried out in identifying 24 enterococci strains isolated from San Simón cow's milk cheese, a traditional Spanish variety. The results of both identification systems coincided exactly in 9 strains (37.5% of the strains studied). In one strain the results obtained using the classical methods did not coincide with those using the API 20 Strep method. 3 strains (12.5%) could not be identified using the API 20 Strep system. However, 11 strains (45%), that remained doubtful between both species E. faecalis and E. faecium on the basis of the classical methods, were identified using the API 20 Strep system. The API 20 Strep system does not include some biochemical tests of importance in identifying of foodborne enterococci and could not identify the atypical strains of Enterococcus. Moreover, this system is adapted to the identification of enterococci of clinical origin and their database does not include some species common in foods. However, it could have an application in combination with the classical methods in order to carry out a reasonably rapid and reliable identification of enterococci related to cheese.

Survey for fumonisin B1 in Korean corn-based food products

Seventy-six corn-based foods collected in Seoul, Korea, including corn flakes, corn snack, cornstarch, corn for popping, roasted corn for tea, canned sweet corn and other corn products were analysed for the occurrence of fumonisin B(1) (FB(1)) by using direct competitive enzyme-linked immunosorbent assay (dcELISA) and high-performance liquid chromatography (HPLC). The average recoveries of FB(1) from the corn flakes sample in the range 5-1000 ng g(-1) were 104% by dcELISA and 82% by HPLC. The limits of detection were approximately 5 ng g(-1) by dcELISA and 20 ng g(-1) by HPLC. The incidences and mean levels of FB were 73.3, 78.6, 50, 58.3, 17.6 and 40% and 41.8, 67.9, 114, 256, 172 and 22 ng g(-1) from corn flakes, corn snack, corn starch, corn for popping, roasted corn for tea and other corn products, respectively, by dcELISA. No FB(1) was found in canned sweet corn. The results obtained by dcELISA were correlated to those by HPLC for FB(1) (r(2) = 0.992). This is the first report on the occurrence of FB(1) in corn-based foods in Korea.

A case-control study of gastric cancer in Venezuela

A case-control study to evaluate risk factors for gastric cancer was carried out among 292 cases of gastric cancer and 485 controls in a high-risk area of Venezuela. Subjects were interviewed using a structured questionnaire, which elicited information on residential history, socio-economic status, family history of gastric diseases, smoking, drinking and dietary habits. Habitual diet was estimated from a meal-structured food frequency questionnaire on 75 food items. There was a strong inverse association with social class, as measured by education and by indicators of poverty. The results of the dietary analysis suggest that a diet high in starch and low in meat, fish and fresh vegetables increases risk of gastric cancer. A protective effect was observed for frequent consumption of allium vegetables. Inverse associations were found with height, which may reflect nutritional status in childhood, and with refrigerator use in the first two decades of life. Alcohol and tobacco consumption was investigated among males only, since the prevalence of alcohol and tobacco use was very low in females. Alcohol drinkers were at higher risk than non-drinkers and there was a small excess risk for current smokers compared with never smokers. There was some evidence of familial aggregation of gastric cancer. These findings will have important implications in planning preventive strategies for gastric cancer in Venezuela.

Toxicity of Fusarium moniliforme culture material containing known levels of fumonisin B1 in ducks

Fusarium moniliforme culture material toxicity containing fumonisin B1 (FB1) was investigated into four groups of five growing ducks, each receiving 0,5,15 or 45 mg/kg FB1 by daily oral administration over 12 days. Treatments did not lead to lethality, but the average body weight gain was slightly retarded in treated versus control animals, without apparent dose relation. A dose-dependent increase of the liver weight with a disorganization of the span and implementation of a microglandular structure in both periportal and centrolobular areas was obtained. In the plasma, together protein, cholesterol, alanine aminotransferase, lactate dehydrogenase, gammaglutamyl transferase and sphinganine to sphingosine ratio (SA/SO) were increased. No sign of apoptosis was present neither in the liver nor in peripheral blood lymphocytes and only moderate oxidative damages were obtained. These results are of interest, because although FB1 increases SA/SO and is hepatotoxic in all investigated species, liver hyperplasia with increased liver weight were obtained in ducks, whereas decreased liver weight and apoptosis are observed in rats. Finally, although ducks appeared resistant to FB1 toxicity in terms of mortality, liver alterations were obtained with only 5 mg/kg per day of FB1 for 12 days. Considering the fact that high levels of FB1 may occur in corn (100-300 mg/kg), liver pathology could have an impact in farming conditions.

Effects of fumonisin B1 present in Fusarium moniliforme culture material on drug metabolising enzyme activities in ducks

The effects of fumonisin B1 (0, 5, 15 and 45 mg/kg/day), obtained from culture material of Fusarium moniliforme, on drug metabolising enzyme activities were investigated in four groups of five growing ducks by daily oral administration over 12 days. No lethality or sign of toxicosis occurred. The liver and kidney weights were increased, whereas microsomal and cytosolic tissue fractions were unaffected. Although the total microsomal P450 content was unaffected, benzphetamine, ethylmorphine, erythromycin N-demethylases and ethoxyresorufin O-deethylase activities were together increased (respectively by 114, 242, 57 and 27% with 5 mg/kg/day and 1024, 969, 200 and 147% with 45 mg/kg/day). By contrast, aminopyrine and nitrosodimethylamine N-demethylases, methoxyresorufin and pentoxyresorufin O-dealkylases, and UDP-glucuronyltransferase activities were only increased by using 45 mg/kg/day, whereas glutathione S-transferases activities remained unaffected.

Effects of mycotoxins on human immune functions in vitro

Immunosuppressive and carcinogenic Fusarium mycotoxins may appear in domestic food products. Therefore, the immunological effects of Fusarium mycotoxins were tested on human peripheral blood mononuclear cells from different blood donors. In the present study we investigated deoxynivalenol (DON), 3-acetyldeoxynivalenol, fusarenon-X, T-2 toxin, zearalenone, alpha-zearalenol, beta-zearalenol and nivalenol for their effects on T and B cells in a proliferation assay, antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) cell activity on human peripheral blood mononuclear cells. The concentrations applied in our experiments were similar to those which can be found in normal human peripheral blood system (0.2--1800 ng/ml). Among the eight mycotoxins tested, T-2 toxin, fusarenon X, nivalenol and deoxynivalenol exerted the highest immunosuppressing effect on human peripheral blood mononuclear cells in vitro. Mycotoxin-induced immunosupression was manifested as depressed T or B lymphocyte activity. Furthermore, by virtue of inhibition of NK cell activity, the protection against tumor development may also be attenuated.