Genotoxic risk in occupational exposure to petrol and its amelioration by vitamin C and vitamin E

Petrol contains mixture of mutagens and carcinogens which have potential health risk after prolonged occupational exposure. We have compared genotoxicity and its amelioration in blood samples from 70 petrol pump attendants, working in congested area of the Ahmedabad city, India and similar number (n = 70) of Control samples from office workers dwelling in less polluted areas of the city. The cytokinesis-block micronucleus assay showed highly significant frequencies of micronucleus in Exposed than in the Controls. The sister chromatid exchanges were also significantly increased while the cell cycle proliferative index was significantly decreased in the Exposed individuals than the Controls. Addition of standardized doses of vitamin C and vitamin E in the lymphocyte cultures (in vitro) significantly improved all the biomarkers. The long-term occupational petrol exposure causes genotoxic effects and use of vitamins C and E for protection should be further explored in randomized controlled studies.

Provitamin A Carotenoids in Grain Reduce Aflatoxin Contamination of Maize While Combating Vitamin A Deficiency

Aflatoxin contamination of maize grain and products causes serious health problems for consumers worldwide, and especially in low- and middle-income countries where monitoring and safety standards are inconsistently implemented. Vitamin A deficiency (VAD) also compromises the health of millions of maize consumers in several regions of the world including large parts of sub-Saharan Africa. We investigated whether provitamin A (proVA) enriched maize can simultaneously contribute to alleviate both of these health concerns. We studied aflatoxin accumulation in grain of 120 maize hybrids formed by crossing 3 Aspergillus flavus resistant and three susceptible lines with 20 orange maize lines with low to high carotenoids concentrations. The hybrids were grown in replicated, artificially-inoculated field trials at five environments. Grain of hybrids with larger concentrations of beta-carotene (BC), beta-cryptoxanthin (BCX) and total proVA had significantly less aflatoxin contamination than hybrids with lower carotenoids concentrations. Aflatoxin contamination had negative genetic correlation with BCX (-0.28, p < 0.01), BC (-0.18, p < 0.05), and proVA (-0.23, p < 0.05). The relative ease of breeding for increased proVA carotenoid concentrations as compared to breeding for aflatoxin resistance in maize suggests using the former as a component of strategies to combat aflatoxin contamination problems for maize. Our findings indicate that proVA enriched maize can be particularly beneficial where the health burdens of exposure to aflatoxin and prevalence of VAD converge with high rates of maize consumption.

Consumed Foodstuffs Have a Crucial Impact on the Toxic Activity of Enteropathogenic Bacillus cereus

Enteropathogenic Bacillus cereus cause diarrhea due to the production of enterotoxins in the intestine. To start this process, spores have to be ingested together with contaminated food and survive the stomach passage. In this study, the influence of consumed foodstuffs on spore survival as well as on cytotoxicity toward colon epithelial cells was investigated. Spore survival of 20 enteropathogenic and apathogenic B. cereus strains during simulated stomach passage was highly strain-specific and did not correlate with the toxic potential. Survival of three tested strains was strain-specifically altered by milk products. Whereas milk, a follow-on formula and rice pudding had only little influence, spores seemed to be protected by milk products with high fat content such as whipped cream and mascarpone. Furthermore, tested milk products decreased the toxic activity of three B. cereus strains toward CaCo-2 cells. Investigating the individual components, lactoferrin, a skim milk powder and vitamins C, B5 and A showed the most inhibiting effects. On the other hand, biotin, vitamin B3 and another skim milk powder even enhanced cytotoxicity. Further studies suggested that these inhibiting effects result only partially from inhibiting cell binding, but rather from blocking the interaction between the single enterotoxin components.

Changes in the regulation and activity of glutathione redox system, and lipid peroxidation processes in short-term aflatoxin B1 exposure in liver of laying hens

The purpose of this study was to investigate the short-term (48 hr) effects of feeding aflatoxin contaminated diet (170.3 μg/kg AFB1) in 49-week-old laying hens. Liver samples were taken at 12-hr intervals. Feed intake, body weight, absolute and relative liver weight were the same in groups. However, there was no feed intake during both dark periods (between 12nd to 24th and 36th to 48th hours of the experiment); therefore, aflatoxin intake was also negligible. Markers of initial phase of lipid peroxidation, conjugated dienes and trienes did not change as effect of aflatoxin, but terminal marker, malondialdehyde content was significantly higher at 12 hr as effect of aflatoxin. No significant difference was found in reduced glutathione concentration and glutathione peroxidase activity between the groups. Expression of glutathione peroxidase 4 gene (GPX4) was significantly reduced due to aflatoxin treatment at 12 and 24 hr, but induced later, while glutathione reductase gene (GSR) expression was significantly lower at 24 hr and glutathione synthetase gene (GSS) in aflatoxin-treated group at 12 hr. The results suggest that aflatoxin induced oxygen-free radical formation, but it did not reach critical level during this short period of time to cause activation of the expression of glutathione system.

Coexistence of Aflatoxicosis with Protein Malnutrition Worsens Hepatic Oxidative Damage in Rats

To investigate the effects of the coexistence of aflatoxin B1 (AFB1) and protein malnutrition in rat liver, weanling rats were fed either normal protein diet (20% protein), low-protein (PEM) diet (5%), normal protein diet + 40 ppb AFB1, or low-protein diet + 40 ppb AFB1. After 8 weeks, biomarkers of hepatic functions and oxidative stress, caspase-3 activity, and tumor suppressor protein 53 (p53) were determined spectrophotometrically. Randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was employed to determine genomic alterations among the groups. Coexistence of aflatoxicosis and PEM significantly decreased glutathione, glutathione-S-transferase, glutathione peroxidase, and superoxide dismutase, while it increased peroxidase and catalase. RAPD-PCR showed genomic alterations that were associated with significant increases in p53 level and caspase-3 activity in rats fed PEM diet + AFB1. In conclusion, the coexistence of aflatoxicosis and protein malnutrition induced oxidative stress with concomitant genomic alterations in the liver of weanling rats.

Effects of aflatoxin B1 on oxidative stress markers and apoptosis of spleens in broilers

The purpose of the present study was to investigate the oxidative damage and apoptosis induced by aflatoxin B1 (AFB1) in spleen of broilers. A total of 200 one-day-old avian male broilers were randomly divided into 4 equal groups of 50 each and were fed for 21 days as follows: a control diet and three AFB1 diets containing 0.15, 0.3, and 0.6 mg AFB1/kg diet. Consumption of AFB1 diets induced oxidative stress in the spleen of chicken as evidenced by reduced glutathione peroxidase, glutathione reductase, and catalase activities, decreased glutathione contents, and increased malondialdehyde contents in explaining the pathogenesis. Flow cytometer method and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay revealed that the apoptotic splenocytes were increased in AFB1 groups. The results suggest that AFB1 induced excessive apoptosis of splenic lymphocytes, which is correlated with increased oxidative stress. The present results may be helpful for explaining the pathogenesis of AFB1-induced immunosuppression.

Assessment of total aflatoxin level in red pepper obtained from Istanbul

Aflatoxins (Aspergillus flavus toxins (AFT)) are biologically active secondary metabolites mostly produced by some Aspergillus species that causes hepatotoxicity, teratogenicity, immunotoxicity, and cancers in human. The aim of this study is to determine the level of total AFT in powdered red pepper in the retail markets in 40 district of Istanbul using enzyme-linked immunosorbent assay. Of the 36 unpacked powdered red pepper samples, 32 samples (88%) contained AFT in the range of 0.2-106.4 µg/kg; 16 samples (44.4%) were above the regulatory limit which is at 10 µg/kg for total AFT in Turkey. More precautions on the production, transport, harvest, and storage of red pepper should be taken on hygiene to prevent toxic and carcinogenic effects of AFT.

Protective role of methanol extracts of two lichens on oxidative and genotoxic damage caused by AFB1 in human lymphocytes in vitro

In this study, the antigenotoxic and antioxidant effects of Umbilicaria vellea (UME) and Xantho somloensis (XME) extracts were determined using sister chromatid exchange (SCE), micronuclei (MN) assays, and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and malondialdehyde (MDA) levels against the effects of aflatoxin B(1) (AFB(1))-induced oxidative stress and genotoxicity in human lymphocytes in vitro. The results showed that the frequencies of SCE, MN, and MDA level decreased, but the activities of SOD and GPx increased when 5 μg/mL and 10 μg/mL doses of UME and XME were added to AFB(1)-treated cultures. Also the present results indicate that strong antioxidative and the antigenotoxicity mechanisms of UME and XME are associated with its antioxidant nature.

Anti-oxidative and anti-genotoxic effects of carnosine on human lymphocyte culture

The aim of this study was to investigate the effects of carnosine, a biological antioxidant, on the oxidative stress and genotoxicity by a single dose of carbon tetrachloride (CCl4; 5 mM) in the human lymphocyte culture. We studied the anti-genotoxic effects of carnosine by using sister chromatid exchange (SCE) test system. Also, the anti-oxidative effects of carnosine were evaluated by using superoxide dismutase (SOD), glutathione peroxidase (GPx), total glutathione (GSH) and malondialdehyde (MDA) assay. The SCE frequency was increased when treated with CCl4. Carnosine at 10 and 20 mM reduced SCE frequency in the human lymphocyte ( p < 0.001). In addition, CCl4 treatment significantly depleted the level of GSH, reduced the activity of SOD and GPx and elevated the level of MDA ( p < 0.001). Carnosine treatment led to significant attenuation of CCl4-induced oxidative stress by normalization of the activities of SOD and GPx and the level of GSH and MDA ( p < 0.05 or 0.001). These results suggest that carnosine could provide anti-oxidative and anti-genotoxic protection for the oxidative and genotoxic agents that cause many diseases including cancer and neurodegenerative disease.

Protective role of methanol extract of Cetraria islandica (L.) against oxidative stress and genotoxic effects of AFB1 in human lymphocytes in vitro

In this study, the antigenotoxic and antioxidant effects of Cetraria islandica methanol (CME) extract were determined by using sister chromatid exchange (SCE), micronuclei (MN) assays and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and malondialdehyde (MDA) levels against effects of aflatoxin B1 (AFB 1) induced oxidative stress and genotoxicity in human lymphocytes in vitro. The results showed that the frequencies of SCE, MN and MDA level decreased, SOD and GPx activities increased when 5 μg/mL and 10 μg/mL doses of CME were added to AFBı-treated cultures. Also, the present results indicate that CME has strong antioxidative and the antigenotoxicity mechanisms of CME are associated with its antioxidant nature.

Protective effects of selenium against sister chromatid exchange induced by AFG 1 in human lymphocytes in vitro

Aflatoxins have been shown to be hepatotoxic, carcinogenic, mutagenic and teratogenic to different species of animals. Besides, at low concentrations, Selenium (Se(4+)) is antimutagenic and anticarcinogenic while it is toxic, mutagenic and carcinogenic at high concentrations. In this study, we aimed to evaluate the effect of Se(4+) against aflatoxin GAFG(1) (AFG(1)) on blood cultures in relation to induction of sister chromatid exchange (SCE). The results showed that at 0.4 and 0.8 parts per million (ppm) concentration of AFG(1), the frequency of SCE increased in cultured human lymphocytes. When different concentration of Se(4+) (0.08 and 8 ppm) were added to AFG(1), the frequencies of SCE decreased. Howewer, when 800 ppm concentration of Se(4+) together with 0.08 ppm AFG(1) were added to cell division inhibited in the cultures. Results suggested that Se(4+) could effectively inhibit AFG(1)-induced SCE. Besides, the protective role of Se(4+) against AFG(1)-induced SCE is probably related to its doses.