Toxicity and oxidative stress induced by T-2 toxin and HT-2 toxin in broilers and broiler hepatocytes

T-2 and HT-2 toxins belong to mycotoxins which are found in human foods and animal chow. We investigated the toxicity and oxidative stress induced by T-2/HT-2 in broilers and chicken hepatocytes. Maize cultures of Fusarium poae was fed to broilers for 42 d, and the physiological index, biochemical index and expression of mRNAs related to oxidative stress were analyzed. Chicken hepatocytes were treated with different levels of T-2/HT-2, and the following parameters were detected: cell viability, GSH and MDA concentration, LDH leakage, activities of ALT/AST, ROS, GSH-PX, SOD and CAT, and expression of mRNA related to oxidative stress. In vivo, high levels of mycotoxins (4 mg/kg T-2 and 0.667 mg/kg HT-2) in feed caused significant reductions in body weight, weight gain, and serum total protein, and significant increases in feed conversion ratio, ALP, ALT/AST activities, and expression of mRNA related to oxidative stress. In vitro, cells treated with T-2/HT-2 showed reductions of GSH concentration and significant increases in LDH leakage, ALT/AST ROS, GSH-PX, SOD and CAT activities, MDA concentration, and expression of mRNA related to oxidative stress. Consequently, F. poae culture material and T-2/HT-2 induced toxicity and oxidative stress in vivo and in vitro, respectively.     

Strawberry consumption alleviates doxorubicin-induced toxicity by suppressing oxidative stress

Doxorubicin (Dox), one of the most used chemotherapeutic agents, is known to generate oxidative stress and block DNA synthesis, which result in severe dose-limiting toxicity. A strategy to protect against Dox toxic effects could be to use dietary antioxidants of which fruits and vegetable are a rich source. In this context, strawberry consumption is associated with the maintenance of good health and the prevention of several diseases, thanks to the antioxidant capacities of its bioactive compounds. The aim of the present study was to evaluate the protective effects of strawberry consumption against oxidative stress induced by Dox in rats. Animals were fed with strawberry enriched diet (15% of the total calories) for two months and Dox (10 mg/kg; i.p.) was injected at the end of the experimental period. Strawberry consumption significantly inhibited ROS production and oxidative damage biomarkers accumulation in plasma and liver tissue and alleviated histopathological changes in rat livers treated with Dox. The reduction of antioxidant enzyme activities was significantly mitigated after strawberry consumption. In addition, strawberry enriched diet ameliorated liver mitochondrial antioxidant levels and functionality. In conclusion, strawberry intake protects against Dox-induced toxicity, at plasma, liver and mitochondrial levels thanks to its high contents of bioactive compounds.     

Atorvastatin induced hepatic oxidative stress and apoptotic damage via MAPKs,mitochondria, calpain and caspase12 dependent pathways

Atorvastatin (ATO), a 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor, is used widely for the treatment of hypercholesterolemia and hypertriglyceridemia. Application of this drug has now been made somehow limited because of ATO associated several acute and chronic side effects. The present study has been carried out to investigate the dose-dependent hepatic tissue toxicity in ATO induced oxidative impairment and cell death in mice. Administration of ATO enhanced ALT, ALP level, increased reactive oxygen species (ROS) production and altered the pro oxidant-antioxidant status of liver by reducing intracellular GSH level, anti-oxidant enzymes activities and increasing intracellular lipid peroxidation. Our experimental evidence suggests that ATO markedly decreased mitochondrial membrane potential, disturbed the Bcl-2 family protein balance, enhanced cytochrome c release in the cytosol, increased the levels of Apaf1, caspase-9, -3, cleaved PARP protein and ultimately led to apoptotic cell death. Besides, ATO distinctly increased the phosphorylation of p38, JNK, and ERK MAPKs, enhanced Caspase12 and calpain level. Histological studies also support the dose-dependent toxic effect of ATO in these organs pathophysiology. These results reveal that ATO induces hepatic tissue toxicity via MAPKs, mitochondria and ER dependent signaling pathway, in which calcium ions and ROS act as the pivotal mediators of the apoptotic signaling.     

Effect of cadmium-polluted water on plasma levels of tumor necrosis factor-α, interleukin-6 and oxidative status biomarkers in rats: Protective effect of curcumin

The present study was designed to investigate the effect of CdCl₂-polluted drinking water (40 mg CdCl₂/L) on the level of TNF-α and IL-6, as well as oxidative status biomarkers in plasma of rats. The possible protective effect of oral administration of curcumin (50 mg/kg body weight/day) was assessed. Results illustrated that Cd exposure significantly elevated the plasma levels of TNF-α and IL-6 (p < 0.001) as compared to normal rats. Also, Cd administration resulted in a significant elevation in the lipid peroxidation and markedly reduction in the activities of SOD and catalase as well as the level of glutathione and total antioxidant capacity in plasma. The co-treatment of Cd with curcumin significantly reduced the levels of TNF-α and IL-6 and ameliorated the alteration in oxidative status biomarkers induced by Cd. Negative correlation between IL-6 or TNF-α was and the plasma activities of catalase, SOD and the level of total antioxidant capacity were found in rats exposed to Cd. Conclusion: Cadmium toxicity induced the release of TNF-α and IL-6 which is associated with systemic oxidative stress. This may be involved in the mechanism of the Cd toxicity. On the other hand, the findings suggest the curative action of curcumin against Cd toxicity.     

A two-year dietary carcinogenicity study of cyadox in Sprague-Dawley rats

To investigate the potential carcinogenicity of cyadox, an antimicrobial agent, four groups of Sprague-Dawley rats (50 rats/sex/group) were fed diets containing cyadox (0, 200, 600 or 2000 mg/kg) for up to two years. There were significant decreases in body weight, feed intake and feed efficiency in both genders during most of the period in the 2000 mg/kg group. Significant decreases in serum ALT were observed in the 2000 mg/kg group at weeks 52, 78 and 104. For the control, 200, 600, and 2000 mg/kg groups, the tumor incidence in females was 33.3%, 37.2%, 40.0% and 19.0%, while it in males it was 18.9%, 2.6%, 17.1% and 13.6%, respectively. At histopathology, no increases in tumor incidence were attributed to treatment with cyadox. The mild swelling and fatty degeneration in hepatocytes, and mild swelling and tubular necrosis in the kidney were observed in 2000 mg/kg group. The no-observed-effect-level (NOEL) for carcinogenicity of cyadox fed to rats was 2000 mg/kg diet (132.18–156.28 mg/kg b.w./day). In conclusion, cyadox was not carcinogenic to rats with the liver and kidney as the target organs, and the side chain may be involved in toxicity and carcinogenicity mediated by QdNOs.     

High calcium diet improves the liver oxidative stress and microsteatosis in adult obese rats that were overfed during lactation

Obesity is related to diabetes, higher oxidative stress and nonalcoholic fatty liver disease, and dietetic therapies, for instance calcium-rich diet, can improve these dysfunctions. Rats raised in small litters (SL) had increased fat depots and insulin resistance at adulthood associated with higher liver oxidative stress and microsteatosis. Thus, we evaluated if dietary calcium can improve these changes. In PN3, litter size was adjusted to 3 pups (SL group) to induce overfeeding, while controls had 10 pups until weaning. At PN120, SL group was randomly divided into: rats fed with standard chow or fed with calcium supplementation (SL–Ca group, 10 g/kg chow) for 60 days. At PN180, dietary calcium normalized food consumption, visceral fat, plasma aspartate aminotransferase (AST) and glycaemia. Concerning oxidative balance, calcium restored both higher hepatic lipid peroxidation and protein carbonylation as well as higher plasma lipid peroxidation. Higher fatty acid synthase (FAS) content, steatosis and lower protein kinase B (Akt) in SL group were normalized by dietary calcium and SL–Ca rats had lower hepatic cholesterol. Thus, calcium supplementation improved the insulin sensitivity, redox balance and steatosis in the liver. Therefore, dietary calcium can be a promising therapy for liver disease in the metabolic syndrome.     

Rat and poultry feeding studies with soybean meal produced from imidazolinone-tolerant (CV127) soybeans

The safety and nutritional properties of CV127 soybeans were evaluated in rat and broiler feeding studies. Some episodic differences were observed between rats fed CV127, Conquista, and the standard diet for the endpoints examined. None of these differences were considered treatment related, adverse, or biologically meaningful. In general, birds fed diets containing CV127, Conquista, or Monsoy 8001 showed no significant differences in growth and performance response variables. Chickens fed diets containing Coodetec 217 had lower body weight and weight gain for all developmental periods compared to CV127, but no significant differences were found in feed conversion for the two diets during any development period. The results of both feeding studies demonstrate that CV127 soybeans are as safe, wholesome, and nutritionally valuable as the other soybean meals tested, including those varieties for which histories of safe use have been established and well documented.     

Identification of novel glutathione adducts of benzbromarone in human liver microsomes

Benzbromarone (BBR) is a potent uricosuric drug that can cause serious liver injury. Our recent study suggested that 1′-hydroxy BBR, one of major metabolites of BBR, is metabolized to a cytotoxic metabolite that could be detoxified by glutathione (GSH). The aim of this study was to clarify whether GSH adducts are formed from 1′-hydroxy BBR in human liver microsomes (HLM). Incubation of 1′-hydroxy BBR with GSH in HLM did not result in the formation of GSH adducts, but 1′,6-dihydroxy BBR was formed. In addition, incubation of 1′,6-dihydroxy BBR with GSH in HLM resulted in the formation of three novel GSH adducts (M1, M2 and M3). The structures of M1 and M2 were estimated to be GSH adducts in which the 1-hydroxyethyl group at the C-2 position and the hydroxyl group at the C-1′ position of 1′,6-dihydroxy BBR were substituted by GSH, respectively. We also found that the 6-hydroxylation of 1′-hydroxy BBR is mainly catalyzed by CYP2C9 and that several CYPs and/or non-enzymatic reaction are involved in the formation of GSH adducts from 1′,6-dihydroxy BBR. The results indicate that 1′-hydroxy BBR is metabolized to reactive metabolites via 1′,6-dihydroxy BBR formation, suggesting that these reactive metabolites are responsible for BBR-induced liver injury.     

Antioxidant power as biochemical endpoint in bread for screening and early managing quality and toxicant-related safety anomalies in food production

Flaxseeds are both a food ingredient and a natural source of antioxidants (e.g. lignans, PUFAs) and pro-oxidant contaminants (e.g. cadmium): the variable mixture of anti- and pro-oxidant substances may impact on the redox homeostasis of flaxseed-enriched foods. The antioxidant power is studied here as biochemical activity of flaxseeds in white wheat bread and as endpoint for possible screening of anomalous variations of bioactive mixtures (antioxidants vs. prooxidants) in food matrices.A bioprobe assay based on the superoxide dismutase (SOD) enzyme (6 channels of the multiprobe bioelectronic platform BEST) was performed on white wheat bread with and without flaxseeds. Nine BEST channels were simultaneously used for validation and monitoring of measuring conditions (temperature, pH, conductivity). Findings were compared with quantitative analysis of antioxidants and pro-oxidant contaminants. Organic and aqueous extracts of both bread types were examined in parallel.The SOD-probe detected the difference in antioxidant power given by 10% flaxseed, thus supporting the use of antioxidant power detected by bioenzymatic screening as sensitive biochemical endpoint. Mixtures of bioactive molecules in foods generate biochemical activities that can be monitored as time-effective indicators of invariability, which is pivotal in the daily control of anomalies in food production and therefore in the protection of consumers′ health.     

Prophylactic neuroprotective efficiency of co-administration of Ginkgo biloba and Trifolium pretense against sodium arsenite-induced neurotoxicity and dementia in different regions of brain and spinal cord of rats

The present study was carried out to evaluate the potential protective role of co-administration of Ginkgo biloba, Trifolium pretenseagainst sodium arsenite-induced neurotoxicity in different parts of brain (Cerebral cortex, Hippocampus, striatum and Hind brain) and in the spinal cord of rats. Sodium arsenite caused impairment in the acquisition and learning in all the behavioral tasks and caused significant increase in tumor necrosis factor-α,thiobarbituric acid-reactive substances andlipid profile, while caused significant decrease in glutathione, total thiol content, total antioxidant capacity, acetylcholinesterase, monoamine oxidase and ATPases activities. These results were confirmed by histopathological, fluorescence and scanning electron microscopy examination of different regions of brain. From these results sodium arsenite-induced neurodegenerative disorder in different regions of brain and spinal cord and this could be mediated through modifying the intracellular brain ions homeostasis, cholinergic dysfunction and oxidative damage. The presence of Ginkgo biloba and/orTrifolium pretense with sodium arsenite minimized its neurological damages. It was pronounced that using Ginkgo biloba and Trifolium pretense in combination was more effective as protective agents compared to use eachone of them alone.     

Extra virgin olive oil phenolic extracts counteract the pro-oxidant effect of dietary oxidized lipids in human intestinal cells

The phenolic fraction of extra virgin olive oil (EVOO) concentrates before absorption in the intestinal lumen, where it may contribute to the modulation of enterocytes response to oxidative and inflammatory stimuli. We evaluated the ability of two monovarietal EVOOs phenolic extracts, Bosana and Nera di Gonnos/Tonda di Cagliari, typical and widespread varieties in Sardinia (Italy), to counteract in enterocytes like Caco-2 cells the pro-oxidant action of oxidized lipids, tert-butyl hydroperoxide (TBH) or a mixture of oxysterols of dietary origin. We confirmed that TBH treatment causes a significant increase of ROS production, GSH depletion, increase of MDA, fatty acids hydroperoxides and 7-ketocholesterol, and showed first evidence of oxidative imbalance and cell damage due to oxysterols exposure. Preincubation of cells with the phenolic extracts significantly attenuated oxidative modifications. Bosana extract showed the highest concentration of total phenols, mainly hydroxytyrosol and tyrosol, and was the most active in presence of TBH, where the free radical scavenging activity of these simple phenols seems to be a determining factor. The two extracts were equally effective, in spite of the different composition, in presence of oxysterols, where ROS production probably occurs according to different and more complex mechanisms.     

Trichloroethylene exposure aggravates behavioral abnormalities in mice that are deficient in superoxide dismutase

Trichloroethylene (TCE) has been implicated as a causative agent for Parkinson’s disease (PD). The administration of TCE to rodents induces neurotoxicity associated with dopaminergic neuron death, and evidence suggests that oxidative stress as a major player in the progression of PD. Here we report on TCE-induced behavioral abnormality in mice that are deficient in superoxide dismutase 1 (SOD1). Wild-type (WT) and SOD1-deficient (Sod1^−/−) mice were intraperitoneally administered TCE (500 mg/kg) over a period of 4 weeks. Although the TCE-administrated Sod1^−/− mice showed marked abnormal motor behavior, no significant differences were observed among the experimental groups by biochemical and histopathological analyses. However, treating mouse neuroblastoma-derived NB2a cells with TCE resulted in the down regulation of the SOD1 protein and elevated oxidative stress under conditions where SOD1 production was suppressed. Taken together, these data indicate that SOD1 plays a pivotal role in protecting motor neuron function against TCE toxicity.     

Safety of dietary conjugated α-linolenic acid (CLNA) in a neonatal pig model

The aim of the present study was to perform a short-term safety evaluation of dietary mono-conjugated α-linolenic acid isomers (CLNA; c9-t11-c15-18:3 + c9-t13-c15-18:3) using a neonatal pig model. CLNA diet was compared with three other dietary fats: (1) conjugated linoleic acid (CLA; c9-t11-18:2 + t10-c12-18:2), (2) non-conjugated n-3 PUFA and (3) n-6 PUFA. Thirty-two piglets weaned at 3 weeks of age were distributed into four dietary groups. Diets were isoenergetic and food intake was controlled by a gastric tube. Mono-CLNA diet did not significantly change body or organ weight, carcass composition and most biochemical parameters including; glucose, cholesterol, triglycerides, creatinine, blood urea nitrogen, hepatic enzymes and electrolytes levels in blood (P ⩾ 0.09). Conversely, the n-3 PUFA composition of the brain, liver and heart decreased by 6–21% in the CLNA-fed group compared to animals fed nonconjugated n-3 PUFA (P < 0.01). Responses to dietary treatments were tissue-specific, with the liver and the brain being the most deprived in n-3 PUFA. Our results support that short-term intake of mono-CLNA is safe in neonatal pigs but n-3 PUFA reduction in tissues deserves to be further investigated before using long-term nutritional supplementation in pigs and other animal models and before moving to clinical trials.     

The Fusarium toxin zearalenone and deoxynivalenol affect murine splenic antioxidant functions,interferon levels,and T-cell subsets

This study aimed to evaluate the effects of the Fusarium toxin zearalenone (ZEA) and deoxynivalenol (DON) on splenic antioxidant functions, IFN levels, and T-cell subsets in mice. Herein, 360 mice were assigned to nine groups for a 12-day study. Mice were administered an intraperitoneal injection for 4 consecutive days with different concentrations of ZEA alone, DON alone, or ZEA + DON. Spleen and blood samples were collected on days 0, 3, 5, 8, and 12. Mice in each of the experimental groups showed dysreglated splenic antioxidant functions, IFN levels, and T-cell subset frequencies, suggesting that the immune system had been affected. The ZEA + DON-treated groups, especially the group that received a higher concentration of ZEA + DON (Group D2Z2), showed more obvious effects on the dysregulation of splenic antioxidant functions, IFN levels, and T-cell subsets. This finding suggested that DON and ZEA exerted synergistic effects.     

Assessment of oxidative stress responses and the cytotoxic and genotoxic potential of the herbicide tembotrione in HepG2 cells

Tembotrione is a triketone herbicide, usually used for post-emergence weed control in corn. Currently, there is little or no published data on its genotoxicity to human cells either in vitro or in vivo. This study evaluated the impact of acute (4 and 24 h) exposure to low concentrations of tembotrione [corresponding to the acceptable daily intake (0.17 μg/mL), residential exposure level (0.002 μg/mL) and acceptable operator exposure level (0.0012 μg/mL)] on human hepatocellular carcinoma cell line HepG2, using biomarkers of oxidative stress, CCK-8 colorimetric assay for cell viability, alkaline comet assay, and cytokinesis-block micronucleus “cytome” assay. Tembotrione applied at concentrations likely to be encountered in occupational and residential exposures induced cytogenetic outcomes in non-target cells despite non-significant changes in the values of oxidative stress biomarkers. We assume that the observed effects were mainly the consequence of impaired metabolic pathways in HepG2 cells due to the inhibition of the enzyme 4-hydroxyphenyl-pyruvate-dioxygenase by tembotrione, which possibly caused a depletion of folate levels leading to excess formation of nuclear buds in the affected cells. Regardless of the fact that tembotrione was previously reported negative for mutations and chromosome aberrations in vitro, our findings call for more precaution in its use.     

Cyto-genotoxicity and oxidative stress induced by zinc oxide nanoparticle in human lymphocyte cells in vitro and Swiss albino male mice in vivo

ZnO-np has immense potential and application in cosmetic and health care sectors. Hence it was imperative to assess the toxicity/safety of these nanoparticles. In this study, we have evaluated the effects of ZnO-np in human peripheral blood mononuclear cells (PBMCs) in vitro and in Swiss albino male mice in vivo for cyto-genotoxicity and oxidative damage. In vitro results showed that ZnO-nps were weakly genotoxic, induced significant decrease in mitochondrial membrane potential and was capable of ROS generation, leading to apoptosis. In bone marrow cells in vivo, reduction of mitochondrial membrane potential (MMP), increased oxidative stress and G0/G1 cell cycle arrest was observed along with chromosome aberrations and micronuclei formation. In liver cells DNA damage and induction of oxidative stress with concurrent decrease in inhibition of antioxidant enzymes were noted. These in vitro and in vivo results demonstrated that ZnO-np induced genotoxic response and ROS production leading to apoptotic cell death and established a good co-relation between the two biological systems. More importantly, the results stress on the need of multiple endpoint assay-approaches, with an in vitro-in vivo study design to assess nanoparticle toxicology.     

Modulatory effects of sesamol in dinitrochlorobenzene-induced inflammatory bowel disorder in albino rats

BackgroundInflammatory bowel disease (IBD) is a chronic inflammatory condition of gastrointestinal tract of immune, genetic and environmental origin. In the present study, we examined the effect of sesamol (SES), the main anti-oxidative constituent of Sesamum indicum (sesame seed) Linn. in the dinitrochlorobenzene (DNCB)-induced model for IBD in rats.MethodsThe groups were divided into normal control, DNCB control, SES and sulfasalazine (SS). On day 24, the rats were killed, colon removed and the macroscopic, biochemical and histopathological evaluations were performed.ResultsThe levels of MPO, TBARS and nitrite increased significantly (p < 0.05) in the DNCB group, whereas reduced significantly in the SES, SS treated groups. Serum nitrite levels were found to be insignificant between the different groups. IL-6 and TNF-α levels were significantly high in the DNCB group.ConclusionsWe conclude the mucosal protective effect of SES on colon due to its potent antioxidant actions. Further investigation is required in a chronic model of different rodent strain for its role involved in the cytokine pathway.     

Lipid-soluble green tea extract: Genotoxicity and subchronic toxicity studies

To assess the potential safety of lipid soluble green tea extract, also referred to as lipid soluble tea polyphenols (LSTP), a series of genotoxicity tests were conducted, including an Ames, in vivo mouse micronucleus, and in vivo mouse sperm abnormality test. The toxicity of LSTP was evaluated in 90- and 30-day feeding studies. LSTP did not show mutagenic activity in the Ames test and no genotoxic potential in the in vivo assays at doses up to 10 g/kg body weight (bw). In the 90-day feeding study, LSTP was given in the diet at levels providing 0, 0.125, 0.25, or 0.50 g/kg bw/day. No significant effects were noted on body weight, food consumption, hematology, clinical chemistry, organ weights, and histopathological examination. The no-observed-adverse-effect level (NOAEL) was therefore considered to be 0.50 g/kg bw/day, the highest dose tested. Likewise, dosing of SD rats by gavage for 30 days also showed no adverse effects of growth, hematology, clinical chemistry, organ weights, or histopathology at doses of 0.58, 1.17, and 2.33 g/kg bw/day. The NOAEL in the 30-day study was considered to be the highest dose tested. These data provide evidence to support the safe use of LSTP in food.