Distribution of ochratoxin A in plasma and tissues of rats fed a naturally contaminated diet amended with micronized wheat fibres: effectiveness of mycotoxin sequestering activity.

The effectiveness of micronized wheat fibres (MWF) alone or in association with yeast cell walls (YCW) as active adsorbents to decrease, in vivo, the levels of ochratoxin A (OTA) was checked in a total of 48 rats, equitably distributed into four groups: (1) control; (2) OTA naturally contaminated diet (2.2 microg/g); (3) OTA naturally contaminated diet (2.2 microg/g) amended with MWF (2%); (4) OTA naturally contaminated diet (2 microg/g) amended with MWF (1.8%) in association with YCW (0.2%). A 4 week experimental period corresponding to a daily intake in the range of 132.2-146.1 microg OTA/kg bw decreased the rat body weight gains, as compared to the controls. The adsorbents did not significantly alleviate the growth depression caused by the contaminated diet. However, a significant protective effect of MWF was observed in terms of OTA concentration in plasma (40.5% decrease), kidney (28.1% decrease) and liver (38.8% decrease). Mixing this sorbent with the YCW did not significantly improve its protective activity against OTA. The faecal OTA concentrations were higher for the MWF and MWF+YCW treated animals, as compared to the positive control (group II). Taken together, these results suggest that MWF are a promising tool to counteract the toxic effects of OTA naturally contaminated diets.     

Effects of dietary Fusarium mycotoxins on intestinal lymphocyte subset populations,cell proliferation and histological changes in avian lymphoid organs

An experiment was conducted to investigate the effects of dietary Fusarium mycotoxins on gut immunity, cell proliferation, and histology of avian lymphoid organs. The efficacy of a polymeric glucomannan mycotoxin adsorbent (GMA) was also determined. Seventy-two one-day-old male turkey poults were fed corn, wheat, and soybean meal-based diets for 21 days. Diets included control grains, contaminated grains and contaminated grains +0.2% GMA. The major contaminant was deoxynivalenol (3.9 μg/g) with lesser amounts of zearalenone (0.67–0.75 μg/g), 15-acetyl-deoxynivalenol (0.34 μg/g) and HT-2 toxin (0.078–0.085 μg/g). T- and B-lymphocyte populations and crypt cellular proliferation in duodenum, jejunum, ileum and cecal tonsil were measured immunohistochemically on day 14 and 21. Histological changes were recorded after 14 and 21 days of feeding. Feeding contaminated grains significantly increased the percentage of B-lymphocytes in ileum on day 14, and reduced (P < 0.05) the percentages of CD8⁺-lymphocytes in cecal tonsil on day 21. GMA supplementation prevented these effects. The feeding of contaminated diets also caused a reduction (P < 0.05) in ileal crypt proliferating cells and a significant increase in spleen secondary follicle on day 21. It was concluded that the feeding of grains naturally contaminated with Fusarium mycotoxins results in adverse effects on gut immunity and mucosal cell proliferation.     

Effects of chitosan oligosaccharides on drug-metabolizing enzymes in rat liver and kidneys

To investigate the effect of chitosan oligosaccharides (COS) on drug-metabolizing enzymes in rat liver and kidneys, male Spraque–Dawley rats were fed a diet containing 1% or 3% COS for 5 weeks. The activities of cytochrome P450 (CYP) enzymes, UDP-glucurosyltransferase (UGT) and glutathione S-transferase (GST) in the liver and kidneys were determined. Significant decreases in microsomal CYP3A-catalyzed testosterone 6β-hydroxylation, CYP2C-catalyzed diclofenac 4-hydroxylation, and CYP4A-catalyzed lauric acid 12-hydroxylation in the liver of rats fed the COS diets were observed compared with those rats fed the control diet. Immunoblot analyses of CYP proteins showed the same trend as with enzyme activities. Increased glutathione content in liver was found in rats fed the 1% COS diet. Increased hepatic NADPH: quinone oxidoreductase 1 (NQO1) activity was found in rats fed the COS diets. In kidneys, COS had little or no effect on CYP enzyme activities. However, increased GST activity was observed in rats fed the COS diets. Moreover, a higher UGT activity was found in rats fed the 1% COS diet. Our results indicate that COS may suppress hepatic CYP enzymes and induce phase II detoxifying reactions in the liver and kidneys of rats.     

A chronic oral exposure of pigs with deoxynivalenol partially prevents the acute effects of lipopolysaccharides on hepatic histopathology and blood clinical chemistry

Lipopolysaccharides (LPS), a cell wall component of gram-negative bacteria, and deoxynivalenol (DON), a prevalent Fusarium-derived contaminant of cereal grains, are each reported to have detrimental effects on the liver. A potentiating toxic effect of the combined exposure was reported previously in a mouse model and hepatocytes in vitro, but not in swine as the most DON-susceptible species. Thus, pigs were fed either a control diet (CON) or a Fusarium contaminated diet (DON, 3.1 mg DON/kg diet) for 37 days. At day 37 control pigs were infused for 1 h either with physiological saline (CON_CON), 100 μg/kg BW DON (CON_DON), 7.5 μg/kg BW LPS (CON_LPS), or both toxins (CON_DON/LPS) and Fusarium-pigs with saline (DON_CON) or 7.5 μg/kg BW LPS (DON_LPS). Blood samples were taken before and after infusion (−30, +30, +60, +120, and +180 min) for clinical blood chemistry. Pigs were sacrificed at +195 min and liver histopathology was performed. LPS resulted in higher relative liver weight (p < 0.05), portal, periportal and acinar inflammation (p < 0.05), haemorrhage (p < 0.01) and pathological bilirubin levels (CON_CON 1.0 μmol/L vs. CON_LPS 5.4 μmol/L, CON_DON/LPS 8.3 μmol/L; p < 0.001). DON feeding alleviated effects of LPS infusion on histopathology and blood chemistry to control levels, whereas DON infusion alone had no impact.     

Evaluation of tolerable levels of dietary quercetin for exerting its antioxidative effect in high cholesterol-fed rats

The tolerable level of dietary quercetin for exerting its antioxidative effect was evaluated in high cholesterol-fed rats, using quercetin-containing diets (31–1260 mg quercetin/kg body weight/day) and onion diets (19–94 mg quercetin aglycone equivalent/kg body weight/day), from the viewpoint of a safety assessment. After feeding for 4 weeks, the urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) levels of the quercetin-containing diet groups fed more than 157 mg quercetin/kg body weight/day were higher than the group fed a quercetin-free diet, although the plasma quercetin metabolite levels and plasma antioxidative activity were elevated depending on the amounts of quercetin or onion diet intake. No significant effect on body weight gain by quercetin-containing diets or onion diets was observed. However, ratios of the liver and kidney weights to the body weight were significantly increased in the quercetin-containing diet groups fed more than 314 mg and 157 mg quercetin/kg body weight/day, respectively, and in the onion diet groups fed more than 47 mg quercetin aglycone equivalent/kg body weight/day. These results indicated that the tolerable level for dietary quercetin for exerting its antioxidative effect was between 126 and 157 mg/kg/day for the quercetin diet and between 19 and 34 mg/kg/day for the onion diet.     

A 90-day subchronic feeding study of genetically modified maize expressing Cry1Ac-M protein in Sprague–Dawley rats

The cry1Ac-M gene, coding one of Bacillus thuringiensis (Bt) crystal proteins, was introduced into maize H99 × Hi IIB genome to produce insect-resistant GM maize BT-38. The food safety assessment of the BT-38 maize was conducted in Sprague–Dawley rats by a 90-days feeding study. We incorporated maize grains from BT-38 and H99 × Hi IIB into rodent diets at three concentrations (12.5%, 25%, 50%) and administered to Sprague–Dawley rats (n = 10/sex/group) for 90 days. A commercialized rodent diet was fed to an additional group as control group. Body weight, feed consumption and toxicological response variables were measured, and gross as well as microscopic pathology were examined. Moreover, detection of residual Cry1Ac-M protein in the serum of rats fed with GM maize was conducted. No death or adverse effects were observed in the current feeding study. No adverse differences in the values of the response variables were observed between rats that consumed diets containing GM maize BT-38 and non-GM maize H99 × Hi IIB. No detectable Cry1Ac-M protein was found in the serum of rats after feeding diets containing GM maize for 3 months. The results demonstrated that BT-38 maize is as safe as conventional non-GM maize.     

Toxicological evaluation of the effect of water contaminated with lead,phenol and benzene on liver,kidney and colon of Albino rats

The effect of water contaminated with phenol, benzene and lead on rats cellular system was investigated. Selected enzyme activity of the kidney and colon of rats was carried out. Standard enzyme assays were also conducted for selected liver enzymes such as alkaline and acid phosphatases, alanine and aspartate transaminases, and gamma glutamyl transpeptidase. Serum indices of liver and kidney function were also determined. The direct bilirubin of test rats were observed to be 3.2 ± 0.2 U/mol/l while that of control rat was 1.2 ± 0.003 U/mol/l. The total bilirubin of test rats was found to be 8.4 ± 0.8 U/mol/l while that of the control was 5.6 ± 0.5 U/mol/l. Generally, enzymes activity in the tissues of test rats were found to be significantly (p < 0.05) lower relative to control, while the enzyme activity of the serum of test rats was significantly (p < 0.05) higher than control. It could be inferred that experimental data suggest possible damage to the tissues and that consumption of polluted water may account for increasing cases of renal and hepatic failure among people in developing countries.     

A probiotic feed additive containing spores of Bacillus subtilis and B. licheniformis does not prevent absorption and toxic effects of the Fusarium toxin deoxynivalenol in piglets

A 35-day piglet experiment starting from weaning (21 days of age, 7.7 ± 1.1 kg), was performed to examine the effects of feeding a control diet (CTR) and of a Fusarium toxin-contaminated diet (FUS) in the absence (−) or presence (+) of a probiotic additive (2.3 × 10⁶ colony-forming units per g diet of a one-to-one ratio of Bacillus subtilis and B. licheniformis) (deoxynivalenol [DON] concentrations of the CTR−, CTR+, FUS− and FUS+ diets were 0.21, 0.20, 2.75 and 2.45 mg/kg, respectively) on performance, blood concentration of DON and on liver function as evaluated by a breath test.     

Pomegranate seed oil, a rich source of punicic acid, prevents diet-induced obesity and insulin resistance in mice

Background

Pomegranate seed oil has been shown to protect against diet induced obesity and insulin resistance.

Objective

To characterize the metabolic effects of punicic acid on high fat diet induced obesity and insulin resistance.

Design

High-fat diet or high-fat diet with 1% Pomegranate seed oil (PUA) was fed for 12 weeks to induce obesity and insulin resistance. We assessed body weight and composition (pSABRE DEXA-scan), energy expenditure (Columbus Instruments) and insulin sensitivity at the end of the 12 weeks.

Results

PSO intake resulted in a lower body weight, 30.5 ± 2.9 vs 33.8 ± 3.2 g PSO vs HFD respectively, p = 0.02, without affecting food intake or energy expenditure. The lower body weight was fully explained by a decreased body fat mass, 3.3 ± 2.3 vs 6.7 ± 2.7 g for PSO and HFD fed mice, respectively, p = 0.02. Insulin clamps showed that PSO did not affect liver insulin sensitivity but clearly improved peripheral insulin sensitivity, 164 ± 52% vs 92 ± 24% for PSO and HFD fed mice respectively, p = 0.01.

Conclusions

We conclude that dietary PSO ameliorates high-fat diet induced obesity and insulin resistance in mice, independent of changes in food intake or energy expenditure.     

Prolonged consumption of flaxseed flour increases the 17β-estradiol hormone without causing adverse effects on the histomorphology of Wistar rats’ penis

Consumption of foods rich in phytoestrogens such as flaxseed has increased due to its chemoprotective effects, especially those related to the cardiovascular system. The flaxseed has components that can interfere with development of male reproductive system. This study aims to investigate the possible effects of prolonged consumption of flaxseed flour on hormonal and histomorphologic penis parameters of adult Wistar rats. Rat dams were divided into two groups during lactation period: the control group that was fed with diet based on casein and the flaxseed group that was fed with diet based on casein containing 25% of flaxseed . At weaning, 10 male offspring from each group continued to receive the experimental diets until 250 days old. Rats fed with diet containing flaxseed showed increased concentrations of 17β-estradiol (p = 0.01) but no changes in testosterone concentrations. With regard to histomorphometric analysis of the penis, supplemented rats had lower values for the total area of the corpus spongiosum (p = 0.01). All other analyzed parameters wer e similar as the control. Results showed that the use of flaxseed flour did not cause adverse effects on the penis morphology but increases the 17β-estradiol hormone, when consumed in integral form for a prolonged period.     

Mycological survey and ochratoxin A natural contamination of swine feedstuffs in Rio de Janeiro State, Brazil

Mycotoxin contamination of animal feeds represents a hazard to human and animal health due to potential transmission to meat and milk. Barley by-products are alternative feeding supplies for animal production. The aims of this assay were to study the mycobiota of feedstuffs and finished swine feed, to determine the ability of Aspergillus and Penicillium isolates to produce ochratoxin A (OTA) and to evaluate OTA occurrence in these substrates. Corn, brewers' grains and finished swine feed samples were collected from different factories. Fungal counts were higher than 2.8 × 10⁴ CFU g⁻¹. Fusarium, Aspergillus and Penicillium genera were isolated at high levels. A 23.7% of the isolates produced 9-116 μg kg⁻¹ of OTA in vitro. Corn samples (44%) were contaminated with 42-224 μg kg⁻¹ of OTA. Finished feed (31%) and brewers' grains samples (13%) were contaminated with 36-120 μg kg⁻¹ and 28-139 μg kg⁻¹ of OTA, respectively. This is the first scientific report on contamination by OTA-producer molds and OTA in swine feedstuffs from Brazil. The presence of OTA in raw materials and finished feed requires periodic monitoring to prevent mycotoxicoses in animal production, reduce economic losses and minimize hazards to human health.     

Effect of water contaminated with phthalate,benzene and cyclohexane on Clarias gariepinus’ cellular system

This study evaluates the effect of water contaminated with phthalate, benzene and cyclohexane (major components of municipal waste in Nigeria) on the cellular system of Clarias gariepinus. Standard enzyme assays were conducted for alkaline phosphatase, acid phosphatase, alanine transaminase, aspartate transaminase, lactate dehydrogenase, gamma glutamyl transpeptidase of selected tissues of C. gariepinus cultivated in contaminated water over a period of 56 days. Generally, a significant decrease in the activity of the enzymes of the tissues of C. gariepinus cultivated in contaminated water was observed relative to the control (p < 0.05). Particularly, activity of alkaline phosphatase of liver of C. gariepinus cultivated in phthalate contaminated water was found to be 8.26 ± 1.42 while that of control was 14.42 ± 1.09. The activity of serum gamma glutamyl transpeptidase of serum of the same group of fish was found to be twice that of control. It could be inferred that membrane integrity of the tissues studied are compromised and that tissue dysfunction may result. Consumption of C. gariepinus cultivated in water contaminated with phthalate, benzene and cyclohexane could pose threats to public health.     

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg⁻¹) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg⁻¹). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance.     

Effects of dietary cyanobacteria of two different sources on growth and recovery of hybrid tilapia (Oreochromis niloticus × O. aureus)

A 115 days feeding trial was conducted to evaluate the effect of dietary cyanobacteria on growth, microcystins (MCs) accumulation in hybrid tilapia (Oreochromis niloticus × O. aureus) and the recovery when the fish were free of cyanobacteria. Three experimental diets were formulated: the control (cyanobacteria free diet); one test diet with cyanobacteria from Lake Taihu (AMt, 80.0 μg MCs g⁻¹ diet) and one with cyanobacteria from Lake Dianchi (AMd, 410.0 μg MCs g⁻¹ diet). Each diet was fed to fish for 60 days and then all fish were free of cyanobacteria for another 55 days.A significant increase in feeding rate (FR) was observed in fish fed AMd diet after a first 30-day exposure (1^st EP), and in fish fed both AMt diet and AMd diet after a second 30-day exposure (2^nd EP). Specific growth rates (SGR) of fish fed AMt diet and AMd diet were both obviously affected after the first 30-day exposure, but SGR was only significantly affected in fish fed AMt diet after the second 30-day exposure. After a 55-day recovery, there were no significant differences among diets in the indices mentioned above. Much higher concentrations of MCs were accumulated in tissues of all fish exposed to cyanobacteria. After the 55-day recovery, MC concentrations in fish tissues were significantly lower than those on day 60.     

Behavior and brain enzymatic changes after long-term intoxication with cadmium salt or contaminated potatoes

This study investigated the cadmium (Cd) intoxication on cognitive, motor and anxiety performance of rats subjected to long-term exposure to diet with Cd salt or with Cd from contaminated potato tubers. Potato plantlets were micropropagated in MS medium and transplanted to plastic trays containing sand. Tubers were collected, planted in sand boxes and cultivated with 0 or 10 μM Cd and, after were oven-dried, powder processed and used for diet. Rats were divided into six groups and fed different diets for 5 months: control, potato, potato + Cd, 1, 5 or 25 mg/kg CdCl₂. Cd exposure increased Cd concentration in brain regions. There was a significant decrease in the step-down latency in Cd-intoxicated rats and, elevated plus maze task revealed an anxiolytic effect in rats fed potato diet per se, and an anxiogenic effect in rats fed 25 mg/kg Cd. The brain structures of rats exposed to Cd salt or Cd from tubers showed an increased AChE activity, but Na⁺,K⁺-ATPase decreased in cortex, hypothalamus, and cerebellum. Therefore, we suggest an association between the long-term diet of potato tuber and a clear anxiolytic effect. Moreover, we observed an impaired cognition and enhanced anxiety-like behavior displayed by Cd-intoxicated rats coupled with a marked increase of brain Cd concentration, and increase and decrease of AChE and Na⁺,K⁺-ATPase activities, respectively.     

Safety evaluation of Algal Oil from Schizochytrium sp.

The safety of Algal Oil from Schizochytrium sp. was evaluated by testing for gene mutations, clastogenicity and aneugenicity, and in a subchronic 90-day Sprague-Dawley rat dietary study. The results of all genotoxicity tests were negative. The 90-day study involved dietary exposure to 0.5, 1.5, and 5 wt.% of Algal Oil and two control diets: a standard low-fat basal diet and a basal diet supplemented with 5 wt.% menhaden oil (the fish oil control). There were no treatment-related effects of Algal Oil on clinical observations, body weight, food consumption, behavior, hematology, clinical chemistry, coagulation, or urinalysis parameters. Increased mean liver weights and alveolar histiocytosis were observed in both the fish oil control and the high-dose Algal Oil-treated animals and were not considered to be adverse. Algal Oil was bioavailable as demonstrated by the dose-related increase of DHA and EPA levels in tissues and plasma. The no observable adverse effect level (NOAEL) for Algal Oil under the conditions of this study was 5 wt.% in the diet, equivalent to an overall average Algal Oil intake of 3250 mg/kg bw/day for male and female rats. Based on the body surface area, the human equivalent dose is about 30 g Algal Oil/day for a 60 kg adult.     

Estimation of ochratoxin A in some Turkish populations: An analysis in urine as a simple,sensitive and reliable biomarker

In this study, ochratoxin A (OTA) occurrence and level in human urine samples, collected from four different regions of Turkey was analyzed by NaHCO₃ dilution, immunoaffinity column clean-up and high-performance liquid chromatography with fluorescent detection. For the repeatability of the method, RSD (%) values were found between 3.83 and 8.86, for the accuracy, the recovery values were found between 85.7% and 110.5% and limit of detection and limit of quantification of the method were measured as 0.006 and 0.018 ng mL⁻¹ respectively. For the analysis, first morning urine samples were collected and the results were adjusted with creatinine levels. From the total collected samples of 233 larger amounts of 83% was contaminated with OTA. Among the calculated to be OTA levels, positive sample rate, average OTA amount and the highest contamination was found in Ankara. (Positive sample rate; 90.1%, average OTA concentration; 14.34 ng g⁻¹ creatinine and highest OTA value; 75.60 ng g⁻¹ creatinine). In order to define the exposure profile of OTA in human a questionnaire was conducted among the voluntaries as well. But related to the gender, age, dietary habits, coffee consumption, smoking and alcohol habits of the volunteers, no correlation was found with the OTA exposure.     

Subchronic feeding study of stacked trait genetically-modified soybean (3Ø5423 × 40-3-2) in Sprague–Dawley rats

The genetically-modified (GM) soybean 3Ø5423 × 40-3-2 expresses siRNA for the fatty acid desaturase-2 enzyme which results in higher concentrations of oleic acid (18:1) relative to linoleic acid (18:2) compared with non-GM soybeans. It also expresses the CP4 EPSPS protein for tolerance to glyphosate. In this study, three different dietary concentrations (7.5%, 15% and 30% wt/wt) of 3Ø5423 × 40-3-2 or non-GM soybeans were fed to Sprague–Dawley rats for 90 days during which in-life nutritional and growth performance variables were evaluated followed by analysis of standard clinical chemistry, hematology and organ variables. Compared with rats fed the non-GM control diet, some statistically significant differences were observed in rats fed the 3Ø5423 × 40-3-2 diet. However the differences were not considered treatment-related and commonly fell within the normal ranges of the control group consuming the commercial diet. These results demonstrated that the GM soybean 3Ø5423 × 40-3-2 is as safe as non-GM soybeans.     

Residues of aflatoxin B1 in broiler meat: Effect of age and dietary aflatoxin B1 levels

This study describes the effect of dietary levels of aflatoxin B1 (AFB1) and age of the birds upon the residue level in liver and muscles of broiler chicks. In three different experiments broiler chicks of 7, 14 and 28 days of age were kept for 7 days on contaminated rations having 1600, 3200 and 6400 μg/kg AFB1. AFB1 residues were detected earlier in younger birds and those fed high AFB1 dietary levels. The highest residue levels in liver and muscles of young chicks fed 6400 μg/kg AFB1 was 6.97 ± 0.08 and 3.27 ± 0.05 ng/g, respectively. Maximum residue concentration was high in birds of young age and those kept on high AFB1 ration. After withdrawal of AF contaminated rations, residues clearance was slow and AFB1 was detectable in liver and muscles of birds for longer duration in younger birds and those fed high AFB1 dietary levels. AFB1 residues in poultry tissues may buildup to high levels in areas with no regulatory limits on AFB1 levels of poultry feed and may pose a risk to consumers health.