Ochratoxin A Group Research Articles

Feeding a diet contaminated with ochratoxin A for broiler chickens at the maximum level recommended by the EU for poultry feeds (0.1 mg/kg). 2. Effects on meat quality, oxidative stress, residues and histological traits

The European Commission Recommendation 2006/576/EC indicates that the maximum tolerable level of ochratoxin A (OTA) in poultry feeds is 0.1 mg OTA/kg. Thirty-six 1-day-old male broiler chicks were divided into two groups, a control (basal diet) and an OTA (basal diet + 0.1 mg OTA/kg) group. The OTA concentration was quantified in serum, liver, kidney, breast and thigh samples. The thiobarbituric acid reactive substances (TBARS) content were evaluated in the liver, kidney, breast and thigh samples. The glutathione (GSH) content, and catalase (CAT) and superoxide dismutase (SOD) activity were measured in the liver and kidney samples. Histopathological traits were evaluated for the spleen, bursa of Fabricius and liver samples. Moreover, the chemical composition of the meat was analysed in breast and thigh samples. In the OTA diet-fed animals, a serum OTA concentration of 1.15 ± 0.35 ng/ml was found, and OTA was also detected in kidney and liver at 3.58 ± 0.85 ng OTA/g f.w. and 1.92 ± 0.21 ng OTA/g f.w., respectively. The TBARS content was higher in the kidney of the ochratoxin A group (1.53 ± 0.18 nmol/mg protein vs. 0.91 ± 0.25 nmol/mg protein). Feeding OTA at 0.1 mg OTA/kg also resulted in degenerative lesions in the spleen, bursa of Fabricius and liver. The maximum tolerable level of 0.1 mg OTA/kg, established for poultry feeds by the EU, represents a safe limit for the final consumer, because no OTA residues were found in breast and thigh meat. Even though no clinical signs were noticed in the birds fed the OTA-contaminated diet, moderate histological lesions were observed in the liver, spleen and bursa of Fabricius.

Increase in Mitochondrial DNA Copy Number in Response to Ochratoxin A and Methanol-Induced Mitochondrial DNA Damage in Drosophila

The current study examined the effects of ochratoxin A (OTA) and methanol on mitochondrial DNA (mtDNA). The results showed that methanol application caused approximately 29 % more damage than the control group, and that there were no significant differences among the other groups in terms of mtDNA damage. The application of 0.04 ng/mL OTA and 0.04 ng/mL OTA with methanol increased mtDNA copy number compared with the control and 0.005 ng/mL OTA with methanol groups. The copy number in the 0.04 ng/mL OTA group was approximately 16 % greater than in the control.

Apoptosis and lipid peroxidation in ochratoxin A- and citrinin-induced nephrotoxicity in rabbits

Ochratoxin A (OTA) and citrinin (CIT) are nephrotoxic mycotoxins produced mainly by fungal species Aspergillus ochraceus and Penicillium citrinum, respectively, which have been found to occur together in various food and feed commodities. In the present study, both OTA and CIT were evaluated for their potential to induce oxidative damage by determining lipid peroxidation (LPO) through malondialdehyde (MDA) assay and apoptosis by flow cytometry, gel electrophoresis and renal ultrastructural morphology in rabbits fed with diets containing OTA (0.75mg/kg feed), CIT (15mg/kg feed) and OTA+CIT (0.75 and 15mg/kg feed, respectively) up to 60days. The concentration of MDA was found significantly higher in OTA and combination-treated groups. OTA and combination-treated groups revealed more apoptotic cells in flow cytometry when compared with the CIT-treated group. Characteristic DNA fragmentation, as evidenced by ladder pattern in electrophoresis appeared in the toxin-treated groups. Ultrastructurally, interstitial cells showed nuclear fragmentation and cytoplasmic blebbing in OTA- and CIT-treated groups; whereas, proximal convoluted tubular epithelial cells, besides interstitial cells, showed nuclear fragmentation in the combined treatment group. The results suggested that low concentrations of OTA and CIT either alone or in combination induced apoptosis in a time-dependent manner and LPO in the rabbit kidney, which appeared to play a major role in the pathogenesis of nephrotoxicity. Furthermore, the interaction of these two nephrotoxic mycotoxins was found to be additive.

Antioxidant Effects of Melatonin and Coenzyme Q10 on Oxidative Damage Caused by Single-Dose Ochratoxin A in Rat Kidney

In the study, the effects of relatively high single-dose of Ochratoxin A (OTA) and the antioxidant effects of Melatonin (Mel) and Coenzyme Q10 (CoQ10) on OTA-induced oxidative damages in rats were investigated. A total of 28 male Sprague-Dawley rats were divided into four groups of 7 rats each: Control, OTA, Mel+OTA and CoQ10+OTA groups. Malondialdehyde (MDA) levels in the plasma and glutathione (GSH) levels in whole blood were measured; kidneys (for histological inspection and for apoptosis detection by TUNEL method) and bone marrow samples (for chromosome aberration and mitotic index) were taken. The rats in the OTA group showed limited degeneration of tubular cells. In some tubules karyomegaly, desquamated cells and vacuolization were observed by light microscopy. Mel and CoQ10 treatment significantly reduced the severity of the lesions. MDA levels of the OTA group were significantly higher than the control, OTA+Mel and OTA+CoQ10 groups, while GSH levels were significantly lower than the control, OTA+Mel and OTA+CoQ10 groups. Higher incidences of apoptotic bodies were observed in the kidneys of the OTA group although OTA administration did not significantly change the incidence of apoptotic bodies when compared to the control and antioxidant administrated groups. Although the percentage of the mitotic index was lowest in the OTA group, no statistical difference was found among the groups. Additionally, OTA had no numerical and structural significant effects on chromosomes. It was observed that single-dose OTA administration caused oxidative damages in rat kidney and Mel or CoQ10 treatment appeared to ameliorate the OTA-induced tissue injuries.

Immunotoxicity of ochratoxin A and citrinin in New Zealand White rabbits.

In the present study, the effects of ochratoxin A (OTA), citrinin (CIT) and their combination on the immunological parameters were studied in 6-8 weeks old New Zealand White rabbits at 60 d post-intoxication. Thirty two rabbits were divided into four groups of eight. OTA, CIT and a combination of the two were given at 0.75 mg/kg, 15 mg/kg and 0.75 plus 15 mg/kg, in feed respectively for up to 60 d of the trial. Other fourth group was used as a control, being fed standard toxin free feed. The toxin treated animals showed a signifi cant decline in antibody titres to sheep red blood cells. The reduction in the cell mediated immune response was more signifi cant in the OTA and combination groups as observed in the skin hypersensitivity test and the lymphocyte proliferation assay. The citrinin-treated rabbits failed to show any signifi cant changes following the lymphocyte transformation assay and the delayed type hypersensitivity test. Histologically, the cellular (mononuclear cells) reaction in the skin in the treated groups was comparatively lesser than that of the control group. Thus, the present study in rabbits indicated signifi cantly lower humoral and cellular immune responses in the OTA and combination groups.

Protective effect of cyanidin 3-O-β-d-glucoside on ochratoxin A-mediated damage in the rat

The aim of the present study was to verify whether the oral administration of cyanidin 3-O-beta-D-glucoside (C3G) might counteract damage induced by chronic exposure (28 d) to ochratoxin A (OTA) in rats and if its effect may be mediated by haeme oxygenase-1 (HO-1). Forty male Sprague-Dawley rats, individually caged, were divided into four groups of ten animals. A control group received a commercial diet, group C3G received the control diet supplemented with C3G (1 g/kg feed), group OTA received the control diet supplemented with 200 parts per billion of OTA, and group OTA+C3G received the OTA group diet supplemented with C3G (1 g/kg feed). After 4 weeks of treatment animals were killed and the liver, kidneys and brain of each rat were collected and homogenised to evaluate non-proteic thiol groups (RSH), lipid hydroperoxide (LOOH) levels, HO-1 expression and DNA fragmentation. Rats of the OTA group showed a significant (P < 0.001) decrease in RSH content of kidney and liver and a significant (P < 0.001) increase of LOOH in all the examined tissues compared with the control group. In the OTA+C3G group both RSH content and LOOH levels were similar to those observed in the control group, demonstrating that C3G was able to counteract the effects of OTA. A significant (P < 0.001) induction of HO-1 was evident in kidney and liver of both OTA and C3G groups. DNA damage occurred in all the examined tissues of the OTA group, whereas C3G was able to prevent it. The present study confirmed that the effects of OTA are mediated by oxidative stress and demonstrated that C3G efficiently counteracted deleterious effects of OTA because of its antioxidant and HO-1-inducing properties.

Experimental ochratoxicosis in broiler chickens

This study describes the toxicity signs that developed when the diet of male broiler chickens was artificially contaminated with different levels of the mycotoxin ochratoxin A (OTA). Chicks were assigned randomly to three groups of 80 chicks that were fed a diet containing 0 parts per billion (ppb) (control, group 1), 400 ppb (group 2) or 800 ppb (group 3) OTA from day 1 to 5 weeks of age. Signs of ochratoxicosis were assessed on the basis of changes in the following criteria: body weight, relative weights of two representative internal organs (gizzard and thymus), feed consumption, feed conversion ratio, mortality, thyroid activity, blood profile, humoral and cell mediated immunity. Feeding OTA at levels of 400 and 800 ppb (groups 2 and 3) significantly decreased the body weight, thymus weight, feed consumption, feed conversion ratio and thyroxine concentration (P < 0.05). The OTA groups developed anaemia manifested by a significant decrease in the red blood cell count, packed cell volume percentage and haemoglobin concentration (P < 0.05). By the end of the experiment both groups that received OTA showed a 37% reduction in red blood cell count compared with the control group. Furthermore, a significant decrease in the white blood cell count, humoral immune response and cell-mediated immunity was found in both groups fed ochratoxin compared with the control group (P < 0.05). The reduction in the above parameters was more noticeable with time and was proportional to the level of OTA exposure. A significant increase in relative gizzard weight, cumulative mortality and triiodothyronine concentration was found in OTA-fed chicks (P < 0.05). These data provide a description of ochratoxicosis in broilers that should be useful in diagnosis and in improved understanding of the practical implications on broiler performance and health, a problem that can threaten the poultry industry.

Effect in rats of simultaneous prenatal exposure to ochratoxin A and aflatoxin B1. I. Maternal toxicity and fetal malformations

Ochratoxin A (OA) and Aflatoxin B1 (AFB1), the food borne mycotoxins are produced by several fungal species of the genera Aspergillus and Penicillium. To determine the teratogenic effects, these mycotoxins were administered orally either individually or in combination to the pregnant Wistar rats on days 6-15 of gestation. OA and AFB1 were dissolved in corn oil and different doses of OA (0.125, 0.25, 0.50, and 0.75 mg/kg), AFB1 (0.125, 0.25, 0.50, and 1.00 mg/kg), and a combination of OA+AFB1 (0.125+0.125; 0.25+0.50; 0.50+0.25 mg/kg) were given by gastric intubation to rats. During dosing period, the body weight and body weight gains significantly decreased at a higher dosage, in both individual and combined treatments. In all the combination treatments, the percent implants resorbed, fetal body weights, and crown-rump lengths were comparable to those of controls and with the individual mycotoxin treatment. The number of dead fetuses was significantly increased in the high OA combination (OA+AFB1 0.50+0.25) group as compared with the other two combinations. OA and AFB1 alone and in combination caused various gross, skeletal, and visceral anomalies. The occurrence was considerably less pronounced in fetuses of AFB1 and combination groups as compared with those of OA group fetuses. The exencephaly, incomplete closure of skull, wavy and fused ribs, agenesis of the ischium bone, and enlarged renal pelvis, recorded in OA treatment and ear abnormality and incomplete ossification of skull bones observed in AFB1 when given individually, were not seen in combination groups. However, new manifestations, such as gastroschisis and syndactyly were observed and the incidence of cardiac defects was increased in fetuses due to the combined treatment. The results of the present study indicated that there is some interaction between these mycotoxins that resulted in reduced teratogenic activity of OA in the presence of AFB1. Apparently, new manifestations observed in combination treatment points to the potential threat of teratogenicity in terms of public health hazards.

Protective role of melatonin in ochratoxin a toxicity in rat heart and lung

Ochratoxin A (OTA) is a mycotoxin produced by different fungi. The most pronounced adverse effect of OTA is hepatonephrotoxicity. Melatonin (MEL) has an antioxidant effect and has free-radical scavenger properties. The effects of OTA on heart and lung tissue and possible ameliorating effects of MEL were investigated in rats. Twenty-four rats were allocated to three groups (each with eight rats): control; OTA-treated group (OTA dose 289 microg kg(-1) per day); and OTA + MEL-treated group (MEL dose 10 mg kg(-1) per day). After 30 days of treatment, the histopathological changes in the heart and lung of all groups were examined. Compared with the control rats, myocardial tissue of rats treated with OTA showed extensive cytoplasmic vacuole formation, necrosis of the myocytes, dissolution of the nucleus, clumped fibres, fibrillolysis, swollen myocardial fibres, small haemorrhagic areas and hyperaemic vessels (P <0.05). In addition, lungs of rats treated with OTA showed alveolar congestion, alveolar cell hyperplasia, prominent alveolar septal vessels, variable intensity loss of alveolar architecture, intraparenchymal inflammatory infiltration, intraparenchymal hyperaemic vessels, respiratory epithelial proliferation, perivascular and peribronchial inflammation, pneumonic infiltration, distorted appearance of lung parenchyma and emphysematous areas (P <0.05). In comparison with the OTA groups, the ameliorating effects of MEL in the lung damage parameters were on alveolar cell hyperplasia, prominent alveolar septal vessels, variable intensity loss of alveolar architecture, intraparenchymal inflammatory infiltration, perivascular inflammatory inflammation, distorted appearance of lung parenchyma and focal emphysematous areas in lung (P <0.05). Melatonin also significantly reduced myocardial damage in most of the parameters: extensive cytoplasmic vacuole formation, necrosis of the myocytes, clumped fibres, fibrillolysis, small haemorrhagic areas and hypaeremic vessels in heart (P <0.05). On the other hand, MEL did not lower the degree of damage in lung and heart to the level of the control rats, except for the parameters of the interstitial oedema and small haemorrhagic areas only in myocardial tissue. Histopathological findings showed that OTA induced damage in heart and lung and MEL treatment significantly reduced the degree of damage.

Ochratoxin A reduces NMDA receptor subunits 2A and 2B concentrations in rat hippocampus: partial protective effect of melatonin.

Ochratoxin A (OTA) is a mycotoxin produced by several fungi. Many foods can be contaminated by OTA, which is consequently found in the blood of humans and animals. It is known that OTA accumulates in the brain. The aim of this study was to investigate the effects of OTA on the brain. For this purpose, the effect of OTA on N-methyl-D-aspartate (NMDA) receptor subunits 2A (NR2A) and 2B (NR2B) in the hippocampus and the protective effect of melatonin were investigated. Three groups of eight rats were used: controls, OTA-treated rats (OTA dose 289 microg/kg per day) and OTA+melatonin-treated rats (melatonin dose 10 mg/kg per day). After four weeks of treatment, electrophoretic examinations were performed using SDS-polyacrylamide gel electrophoresis and Western blotting of hippocampal homogenates of the different groups. The concentrations of NR2A and NR2B in the OTA group were significantly lower than in the control group. The concentration of NR2B was significantly increased when melatonin was co-administered with OTA compared with OTA only. There was also a significant increase in NR2A levels when melatonin was co-administered with OTA. As a result, subchronic administration of OTA reduced hippocampal NMDA receptor subunits 2A and 2B concentrations in rats. It was thought that this alteration might affect cognitive functions because hippocampal NMDA receptors are involved in the memory and learning processes. Melatonin exhibited a partially protective effect on NR2A and NR2B against OTA.

Influence of Ochratoxin A and Deoxynivalenol on Growing Broiler Chicks

The effects of feeding diets containing ochratoxin A (OA) (2.0 mg/kg) and deoxynivalenol (DON) (16 mg/kg) singly and in combination were characterized in male broiler chicks from 1 to 3 wk of age. Body weight gains and efficiency of feed utilization were significantly reduced by feeding OA singly, DON singly, and the OA/DON combination. Increased relative liver, kidney, and proventriculus weights were observed in the OA and OA-DON groups and blood urea nitrogen (BUN) was increased in the DON group. Serum uric acid, creatinine, and triglycerides were significantly elevated, and total protein, albumin, cholesterol, and aspartate amino transferase (AST) activity were decreased in the OA group. Histopathological examination of the liver, kidney, spleen, proventriculus, gizzard, and bursa revealed that lesions were confined primarily to mild hepatocellular degeneration, with milk diffuse lipidosis of the liver and mild swelling of the renal tubular epithelium of the OA and OA/DON combination groups. For a few parameters such as efficiency of utilization and relative liver, gizzard, and spleen weights, OA and DON appear to interact additively. However, many of the parameters such as body weights, body weight gains, BUN, total protein, and AST show significant interactions that can best be described as less than additive or in some cases antagonistic.

Toxicity of Ochratoxin A and Tannic Acid to Growing Chicks

The effects of ochratoxin A (OA) and tannic acid (TA) on growing chicks were determined. One-day-old male broiler chicks were fed a diet containing the following additives for 26 days: A) none; B) 3.0 ppm OA; C) 1.5% TA; D) 3.0 ppm OA plus 1.5% TA. When compared to the controls, body weights and feed efficiencies were significantly depressed in the OA and TA groups. There was a further depression in body weights and a dramatic depression of feed efficiency in the OA-TA combination group. Pigmentation, as measured by visual shank scores, was reduced in chicks fed OA singly or in combination with TA but was not affected by feeding TA singly. There were no consistent treatment differences in the relative weights of the kidney, gizzard, proventriculus, liver, bursa, or pancreas, although there was a trend toward an elevated relative kidney weight in the groups receiving OA. Serum uric acid levels were significantly elevated in the OA and the OA-TA combination group indicating impaired renal excretory function attributable to OA. Total serum protein levels were significantly depressed in the groups receiving OA, and serum calcium levels were depressed in all treatment groups. Serum phosphorus levels were decreased in the OA and OA-TA groups but were only decreased significantly in the OA group. There were no consistent treatment differences in the hematology and other blood chemistry and mineral values.