Low Doses of Ochratoxin-A Decrease IgY and IgA Production in Broiler Chicks

Effects of natural extract from medicinal herbs on broilers experimentally infected with Eimeria tenella

This study aimed to evaluate the effects of natural extracts from nine medicinal herbs (SMA) on the growth performance, immunity, and intestinal integrity of broilers experimentally infected with Eimeria tenella. A total of 252 one-day-old broiler chicks were divided into 7 groups with 3 replicates per group and 12 broilers per cage. The groups were uninfected-untreated blank control group (BC), infected-untreated negative control group (NC), SMA treatment groups, Chinese medicine positive control group (CM), and chemical drug positive control group (CD). The SMA groups were infected and fed a basal diet supplemented with 0.6 (SMA-L), 0.8 (SMA-M), and 1.0 (SMA-H) g/kg SMA. The CM and CD groups were infected and fed a basal diet supplemented with 15 g/kg Jiqiuchong San and 0.2 g/kg Diclazuril, respectively. Results showed that feeding SMA could significantly reduce the number of oocysts in infected chickens, especially 1.0 g/kg SMA, which exhibited moderate anticoccidial efficacy. When infected with E. tenella, the supplementation of 1.0 g/kg SMA increased the renal index; restored the hepatic, splenic, and bursal indexes to BC levels; increased the levels of immunoglobulin A (IgA), IgM, and IgY; and reduced the contents of tumor necrosis factor (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6), and IL-10 of the infected chickens. Moreover, treatment with 1.0 g/kg SMA alleviated the pathological changes in cecal tissue and increased the contents of zonula occludens-1 (ZO-1), occludin, claudin-1, and mucoprotein 2 (mucin-2) in cecal tissues of E. tenella-infected chickens. We found that 1.0 g/kg SMA reduced the number of oocysts, improved immunity, and alleviated intestinal barrier damage, which could improve the growth performance of infected chickens. Thus, SMA proved to be an effective natural extract against E. tenella and has the potential to be used as an efficient anticoccidial drug or additive.

Risks for animal health related to the presence of ochratoxin A (OTA) in feed

In 2004, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks to animal health and transfer from feed to food of animal origin related to the presence of ochratoxin A (OTA) in feed. The European Commission requested EFSA to assess newly available scientific information and to update the 2004 Scientific Opinion. OTA is produced by several fungi of the genera Aspergillus and Penicillium. In most animal species it is rapidly and extensively absorbed in the gastro-intestinal tract, binds strongly to plasma albumins and is mainly detoxified to ochratoxin alpha (OTalpha) by ruminal microbiota. In pigs, OTA has been found mainly in liver and kidney. Transfer of OTA from feed to milk in ruminants and donkeys as well as to eggs from poultry is confirmed but low. Overall, OTA impairs function and structure of kidneys and liver, causes immunosuppression and affects the zootechnical performance (e.g. body weight gain, feed/gain ratio, etc.), with monogastric species being more susceptible than ruminants because of limited detoxification to OTalpha. The CONTAM Panel considered as reference point (RP) for adverse animal health effects: for pigs and rabbits 0.01 mg OTA/kg feed, for chickens for fattening and hens 0.03 mg OTA/kg feed. A total of 9,184 analytical results on OTA in feed, expressed in dry matter, were available. Dietary exposure was assessed using different scenarios based on either model diets or compound feed (complete feed or complementary feed plus forage). Risk characterisation was made for the animals for which an RP could be identified. The CONTAM Panel considers that the risk related to OTA in feed for adverse health effects for pigs, chickens for fattening, hens and rabbits is low.

The relationship between ochratoxin A and blood pressure in adolescents

Ochratoxin A (OTA) is a chemical produced by some fungal species, and although its toxic effects have been shown in many animal studies, there are limited studies in humans. We aimed to examine the relationship between OTA and hypertension. 50 newly diagnosed hypertensive patients and 33 healthy individuals aged between 12 and 14 were included in the study. Anthropometric measurements, blood pressure measurements, complete blood count, blood biochemical parameters, urine lead level and urine OTA level were measured. OTA was detected in the urine samples of 90.9% of the control group, 100% of the hypertensive group and 85.7% of the obese+hypertensive group. Median urinary OTA was 32.9 ng/g creatinine for hypertensive group, 32.2 ng/g creatinine for hypertensive+obese group, 18.8 ng/g creatinine for the control group. Multivariate logistic regression analysis revealed a positive association between last quartile of urinary OTA level and being hypertensive [AOR:5.93 (95%CI: 1.27-27.61)] in adolescents without obesity. Hypertensive cases could be evaluated for OTA exposure in further studies.

Quercetin ameliorates ochratoxin A-Induced immunotoxicity in broiler chickens by modulation of PI3K/AKT pathway

Ochratoxin A (OTA) is a fungal secondary metabolite produced by certain species of Aspergillus and Penicillium, and exerts immunosuppressive effect on humans and animals. Quercetin (QUE) is one of the flavonoids produced as a plant-secondary metabolite. The present study was designed to evaluate the efficacy of QUE against the immunotoxic hazard of OTA in broiler chickens. Forty one-day-old broiler chicks were randomly and equally allocated into four groups; control, OTA (0.5 mg/kg feed), QUE (0.5 g/kg feed) and OTA + QUE (0.5 mg/kg OTA + 0.5 g/kg QUE). The results revealed that dietary OTA induced a significant decrease in the antibody response to Newcastle Disease (ND), Infectious Bronchitis (IB) and Avian Influenza (AI) vaccination and in the lymphoproliferative response to Phytohemagglutinin-P (PHA-P). Ochratoxin A also induced oxidative stress and lipid peroxidation in the bursa of Fabricius, spleen and thymus tissues of chickens as demonstrated by decreased CAT and GSH levels and increased TBARS content. In addition, administration of OTA resulted in apoptosis, which was evident by the increased expression level of PTEN, Bax and Caspase-3 genes and decreased expression level of PI3K, AKT and Bcl-2 genes. Furthermore, exposure to OTA resulted in various pathological lesions in the bursa of Fabricius, spleen and thymus of chickens. On the other hand, administration of QUE ameliorated most of the immunotoxic effects of OTAby its immunomodulatory, antioxidant and anti-apoptotic activities. Taken together, the results suggested that QUE potentially alleviated the OTA-induced immunotoxicity in broiler chickens, probably through amelioration of oxidative stress and activation of the PI3K/AKT signaling pathway.

Toxicological and physiological effects of successive exposure to ochratoxin A at food regulatory limits

Ochratoxin A (OTA), a potent mycotoxin, is a common contaminant of agro-products, which seriously threatens food safety. The OTA regulatory limits vary from different countries/regions. However, little is known about the toxicological effects of successive exposure to regulatory levels of OTA. In this study, feedstuffs contaminated with 0.5-20 μg kg^-1 OTA were evaluated in Sprague-Dawley (SD) rats. During the study, poisoning-associated behaviors, and significant differences of body weight and food intake, were not observed between OTA-treated rats and control group. However, the renal function indexes of blood urea nitrogen (BUN) and creatinine (CR) increased, and architecture destruction of glomeruli and tubuli was observed from the OTA-treated groups. The apoptosis study indicated that at a concentration of 20 μg kg^-1, OTA modulated apoptosis in renal tissues via the Bcl-2/Bax pathway. The results of this study suggest that exposure to low doses of OTA successively at levels lower than the regulatory limits of certain countries could induce nephrotoxicity, and modulate apoptosis. Therefore, agencies pertaining to food safety should establish strict OTA regulatory limits for food and feedstuff.

Tryptophan Attenuates the Effects of OTA on Intestinal Morphology and Local IgA/IgY Production in Broiler Chicks

Ochratoxin A (OTA) is a mycotoxin produced by species of Penicillium and Aspergillus that can contaminate products of plant origin that are used as animal feed. Through oral exposure, this mycotoxin primarily affects the chicken gastrointestinal system. The present study evaluated the intestinal toxic effects of OTA and the introduction of L-tryptophan to alleviate these effects in chickens. One-day-old chicks were exposed to a single OTA dose (1.4 mg/kg body weight—b.w.) and treated with or without four daily doses of L-tryptophan (100 mg/kg b.w.). Duodenal villus height/crypt depth, fecal immunoglobulin A/immunoglobulin Y (IgA/IgY) levels, and duodenal positive immunoglobulin A cells (IgA⁺) were evaluated by histology, ELISA, and immunohistochemistry, respectively, on the 14th day. There were significant changes in the duodenal villus height, crypt depth, and levels of fecal IgA/IgY and duodenal IgA⁺ cells (p < 0.05) in groups exposed to OTA. On the other hand, groups exposed to OTA and treated with L-tryptophan showed similar levels of villus height, IgA/IgY levels, and duodenal IgA⁺ cells to those of the control group (p > 0.05). In conclusion, exposure to a single dose of OTA orally induces changes in intestinal morphology, levels of IgA/IgY antibodies, and IgA⁺ cells. Thus, treatment with L-tryptophan may be a valid alternative means to reduce the harmful effects of OTA on the intestinal mucosa, which requires further study.

Grape Pomace Valorization: A Systematic Review and Meta-Analysis

This systematic review aimed to collect data and analyze the possible use of grape pomace, a winemaking industry byproduct, in the production of fortified foods. The English articles found in Web of Science, Scopus, and Google Scholar, from January 2006 until May 2020, were used for the conduction of overview tables and meta-analysis. The systematic review emphasized the two main issues concerning grape pomace application to other food products: (i) grape pomace contains high amounts of health promoting compounds; and (ii) the use of grape pomace is influencing the waste management. The grape pomace has been used in the fortification of plant origin food, meat, fish, and dairy products, mainly due to higher polyphenols and dietary fiber contents. The fortification was declared as successful in all studied food types. The change of color, caused by polyphenolic compounds, was mainly observed as an adverse effect of the fortification. Higher levels of fortification also caused notable undesirable changes in texture. The most valuable influence of the grape pomace addition according to included papers and meta-analysis is certainly a higher nutritional quality and oxidative stability of fortified products, reflected as higher polyphenol and total dietary fiber content.

Impact of dietary Trichosporon mycotoxinivorans on ochratoxin A induced immunotoxicity; In vivo study

Ochratoxin A (OA), the secondary metabolite of certain Aspergillus and Penicillium species, is one of the potent biological immune-suppressor. The present study was designed to explore the in-vivo efficacy of Trichosporon mycotoxinivorans (TR); yeast strain isolated from the hindgut of the termite Mastotermes darwiniensis, against the immunotoxicity of OA in broiler birds. For this purpose, broiler chicks were offered diet added with TR (0.5, 1.0 or 2.0 g/kg feed) and/or OA (0.15, 0.3 or 1.0 mg/kg feed) for 42 days. Dietary OA at all levels, resulted in significant reduction (p ≤ 0.05) in the immune response of broiler birds as recorded by vacuolation and darkly stained pyknotic nuclei in bursa of Fabricius and thymus, humoral immune responses to sheep red blood cells (SRBC), in-vivo lymphoproliferative response to Phytohemagglutinin-P (PHA-P) and mononuclear phagocytic system function assay. Addition of TR in broiler diet significantly reduced (p ≤ 0.05) the immunotoxicity of OA at 0.15 and 0.30 mg/kg; however, against higher dietary level of OA (1.0 mg/kg), a partial protection was observed. Feeding TR alone had no immunomodulatory effect at any of tested level. Dietary addition of TR is proposed as an approach to combat the OA mediated immunological damages in broiler birds.

Effects of Subcutaneous Ochratoxin-A Exposure on Immune System of Broiler Chicks

Ochratoxin A (OTA), an immunosuppressive mycotoxin, can increase the risk of many infectious diseases and contribute to economic losses to the poultry industry. The immunosuppressive effect has mainly been investigated through oral exposure; however, birds may also be contaminated through skin absorption. The present study investigated the influence of OTA exposure on the defense system of broiler chicks through the subcutaneous route and including low doses. Groups of broiler chicks (Cobb), 05 days old, were exposed to subcutaneous inoculation of OTA at concentrations of 0.1; 0.5; 0.9; 1.3; and 1.7 mg OTA/kg body weight. The size of the lymphoid organs, circulating immune cells, and total IgY and IgA levels were evaluated 21 days post inoculation. Subcutaneous OTA exposure decreased the weight of the thymus, spleen, and bursa of Fabricius, and leukocytopenia (p < 0.05) was detected in chicks of the OTA treated groups. In a dose-dependent way, decreased levels of circulating lymphocytes and heterophils (p < 0.05), and increased levels of monocytes (p < 0.05) were detected. Decreased IgY and IgA serum concentrations were noted in the OTA treated groups (p < 0.05). In conclusion, subcutaneous OTA exposure induces immunosuppression even at low levels.