Aflatoxin B1 (AFB1) causes hepatotoxicity, immunotoxicity, and kidney damage, and it is included in group I of human carcinogens. The European Commission has established maximum limits of AFB1 in feed, ranging from 5 to 20 μg/kg. Chicken is moderately sensitive to AFB1, which results in reduced growth performance and economic losses. Oxidative stress triggered by AFB1 plays a crucial role in kidney damage and the antioxidant activity of Curcumin (CURC) could help in preventing such adverse effect. Twenty-days-old broilers were treated for 10 days with AFB1 (0.02 mg/kg feed), alone or in combination with CURC (400 mg/kg feed), to explore the effects on the renal tissue. Animals exposed to AFB1 alone displayed alterations of the oxidative stress parameters compared with controls: serum antioxidant capacity, and enzymatic activity of kidney superoxide dismutase, catalase and glutathione peroxidase were decreased, while renal malondialdehyde levels and NADPH oxidase complex expression were increased. The administration of CURC attenuates all the oxidative stress parameters modified by AFB1 in the chicken kidney, opening new perspectives in the management of aflatoxicosis.

The most frequent adverse effects of AFB1 in chicken are low performance, the depression of the immune system, and a reduced quality of both eggs and meat, leading to economic losses. Since oxidative stress plays a major role in AFB1 toxicity, natural products are increasingly being used as an alternative to mineral binders to tackle AFB1 toxicosis in farm animals. In this study, an in vivo trial was performed by exposing broilers for 10 days to AFB1 at dietary concentrations approaching the maximum limits set by the EU (0.02 mg/kg feed) in the presence or absence of turmeric powder (TP) (included in the feed at 400 mg/kg). The aims were to evaluate (i) the effects of AFB1 on lipid peroxidation, antioxidant parameters, histology, and the expression of drug transporters and biotransformation enzymes in the liver; (ii) the hepatic accumulation of AFB1 and its main metabolites (assessed using an in-house-validated HPLC-FLD method); (iii) the possible modulation of the above parameters elicited by TP. Broilers exposed to AFB1 alone displayed a significant increase in lipid peroxidation in the liver, which was completely reverted by the concomitant administration of TP. Although no changes in glutathione levels and antioxidant enzyme activities were detected in any treatment group, AFB1 significantly upregulated and downregulated the mRNA expression of CYP2A6 and Nrf2, respectively. TP counteracted such negative effects and increased the hepatic gene expression of selected antioxidant enzymes (i.e., CAT and SOD2) and drug transporters (i.e., ABCG2), which were further enhanced in combination with AFB1. Moreover, both AFB1 and TP increased the mRNA levels of ABCC2 and ABCG2 in the duodenum. The latter changes might be implicated in the decrease in hepatic AFB1 to undetectable levels (<LOD) in the TP supplemented group. Overall, our findings further support the use of TP as an effective feeding strategy to prevent AFB1-related adverse effects in broilers.

Canine acute enteropathies (AE) are common morbidities primarily managed with supportive therapy. However, in some cases, unnecessary courses of antibiotics are empirically prescribed. Recent studies in humans have hypothesized the use of antioxidants as a possible alternative and/or support to antimicrobial drugs in uncomplicated cases. Considering the global need to reduce the antibiotic use, the aim of the study was to compare the oxidative burden of the diarrhetic population to that of healthy dogs. Forty-five patients suffering from uncomplicated acute diarrhea (AD) and 30 controls were screened for clinical and biochemical parameters, and serum redox indices (reactive oxygen metabolites, dROMs; serum antioxidant capacity, SAC; oxidative stress index, OSi). The average levels of dROMs in AD dogs were significantly higher (p < 0.001) than in healthy dogs, while SAC did not significantly differ between the two groups. However, the OSi values (ratio between dROMs and SAC) significantly increased (p < 0.001) in AD dogs compared to controls. The study demonstrates that canine AD could induce redox imbalance. Although its role in the etiopathogenesis and evolution of the disease should be further investigated, our results suggest that the improvement of the patient oxidative status, possibly through the dietary administration of antioxidants, could support the management of canine AE, reducing the use of antibiotics.

The treatment of choice for feline hyperthyroidism is the administration of the antithyroid drug methimazole. Both the endocrinopathy and the drug adverse reactions (e.g., hepatotoxicosis, gastrointestinal disorders, and renal injury) are partly due to oxidative stress and redox unbalance. This study investigated the free radical production and the impairment of the antioxidant barrier induced by methimazole in an in vitro model of feline renal epithelium. The protective effects of quercetin and resveratrol were also explored. CRFK cells were incubated with a methimazole concentration equivalent to the maximum plasma levels in orally treated cats (4 µM), in the presence or absence of either one of the two selected antioxidants at different time-points (up to 72 h). Cell viability, ROS production, GSH levels, and mRNA expression of antioxidant enzymes (i.e., CAT, SOD, GPx, and GST) were assessed. Methimazole impaired cell viability and increased ROS levels in a time-dependent manner. Similarly, GSH content and CAT, SOD, and GPx3 expression were higher compared with control cells. Such effects were significantly counteracted by quercetin. These results provide new insights about the mechanisms underlying the methimazole-related side effects frequently observed in hyperthyroid cats. They also support the use of quercetin in the management of feline hyperthyroidism.

Aflatoxin B1 (AFB1), the mainly Aspergillus fungi derived mycotoxin, is well known for its carcinogenic effects on liver, and frequently occurs in food supplies, leading to fatal consequences in both farm animals and humans. Poultry, one of the most important segments of agro-industry, has been demonstrated to be extremely sensitive to AFB1 intake, which results in chickens’ low performance, decreased quality of both eggs and meat and a negative economic feedback. Oxidative stress caused by AFB1 plays a crucial role in chickens’ kidney damage by generating lipid peroxidation accompanied by a concomitant increase in the antioxidant enzymes involved in ROS metabolism (NADPH oxidase isoform 4 (NOX4) and its regulatory subunit p47-phox). The aim of the present work was to investigate the benefits of dietary supplementation, in chickens affected by AFB1 mycotoxicosis, using a new Feed additive (FA) containing a mixture of a tri-octahedral Na-smectite with a ligno-cellulose-based material an antioxidant adjuvant. Exposure of AFB1-treated chickens to the feed additive induced a significant down-regulation of both NOX4 and p47-phox genes expression levels. This trend was confirmed by their protein expression, demonstrating the great potential of the FA to counteract oxidative stress. To conclude, these results could open new perspectives in the methods of feeding chickens, using eco-friendly dietary supplements able to reduce AFB1-induced mycotoxicosis and to ameliorate poultry performances.