Selenium Rescues Aflatoxin B1-Inhibited T Cell Subsets and Cytokine Levels in Cecal Tonsil of Chickens

Effects of aflatoxin on the immune system: Evidence from human and mammalian animal research

Shortly after its discovery in 1960, aflatoxin - a group of fungal toxins or mycotoxins produced by the fungi Aspergillus flavus and A. parasiticus in food crops such as maize, peanuts and tree nuts - was found to cause liver cancer in humans and multiple animal species. Hence, regulations on maximum allowable aflatoxin levels in food worldwide have focused on protecting humans from aflatoxin's carcinogenic effects. However, aflatoxin may also have non-carcinogenic health effects (e.g., immunotoxicity) that are particularly relevant today. Our current review highlights the growing evidence that aflatoxin exposure adversely affects immunity. Here, we comprehensively evaluated human and mammalian animal studies that link aflatoxin exposure with adverse effects on the immune system. We organized the review by organism as well as by the effects on adaptive and innate immune functions. There is abundant evidence that aflatoxin exhibits immunotoxicity, and therefore may compromise the ability of both humans and animals to resist infections. However, the reported effects of aflatoxin on certain specific immune biomarkers are inconsistent in the existing literature. The extent of the immunotoxic effects of aflatoxin must be clarified, so that the contribution of such immunotoxicity to the overall burden of aflatoxin-related diseases can be established.

Protective and detoxifying effects conferred by selenium against mycotoxins and livestock viruses: A review

Animal feed can easily be infected with molds during production and storage processes, and this can lead to the production of secondary metabolites, such as mycotoxins, which eventually threaten human and animal health. Furthermore, livestock production is also not free from viral infections. Under these conditions, the essential trace element, selenium (Se), can confer various biological benefits to humans and animals, especially due to its anticancer, antiviral, and antioxidant properties, as well as its ability to regulate immune responses. This article reviews the latest literature on the antagonistic effects of Se on mycotoxin toxicity and viral infections in animals. We outlined the systemic toxicity of mycotoxins and the primary mechanisms of mycotoxin-induced toxicity in this analysis. In addition, we pay close attention to how mycotoxins and viral infections in livestock interact. The use of Se supplementation against mycotoxin-induced toxicity and cattle viral infection was the topic of our final discussion. The coronavirus disease 2019 (COVID-19) pandemic, which is currently causing a health catastrophe, has altered our perspective on health concerns to one that is more holistic and increasingly embraces the One Health Concept, which acknowledges the interdependence of humans, animals, and the environment. In light of this, we have made an effort to present a thorough and wide-ranging background on the protective functions of selenium in successfully reducing mycotoxin toxicity and livestock viral infection. It concluded that mycotoxins could be systemically harmful and pose a severe risk to human and animal health. On the contrary, animal mycotoxins and viral illnesses have a close connection. Last but not least, these findings show that the interaction between Se status and host response to mycotoxins and cattle virus infection is crucial.

Estimation of Tolerable Daily Intake (TDI) for Immunological Effects of Aflatoxin

Aflatoxins are toxic chemicals produced by the fungi Aspergillus flavus and Aspergillus parasiticus. In warm climates, these fungi frequently contaminate crops such as maize, peanuts, tree nuts, and sunflower seeds. In many tropical and subtropical regions of the world, populations are coexposed to dietary aflatoxin and multiple infectious pathogens in food, water, and the environment. There is increasing evidence that aflatoxin compromises the immune system, which could increase infectious disease risk in vulnerable populations. Our aim was to conduct a dose-response assessment on a noncarcinogenic endpoint of aflatoxin: immunotoxicological effects. We sought to determine a noncarcinogenic tolerable daily intake (TDI) of aflatoxin, based on the existing data surrounding aflatoxin and biomarkers of immune suppression. To conduct the dose response assessment, mammalian studies were assessed for appropriateness of doses (relevant to potential human exposures) as well as goodness of data, and two appropriate mouse studies that examined decreases in leukocyte counts were selected to generate dose response curves. From these, we determined benchmark dose lower confidence limits (BMDL) as points of departure to estimate a range of TDIs for aflatoxin-related immune impairment: 0.017-0.082 μg/kg bw/day. As aflatoxin is a genotoxic carcinogen, and regulations concerning its presence in food have largely focused on its carcinogenic effects, international risk assessment bodies such as the Joint Expert Committee on Food Additives (JECFA) have never established a TDI for aflatoxin. Our work highlights the importance of the noncarcinogenic effects of aflatoxin that may have broader public health impacts, to inform regulatory standard-setting.

Dietary Lycopene Supplementation Could Alleviate Aflatoxin B1 Induced Intestinal Damage through Improving Immune Function and Anti-Oxidant Capacity in Broilers

The present study aims to evaluate the effects of lycopene (LYC) supplementation on the intestinal immune function, barrier function, and antioxidant capacity of broilers fed with aflatoxinB1 (AFB1) contaminated diet. A total of 144 one-day-old male Arbor Acres broilers were randomly divided into three dietary treatment groups; each group consisted of six replicates (eight birds in each cage). Treatments were: (1) a basal diet containing neither AFB1 nor LYC (Control), (2) basal diet containing 100 µg/kg AFB1, and (3) basal diets with 100 µg/kg AFB1 and 200 mg/kg LYC (AFB1 and LYC). The results showed that dietary LYC supplementation ameliorated the AFB1 induced broiler intestinal changes by decreasing the inflammatory cytokines interferon-γ (IFN-γ), interleukin 1beta (IL-1β), and increasing mRNA abundances of cludin-1 (CLDN-1) and zonula occludens-1 (ZO-1) in the jejunum mucosa. On the other hand, AFB1-induced increases in serum diamine oxidase (DAO) activities, D-lactate concentration, mucosal malondialdehyde (MDA), and hydrogen peroxide (H2O2) concentrations were reversed by dietary LYC supplementation (p < 0.05). Additionally, LYC supplementation ameliorated the redox balance through increasing the antioxidant enzyme activities and their related mRNA expression abundances compared to AFB1 exposed broilers. In conclusion, dietary supplementation with LYC could alleviate AFB1 induced broiler intestinal immune function and barrier function damage and improve antioxidants status.

Toward improved human health: efficacy of dietary selenium on immunity at the cellular level

Selenium, an essential trace element in the body, participates in various biological processes in the form of selenoproteins. In humans, a suitable concentration of selenium is essential for maintaining normal cellular function. Decreased levels of selenoproteins can lead to obstruction of the normal physiological functions of tissues and cells and even death. In addition, the level of selenium in the body affects cellular immunity, humoral immunity, and the balance between type 2 and type 1 helper T cells. Selenium can affect the immune function of the body through the reactive oxygen species (ROS), NF-κB, ferroptosis and NRF2 pathways. This paper reviews the immune effect of selenium on the body and the process of signal transduction and aims to serve as a reference for follow-up studies of immune function and research on the development of new selenium compounds and active targets.

Advances in nanomaterial-based electrochemical biosensors for the detection of microbial toxins, pathogenic bacteria in food matrices

There is a growing demand to protect food products against the hazard of microbes and their toxins. To satisfy such goals, it is important to develop highly sensitive, reliable, sophisticated, rapid, and cost-effective sensing techniques such as electrochemical sensors/biosensors. Although diverse forms of nanomaterials (NMs)-based electrochemical sensing methods have been introduced in markets, the reliability of commercial products is yet insufficient to meet the practical goal. In this review, we focused on: 1) sources of pathogenic microbes and their toxins; 2) possible routes of their entrainment in food, and 3) current development of NM-based biosensors to realize real-time detection of the target analytes. At last, future prospects and challenges in this research field are discussed.

Harmful Effects and Control Strategies of Aflatoxin B₁ Produced by Aspergillus flavus and Aspergillus parasiticus Strains on Poultry: Review

The presence of aflatoxin B₁ (AFB₁) in poultry diets decreases the hatchability, hatchling weight, growth rate, meat and egg production, meat and egg quality, vaccination efficiency, as well as impairing the feed conversion ratio and increasing the susceptibility of birds to disease and mortality. AFB₁ is transferred from poultry feed to eggs, meat, and other edible parts, representing a threat to the health of consumers because AFB₁ is carcinogenic and implicated in human liver cancer. This review considers how AFB₁ produced by Aspergillus flavus and Aspergillus parasiticus strains can affect the immune system, antioxidant defense system, digestive system, and reproductive system in poultry, as well as its effects on productivity and reproductive performance. Nutritional factors can offset the effects of AFB₁ in poultry and, thus, it is necessary to identify and select suitable additives to address the problems caused by AFB₁ in poultry.