Liver and kidney serum profile abnormalities in workers exposed to aflatoxin B1 in urban solid waste management centers

Cytotoxic and oxidative changes in individuals occupationally exposed to recyclable municipal solid waste

aste collectors are exposed to a wide variety of bacteria, endotoxins, fungi, allergens, particulate matter, irritating inhalants, and vehicle exhaust, making them more prone to development of chronic diseases. Although several studies described the impact of occupational exposure on the overall health of waste collectors, few investigations were conducted regarding cellular and molecular changes that may occur due to exposure. The aim of this study was to assess biomarkers of oxidative stress such as levels of reactive oxygen species (ROS), lipoperoxidation, total antioxidant capacity (TAC), apoptosis, butyrylcholinesterase (BChE) activity and mitochondrial function (MitoTrackerTM Green FM and MitoTrackerTM Red) using the peripheral blood from individuals occupationally exposed to recyclable solid waste in Southern Brazil. The study included 30 waste collectors and 30 control individuals, who did not perform activities with recognized exposure to biological and chemical substances. Waste collectors were found to exhibit in peripheral blood leukocytes (PBL) higher rates of apoptosis, increased production of ROS, and reduced mitochondrial membrane potential (MMP), associated with decreased total antioxidant capacity (TAC) and elevated activity of BChE in plasma. Therefore, evidence indicates that cytotoxicity, oxidative stress, and inflammatory responses may be involved in the multiplicity of adverse health outcomes related to contaminant exposure in waste collectors. It is thus necessary to implement and/or improve occupational health programs aimed at workers as well as mandatory inspections for the use of personal protective equipment.

Curcumin Alleviates Aflatoxin B1-Induced Liver Pyroptosis and Fibrosis by Regulating the JAK2/NLRP3 Signaling Pathway in Ducks

Aflatoxin B₁ (AFB₁) is a serious pollutant in feed and food which causes liver inflammation, fibrosis, and even cirrhosis. The Janus kinase 2 (JAK2)/signal transducers and activators of the transcription 3 (STAT3) signaling pathway is widely involved in inflammatory response and promotes the activation of nod-like receptor protein 3 (NLRP3) inflammasome, thus leading to pyroptosis and fibrosis. Curcumin is a natural compound with anti-inflammatory and anti-cancer properties. However, whether AFB₁ exposure leads to the activation of the JAK2/NLRP3 signaling pathway in the liver and whether curcumin can regulate this pathway to influence pyroptosis and fibrosis in the liver remains unclear. In order to clarify these problems, we first treated ducklings with 0, 30, or 60 µg/kg AFB₁ for 21 days. We found that AFB₁ exposure caused growth inhibition, liver structural and functional damage, and activated JAK2/NLRP3-mediated liver pyroptosis and fibrosis in ducks. Secondly, ducklings were divided into a control group, 60 µg/kg AFB₁ group, and 60 µg/kg AFB₁ + 500 mg/kg curcumin group. We found that curcumin significantly inhibited the activation of the JAK2/STAT3 pathway and NLRP3 inflammasome, as well as the occurrence of pyroptosis and fibrosis in AFB₁-exposed duck livers. These results suggested that curcumin alleviated AFB₁-induced liver pyroptosis and fibrosis by regulating the JAK2/NLRP3 signaling pathway in ducks. Curcumin is a potential agent for preventing and treating liver toxicity of AFB₁.

Route exposure and adverse effects monitoring of Aflatoxin B1 in the workers of wet waste management, the role of body redox system modulation

Exposure to dust, containing different fungi metabolites such as aflatoxins is a risk factor for developing liver and kidney health abnormalities. Occupational evaluation of the aflatoxin's exposure-induced health abnormalities should include the monitoring of bioaerosols in the workplace and personal air, and applying of appropriate blood biomarkers to assess Aflatoxin B₁ (AFB₁) detrimental effects on a worker's health. However, to the best of our knowledge, these appropriate methods, especially determining the associated-adverse effects on health, following exposure, haven't been well documented in the literature at the wet waste handling sites. In the current study, the AFB₁ quantity in the area, personal, and settled dust in wet household waste handling samples and AFB₁-Albumin levels in the serum of workers in comparison with the control group were determined using high-pressure liquid chromatography with a fluorescent detector (HPLC-FLD) methods. Moreover, the adverse effects of AFB₁ on the liver and kidney biochemical profiles of the exposed workers and its relation to antioxidant capacity in the household wet waste sorting were recorded in a consolidated investigation. The results demonstrated that the average airborne dust concentration and its associated AFB₁ content were significantly higher in wet waste management sections as compared to the control place, corresponding to the serum AFB₁-Albumin levels of workers. Furthermore, AFB₁-induced changes in the serum biochemicals evaluating liver and kidney function tests and antioxidant profiles of workers in wet waste handling sections were indicative of their function abnormalities. The results imply AFB₁-induced adverse effects on the liver and kidney functions may be mediated through the body redox system modulation.

Protective activities of ellagic acid and urolithins against kidney toxicity of environmental pollutants: A review

Oxidative stress and inflammation are two possible mechanisms related to nephrotoxicity caused by environmental pollutants. Ellagic acid, a powerful antioxidant phytochemical, may have great relevance in mitigating pollutant-induced nephrotoxicity and preventing the progression of kidney disease. This review discusses the latest findings on the protective effects of ellagic acid, its metabolic derivatives, the urolithins, against kidney toxicity caused by heavy metals, pesticides, mycotoxins, and organic air pollutants. We describe the chelating, antioxidant, anti-inflammatory, antifibrotic, antiautophagic, and antiapoptotic properties of ellagic acid to attenuate nephrotoxicity. Furthermore, we present the molecular targets and signaling pathways that are regulated by these antioxidants, and suggest some others that should be explored. Nevertheless, the number of reports is still limited to establish the efficacy of ellagic acid against kidney damage induced by environmental pollutants. Therefore, additional preclinical studies on this topic are required, as well as the development of well-designed clinical trials.

Arabic Gum Could Alleviate the Aflatoxin B1-provoked Hepatic Injury in Rat: The Involvement of Oxidative Stress, Inflammatory, and Apoptotic Pathways

Aflatoxin B₁ (AF) is an unavoidable environmental pollutant that contaminates food, feed, and grains, which seriously threatens human and animal health. Arabic gum (AG) has recently evoked much attention owing to its promising therapeutic potential. Thus, the current study was conducted to look into the possible mechanisms beyond the ameliorative activity of AG against AF-inflicted hepatic injury. Male Wistar rats were assigned into four groups: Control, AG (7.5 g/kg b.w/day, orally), AF (200 µg/kg b.w), and AG plus AF group. AF induced marked liver damage expounded by considerable changes in biochemical profile and histological architecture. The oxidative stress stimulated by AF boosted the production of plasma malondialdehyde (MDA) level along with decreases in the total antioxidant capacity (TAC) level and glutathione peroxidase (GPx) activity. Additionally, AF exposure was associated with down-regulation of the nuclear factor erythroid2–related factor2 (Nrf2) and superoxide dismutase1 (SOD1) protein expression in liver tissue. Apoptotic cascade has also been evoked following AF-exposure, as depicted in overexpression of cytochrome c (Cyto c), cleaved Caspase3 (Cl. Casp3), along with enhanced up-regulation of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, inducible nitric oxide synthase (iNOS), and nuclear factor kappa-B transcription factor/p65 (NF-κB/p65) mRNA expression levels. Interestingly, the antioxidant and anti-inflammatory contents of AG may reverse the induced oxidative damage, inflammation, and apoptosis in AF-exposed animals.

Alleviation of Oral Exposure to Aflatoxin B1-Induced Renal Dysfunction, Oxidative Stress, and Cell Apoptosis in Mice Kidney by Curcumin

Aflatoxin B1 is a contaminant widely found in food and livestock feed, posing a major threat to human and animal health. Recently, much attention from the pharmaceutical and food industries has been focused on curcumin due to its strong antioxidant capacity. However, the therapeutic impacts and potential mechanisms of curcumin on kidney damage caused by AFB1 are still incomplete. In this study, AFB1 triggered renal injury in mice, as reflected by pathological changes and renal dysfunction. AFB1 induced renal oxidative stress and interfered with the Keap1–Nrf2 pathway and its downstream genes (CAT, SOD1, NQO1, GSS, GCLC, and GCLM), as manifested by elevated oxidative stress metabolites and reduced antioxidant enzymes activities. Additionally, AFB1 was found to increase apoptotic cells percentage in the kidney via the TUNEL assay, along with increased expression of Cyt-c, Bax, cleaved-Caspase-3, Caspase-9, and decreased expression of Bcl-2 at the transcriptional and protein levels; in contrast, for mice given curcumin, there was a significant reversal in kidney coefficient, biochemical parameters, pathological changes, and the expression of genes and proteins involved in oxidative stress and apoptosis. These results indicate that curcumin could antagonize oxidative stress and apoptosis to attenuate AFB1-induced kidney damage.

Ameliorative effect of nanocurcumin and Saccharomyces cell wall alone and in combination against aflatoxicosis in broilers

Background

The adverse effect of aflatoxin in broilers is well known. However, dietary supplementation of Saccharomyces cell wall and/or Nanocurcumin may decrease the negative effect of aflatoxin B1 because of the bio-adsorbing feature of the functional ingredients in Yeast Cell Wall and the detoxification effect of curcumin nanoparticles. The goal of this study was to see how Saccharomyces cell wall/Nanocurcumin alone or in combination with the aflatoxin-contaminated diet ameliorated the toxic effects of aflatoxin B1 on broiler development, blood and serum parameters, carcass traits, histology, immune histochemistry, liver gene expression, and aflatoxin residue in the liver and muscle tissue of broilers for 35 days. Moreover, the withdrawal time of aflatoxin was measured after feeding the aflatoxicated group an aflatoxin-free diet. Broiler chicks one day old were distributed into five groups according to Saccharomyces cell wall and/or nanocurcumin with aflatoxin supplementation. The G1 group was given a formulated diet without any supplements. The G2 group was supplemented with aflatoxin (0.25 mg/kg diet) in the formulated diet. The G3 group was supplemented with aflatoxin (0.25 mg/kg diet) and Saccharomyces cell wall (1 kg/ton diet) in the formulated diet. The G4 group was supplemented with aflatoxin (0.25 mg/kg diet) and nanocurcumin (400 mg/kg) in the formulated diet. The G5 group was supplemented with aflatoxin (0.25 mg/kg diet) and Saccharomyces cell wall (1 kg/ton diet) in combination with nanocurcumin (200 mg/kg) in the formulated diet.

Results

According to the results of this study, aflatoxin supplementation had a detrimental impact on the growth performance, blood and serum parameters, carcass traits, and aflatoxin residue in the liver and muscle tissue of broilers. In addition, aflatoxin supplementation led to a liver injury that was indicated by serum biochemistry and pathological lesions in the liver tissue. Moreover, the shortening of villi length in aflatoxicated birds resulted in a decrease in both the crypt depth ratio and the villi length ratio. The expression of CYP1A1 and Nrf2 genes in the liver tissue increased and decreased, respectively, in the aflatoxicated group. In addition, the aflatoxin residue was significantly (P ≤ 0.05) decreased in the liver tissue of the aflatoxicated group after 2 weeks from the end of the experiment.

Conclusion

Saccharomyces cell wall alone or with nanocurcumin attenuated these negative effects and anomalies and improved all of the above-mentioned metrics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03256-x.

PINK1/Parkin-mediated mitophagy is activated to protect against AFB1-induced kidney damage in mice

Aflatoxin B₁ (AFB₁) is a toxic food pollutant that has extensive deleterious impacts on the kidney. Oxidative stress represents the primary mechanism of AFB₁ nephrotoxicity and can also cause mitochondrial damage. Damaged mitochondria can trigger apoptosis leading to kidney injury. PINK1/Parkin-mediated mitophagy can alleviate mitochondrial injury to maintain cellular homeostasis, however, its role in AFB₁-induced kidney damage is unknown. To investigate the effect of PINK1/Parkin-mediated mitophagy on kidney impairment triggered by AFB₁, 40 male wild-type (WT) C57BL/6N mice were first assigned to 4 groups and orally exposed to AFB₁ at 0, 0.5, 0.75, and 1 mg/kg body weight (BW) for 28 days. The results revealed that AFB₁ induced kidney damage, oxidative stress, mitochondrial damage, apoptosis and activated PINK1/Parkin-mediated mitophagy with a dose-dependent effect. Then, 20 male WT C57BL/6N mice and 20 male Parkin knockout (Parkin^-/-) C57BL/6N mice were assigned to 4 groups and orally exposed to AFB₁ at 0, 1, 0, and 1 mg/kg BW for 28 days. The results revealed that Parkin^-/- suppressed mitophagy and exacerbated kidney damage, oxidative stress, mitochondrial damage, and apoptosis under AFB₁ exposure. The aforementioned evidences demonstrate that PINK1/Parkin-mediated mitophagy is activated by AFB₁ and protects against kidney damage in mice.

Aflatoxin B1: metabolism, toxicology, and its involvement in oxidative stress and cancer development

Aflatoxins are a class of carcinogenic mycotoxins produced by Aspergillus fungi, which are widely distributed in nature. Aflatoxin B1 (AFB1) is the most toxic of these compounds and its metabolites have a variety of biological activities, including acute toxicity, teratogenicity, mutagenicity and carcinogenicity, which has been well-characterized to lead to the development of hepatocellular carcinoma (HCC) in humans and animals. This review focuses on the metabolism of AFB1, including epoxidation and DNA adduction, as it concerns the initiation of cancer and the underlying mechanisms. In addition to DNA adduction, inflammation and oxidative stress caused by AFB1 can also participate in the occurrence of cancer. Therefore, the main carcinogenic mechanism of AFB1 related ROS is summarized. This review also describes recent reports of AFB1 exposures in occupational settings. It is hoped that people will pay more attention to occupational health, in order to reduce the incidence of cancer caused by occupational exposure.

Fucoidan supplementation modulates hepato-renal oxidative stress and DNA damage induced by aflatoxin B1 intoxication in rats

Aflatoxins are a common food contaminant of global concern. Aflatoxin B₁ (AFB₁) intoxication is associated with serious health hazards. Recently, fucoidan (FUC) has gained much attention from pharmaceutical industry due to its promising therapeutic effects. The impacts of FUC on AFB₁-induced liver and kidney injures have not been sufficiently addressed. This research was conducted to evaluate the ameliorative effect of FUC in AFB1-induced hepatorenal toxicity model in rats over 14 days. Five groups were assigned; control, FUC (200 mg/kg/day, orally), AFB₁ (50 μg/kg, i.p.), and AFB₁ plus a low or high dose of FUC. AFB₁ induced marked hepatorenal injury elucidated by substantial alterations in biochemical tests and histological pictures. The oxidative distress instigated by AFB₁ enhanced production of malondialdehyde (MDA) and nitric oxide (NO) along with reduction in the reduced-glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities. DNA damage in the liver and kidney tissues has been demonstrated by overexpression of proliferating cell nuclear antigen (PCNA). Unambiguously, FUC consumption alleviates the AFB₁-induced mitochondrial dysfunction, oxidative harm, and apoptosis. These ameliorated effects are proposed to be attributed to fucoidan's antioxidant and anti-apoptotic activities. Our results recommend FUC supplementation to food because it exerts both preventive and therapeutic effects against AFB₁-induced toxicity.

Aflatoxin B1 and Aflatoxin M1 Induce Compromised Intestinal Integrity through Clathrin-Mediated Endocytosis

With the growing diversity and complexity of diet, humans are at risk of simultaneous exposure to aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1), which are well-known contaminants in dairy and other agricultural products worldwide. The intestine represents the first barrier against external contaminants; however, evidence about the combined effect of AFB1 and AFM1 on intestinal integrity is lacking. In vivo, the serum biochemical parameters related to intestinal barrier function, ratio of villus height/crypt depth, and distribution pattern of claudin-1 and zonula occluden-1 were significantly affected in mice exposed to 0.3 mg/kg b.w. AFB1 and 3.0 mg/kg b.w. AFM1. In vitro results on differentiated Caco-2 cells showed that individual and combined AFB1 (0.5 and 4 μg/mL) and AFM1 (0.5 and 4 μg/mL) decreased cell viability and trans-epithelial electrical resistance values as well as increased paracellular permeability of fluorescein isothiocyanate-dextran in a dose-dependent manner. Furthermore, AFM1 aggravated AFB1-induced compromised intestinal barrier, as demonstrated by the down-regulation of tight junction proteins and their redistribution, particularly internalization. Adding the inhibitor chlorpromazine illustrated that clathrin-mediated endocytosis partially contributed to the compromised intestinal integrity. Synergistic and additive effects were the predominant interactions, suggesting that these toxins are likely to have negative effects on human health.

Investigating Multi-Mycotoxin Exposure in Occupational Settings: A Biomonitoring and Airborne Measurement Approach

Investigating workplace exposure to mycotoxins is of the utmost importance in supporting the implementation of preventive measures for workers. The aim of this study was to provide tools for measuring mycotoxins in urine and airborne samples. A multi-class mycotoxin method was developed in urine for the determination of aflatoxin B1, aflatoxin M1, ochratoxin A, ochratoxin α, deoxynivalenol, zearalenone, α-zearalenol, β-zearalenol, fumonisin B1, HT2-toxin and T2-toxin. Analysis was based on liquid chromatography-high resolution mass spectrometry. Sample pre-treatments included enzymatic digestion and an online or offline sample clean-up step. The method was validated according to the European Medicines Agency guidance procedures. In order to estimate external exposure, air samples collected with a CIP 10 (Capteur Individuel de Particules 10) personal dust sampler were analyzed for the quantification of up to ten mycotoxins, including aflatoxins, ochratoxin A, deoxynivalenol, zearalenone, fumonisin B1 and HT-2 toxin and T-2 toxin. The method was validated according to standards for workplace exposure to chemical and biological agents EN 482. Both methods, biomonitoring and airborne mycotoxin measurement, showed good analytical performances. They were successfully applied in a small pilot study to assess mycotoxin contamination in workers during cleaning of a grain elevator. We demonstrated that this approach was suitable for investigating occupational exposure to mycotoxins.