Alpha-class glutathione S-transferases involved in the detoxification of aflatoxin B1 in ducklings.

The objective of this study was to identify the key glutathione S-transferase (GST) isozymes involved in the detoxification of Aflatoxin B1 (AFB1) in ducks' primary hepatocytes. The full-length cDNA encoding the 10 GST isozymes (GST, GST3, GSTM3, MGST1, MGST2, MGST3, GSTK1, GSTT1, GSTO1 and GSTZ1) were isolated/synthesized from ducks' liver and cloned into the pcDNA3.1(+) vector. The results showed that pcDNA3.1(+)-GSTs plasmids were successfully transferred into the ducks' primary hepatocytes and the mRNA of the 10 GST isozymes were overexpressed by 1.9-3274.7 times. Compared to the control, 75 µg/L (IC30) or 150 µg/L (IC50) AFB1 treatment reduced the cell viability by 30.0-50.0% and increased the LDH activity by 19.8-58.2% in the ducks' primary hepatocytes. Notably, the AFB1-induced changes in cell viability and LDH activity were mitigated by overexpression of GST and GST3. Compared to the cells treated with AFB1, exo-AFB1-8,9-epoxide (AFBO)-GSH, as the major detoxified product of AFB1, was increased in the cells overexpression of GST and GST3. Moreover, the sequences, phylogenetic and domain analysis revealed that the GST and GST3 were orthologous to Meleagris gallopavo GSTA3 and GSTA4. In conclusion, this study found that the ducks' GST and GST3 were orthologous to Meleagris gallopavo GSTA3 and GSTA4, which were involved in the detoxification of AFB1 in ducks' primary hepatocytes.

Mitigation of Aflatoxin B1 Hepatoxicity by Dietary Hedyotis diffusa Is Associated with Activation of NRF2/ARE Signaling in Chicks.

The objective of this study was to explore the mechanism of Hedyotis diffusa (HD) in mediating the detoxification of aflatoxin B1 (AFB1)-induced hepatic injury in chicks. A total of 144 one-day-old male broilers (Cobb 500) were randomly assigned to four treatment groups (n = 6 cages/diet, 6 chicks/cage). After three days of acclimation, the broilers were fed either a control diet (Control), Control plus 0.5 mg/kg of AFB1, or Control plus 0.5 mg/kg AFB1 with 500 or 1000 mg/kg HD for two weeks. Both serum and liver were collected at the end of the feeding trial for biochemistry, histology, and NF-E2-related nuclear factor 2 (NRF2)/antioxidant response element (ARE) signaling analysis. Compared with Control, the AFB1 treatment caused liver injury and decreased (p < 0.05) body weight gain, feed intake, feed conversion ratio, and serum albumin and total protein by 6.2-20.7%. AFB1 also induced swelling, necrosis, and severe vacuolar degeneration in chicks' livers. Notably, HD supplementation at 500 and 1000 mg/kg mitigated (p < 0.05) the alterations induced by AFB1. HD supplementation alleviated (p < 0.05) AFB1-induced impairment in hepatic glutathione peroxidase activity, protein carbonyl, and exo-AFB1-8,9-epoxide (AFBO)-DNA concentrations by 57.7-100% and increased (p < 0.05) the activities of superoxide dismutase and catalase by 23.1-40.9% more than those of AFB1 treatment alone. Furthermore, HD supplementation at the two doses upregulated (p < 0.05) NRF2, NAD(P)H: quinone oxidoreductase-1, heme oxygenase-1, glutathione cysteine ligase catalytic subunit, and glutathione-S transferase A2 and A3 in livers relative to the AFB1 group by 0.99-3.4-fold. Overall, dietary supplementation of HD at a high dose displayed better protection effects against aflatoxicosis. In conclusion, a dietary HD supplementation at 500 and 1000 mg/kg protected broilers from AFB1-induced hepatotoxicity, potentially due to the activation of NRF2/ARE signaling in the chicks.

Dietary Se deficiency dysregulates metabolic and cell death signaling in aggravating the AFB1 hepatotoxicity of chicks.

The objective of this study was to use isobaric tags for relative and absolute quantitation (iTRAQ) proteomic technology to systematically analyze the hepatotoxic mechanism of aflatoxin B1 (AFB1) and its prevention by Se in broilers. Four groups of day-old broilers were allocated into a 2 × 2 factorial design trial that fed a Se-deficient based diet (BD) or the BD + 1.0 mg AFB1/kg, 0.3 mg Se/kg, or 1.0 mg AFB1/kg plus 0.3 mg Se/kg for 3 wk. Dietary AFB1 increased serum ALT and decreased total protein and albumin concentrations, and induced hepatic histopathological lesions in Se adequate groups. Notably, Se deficiency exacerbated these AFB1-induced changes. Furthermore, Se deficiency reduced hepatic glutathione peroxidase but increased thioredoxin reductase and glutathione S-transferase activities and 8-hydroxydeoxyguanosine concentration in AFB1 administrated groups. Moreover, AFB1 dysregulated 261 co-differentially expressed proteins (DEPs) in both Se adequate and deficiency diets, and Se deficiency dysregulated 64 DEPs in AFB1 administrated diets. These DEPs are mainly related to phase I and II metabolizing enzymes, heat shock proteins, DNA repair, fatty acid metabolism and apoptosis. The in vitro study has verified that aldo-keto reductase family1, member10 plays an important role in AFB1-induced hepatotoxicity and Se-mediated detoxification of AFB1 in a chicken leghorn male hepatoma cells. Conclusively, this study has analyzed the hepatic proteome response to dietary AFB1 and Se, and thus shed new light on the mechanisms of hepatotoxicity of AFB1 and its detoxification by Se in broilers.

Effect of deoxynivalenol on the porcine acquired immune response and potential remediation by a novel modified HSCAS adsorbent.

The objective of this study was to determine the immunotoxic effects of deoxynivalenol (DON) in weaning piglets, and potential efficacy of a modified hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce DON toxicity. Four groups of 21-day-old male piglets (n = 7/group) were fed a control diet or diet containing 1.0 or 3.0 mg DON/kg, or 3.0 mg DON/kg plus 0.05% modified HSCAS for 4 weeks. Compared to the control, the DON diets decreased serum porcine circovirus antibody titer and the dermal hypersensitivity response to OVA at day 21 or 28. DON also induced focal necrosis and proliferation of cortical lymphocytes and apoptosis and increased the total antioxidant capacity and reduced glutathione, protein carbonyl concentrations in thymus. DON increased thymus mRNA, protein and (or) enzyme levels, cytokines (IL-6, IL-10, and TNF-α) and apoptosis-related genes (Caspase-3), while hematopoietic cell kinase (HCK) decreased. Intriguingly, the modified HSCAS alleviated the DON-induced changes on serum antibody titer, and thymic histopathology, apoptosis, redox status, inflammation and apoptosis signaling. In conclusion, these findings help to explain the toxic effects and mechanisms of DON and demonstrated the modified HSCAS adsorbent could be used to reduce the toxicity of DON in weaning piglets.