Detoxification, metabolism, and glutathione pathway activity of aflatoxin B1 by dietary lactic acid bacteria in broiler chickens

A consortium of detoxifying bacteria mitigates the aflatoxin B1 toxicosis on performance, health, and blood constituents of laying hens

Detoxification approaches are evolving from physical to biological to eliminate the toxins altogether. The current study was conducted to compare the impact of 2 newly developed toxin deactivators, Magnotox-alphaA (MTA) and Magnotox-alphaB (MTB) with a commercially available toxin binder, Mycofix Plus^{MTV INSIDE} (MF) in alleviating the pernicious effects of aflatoxin B1 (AFB1) in laying hens. The treatments were: 1) negative control (NC; without AFB1), 2) positive control (PC; contaminated with 500 ppb AFB1), 3) MF (PC + 2 kg MF/ton feed), 4) MTA (PC + 2 kg MTA/ton feed), and 5) MTB (PC + 2 kg MTB/ton feed). Detoxifying bacteria revealed a substantial reduction of different toxins in vitro, in which 98.8, 94.5, and 73.3% degradation rates were achieved, respectively, for zearalenone (ZEN), patulin, and AFB1 in the first 1 h of exposure. The PC group had a sharp decline in egg production (EP; 68.83%) while MTB showed the superior EP (95.74%) followed by NC (90.66%), MF (86.57%), and MTA (82.08%; P ≤ 0.05). Egg weight (EW) was also observed to be inferior in PC group (53.80 g; P ≤ 0.05). Egg mass (EM) was higher in MTB (57.55 g) and NC (54.33 g) groups while PC produced the lowest (39.64 g; P ≤ 0.05). MTB and NC groups also demonstrated the best FCR, 1.62 and 1.68, respectively, and PC manifested the poorest FCR (1.98) with higher ADFI (P ≤ 0.05). MTB also produced a superior moisture content (MC; 82.11%) with inferior DM (17.89%) in ileum content (P ≤ 0.05). The greatest liver fat content was found in MF group (48.19%) and MTA yielded the superior serum β-carotene and Vit A. MDA level in yolk samples was influenced by treatments, rendering the highest level in PC group (P ≤ 0.05). Ileum microbiota and blood characteristics were also affected by treatments. In general, MTB proves to be a toxin-deactivator candidate with comparable results to that of commercially available toxin-binders.

Effect of rapeseed meal degraded by enzymolysis and fermentation on the growth performance, nutrient digestibility and health status of broilers

The purpose of this study is to investigate the nutritional changes of degraded rapeseed meal and its effects on growth performance, nutrient digestibility and health status of broilers. Raw rapeseed meal (CON), degraded by enzymolysis (protease, ERM), fermentation (Bacillus subtilis, FRM) or both (DRM) were included in diets at 25% and fed to 480 yellow-feathered broilers at 22-63 d of age. Results showed that rapeseed peptide contents (≤1 kDa) were increased (p < 0.05) from 4.13% (CON) to 35.5% (ERM), 24.1% (FRM) and 50.4% (DRM); glucosinolate and erucic acid in DRM were decreased (p < 0.05) by 71.6% and 86.2%, respectively, compared to CON. There were increases (p ≤ 0.029) in feed intake, body weight gain, feed efficiency and precaecal digestibility of dry matter, crude protein, methionine, isoleucine, leucine, lysine, cysteine, phenylalanine, tyrosine, threonine, tryptophan and valine in the three degraded diets. Also, serum immunoglobulin (Ig) A, IgG, glutathione peroxidase, superoxide dismutase and catalase were raised (p ≤ 0.034) in the degraded diets. Additionally, DRM showed more pronounced effects (p < 0.05) on variables related to growth, digestibility and health than ERM and FRM. It is concluded that rapeseed meal degraded by both enzymolysis and fermentation can increase its nutritional values and application in broilers.

Effect of Salvia miltiorrhiza aerial parts on growth performance, nutrient digestibility, and digestive enzymes in rabbits

Objective

This study aimed to investigate the effect of Salvia miltiorrhiza (S.m.) aerial parts as an alternative ingredient on growth performance, nutrient digestibility, and digestive enzymes in growing rabbits.

Methods

Treatments included five tested diets: a control (basal diet), antibiotic (basal diet +enramycin at 5 mg/kg), and S.m. aerial parts powder added at 3.0%, 6.0%, and 9.0% of feed using 300 growing rabbits.

Results

The diets with S.m. aerial parts addition at 9.0% decreased (p<0.05) feed/gain compared to the control, but there were no differences in feed intake and body weight gain. In contrast with the control, the addition of antibiotic increased (p<0.05) digestibility of dry matter, crude protein, energy, fiber, and ash. The herb addition did not cause differences in the digestibility of most nutrients compared to the antibiotic, but fiber digestibility of the herb at 6.0% and 9.0% was lower (p<0.05) than that of the antibiotic. Moreover, the antibiotic and the herb also similarly increased (p<0.05) the activities of duodenal α-amylase, maltase, lipase, and trypsin, compared to the control, and the herb at 6.0% and 9.0% showed a greater (p<0.05) activity of elastase than the dose 3.0%.

Conclusion

The obtained data indicate that S.m. aerial parts can be a potential forage in rabbit’s diet at 9.0% with a beneficial regulation on nutrition and digestion.

The effects of Nigella sativa seeds and thymoquinone on aflatoxin phase-2 detoxification through glutathione and glutathione-S-transferase alpha-3, and the relationship between aflatoxin B1-DNA adducts in broilers

The primary pathway of the detoxification of aflatoxin (AF) metabolites occurring at the end of phase-1 biotransformation is glutathione (GSH) conjugation via glutathione-S-transferase (GST) enzyme in phase-2. In this study, the activity of Nigella sativa seeds (NS) and thymoquinone (TQ) on phase-2 detoxification pathways of AF was investigated in light of GSH, GST alpha-3 (GSTA3), and AFB1-DNA adducts detected by the immunohistochemical method in broilers' livers. One-hundred twenty chickens at one-day-old were divided into six groups as the control (CNT), AF, TQ, NS, AF + TQ, and AF + NS groups and fed for 28 days. AF, TQ, and NS were added to the relevant diets at 2 mg/kg, 300 mg/kg, and 5%, respectively. The administration of AF alone strongly stimulated the formation of AFB1-DNA adduct and reduced GSH and GSTA3 levels in hepatocytes (p < 0,01). In contrast, TQ and NS were found to reduce significantly the amount of AFB1-DNA adducts in AF + TQ and AF + NS groups (p < 0,01). We concluded that NS and TQ achieved this by increasing GSH and GSTA3 levels (p < 0,01) thanks to their antioxidant properties, and hence detoxifying the reactive metabolites of AF. Also, we consider that the AFB1-DNA adduct constituted in 28 days can be used as a biomarker for exposure to AF in broilers.

Research progress on the protection and detoxification of phytochemicals against aflatoxin B1-Induced liver toxicity

Aflatoxin B₁ (AFB₁) is a potent hepatotoxic toxin, which can cause hepatitis, cirrhosis, and liver immunological damage. It has been involved in the etiology of human hepatocellular carcinoma. AFB₁ can cause oxidative stress in the body's metabolism process, and then cause cytotoxicity, such as apoptosis and DNA damage. Scientific research has discovered that phytochemicals can induce the detoxification pathway of AFB₁ through its biotransformation, thereby reducing the damage of AFB₁ to the human body. In clinical treatment, certain phytochemicals have been effectively used in the treatment of liver injury due to the advantages of multiple targets, multiple pathways, low toxicity and side effects. Therefore, the article summarizes the toxic mechanism of AFB₁-induced hepatoxicity, and the related research progress of phytochemicals for preventing and treating its cytotoxicity and genotoxicity. We also look forward to the existing problems and application prospects of phytochemicals in the pharmaceutical industry, in order to provide theoretical reference for the prevention and treatment of AFB₁ poisoning in future research work.

Decontamination of Aflatoxins by Lactic Acid Bacteria

Aflatoxins are toxic secondary metabolic products, which exert great hazards to human and animal health. Decontaminating aflatoxins from food ingredients to a threshold level is a prime concern for avoiding risks to the consumers. Biological decontamination processes of aflatoxins have received widespread attention due to their mild and environmental-friendly nature. Many reports have been published on the decontamination of aflatoxins by microorganisms, especially lactic acid bacteria (LAB), a well-explored probiotic and generally recognized as safe. The present review aims at updating the decontamination of produced aflatoxins using LAB, with an emphasis on the decontamination mechanism and influence factors for decontamination. This comprehensive analysis provides insights into the binding mechanisms between LAB and aflatoxins, facilitating the theoretical and practical application of LAB for decontaminating hazardous substances in food and agriculture.

Synthesized Geopolymers Adsorb Bacterial Proteins, Toxins, and Cells

Pore-forming and hemolytic toxins are bacterial cytotoxic proteins required for virulence in many pathogens, including staphylococci and streptococci, and are notably associated with clinical manifestations of disease. Inspired by adsorption properties of naturally occurring aluminosilicates, we engineered inexpensive, laboratory-synthesized, aluminosilicate geopolymers with controllable pore and surface characteristics to remove pathogenic or cytotoxic material from the surrounding environment. In this study, macroporous and mesoporous geopolymers were produced with and without stearic acid surface modifications. Geopolymer binding efficacies were assessed by measuring adsorption of methicillin-resistant Staphylococcus aureus (MRSA) culture filtrate proteins, α-hemolysin and streptolysin-O toxins, MRSA whole cells, and antibiotics. Macroporous and mesoporous geopolymers were strong non-selective adsorbents for bacterial protein, protein toxins, and bacteria. Although some geopolymers adsorbed antibiotics, these synthesized geopolymers could potentially be used in non-selective adsorptive applications and optimized for adsorption of specific biomolecules.

Turn-On Fluorescence Aptasensor on Magnetic Nanobeads for Aflatoxin M1 Detection Based on an Exonuclease III-Assisted Signal Amplification Strategy

In order to satisfy the need for sensitive detection of Aflatoxin M1 (AFM1), we constructed a simple and signal-on fluorescence aptasensor based on an autocatalytic Exonuclease III (Exo III)-assisted signal amplification strategy. In this sensor, the DNA hybridization on magnetic nanobeads could be triggered by the target AFM1, resulting in the release of a single-stranded DNA to induce an Exo III-assisted signal amplification, in which numerous G-quadruplex structures would be produced and then associated with the fluorescent dye to generate significantly amplified fluorescence signals resulting in the increased sensitivity. Under the optimized conditions, this aptasensor was able to detect AFM1 with a practical detection limit of 9.73 ng kg⁻¹ in milk samples. Furthermore, the prepared sensor was successfully used for detection of AFM1 in the commercially available milk samples with the recovery percentages ranging from 80.13% to 108.67%. Also, the sensor performance was evaluated by the commercial immunoassay kit with satisfactory results.

Effect of yeast cell wall on the growth performance and gut health of broilers challenged with aflatoxin B1 and necrotic enteritis

This study aimed to investigate the effect of yeast cell walls (YCW) on the growth performance, visceral lesions, intestinal integrity, enterotoxicity, and bacteria of broilers challenged with aflatoxin B1 (AF) and necrotic enteritis (NE) from 1 to 21 d of age. A total of 576 one-day-old broilers were assigned to a 2 × 2 × 2 design for diets containing AFB1 (0 or 40 μg/kg), NE (challenged or unchallenged), or YCW (0 or 500 mg/kg). The main effect analysis showed that AF depressed (P < 0.01) average daily feed intake (ADFI), average daily body weight gain (ADG), the mRNA profiles of polymeric Ig receptor (pIgR), claudin-1, and occludin, but increased (P < 0.001) liver lesion scores, serum endotoxin, and diamine oxidase (DAO). The NE challenge depressed (P < 0.01) ADFI, ADG, secretory IgA (sIgA), pIgR, claudin-1, occludin, and the populations of Lactobacilli and Bifidobacteria, but increased (P < 0.001) visceral lesions, endotoxins, and DAO. The main effect of YCW on growth performance, visceral lesions, and intestinal integrity was not significant, but decreased (P < 0.01) mortality, endotoxin, DAO, and C. perfringens, and increased (P < 0.05) the populations of Lactobacilli and Bifidobacteria. There were 3-way interactions (P < 0.05) on growth performance, intestinal lesions, integrity, and gut bacteria. Compared with the treatment with the dual challenges, there were pronounced effects (P < 0.05) of YCW on ADFI, ADG, lesions, DAO, pIgR, and Bifidobacteria. The results suggest that with the concurrent challenges of AF and NE, the YCW can partially protect the growth performance and intestinal health of broilers.