Turmeric Powder Counteracts Oxidative Stress and Reduces AFB1 Content in the Liver of Broilers Exposed to the EU Maximum Levels of the Mycotoxin.

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 (

Antimicrobial Activity of Yeast Cell Wall Products Against Clostridium perfringens.

Yeast cell wall (YCW) products are used worldwide as alternatives to antibiotics growth promoters for health and performances improvement in livestock. The success of yeast and YCW products as feed additives in farm animals' nutrition relies on their capacity to bind enteropathogenic bacteria and on their immunomodulatory activity. In vivo studies report their anti-infectious activity on Gram-positive pathogens like clostridia. However, the in vitro antimicrobial activity of YCW products seems to be limited to some Gram-negative enteropathogens, and literature lacks in vitro evidences for antimicrobial effect of YCW products against Clostridium perfringens. This study aims to measure the antimicrobial activity of YCW products on C. perfringens. Five different YCW products were assayed for their capacity to inhibit the growth of C. perfringens, by analyzing the growth kinetics of the pathogen. All YCW products inhibited the growth of the pathogen, by reducing the growth rate and the maximum growth value and extending the lag phase duration. The effect on the growth parameters was product and dosage dependent. The most effective YCW (namely YCW2), at the minimum effective concentration of 1.25 mg/mL, increased the lag phase duration by 3.6 h, reduced the maximum growth rate by >50%, and reduced the final cell count by 102 colony-forming unit per milliliter in 24 h, with respect to the control. YCW products did not show a strain-dependent impact on C. perfringens growth when tested on different strains of the bacterium.

Equilibrium Isotherm Approach to Measure the Capability of Yeast Cell Wall to Adsorb Clostridium perfringens.

Yeast cell wall (YCW) products are currently used as substitutes to antibiotic growth promoters, to improve animal performances, and to reduce the incidence of infectious diseases in livestock. They are claimed to bind enteropathogens, thus interfering with their colonization in the intestinal mucosa. Although the anti-infectious activity of YCW products on Gram-positive pathogens like Clostridium perfringens has been reported in vivo, in vitro evidences on the adsorption of C. perfringens by YCW fractions are not yet available. Preliminary results showed that purified YCW products exert antimicrobial activity toward C. perfringens. Using the adsorption isotherm approach, we measured the ability of YCW products in adsorbing C. perfringens, thus reducing its viability. Dosages of YCW products >1 mg/mL adsorbed 4 Log colony-forming unit (CFU)/mL of C. perfringens in buffered solution. The maximum adsorption of the bacterium was reached in 3 h, whereas only one product of four YCW products retained the adsorption up to 6 h. The analysis of equilibrium isotherms and adsorption kinetics revealed that all products adsorb C. perfringens in a dose- and time-dependent manner, with high affinity and capacity, sequestering up to 4 Log CFU/mg of product. The determination of adsorption parameters allows to differentiate among adsorbents and select the most efficient product. This approach discriminated among YCW products more efficiently than the antimicrobial assay. In conclusion, this study suggests that the ability of YCW products in reducing C. perfringens viability can be the result of an adsorption mechanism.

Comparative efficacy of agricultural by-products in sequestering mycotoxins.

BACKGROUND: Biosorption using agricultural by-products has been proven as a low-cost and safe way to sequester mycotoxins. Few agricultural by-products have been studied for their efficacy in adsorbing simultaneously a large range of mycotoxins. The present work compared the ability of 51 agricultural by-products to adsorb mycotoxins from liquid mediums simulating physiological pH values, and it studied the mechanism for mycotoxin adsorption by isotherm adsorption experiments. RESULTS: Grape pomaces, artichoke wastes, and almond hulls were selected as promising biosorbents for mycotoxins, being quite effective towards aflatoxin B1 (AFB1 ), zearalenone (ZEA), and ochratoxin A (OTA). Their adsorption was not affected by medium pH, and the adsorbed fraction was not released when pH rose from acid to neutral values. Fumonisin B1 (FB1 ) was adsorbed to a lesser extent, and deoxynivalenol adsorption was not recorded. For the selected biosorbents, maximum adsorption capacity calculated by the best fitting model (Freundlich, Langmuir, or Sips equation) ranged from 1.2 to 2.9 µg mg-1 for AFB1 , 1.3 to 2.7 µg mg-1 for ZEA, 0.03 from 2.9 µg mg-1 for OTA, and 0.01-1.1 µg mg-1 for FB1 . CONCLUSION: This study confirms that some agricultural by-products can find technological applications as feed/food additives for mycotoxin reduction. © 2018 Society of Chemical Industry.

Antimicrobial properties of rosin acids-loaded nanoparticles against antibiotic-sensitive and antibiotic-resistant foodborne pathogens.

Rosin acids (RA) from coniferous trees are used in folk medicine for healing various skin infections. Despite the antimicrobial potential of RA, their poor solubility in aqueous media may limit their use. In this work RA-loaded polyethylene glycol-poly(lactic-co-glycolic acid) nanoparticles (RA-NPs) with enhanced antimicrobial properties against foodborne bacterial pathogens were produced. RA-NPs were prepared by solvent displacement technique and characterized for relevant colloidal features by dynamic light scattering, laser Doppler anemometry and transmission electron microscopy. Association of RA to NPs occurred with high yields (86% w/w). RA and RA-NPs (∼130 nm) were strongly active against antibiotic-sensitive Gram + pathogens, i.e. Clostridium perfringens, Listeria monocytogenes and antibiotic-resistant Staphylococcus aureus. However, both failed in inhibiting the growth of Gram - pathogens (Campylobacter jejuni, Campylobacter coli, Escherichia coli and Salmonella enterica). Association to NPs enhanced the antimicrobial activity of RA. MIC, IC50, IC90, and MBC values of RA-NPs were ten-times lower than RA. RA-NPs did not change the intrinsic toxicity potential of RA. This is the first study on the enhancement of the antimicrobial activity of RA when associated to nanocarriers. This approach may be an effective strategy to produce aqueous-based RA solutions with enhanced antimicrobial activity against antibiotic-sensitive and antibiotic-resistant Gram + pathogens.