Search results for "Toxins."
showing 10 items of 797 documents
Oxidative damage and disturbance of antioxidant capacity by zearalenone and its metabolites in human cells.
2017
Mycotoxin contamination of foods and feeds represent a serious problem worldwide. Zearalenone (ZEA) is a secondary metabolite produced by Fusarium species. This study explores oxidative cellular damage and intracellular defense mechanisms (enzymatic and non-enzymatic) in the hepatoma cell line HepG2 after exposure to ZEA and its metabolites (α-zearalenol, α-ZOL; β-zearalenol, β-ZOL). Our results demonstrated that HepG2 cells exposed to ZEA, α-ZOL or β-ZOL at different concentrations (0, 6.25, 12.5 and 25μM) showed: (i) elevated ROS levels (1.5- to 7-fold) based on the formation of the highly fluorescent 2',7'-dichlorofluorescein (DCF), (ii) increased DNA damage measured by the comet assay (…
Electrochemical identification of toxigenic fungal species using solid-state voltammetry strategies.
2018
An electrochemical methodology for the characterization of mycotoxin-producing fungal species from the genera Aspergillus and Fusarium using solid-state voltammetry is described. Upon attachment of fungal colony microsamples to glassy carbon electrodes in contact with aqueous acetate buffer, characteristic voltammetric signals mainly associated to the oxidation of polyphenolic metabolites are recorded. The possibility of fungi-localized electrochemical processes was assessed by means of electron microscopy and field emission scanning electrochemical microscopy coupled to the application of oxidative potential inputs. Using pattern recognition methods, the determined voltammetric profiles we…
Insecticidal Activity and Synergistic Combinations of Ten Different Bt Toxins against Mythimna separata (Walker)
2018
The oriental armyworm (OAW), Mythimna separata (Walker), is a destructive pest of agricultural crops in Asia and Australia. Commercialized Bt crops have performed very well against their target pests
Correction for Chakroun et al., Bacterial Vegetative Insecticidal Proteins (Vip) from Entomopathogenic Bacteria
2016
Entomopathogenic bacteria produce insecticidal proteins that accumulate in inclusion bodies or parasporal crystals (such as the Cry and Cyt proteins) as well as insecticidal proteins that are secreted into the culture medium. Among the latter are the Vip proteins, which are divided into four families according to their amino acid identity. The Vip1 and Vip2 proteins act as binary toxins and are toxic to some members of the Coleoptera and Hemiptera. The Vip1 component is thought to bind to receptors in the membrane of the insect midgut, and the Vip2 component enters the cell, where it displays its ADP-ribosyltransferase activity against actin, preventing microfilament formation. Vip3 has no …
Susceptibility, mechanisms of response and resistance to Bacillus thuringiensis toxins in Spodoptera spp.
2016
Bioinsecticides based on Bacillus thuringiensis have long been used as an alternative to synthetic insecticides to control insect pests. In this review, we focus on insects of the genus Spodoptera, including relevant polyphagous species that are primary and secondary pests of many crops, and how B. thuringiensis toxins can be used for Spodoptera spp. pest management. We summarize the main findings related to susceptibility, midgut binding specificity, mechanisms of response and resistance of this insect genus to B. thuringiensis toxins.
Host-based lipid inflammation drives pathogenesis in Francisella infection
2017
Mass spectrometry imaging (MSI) was used to elucidate host lipids involved in the inflammatory signaling pathway generated at the host-pathogen interface during a septic bacterial infection. Using Francisella novicida as a model organism, a bacterial lipid virulence factor (endotoxin) was imaged and identified along with host phospholipids involved in the splenic response in murine tissues. Here, we demonstrate detection and distribution of endotoxin in a lethal murine F. novicida infection model, in addition to determining the temporally and spatially resolved innate lipid inflammatory response in both 2D and 3D renderings using MSI. Further, we show that the cyclooxygenase-2-dependent lip…
Mediterranean diet and prudent diet are both associated with low circulating esterified 3-hydroxy fatty acids, a proxy of LPS burden, among older adu…
2021
Background LPS-type endotoxins, naturally found in the gut microbiota, are recognized as triggers of inflammation and emerge as detrimental factors of healthy aging. Nutrition represents a promising strategy to reduce LPS burden, yet little is known about the relation of diet to circulating LPS concentrations. Objective The aim was to evaluate the associations between food groups, dietary patterns, and circulating 3-hydroxy fatty acids (3-OH FAs), a proxy of LPS burden. Methods In a cross-sectional study of 698 French older community-dwelling individuals, 3-OH FA concentrations were measured by LC-tandem MS. Dietary patterns were determined using food-frequency questionnaires. Adherence to …
Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?
2017
Background Due to increased formaldehyde exposure, carcinogenic to humans, several researches have been studying the potential toxicity and the safe levels for human beings. The aim of this study was to investigate mutagenicity and cytotoxicity in buccal epithelial exfoliated cells (BEC) of students subjected to formaldehyde (FA) during anatomy classes. Material and Methods BEC were collected periodically from 17 volunteers of undergraduate programs, who had participated in practical anatomy classes, before and after FA exposure. Cells were stained according to Feulgen method and then micronucleus test was applied. A total of 1,500 cells were assessed per individual in this study for the mi…
Dopamine, Noradrenaline and Serotonin Receptor Densities in the Striatum of Hemiparkinsonian Rats following Botulinum Neurotoxin-A Injection.
2017
Abstract Parkinson’s disease (PD) is characterized by a degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) that causes a dopamine (DA) deficit in the caudate-putamen (CPu) accompanied by compensatory changes in other neurotransmitter systems. These changes result in severe motor and non-motor symptoms. To disclose the role of various receptor binding sites for DA, noradrenaline, and serotonin in the hemiparkinsonian (hemi-PD) rat model induced by unilateral 6-hydroxydopamine (6-OHDA) injection, the densities of D1, D2/D3, α1, α2, and 5HT2A receptors were longitudinally visualized and measured in the CPu of hemi-PD rats by quantitative in vitro receptor autorad…
Editorial for Special Issue: The Insecticidal Bacterial Toxins in Modern Agriculture.
2017
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