Impact of Simulated Human Gastrointestinal Digestion on the Bioactive Fraction of Upcycled Pineapple By-Products

Pineapple by-products (peels and stems) from fruit processing industries were evaluated to understand its potential application as a functional food. Therefore, the bioactive compounds of pineapple by-products were characterized for prebiotic and antioxidant activities. A total characterization of soluble carbohydrates profile (simples and complex carbohydrates), as well as polyphenols was performed, after removal of enzymatic fraction from pineapple crude juice, allowing the decrease of proteolytic activity and improving the other biological activities. Results showed that pineapple liquid fraction, from stem and peels, can be applied as a prebiotic enhancer, promoting the growth of five probiotic microorganisms (two strains of Lactobacillus sp. and three strains of Bifidobacterium sp.), as a single carbohydrate source. Moreover, through HPLC (High Performance Liquid Chromatography) analysis, 10 polyphenols were identified in pineapple liquid fractions, with some expected differences between both evaluated by-products. Gastrointestinal tract was simulated, in a continuous mode to understand the impact of pH changes and gastrointestinal enzymes into pineapple liquid fractions. Results showed a digestion of high molecular weight polysaccharides into small molecular weight tri-, di-, and monosaccharides. There was an increase of samples antioxidant activity through the gastrointestinal stage, followed by the release of specific polyphenols, such as chlorogenic, coumaric, and ferulic acids. The prebiotic activity did not improve throughout the simulation, in fact, the prebiotic potential decreased throughout the different stages.

Combinations of mycotoxins in feed and their accumulation in internal organs of broiler chickens

The issue of safety of production and processing of agricultural raw materials for obtaining quality food is becoming more and more topical. Of particular concern in most countries of the world is the contamination with mycotoxins of plant and livestock products. Plant food is contaminated as a result of pathogenic fungi growth, and livestock due to the accumulation of toxins in the body. They enter the human food chain continuously dire0ctly with cereals, seeds, spices, fruit, drinks and other plant products, as well as directly through food obtained from animals and birds that have consumed feed contaminated with mycotoxins. The real threat from mycotoxins can be extremely high, as they accumulate in the tissues and internal organs of animals and birds, and the consumption of broiler meat is increasing every year, being a more accessible protein product. Because of the small molecular weight of mycotoxins, the body does not produce antibodies to them, thus no immunity occurs, so warm-blooded animals and humans remain sensitive to them throughout life. The aim of our investigation (research) was: 1 - to determine the effect of fodder contaminated with a combined group of mycotoxins (Fumonizin B1, Zearalenone, DON and T-2 toxin) exceeding the maximum allowable concentration on growth and development of young chickens. 2-determine histological changes in the structures of internal organs (liver and kidney), which are directly related to the general health of broiler chickens. Under the influence of mycotoxins the liver is subjected to dystrophic changes. It increases in volume, changes the structure of the liver becoming brittle or friable, the color becomes pale or filled with blood. Sinusoidal capillaries are filled with blood, perivascular infiltration with round cellular elements in the area of triads. Granulomas - clusters of lymphoid cells appear in thickness of lobules. Among lymphoid cells a large number of hepatocytes in a state of hyaline-droplet dystrophy and in a state of necrosis. In the kidneys cause edema in the middle part of the cortical substance, due to which, subcapsular renal corpuscles are pushed back to the kidney capsule and capillaries overflow with blood. Vascular glomeruli thickening decrease in size and go into a state of disintegration of loops. In the convoluted tubules, some cells are in a state of hyaline-capillary dystrophy, some - in a state of necrosis, resulting in violation of the architectonics of the tubule, subcapsular hemorrhages appear. Causes venous hyperemia.

Reproducibility Evaluation of Urinary Peptide Detection Using CE-MS

In recent years, capillary electrophoresis coupled to mass spectrometry (CE-MS) has been increasingly applied in clinical research especially in the context of chronic and age-associated diseases, such as chronic kidney disease, heart failure and cancer. Biomarkers identified using this technique are already used for diagnosis, prognosis and monitoring of these complex diseases, as well as patient stratification in clinical trials. CE-MS allows for a comprehensive assessment of small molecular weight proteins and peptides (<20 kDa) through the combination of the high resolution and reproducibility of CE and the distinct sensitivity of MS, in a high-throughput system. In this study we assessed CE-MS analytical performance with regards to its inter- and intra-day reproducibility, variability and efficiency in peptide detection, along with a characterization of the urinary peptidome content. To this end, CE-MS performance was evaluated based on 72 measurements of a standard urine sample (60 for inter- and 12 for intra-day assessment) analyzed during the second quarter of 2021. Analysis was performed per run, per peptide, as well as at the level of biomarker panels. The obtained datasets showed high correlation between the different runs, low variation of the ten highest average individual log2 signal intensities (coefficient of variation, CV < 10%) and very low variation of biomarker panels applied (CV close to 1%). The findings of the study support the analytical performance of CE-MS, underlining its value for clinical application.

Expanding the Reactive Sulfur Metabolome: Intracellular and Efflux Measurements of Small Oxoacids of Sulfur (SOS) and H2S in Human Primary Vascular Cell Culture

Hydrogen sulfide (H2S) is an endogenous signaling molecule which is important for cardiovascular health, but its mechanism of action remains poorly understood. Here, we report measurements of H2S as well as its oxidized metabolites, termed small oxoacids of sulfur (SOS = HSOH and HOSOH), in four human primary vascular cell lines: smooth muscle and endothelial cells derived from both human arterial and coronary tissues. We use a methodology that targets small molecular weight sulfur species; mass spectrometric analysis allows for species quantification to report cellular concentrations based on an H2S calibration curve. The production of H2S and SOS is orders of magnitude higher in smooth muscle (nanomolar) as compared to endothelial cell lines (picomolar). In all the primary lines measured, the distributions of these three species were HOSOH >H2S > HSOH, with much higher SOS than seen previously in non-vascular cell lines. H2S and SOS were effluxed from smooth muscle cells in higher concentrations than endothelial cells. Aortic smooth muscle cells were used to examine changes under hypoxic growth conditions. Hypoxia caused notable increases in HSOH and ROS, which we attribute to enhanced sulfide quinone oxidase activity that results in reverse electron transport.

PmtA Regulates Pyocyanin Expression and Biofilm Formation in Pseudomonas aeruginosa

The opportunistic pathogen Pseudomonas aeruginosa expresses a small molecular weight, cysteine-rich protein (PmtA), identified as a metallothionein (MT) protein family member. The MT family proteins have been well-characterized in eukaryotes as essential for zinc and copper homeostasis, protection against oxidative stress, and the ability to modify a variety of immune activities. Bacterial MTs share sequence homology, antioxidant chemistry, and heavy metal-binding capacity with eukaryotic MTs, however, the impact of bacterial MTs on virulence and infection have not been well-studied. In the present study, we investigated the role of PmtA in P. aeruginosa PAO1 using a PmtA-deficient strain (ΔpmtA). Here we demonstrated the virulence factor, pyocyanin, relies on the expression of PmtA. We showed that PmtA may be protective against oxidative stress, as an alternative antioxidant, glutathione, can rescue pyocyanin expression. Furthermore, the expression of phzM, which encodes a pyocyanin precursor enzyme, was decreased in the ΔpmtA mutant during early stationary phase. Upregulated pmtA expression was previously detected in confluent biofilms, which are essential for chronic infection, and we observed that the ΔpmtA mutant was disrupted for biofilm formation. As biofilms also modulate antibiotic susceptibility, we examined the ΔpmtA mutant susceptibility to antibiotics and found that the ΔpmtA mutant is more susceptible to cefepime and ciprofloxacin than the wild-type strain. Finally, we observed that the deletion of pmtA results in decreased virulence in a waxworm model. Taken together, our results support the conclusion that PmtA is necessary for the full virulence of P. aeruginosa and may represent a potential target for therapeutic intervention.

Metabolomics to Diagnose Oxidative Stress in Perinatal Asphyxia: Towards a Non-Invasive Approach

There is a need for feasible and non-invasive diagnostics in perinatal asphyxia. Metabolomics is the study of small molecular weight products of cellular metabolism that may, directly and indirectly, reflect the level of oxidative stress. Saliva analysis is a novel approach that has a yet unexplored potential in metabolomics in perinatal asphyxia. The aim of this review was to give an overview of metabolomics studies of oxidative stress in perinatal asphyxia, particularly searching for studies analyzing non-invasively collected biofluids including saliva. We searched the databases PubMed/Medline and included 11 original human and 4 animal studies. In perinatal asphyxia, whole blood, plasma, and urine are the most frequently used biofluids used for metabolomics analyses. Although changes in oxidative stress-related salivary metabolites have been reported in adults, the utility of this approach in perinatal asphyxia has not yet been explored. Human and animal studies indicate that, in addition to antioxidant enzymes, succinate and hypoxanthine, as well acylcarnitines may have discriminatory diagnostic and prognostic properties in perinatal asphyxia. Researchers may utilize the accumulating evidence of discriminatory metabolic patterns in perinatal asphyxia to develop bedside methods to measure oxidative stress metabolites in perinatal asphyxia. Although only supported by indirect evidence, saliva might be a candidate biofluid for such point-of-care diagnostics.

Engineering of Marine-derived Antimicrobial Peptides (mAMPs) into Improved Anti-infective Drug Leads: A Mini-review

Marine-derived antimicrobial compounds possess chemical diversity varying from peptides, fatty acids to terpenes, alkaloids, and polyketides. These compounds, especially of peptide origin called antimicrobial peptides (AMPs), are present in the majority of marine organisms, including microbes (bacteria and fungi), invertebrates (molluscs, echinoderms, and sponges), vertebrates (fish and mammals), and plants (marine algae). They are defined by small molecular weight (less than 10 kDa), a net positive charge, and amphipathic structures. Moreover, due to their profound in vitro antimicrobial and cytotoxic activities and a low risk for resistance development, naturally occurring marine-derived AMPs (mAMPs) have been used as drug design templates for a large variety of semi-synthetic or synthetic AMPs, some of which have reached clinical trials. This mini-review aims to discuss AMPs from marine sources, mainly emphasizing the engineering of these peptides with improved pharmacological properties to develop drug candidates. Some selected recent examples of these engineered mAMPs as anti-infective drug leads are herein highlighted.

New therapies in atopic dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases. Despite of this, the pathomechanism of the disease is still not fully understood. In recent years, several scientific results led to the better understanding of the disease. Meantime, new therapeutical options have emerged which were developed specifically for AD patients. In this manuscript new therapies, namely dupilumab and baricitinib, which are already licenced in Hungary, are reviewed. A detailed description of therapies e.g. biological therapy, small molecular weight drugs, topical therapy and antipruritics which are currently in clinical research have been also summarized.

Small but effective: light-weight additives modulate prenucleation clusters by specific interactions on the molecular level

Small-molecular-weight (MW) additives can strongly impact amorphous calcium carbonate (ACC), playing an elusive role in biogenic, geologic, and industrial calcification. Here, we present molecular mechanisms by which additives regulate stability and composition of solid ACC and CaCO3 solutions simultaneously. Effective precipitation inhibition arises from pronounced interaction of additives with prenucleation clusters (PNC). Potent antiscalants specifically trigger and integrate into PNCs. Only PNC-interacting additives are traceable in solid ACC, considerably stabilizing ACC against transformation. This co-precipitation specificity facilitates a chemical labeling of PNCs, evidencing ACC as a molecular precipitate of PNCs. Our results reveal additive-cluster interactions that operate beyond established mechanistic conceptions and thus reassess the role of small-MW molecules in crystallization and especially in biomineralization while breaking grounds for new sustainable antiscalants.