Dominik Szwajgier

Anticholinesterase activities of selected polyphenols - a short report.

Abstract In this work, anticholinesterase activities of 24 polyphenolic compounds were tested using the modified Ellman’s spectrophotometric method. The most efficient acetyl- and butyrylcholinesterase inhibitors were anthocyanins (pelargonidin, delphinidin and cyanidin), flavones (apigenin and luteolin), flavonols (quercetin, kaempferol and myricetin), as well as dihydrochalcone phloridzin and prenylated chalcone xanthohumol. It was established that all the tested compounds were within a narrow molecular weight range of 254.24-354.40 g/mol, which probably was not discriminative for their inhibitory activity. Among all the classes of polyphenolic compounds, the lowest activities were exerted by flavan-3-ols. The inhibitory activity of the tested polyphenols was decreased by the presence of a 3-hydroxyl group. A simultaneous substitution of a carbonyl group at position 4 and a hydroxyl group at position 3 or a lack of both of these substitutions had no effect on the activity of the investigated compounds. The number and position of other hydroxyl groups in the tested molecules played a minor role in this context. Aglycons were more effective cholinesterase inhibitors than their corresponding glycosylated forms. Overall, the results show that phenolic acids can play a role in neuroprotection. However, further in vitro and in vivo studies involving a larger number of polyphenolic compounds simultaneously with well-known cholinesterase inhibitors should be performed in the nearest future to confirm these findings

Biosorption of Al(+3) and Cd(+2) by an exopolysaccharide from Lactobacillus rhamnosus.

The aim of this study was to assess the removal of Cd(2+) and Al(3+) from aqueous solutions by an exopolysaccharide (EPS) from Lactobacillus rhamnosus E/N. The biosorption kinetics of EPS for Cd(2+) and Al(3+) were studied by equilibrium dialysis after incubation from 0 h to 58 h. The actual concentrations of Cd(2+) and Al(3+) in external solutions were measured by a fluorescence method after complexation with 8-hydroxyquinoline. Binding of metal ions by EPS was observed, with maximum adsorption after 0 to 24 and 48 to 58 h for Cd(2+) , and after 24 h for Al(3+) . The existing analytical method, involving the binding of metal ions was measured using a dialysis membrane was significantly improved in our study. This new method could be applied in future studies of this type. The results of this study demonstrate that EPS from Lb. rhamnosus E/N has a Cd(2+) and Al(3+) biosorption capacity. Surface adsorption of the metal ions at surface of EPS was confirmed through scanning electron microscopy. Fourier transform-infrared spectroscopy analysis suggests a role of the functional groups ─OH, C═O, and COO(-) from EPS in the binding of Cd(2+) and Al(3+) ions.

The Neuroprotective Effects of Phenolic Acids: Molecular Mechanism of Action

The neuroprotective role of phenolic acids from food has previously been reported by many authors. In this review, the role of phenolic acids in ameliorating depression, ischemia/reperfusion injury, neuroinflammation, apoptosis, glutamate-induced toxicity, epilepsy, imbalance after traumatic brain injury, hyperinsulinemia-induced memory impairment, hearing and vision disturbances, Parkinson’s disease, Huntington’s disease, anti-amyotrophic lateral sclerosis, Chagas disease and other less distributed diseases is discussed. This review covers the in vitro, ex vivo and in vivo studies concerning the prevention and treatment of neurological disorders (on the biochemical and gene expression levels) by phenolic acids.

Effect of lactic acid fermentation on antioxidant properties and phenolic acid contents of oyster (Pleurotus ostreatus) and chanterelle (Cantharellus cibarius) mushrooms

Fruiting bodies of Pleurotus ostreatus (oyster) and Cantharellus cibarius (chanterelle) mushrooms underwent acid fermentation using 3 strains of lactic acid bacteria (LAB) as starter cultures. Polyphenol contents, antioxidant activities, and phenolic acid contents in fresh, blanched, and fermented mushrooms were investigated. Fruiting bodies of oyster mushrooms exhibited higher total phenolic contents than chanterelle mushrooms. Blanching caused a decrease in polyphenol contents and antioxidant activities in both mushroom types. No important differences were observed in total phenolic compound contents (measured using Folin-Ciocalteau reagent) in mushrooms using different LAB strains. Lactobacillus plantarum was the most useful microorganism for lactic acid fermentation of fruiting bodies for reduction of the pH value. The highest concentrations of single phenolic acids: gallic, homogentisic, and ferulic acids were present in mushrooms fermented using L. plantarum.

Phenolic Acids Exert Anticholinesterase and Cognition-Improving Effects

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimers disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.

κ-Casein as a source of short-chain bioactive peptides generated by Lactobacillus helveticus

Abstract This paper explores the ability of Lactobacillus helveticus strains to release sequences of short biologically active peptides (containing 2–10 amino acid residues) from casein. The proteolytic enzymes of the tested strains exhibit different patterns of cleavage of CN fractions. The modification of κ-casein (κ-CN) with pyrrolidone carboxylic acid inhibits the proteolytic activity of strains L. helveticus 141 and the reference strain (DSMZ 20075), while the modification with phosphothreonine inhibits enzymes of all the tested bacteria. The peptide sequencing analysis indicated that the examined strains produced functional peptides very efficiently. κ-CN proved to be the main source of short peptides released by bacterial enzymes, and the hydrolysis of κ-CN yielded eighty-two bioactive peptides. The hydrolysis of αS2-casein, αS1-casein, and β-casein yielded six, two, and one short-chain bioactive peptides, respectively. The isolated bioactive peptides exhibited antioxidative, opioid, stimulating, hypotensive, immunomodulating, antibacterial, and antithrombotic activities. A vast majority of the isolated bioactive peptides caused inhibition of the angiotensin-converting enzyme and dipeptidyl peptidase IV. The role of hydrolysis products as neuropeptides is also pointed out. The highest number of cleavage sites in κ-casein and functional activities of short-chain peptides were obtained in hydrolyzates produced by L. helveticus strain T105.