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β-Glucans are a group of non-starchy polysaccharides, or (1,3),(1,4)-β-D-glucans, that can be found in the cell walls of several species of bacteria, algae, lichens, fungi, and cereal grains. These carbohydrates are extensively used in food industry, cosmetics, pharmaceuticals and healthcare, therefore optimization of the extraction and isolation of β-glucans from grain sources has an especial importance in various fields of biotechnology, drug design, food science and technology. The aim of the study was to develop an optimized technological scheme for isolation of β-glucans from oat bran based on ultrasonic and enzymatic processing of raw material. Materials and methods. β-Glucans were isolated from grinded oat cereals during multi-stage process, which includes extraction of grain fats, hydrobarothermic processing, ultrasonification, enzymatic hydrolysis of concomitant starch and proteins, precipitation of β-glucan fraction by ethanol, centrifugation, and dry-freezing. Yield of β-glucans from raw material and its concentration in the final product were determined after hydrolysis by sulfuric acid or enzymatic cleavage by endo-1,3(4)-β-glucanase. Results. As shown by acidic hydrolysis of the final product, the yield of β-glucans was 10.8 ± 0.23% and concentration was 79.6 ± 3.89%, while enzymatic hydrolysis gave 8.7 ± 0.82% and 65.1 ± 4.72%, respectively. Thus, the use of hydrobarothermic and ultrasound pre-treatment of raw material in combination with proteolytic digestion of ballast lipids and proteins allowed producing oat β-glucans in amounts comparable with those in case of acid- or alkali-based procedures. Conclusions. The described technological scheme of β-glucan isolation from oat bran based on sequential hydrobarothermic processing, ultrasonification, and enzymatic removing starch and proteins can be widely used for routine β-glucan production for various purposes in food technology, pharmacological industry, and medicine. [ABSTRACT FROM AUTHOR]

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Pericellular plasmin generation triggers apoptosis/anoikis in normal adherent cells. However, cancer cells are notoriously resistant to anoikis, enabling metastasis and new tumor growth beyond their original environment. Autophagy can be a major contributor to anoikis resistance in cancer., Aim: To investigate if protective autophagy can be induced in lung adenocarcinoma cells in response to plasminogen treatment., Materials and Methods: Human lung adenocarcinoma A549 cells were incubated with Glu-plasminogen (0.1-1.0 µM) for 24 h. Pericellular plasmin activity was monitored spectrophotometrically by a cleavage of the specific chromogenic- substrate S-2251. Cell survival was assessed by 3-[4,5-dimethyl thiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT)-test. Degradation of fibronectin, levels of autophagy markers (beclin-1 and light chain 3 (LC3)) and glycolysis regulator (TIGAR) were evaluated by western blot. Intracellular localization of LC-3 was visualized by immunocytochemistry., Results: It was shown that plasminogen is converted into plasmin on the surface of adenocarcinoma cells in a dose-dependent manner. Plasmin disrupted cellular adhesive contacts resulting in cell detachment. A549 cells did not loss their viability after plasminogen treatment for 24 h, while 1.0 µM plasminogen was cytotoxic for non-transformed fibroblasts. Plasminogen 0.1, 0.5, and 1.0 µM induced 7.08-, 5.18-, and 3.78-fold elevation of TIGAR expression (p < 0.05), respectively. Enhanced TIGAR expression indicates switch on pentose phosphate pathway, protection against oxidative stress to prevent apoptosis, facilitation of DNA repair and the degradation of their own organelles (autophagy). Exposure of adenocarcinoma cells to plasminogen in concentrations of 0.1 and 0.5 µM caused 1.74- and 2.19-fold elevation of beclin-1 expression vs untreated cells (p < 0.05), respectively. Unlike K1-3 fragment, plasminogen treatment (0.1-0.5 µM) resulted in increased expression of LC3-I and stimulated rapid conversion of LC3-I to LC3-II. Up-regulation of beclin-1 levels and enhanced LC3-I/II conversion in plasminogen-treated A549 cells are the hallmarks of autophagy induction. According to immunocytochemistry data, increased LC3 puncta and autophagosome formation after exposure to plasminogen could reflect autophagy activation., Conclusions: Therefore, we showed stimulation of prosurvival signals and induction of autophagy in plasminogen-treated adenocarcinoma cells rendering them resistant to apoptosis/anoikis. Based on the obtained data, autophagy has a great potential for novel targets that affect cancer cell death, in addition to the current cytotoxic agents.