Dialyzable Fraction Research Articles

Bioaccessibility and potential bioactivity of fresh and mature fava bean flavonoids

The bioaccessibility of total flavonoids, catechin, epigallocatechin, epigallocatechin gallate, epicatechin, rutin, quercetin, isoquercetin, and kaempferol, and changes in antioxidant activities in fresh and mature fava bean seeds during simulating gastrointestinal conditions has been investigated. The portion of bioaccessible flavonoids potentially available for further uptake varies between pods. Flavonoids of mature and fresh seeds after the gastric phase, intestinal phase, and dialysable fraction, simulating bioaccessible flavonoids, were 6.62% and 1.78%, respectively, compared with no-digested pods. Total antioxidant capacities in the bioaccessible fractions were significantly lower than the control. Furthermore, potential bioactivity as a PPAR-gamma antagonist was evaluated, where epigallocatechin gallate presents at -9.50 Kcal/mol vs. -6.53 Kcal/mol, present in troglitazone. These results highlighted that gastrointestinal digestion may substantially affect the absorption of flavonoids in mature and green fava beans and present a potential bioactivity against obesity.

Probiotic fermentation enhances bioaccessibility of lycopene, polyphenols and antioxidant capacity of guava fruit (Psidium guajava L)

This study investigated bio-accessibility of lycopene and total polyphenols using simulated gastrointestinal digestion, in guava pulp (Psidium guajava L) pulp fermented with two probiotic LAB strains Lactococcus lactis subsp lactis and Lactobacillus casei. Physicochemical parameters, and antioxidant contents were also evaluated. Results indicated that LAB fermentation reduced the pH of pulp from 3.8 to 2.6, with increase of TA and reduced the TSS content of the pulp to 13.06 and 12.67◦Bx, respectively after 8 h of fermentation. Compositional analysis of fermented guava pulps indicated decrease in carbohydrates (29.6%), lipids (4.6%), moisture (19.7%) and slight increase in proteins (0.7%). The total poly phenolics (701mg/GAE/g) and DPPH radical scavenging activity (81%) was significantly (p < 0.05) higher in comparison to unfermented counterparts while Vitamin C content was not affected. Guava pulp fermented by both strains improved overall sensorial acceptability with no notable differences in sensory scores after storage under refrigerated conditions for up to 7 days. Simulated gastrointestinal digestion studies revealed that pulp fermentation substantially improved the bioaccessibility of total phenols by 70% and 63% and lycopene content by 13.33 and 12.24% in L. lactis and L. casei fermented pulp in comparison to control (unfermented pulp). DPPH free radical scavenging activities of the dialyzable fractions of fermented guava pulp were 71.3 and 69.3% respectively. Overall, the results of this study were encouraging and indicate that fermentation of guava pulp with LAB can potentially enhance bioactives and their subsequent bioaccessibility implying beneficial impacts upon consumption.

Cooking African Pumpkin Leaves (Momordicabalsamina L.) by Stir-Frying Improved Bioactivity and Bioaccessibility of Metabolites-Metabolomic and Chemometric Approaches.

The leaves of African pumpkins (Momordica balsamina L.) are a commonly consumed traditional vegetable. They are a good source of polyphenolic antioxidants and carotenoids, which are, however, affected by cooking or digestion. We investigated the effect of household cooking methods (stir-frying or boiling) on the changes in bioactive metabolites, antioxidant capacity, release and accessibility of β-carotene and also inhibition of inhibitory activity against α-amylase and α-glucosidase enzymes during in vitro digestion of African pumpkin leaves compared to the raw leaves. Compared to boiled or raw leaves, stir-frying improved the availability of bioactive metabolites at the gastrointestinal phase. Quercetin 3-galactoside and rhamnetin 3-O-glucoside (marker compounds) discriminated the stir-fried leaves from raw leaves and boiled leaves after digestion. Stir-frying improved the release and accessibility of β-carotene and enhanced the antioxidant activities compared to boiling. Dialysable fractions of stir-fried leaves exhibited the greatest inhibitory activity against α-amylase and α-glucosidase enzymes compared to the raw and boiled leaves, as well as acarbose. Stir-frying, therefore, is recommended for use in household cooking to benefit consumers by increasing the intake of phenolics and β-carotene.

Physicochemical Parameters and Bioaccessibility of Lactic Acid Bacteria Fermented Chayote Leaf (Sechium edule) and Pineapple (Ananas comosus) Smoothies.

In this study, popularly consumed traditional chayote leaves and locally produced pineapple fruit were used to develop a fermented smoothie using lactic acid bacteria (LAB) strains: Lactobacillus plantarum (L75), Weissella cibaria (W64), and their combination (LW64 + 75). The physicochemical parameters [pH, total soluble solids (TSS), and color], total phenols, and carotenoid contents of the smoothies fermented for 48 h and stored for 7 days at 4°C were compared with the unfermented (control) smoothies. Results indicated that LAB fermentation reduced the pH from 3.56 to 2.50 after 48 h (day 2) compared with the non-fermented smoothie at day 2 (pH 3.37). LAB strain L75 significantly reduced the TSS content of the smoothies to 13.06°Bx after 2 days of fermentation. Smoothies fermented by L75 showed overall acceptability after 7 days of storage compared with the non-fermented puree on day 0. The LW64 + 75 significantly reduced the color change (ΔE), which was similar to the control. L75 increased the phenolic content, and W64 enhanced the total carotenoid content of the smoothies after 2 days of fermentation compared with other treatments. The use of an in vitro model simulating gastrointestinal (GI) digestion showed that fermentation with L75 improved the total phenol recovery by 65.96% during the intestinal phase compared with the control. The dialysis phase mimicked an epithelial barrier, and 53.58% of the recovered free soluble are bioavailable from the L75 fermented smoothies compared with the control. The antioxidant capacity of dialyzable fraction of the L75 fermented smoothie was significantly higher than that of the control and smoothies fermented with W64 or LW64 + 75.

Anemonia sulcata and Its Symbiont Symbiodinium as a Source of Anti-Tumor and Anti-Oxoxidant Compounds for Colon Cancer Therapy: A Preliminary in Vitro Study.

Simple SummaryColorectal cancer is one of the most frequent types of cancer in the population. Recently, invertebrate marine animals have been investigated for the presence of natural products which can damage tumor cells, prevent their spread to other tissues or avoid cancer develop. We analyzed the anemone Anemonia sulcata with and without the presence of its microalgal symbiont (Symbiodinium) as a source of bioactive molecules for the colorectal cancer therapy and prevention. Colon cancer tumor cells were exposed to Anemone extracts observing a remarkable cell death and a great antioxidant capacity. These preliminary results support that Anemonia sulcata could be a source of bioactive compounds against colorectal cancer and that the absence of its symbiont may enhance these properties. Further studies will be necessary to define the bioactive compounds of Anemonia sulcata and their mechanisms of action.Recently, invertebrate marine species have been investigated for the presence of natural products with antitumor activity. We analyzed the invertebrate Anemonia sulcata with (W) and without (W/O) the presence of its microalgal symbiont Symbiodinium as a source of bioactive compounds that may be applied in the therapy and/or prevention of colorectal cancer (CRC). Animals were mechanically homogenized and subjected to ethanolic extraction. The proximate composition and fatty acid profile were determined. In addition, an in vitro digestion was performed to study the potentially dialyzable fraction. The antioxidant and antitumor activity of the samples and the digestion products were analyzed in CRC cells in vitro. Our results show a high concentration of polyunsaturated fatty acid in the anemone and a great antioxidant capacity, which demonstrated the ability to prevent cell death and a high antitumor activity of the crude homogenates against CRC cells and multicellular tumor spheroids, especially W/O symbiont. These preliminary results support that Anemonia sulcata could be a source of bioactive compounds with antioxidant and antitumor potential against CRC and that the absence of its symbiont may enhance these properties. Further studies will be necessary to define the bioactive compounds of Anemonia sulcata and their mechanisms of action.

In vitro assessment of major and trace element bioaccessibility in tea samples

Bioaccessibility of trace elements (Li, Be, Ti, Ga, Cu, Ag, Hg, Cd, Cs, Pt, Tl, Pb, As, Cr, Co, Ni, V, Se, Sn and Sb) and major elements (Rb, Ba, Al, Fe, Zn, Si, Ca, Mg, Mn, Mo, Sr, P and K) in tea infusions has been assessed using an in vitro dialyzability protocol. Gastric simulation (using pepsin solution) and intestinal simulation (using pancreatin and bile salts) were used to perform the in vitro digestion. ICP-MS, ICP-OES and FAES were used for elements determination in digested tea leaves, their infusions and the dialyzate fractions from tea infusions. Microwaves assisted acid digestion was used for the total element determination in tea leaves, while tea infusions were prepared by brewing tea leaves for 5 min in boiling water. The LODs for elements determined in tea leaves were in the range of 0.11–656 ng g−1 and 0.02–145.6 μg g−1 for trace and major elements, respectively. For elements’ determination in tea infusions, the LODs were ranged between 0.23 and 399.9 ng L−1 for trace elements and 0.2–1248 μg L−1 for major elements. The LODs for the elements in the dialyzable fraction varied from 0.018 to 142 μg L−1. The accuracy of the total element determination was evaluated using certified reference materials (Tea Leaves INCT-TL-1 and Rye Grass). The analytical recoveries were also assessed for analyzed elements in digested tea leaves (95–114%) and their infusions (92–115%), showing good recoveries. Among the studied elements, K was the most abundant element in tea leaves and tea infusions in almost all samples, followed by Ca, Mg, and P. Zn, Cs, and K showed the highest dialyzability percentages up to 84%, 76%, and 54%, respectively, followed by Si and Ca and K that show moderate to high dialyzability percentages. The accuracy of the dialysis process was evaluated using a mass-balance study.

Assessment of bioaccessible and dialyzable fractions of nickel in food products and their impact on the chronic exposure of Belgian population to nickel

This study aimed to investigate bioaccessible/dialyzable fractions of nickel in selected foods and to clarify the impact of the food digestion/absorption on the final exposure of consumers to nickel. In vitro gastrointestinal incubation experiments were conducted to estimate the bioaccessibility of nickel in different foods. For estimation of a dialyzable fraction, dialysis filtration was conducted. Highest bioaccessibility (99.6%) was observed for wheat-based breakfast cereals. Lowest bioaccessibilities was observed for dried-fruits (on average 20.4%). Highest (61.5%) and lowest (24.5%) dialyzable fractions were observed for wheat-based breakfast cereal and chocolate respectively. Bioaccessible/dialyzable fractions based exposure assessments were highlighted the overestimation of exposures calculated based on total nickel concentrations in foods. This is particularly important when exposure values were compared with toxicological thresholds in a risk characterization study. When threshold values have been obtained through animal studies in which nickel was dosed at 100% accessibility/availability, e.g. nickel salts this is even more important.

Changes in bio-accessibility, polyphenol profile and antioxidants of quinoa and djulis sprouts during in vitro simulated gastrointestinal digestion.

This study aimed to evaluate the bio‐accessibility of the phenolics and flavonoid, the polyphenolic profile and the antioxidant activity of sprouts obtained from four different quinoa genotypes and one djulis cultivar during in vitro gastrointestinal digestion. Compared to their content in sprouts, the bioavailable phenolics after the oral phase, the gastric phase, the intestinal phase, and in the dialyzable fraction were in the ranges of 45.7%–63.5%, 87.6%–116.7%, 89.6%–124.5%, and 7.4%–10.9%, respectively. The trend in flavonoid bio‐accessibility was similar to the polyphenols. The dialyzable flavonoid recoveries varied between 4.2% and 12.4%. Correspondingly, the free radical scavenging activity of the dialyzable phase decreased significantly from 84.7% to 96.5%. The main phenolic acids were vanillic acid, caffeic acid, and syringic acid during digestion. The results suggest that gastrointestinal digestion greatly affected the absorption of polyphenols and flavonoid of quinoa and djulis sprouts, as well as their antioxidant capacity.

Formulation of microencapsulated rutin and evaluation of bioactivity and stability upon in vitro digestive and dialysis conditions

Rutin, a flavanol, has been demonstrating excellent antioxidant, anti-inflammatory, anti-diabetic, and anti-carcinogenic properties. However, bioavailability is low due to low stability, solubility, digestion, and absorption by the intestine. This study aims to encapsulate rutin with three types of carrier materials using three different techniques and evaluate their antioxidant activity and bioactivity retention under in vitro gastrointestinal and dialysis conditions. Results showed that the rutin encapsulated lipid carrier has the highest radical inhibition activity for all the digestive phases, the highest singlet oxygen scavenging activity after the gastric phase and the highest anti-inflammatory activity for the dialyzable fraction. The rutin content of encapsulated lipid carriers for all the digestive phases was significantly higher (P≤0.05) comparatively. Fourier Transform Infrared spectroscopy, Particle size analysis, and Scanning Electron micrographs showed that rutin encapsulated lipid carrier was 1.7 μm with a polydispersity index of 0.909 indicating micro-encapsulation with heterogeneous dispersion.

The bioavailability of arsenic species in rice.

Rice is the principal food in many countries for billions of people and one of the most consumed cereals in the world. The rice plant has the ability to bioaccumulate essential and toxic trace elements such as arsenic. The toxicity of the elements depends not only on their concentration but also on their chemical form and their bioavailability. The inorganic forms of arsenic are more toxic than the organic forms and the toxicity increases with decreasing oxidation states. The consumers of rice in Europe who are the most exposed to inorganic arsenic are children under three, thorough diet (rice-based food). Recently, the European Commission established the maximum levels of inorganic arsenic in foodstuffs. This regulation establishes a maximum level of inorganic arsenic of 100μgkg-1 in rice destined for the production of food for infants and young children. In order to know the relation between the As ingested and the arsenic absorbed, studies of bioavailability are necessary. We proposed an in vitro digestion method with dialysis to estimate this relation. Furthermore, a bioavailability study of As species in rice was performed in order to know if a change in As species occurred during the gastrointestinal digestion process. Arsenic species were determined in rice and in the dialysate fraction by high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The proposed method has been applied to different rice samples acquired in the local Spanish market. Graphical abstract.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80–5.0%), accuracy (< 5%), recoveries of elements (97.4–105%), and their detection limits (0.075–1.1 μg L−1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)–40.7% (Ca) and 4.65% (Al)–46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

In vitro evaluation of an intravenous microdialysis catheter for therapeutic drug monitoring of gentamicin and vancomycin.

A central venous catheter with a built‐in microdialysis membrane is available for continuous lactate and glucose monitoring in the intensive care unit (ICU). As this catheter might also be suitable for repeated measurements of unbound drug levels, we studied in vitro the feasibility of monitoring unbound antibiotic concentrations. The catheter was placed in various media at 37°C spiked with gentamicin or vancomycin. Dialysate fractions were repeatedly collected over 3 hours with a NaCl 0.9% perfusate flow of 5 μL/min. Total and unbound drug concentrations in medium and perfusate were measured by immunoassay. After 60 minutes stable recovery for both drugs was observed, with mean ±SD relative recoveries of vancomycin and gentamicin in human serum of 64% ±0.4% and 73% ±3%. The recoveries of the unbound concentrations were 91% ±3% and 91% ±4%. This intravenous microdialysis system may be a very useful platform for therapeutic drug monitoring in the ICU.

Toll-Like Receptor-Dependent Immunomodulatory Activity of Pycnogenol®.

Background: Pycnogenol® (PYC), an extract of French maritime pine bark, is widely used as a dietary supplement. PYC has been shown to exert anti-inflammatory actions via inhibiting the Toll-like receptor 4 (TLR4) pathway. However, the role of the other receptors from the TLR family in the immunomodulatory activity of PYC has not been described so far. Aim: The aim of this study was to investigate whether PYC might exert its immunomodulatory properties through cell membrane TLRs (TLR1/2, TLR5, and TLR2/6) other than TLR4. Moreover, the effect of gastrointestinal metabolism on the immunomodulatory effects of PYC was investigated. Findings: We showed that intact non-metabolized PYC dose-dependently acts as an agonist of TLR1/2 and TLR2/6 and as a partial agonist of TLR5. PYC on its own does not agonize or antagonize TLR4. However, after the formation of complexes with lipopolysaccharides (LPS), it is a potent activator of TLR4 signaling. Gastrointestinal metabolism of PYC revealed the immunosuppressive potential of the retentate fraction against TLR1/2 and TLR2/6 when compared to the control fraction containing microbiota and enzymes only. The dialyzed fraction containing PYC metabolites revealed the capacity to induce anti-inflammatory IL-10 secretion. Finally, microbially metabolized PYC affected the colonic microbiota composition during in vitro gastrointestinal digestion. Conclusions: This study showed that gastrointestinal metabolism of PYC reveals its biological activity as a potential inhibitor of TLRs signaling. The results suggest that metabolized PYC acts as a partial agonist of TLR1/2 and TLR2/6 in the presence of the microbiota-derived TLR agonists (retentate fraction) and that it possesses anti-inflammatory potential reflected by the induction of IL-10 from THP-1 macrophages (dialysate fraction).

Fibrinogenolytic activity of serine proteases(s) from Cucumis dipsaceus

Cucurbitaceae species plants have been widely used in traditional medicine for wound care management and hemostasis. This study aims to explore the possible involvement of Cucumis dipsaceus fruit extract on the blood coagulation pathway. The aqueous Cucumis dipsaceus dialysate fraction (AqCDF) hydrolyzes casein and exhibiting a protease activity in a dose-dependent manner. Casein zymography further reveals the presence of high molecular weight protease(s). The inhibition of proteolytic activity by phenylmethanesulfonyl fluoride (PMSF) suggesting the presence of serine protease. The serine protease(s) fraction exhibiting a promising fibrinogenolytic activity at 25 μg and 50 μg concentration by hydrolyzing Aα and Bβ subunit of fibrinogen, whereas γ-subunit undergo partial degradation. The stability of protease activity against various parameters viz., temperature, pH has been evaluated and its optimum activity was found to be 60 °C & pH 7.0 respectively. The AqCDF shows a promising recalcification time up to 80% against trypsin. More interestingly AqCDF (300 μg) did not induce hemolysis even at higher concentration. These findings suggest the possible role of the dialyzed fraction of Cucumis dipsaceus in hemostasis and the wound healing process.

Method Validation for Multi-Elemental Analysis of Dialyzable and Non-dialyzable Fractions of Coffee Brews by F AAS and ICP OES: a Bioaccessibility Study

A simple and fast, non-digestion treatment, and fully validated preparation procedures of dialyzable and non-dialyzable fractions of brews of ground (GCs) and instant (ICs) coffees prior to their elemental analysis (Al, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Sr, and Zn) by flame atomic absorption spectrometry (F AAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed. Three different procedures: wet digestions (P1), direct analysis (P2), and acidification with HNO3 (P3) were tested. Among tested procedures, the direct analysis (P2) gave the most satisfactory results, i.e., precision from 0.54% (Fe) to 5.9% (Cu), recoveries ranging between 98.0% (Sr) and 104% (Al), detection limits within 0.095 (Ba)–1.8 (Ni) μg L−1, and quantification limits from 0.32 (Ba) to 6.0 (Ni) μg L−1. The chosen procedure was applied to determine bioaccessibility of 11 elements in GCs and ICs coffees using in vitro gastrointestinal digestion. Average contributions of the bioaccessible fraction (%) of elements in brews were as follows: Al (19.0, 23.0), Ba (42.8, 48.4), Ca (35.0, 38.9), Cr (< LOD, 31.1), Cu (15.0, 14.3), Fe (5.08, 2.81), Mg (32.2, 37.9), Mn (28.1, 29.1), Ni (40.9, 60.0), Sr (43.2, 45.6), and Zn (11.5, 9.57) for GCs and ICs coffees, respectively. Generally, bioaccessibility of most elements, i.e., Al, Ba, Ca, Cu, Mg, Mn, Ni, and Sr in brews of GCs was lower than this determined in ICs and varied from 4% (Mn) to 47% (Ni). In contrast, higher contributions of the bioaccessible fraction of Fe and Zn were assessed for GCs brews (47% and 17%, respectively), than these evaluated in ICs brews. Additionally, results on total concentrations of elements in brews of GCs and ICs and concentrations of elements in the dialyzable fraction separated from these brews were applicable to differentiate and classify all analyzed coffees by principal component analysis (PCA).

Manganese Preconcentration and Speciation in Bioaccessible Fraction of Enteral Nutrition Formulas by Cloud Point Extraction (CPE) and Atomic Absorption Spectroscopy

The present study develops a new method for manganese (Mn) preconcentration and speciation in bioaccessible fraction (soluble and dialyzable fraction) of enteral nutrition formulas by cloud point extraction (CPE) and atomic absorption spectroscopy (AAS). For this purpose, a non-ionic surfactant (Triton X-100) and three chelating reagents [8-hydroxyquinoline (8-HQ); 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP); and ammonium pyrrolidine dithiocarbamate (APDC)] were used with different operating conditions. The results showed that an efficient extraction of ionic Mn could be achieved with the following conditions: pH = 10; chelating reagent concentrations of [8-HQ] = 0.36 M, [PMBP] = 0.09 M, and [APDC] = 0.09 M; surfactant Triton X-100 at 25% (w/v), and equilibration temperature-time of 85 °C and 30 min. Limits of detection and quantitation are 0.015 and 0.050 mg L−1 respectively. Furthermore, when analyzing the bioaccessible fraction of the enteral nutrition formulas, the proposed approach can be used to distinguish between ionic (free) Mn and Mn that has been previously bound to existing substances obtained from enzymatic digestion. These Mn speciation findings can be used to validate results obtained from the bioaccessibility assays.

Bioaccessible peptides released by in vitro gastrointestinal digestion of fermented goat milks

In this study, ultrafiltered goat milks fermented with the classical starter bacteria Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarus subsp. thermophilus or with the classical starter plus the Lactobacillus plantarum C4 probiotic strain were analyzed using ultra-high performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) and/or high performance liquid chromatography-ion trap (HPLC-IT-MS/MS). Partial overlapping of the identified sequences with regard to fermentation culture was observed. Evaluation of the cleavage specificity suggested a lower proteolytic activity of the probiotic strain. Some of the potentially identified peptides had been previously reported as angiotensin-converting enzyme (ACE) inhibitory, antioxidant, and antibacterial and might account for the in vitro activity previously reported for these fermented milks. Simulated digestion of the products was conducted in the presence of a dialysis membrane to retrieve the bioaccessible peptide fraction. Some sequences with reported physiological activity resisted digestion but were found in the non-dialyzable fraction. However, new forms released by digestion, such as the antioxidant αs1-casein 144YFYPQL149, the antihypertensive αs2-casein 90YQKFPQY96, and the antibacterial αs2-casein 165LKKISQ170, were found in the dialyzable fraction of both fermented milks. Moreover, in the fermented milk including the probiotic strain, the k-casein dipeptidyl peptidase IV inhibitor (DPP-IV) 51INNQFLPYPY60 as well as additional ACE inhibitory or antioxidant sequences could be identified. With the aim of anticipating further biological outcomes, quantitative structure activity relationship (QSAR) analysis was applied to the bioaccessible fragments and led to potential ACE inhibitory sequences being proposed. Graphical abstract Ultrafiltered goat milks were fermented with the classical starter bacteria (St) and with St plus the L. plantarum C4 probiotic strain. Samples were analyzed using HPLC-IT-MS/MS and UPLC-Q-TOF-MS/MS. After simulated digestion and dialysis, some of the active sequences remained and new peptides with reported beneficial activities were released.

Suppression of cellular immunity factors by toxic fraction of supernatant of broth culture Pasteurella haemolytica

In the etiology of many infectious animal diseases, Pasteurella haemolytica belongs to a specific place. An important factor in the pathogenicity of this microorganism, like the Pasteurella multocida serotype D, is the thermostable exotoxin. It can be obtained from bacterial-purified culture fluid. Although the study of toxin formation among microorganisms is quite popular, however, the features of toxin formation in hemolytic pasteurals, depending on the virulence of the pathogen, the nature of the toxic effects of these objects in vivo remain unclear. Materials for research were 16 isolates of Pasteurella haemolytica, isolated from pathological and biological material obtained during the outbreaks of respiratory pathology in farm animals. Initially, the nature of the research concerned the establishment of the potential for toxin formation in the isolates obtained. The method provided for a comparative analysis of the DNA nucleotide sequences of each of the investigated isolates P. haemolytica and information obtained from the international database. Another part of the work concerned the actual allocation of the major groups of toxic components of Pasteurella haemolytica by extraction to determine their biochemical nature. Exotoxin isolation was carried out from the Pasteurella spp. The components of the sediment and supernatant were separated by ion exchange chromatography on TSK gels. In order to detect the harmful effects of toxin hemolytic pasteurals on the body, they used the method of determining the opsonic index (the ratio of the phagocytic number in the mixture without the products of toxic fractions to the mixture with the toxin-containing fraction). It has been established that an important factor of the pathogenetic effect in Pasteurella haemolytica is the toxic fraction. Electrophoregram analysis of the results of DNA amplification in a comparative aspect with the data of standard samples helped to determine the presence of elements of the genome, which indicate the potential for toxin formation in isolated hemolytic pasteurized isolates from the test material. Toxic fractions isolated from Pasteurella haemolytica broth culture supernatant are substances of protein-carbohydrate nature. The isolated peak toxicogenic fractions of dialysate of a bacterial culture sieve contained protein and carbohydrates within the limits of 12.5–20 μg / ml and 0–20 μg/ml, respectively. In the dialysate of the broth culture supernatant, where 5 groups of toxigenic fractions were identified, the content of protein and carbohydrates in them varied, respectively, in the range from 20 to 95 μg/ml and from 3.3 to 26.62 μg/ml. At reproduction of opsono-phagocytic reaction with participation of toxigenic fractions of hemolytic pasteurel, a sufficiently expressed immunosuppressive effect of these complexes on the body of warm-blooded substances with an opsonic index of 3 ± 0.03 was established. During further research it is planned to determine the dermal necrotic and lethal effects of the isolated toxicogenic fractions of hemolytic pasteuride on the body of warm-blooded ones.

Effects of the new generation \u03b1-pyrrolidinophenones on spontaneous locomotor activities in mice, and on extracellular dopamine and serotonin levels in the mouse striatum

PurposePyrovalerone derivatives (α-pyrrolidinophenones) form a distinct branch of synthetic cathinones, a popular group of novel psychoactive substances, and exert strong psychostimulatory effects resulting from their high potency to inhibit dopamine (DA) and norepinephrine transporters, with negligible activity at the serotonin (5-HT) transporter. In contrast to the old generation α-pyrrolidinophenones, 3,4-MDPV and α-PVP, there is limited data on the pharmacology and toxicology of the novel analogs. Therefore, the present study assesses the in vivo effects of two new pyrovalerones, PV8 and PV9, along with those of α-PVP, on spontaneous locomotor activities of mice and extracellular DA and 5-HT levels in the mouse striatum.MethodsSpontaneous locomotor activity was measured using Opto-Varimex Auto-Track. Effects of tested compounds on extracellular levels of DA and 5-HT in the striatum were studied by an in vivo microdialysis technique; their concentrations in dialysate fractions were analyzed by high-performance liquid chromatography with electrochemical detection.Resultsα-PVP, PV8 and PV9 stimulated mice locomotor activity (an effect being blocked by D1-dopamine receptor antagonist, SCH 23390), and increased extracellular levels of DA and 5-HT in the striatum. Observed effects depend on dose, time and compound under investigation, with α-PVP being more potent than PV8 and PV9. When used at the same dose, the pyrovalerones produced effects significantly weaker than a model, old generation psychostimulant, methamphetamine.ConclusionsEnhancement of dopaminergic neurotransmission plays a dominant role in the psychomotor stimulation caused by α-PVP, PV8 and PV9. Extending an aliphatic side chain beyond a certain point leads to the decrease in their potency in vivo.

Polyphenol bioavailability in nuts and seeds by an in vitro dialyzability approach

An in vitro dialyzability approach has been undertaken to elucidate the bioavailable fraction of the total polyphenols (TPs) of edible nuts and seeds. The TP contents in samples and in dialyzates were assessed by the Folin-Ciocalteu spectrophotometric method. Antioxidant activity was determined in selected samples, using a modified method against Trolox®. TPs and antioxidant activity in nuts/seeds were determined after applying a pressurized liquid extraction sample pre-treatment. High dialyzability ratios were assessed in most nuts/seeds (TP dialyzability percentages within the 25–91% range). The highest TP dialyzability ratios were found in raw Brazil nuts (81 ± 5%), toasted pistachios (88 ± 9%), and fried cashews (89 ± 9%), whereas TPs in pumpkin seeds were found to be very low (TPs were not detected in the dialyzable fraction). TP dialyzability was correlated with the copper content in nuts and seeds.