Phenolic Compounds from Sour Cherry Pomace: Microencapsulation, in Vitro Digestion, and Cell Growth Activities.

The objective of this work was the valorisation of sour cherry (Prunus cerasus L.) pomace as a source of biologically active compounds. To formulate microcapsules, polyphenolic compounds were extracted and encapsulated with maltodextrin as wall material, by freeze-drying. An in vitro digestion study was carried out on obtained encapsulates but also on sour cherry pomace extract and sour cherry pomace freeze-dried powder. The results indicated that encapsulation, as well as freeze-drying, provided a good protective effect on bioactive compounds during digestion. Furthermore, the potential antiproliferative and cytotoxic activities of encapsulates and sour cherry pomace extract were evaluated using breast adenocarcinoma MCF7 cell lines, colon adenocarcinoma HT-29 cell lines, and noncancer cell line. Encapsulates and sour cherry pomace extract showed variable anti-proliferative activity towards all cell lines. Obtained results showed that encapsulation of sour cherry pomace could be useful for improving the stability of polyphenolic compounds in the gastrointestinal tract. The results highlight the bioactive potential of sour cherry pomace as a nutraceutical resource and the protective effects of microencapsulation on the digestion of bioactive compounds.

Novel extraction of polyphenols from sour cherry pomace using natural deep eutectic solvents - Ultrafast microwave-assisted NADES preparation and extraction.

In this work, new approaches for the green extraction of polyphenols from sour cherry pomace were explored. Three Natural Deep Eutectic Solvents (NADES) systems based on choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and malic acid, urea, and fructose (MalA, Ur, and Fru) as hydrogen bond donors (HBD) were used. NADES systems were prepared by heating and stirring (H&S), ultrasound (US), and microwave (MW) methods. It was found that MW-assisted preparation was the fastest requiring less than 30 s. Polyphenol extraction from cherry pomace was performed also by three mentioned methods, and compared with conventional methods. MW extraction was the most rapid with less than 5 min necessary for the extract preparation. All three NADES systems were highly efficient for anthocyanin extraction, but the most efficient was ChCl:MalA system. Extract based on ChCl:MalA system was for 62.33% more efficient for anthocyanin extraction comparing with the conventional solvent.

Medicinal Plants Extracts Impact on Oxidative Stress in Mice Brain Under the Physiological Conditions: the Effects of Corn Silk, Parsley, and Bearberry.

This study was performed to examine the effects of medicinal plant extracts of corn silk (Stigma maydis), parsley leaf (Petroselini folium), and bearberry leaf (Uvae ursi folium) on antioxidant status of the brain of experimental animals (mice) under the physiological conditions. Biological properties of these plants are insufficiently investigated and the aim was to explore their possible antioxidant effects that can alleviate oxidative damage of the brain tissue. Corn silk extract showed positive effect on activities of antioxidant enzymes in mice brain tissue. Parsley extract induced the increase in glutathione content and decrease of lipid peroxidation. Bearberry leaf extract induced catalase activity and decrease of hydroxyl radical content, while malonyldialdehide accumulation was maintained at the control level. Results obtained in this study support the use of corn silk, parsley and bearberry leaves as natural antioxidant sources in the prevention and treatment of brain tissue damages and different diseases caused by oxidative stress.

Exploring fruits from genus Prunus as a source of potential pharmaceutical agents - In vitro and in silico study.

Prunus fruits are recognized to be rich sources of polyphenols with health promoting effect. In this work we evaluated the phenolic profile and bioactivity, namely antioxidant capacity, antiproliferative effect in HT29, and inhibition capacity of α-glucosidase (α-Gls), α-amylase (α-Amy) and human dipeptidyl peptidase III (hDPP III) activities, of traditional Prunus fruits grown in Serbia. Fifteen Prunus samples were investigated and compared: common European plum and three old plum subspecies ('vlaskaca', damson plum and white damson), purple-leaf cherry plum, red and white cherry plum, sweet cherry, sweet cherry-wild type, sour cherry, steppe cherry, mahaleb cherry, blackthorn, peach, and apricot. Principal Component Analysis highlighted steppe cherry and blackthorn as Prunus species with the highest bioactive potential. In silico analysis pointed out rutinoside derivatives of cyanidin and quercetin as the most potent inhibitors of α-Gls, α-Amy and hDPP III enzymes. Quercetin 3-O-rutinoside showed the highest binding energy to α-Gls (-10.6 kcal/mol).

An in vitro and in silico evaluation of bioactive potential of cornelian cherry (Cornus mas L.) extracts rich in polyphenols and iridoids.

In the present research, seven different cornelian cherry (Cornus mas L.) cultivars and selections were examined. In vitro and in silico methods were applied for determining and correlating phytochemical constituents and biological potential. Loganic acid, cornuside, cyanidin3-galactoside, and pelargonidin 3-galactoside were determined as the most dominant compounds, presenting ≥90% of the all detected iridoid and phenolic constituents in the extracts. Cornelian cherry fruits were characterized by high antioxidant capacity and antiproliferative activity on human colon cancer cells (HT29). It was observed the strong inhibitory potential of α-amylase, α-glucosidase, and dipeptidyl peptidase III (DPP III) enzyme activities. Principal component analysis (PCA) was used as a very helpful tool to discriminate the constituents with the highest contribution to tested bioactivities and to highlight the most potent genotypes. PCA, together with binding energies measurements and docking analysis, pointed out pelargonidin 3-robinobioside as the strongest inhibitor of α-glucosidase.

Features of CRISPR-Cas Regulation Key to Highly Efficient and Temporally-Specific crRNA Production.

Bacterial immune systems, such as CRISPR-Cas or restriction-modification (R-M) systems, affect bacterial pathogenicity and antibiotic resistance by modulating horizontal gene flow. A model system for CRISPR-Cas regulation, the Type I-E system from Escherichia coli, is silent under standard laboratory conditions and experimentally observing the dynamics of CRISPR-Cas activation is challenging. Two characteristic features of CRISPR-Cas regulation in E. coli are cooperative transcription repression of cas gene and CRISPR array promoters, and fast non-specific degradation of full length CRISPR transcripts (pre-crRNA). In this work, we use computational modeling to understand how these features affect the system expression dynamics. Signaling which leads to CRISPR-Cas activation is currently unknown, so to bypass this step, we here propose a conceptual setup for cas expression activation, where cas genes are put under transcription control typical for a restriction-modification (R-M) system and then introduced into a cell. Known transcription regulation of an R-M system is used as a proxy for currently unknown CRISPR-Cas transcription control, as both systems are characterized by high cooperativity, which is likely related to similar dynamical constraints of their function. We find that the two characteristic CRISPR-Cas control features are responsible for its temporally-specific dynamical response, so that the system makes a steep (switch-like) transition from OFF to ON state with a time-delay controlled by pre-crRNA degradation rate. We furthermore find that cooperative transcription regulation qualitatively leads to a cross-over to a regime where, at higher pre-crRNA processing rates, crRNA generation approaches the limit of an infinitely abrupt system induction. We propose that these dynamical properties are associated with rapid expression of CRISPR-Cas components and efficient protection of bacterial cells against foreign DNA. In terms of synthetic applications, the setup proposed here should allow highly efficient expression of small RNAs in a narrow time interval, with a specified time-delay with respect to the signal onset.

Understanding key features of bacterial restriction-modification systems through quantitative modeling.

BACKGROUND: Restriction-modification (R-M) systems are rudimentary bacterial immune systems. The main components include restriction enzyme (R), which cuts specific unmethylated DNA sequences, and the methyltransferase (M), which protects the same DNA sequences. The expression of R-M system components is considered to be tightly regulated, to ensure successful establishment in a naïve bacterial host. R-M systems are organized in different architectures (convergent or divergent) and are characterized by different features, i.e. binding cooperativities, dissociation constants of dimerization, translation rates, which ensure this tight regulation. It has been proposed that R-M systems should exhibit certain dynamical properties during the system establishment, such as: i) a delayed expression of R with respect to M, ii) fast transition of R from "OFF" to "ON" state, iii) increased stability of the toxic molecule (R) steady-state levels. It is however unclear how different R-M system features and architectures ensure these dynamical properties, particularly since it is hard to address this question experimentally. RESULTS: To understand design of different R-M systems, we computationally analyze two R-M systems, representative of the subset controlled by small regulators called 'C proteins', and differing in having convergent or divergent promoter architecture. We show that, in the convergent system, abolishing any of the characteristic system features adversely affects the dynamical properties outlined above. Moreover, an extreme binding cooperativity, accompanied by a very high dissociation constant of dimerization, observed in the convergent system, but absent from other R-M systems, can be explained in terms of the same properties. Furthermore, we develop the first theoretical model for dynamics of a divergent R-M system, which does not share any of the convergent system features, but has overlapping promoters. We show that i) the system dynamics exhibits the same three dynamical properties, ii) introducing any of the convergent system features to the divergent system actually diminishes these properties. CONCLUSIONS: Our results suggest that different R-M architectures and features may be understood in terms of constraints imposed by few simple dynamical properties of the system, providing a unifying framework for understanding these seemingly diverse systems. We also provided predictions for the perturbed R-M systems dynamics, which may in future be tested through increasingly available experimental techniques, such as re-engineering R-M systems and single-cell experiments.