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.

Cytotoxicity profiling of choline chloride-based natural deep eutectic solvents

This study aims to examine in detail for the first time the cytotoxic profile of twelve choline chloride-based deep eutectic solvents (NADES) against HT-29, Caco-2, MCF-7, and MRC-5 cell lines. All NADES systems were synthesized by microwave synthesis using choline chloride as a hydrogen bond acceptor (HBA) and selected sugars, alcohols, organic acids, and urea as hydrogen bond donors (HBD) with the addition of 20% water (w/w) to all systems. It was observed that the cytotoxic effect predominantly depended on the structure of HBD. Acidic systems, where HBDs were organic acids showed the highest cytotoxic effects in all investigated cell lines. The cytotoxicity depended mostly on the concentration of the NADES system in the cell medium as well as on the chemical constitution of the investigated systems. The highest cytotoxic effects showed acidic systems, especially to the HT-29 cell line. The EC₅₀ value for the citric acid-based system was 3.91 mg mL^-1 for the HT-29 cell line which was the most vulnerable to acidic NADES systems.

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.

Coumarin Derivatives Act as Novel Inhibitors of Human Dipeptidyl Peptidase III: Combined In Vitro and In Silico Study

Dipeptidyl peptidase III (DPP III), a zinc-dependent exopeptidase, is a member of the metalloproteinase family M49 with distribution detected in almost all forms of life. Although the physiological role of human DPP III (hDPP III) is not yet fully elucidated, its involvement in pathophysiological processes such as mammalian pain modulation, blood pressure regulation, and cancer processes, underscores the need to find new hDPP III inhibitors. In this research, five series of structurally different coumarin derivatives were studied to provide a relationship between their inhibitory profile toward hDPP III combining an in vitro assay with an in silico molecular modeling study. The experimental results showed that 26 of the 40 tested compounds exhibited hDPP III inhibitory activity at a concentration of 10 µM. Compound 12 (3-benzoyl-7-hydroxy-2H-chromen-2-one) proved to be the most potent inhibitor with IC₅₀ value of 1.10 μM. QSAR modeling indicates that the presence of larger substituents with double and triple bonds and aromatic hydroxyl groups on coumarin derivatives increases their inhibitory activity. Docking predicts that 12 binds to the region of inter-domain cleft of hDPP III while binding mode analysis obtained by MD simulations revealed the importance of 7-OH group on the coumarin core as well as enzyme residues Ile315, Ser317, Glu329, Phe381, Pro387, and Ile390 for the mechanism of the binding pattern and compound 12 stabilization. The present investigation, for the first time, provides an insight into the inhibitory effect of coumarin derivatives on this human metalloproteinase.

The evaluation of phenolic content, in vitro antioxidant and antibacterial activity of Mentha piperita extracts obtained by natural deep eutectic solvents

The focus of this study was to evaluate whether six choline chloride-based natural deep eutectic solvents (NADES) could serve as solvents for the extraction of bioactives from the leaves of Mentha piperita. NADES extracted significantly higher amounts of phenols from peppermint than 70% ethanol and may be useful in the extraction of targeted major compounds from peppermint, like rosmarinic acid, at a similar level as 70% ethanol. The microdilution method for in vitro antibacterial activity showed that all NADES exhibit bacterial growth inhibition at a lower concentration than 70% ethanol, especially NADESs containing organic acids. The majority of NADES extracts neutralize DPPH radical at a lower concentration than conventional solvent and showed similar ability to reduce Fe³⁺ to Fe²⁺ ions in FRAP assay. NADES can be useful in the isolation of phenolic compounds from plant sources and should be considered as novel, sustainable, and low-cost solvents with a variety of applications.

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 ('vlaškača', 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.

Comparison between polyphenol profile and bioactive response in blackthorn (Prunus spinosa L.) genotypes from north Serbia-from raw data to PCA analysis

The aim of this work was to investigate and compare the phenolic profile of 15 wild growing blackthorn (Prunus spinosa L.) genotypes from the slopes of Fruška Gora mountain in north Serbia. Their effect in inhibiting i) α-amylase and α-glucosidase activities and ii) colorectal cancer cell line (HT29) growth was also studied. Blackthorn fruit extracts exhibited high phenolic content being enrich in anthocyanins. Principal component analysis was used to correlate the bioactive response with phenolic composition. It was found that derivatives quercetin and anthocyanin peonidin are the major contributors of the inhibition of carbohydrates hydrolyzing enzymes as well as with the antiproliferative effect of blackthorn. Among all samples, the genotype from Beška locality showed the higher capacity in inhibiting alpha-amylase, alpha-glucosidase and HT29 cell growth. Because of high anthocyanin content and higher bioactive response, these genotypes could be recommended for the further cultivation and investigation.

Comparison between Organic and Conventional Spelt and Wheatgrass juice

This work is aimed to compare antioxidant and scavenger properties of conventionally and organically produced speltgrass. Moreover, the antioxidant status of spelt was compared with wheatgrass. Three spelt varieties were analyzed:Nirvana, Ebners–Rotkorn variety and Eco-10. Antioxidant enzymes, superoxide-dismutase and guiacol-peroxidase, were determined as well as ferric reducing antioxidant power and DPPH-antiradical power. Total soluble proteins and total phenols were determined and also lipid peroxidation as a parameter of oxidative stress. The organically produced spelt was exposed to the higher levels of oxidative stress than conventionally produced spelt, and also DPPH antiradical power was induced by conventional production, which is also demonstrated using the relative antioxidant capacity index. The best antioxidant properties, better than wheat, showed organically produced spelt genotype Ebners–Rotkorn which is determined by the highest phenol content, superoxide-dismutase activity, DPPH antiradical power and ferric reduced antioxidant power and consequently with the lowest lipid peroxidation intensity.

Biochemical response of hybrid black poplar tissue culture (Populus × canadensis) on water stress

In this study, poplar tissue culture (hybrid black poplar, M1 genotype) was subjected to water stress influenced by polyethyleneglycol 6000 (100 and 200 mOsm PEG 6000). The aim of the research was to investigate the biochemical response of poplar tissue culture on water deficit regime. Antioxidant status was analyzed including antioxidant enzymes, superoxide-dismutase (SOD), catalase (CAT), guiacol-peroxidase (GPx), glutathione-peroxidase (GSH-Px), glutathione-reductase, reduced glutathione, total phenol content, Ferric reducing antioxidant power and DPPH radical antioxidant power. Polyphenol oxidase and phenylalanine-ammonium-lyase were determined as enzymatic markers of polyphenol metabolism. Among oxidative stress parameters lipid peroxidation, carbonyl-proteins, hydrogen-peroxide, reactive oxygen species, nitric-oxide and peroxynitrite were determined. Proline, proline-dehydrogenase and glycinebetaine were measured also as parameters of water stress. Cell viability is finally determined as a biological indicator of osmotic stress. It was found that water stress induced reactive oxygen and nitrogen species and lipid peroxidation in leaves of hybrid black poplar and reduced cell viability. Antioxidant enzymes including SOD, GPx, CAT and GSH-Px were induced but total phenol content and antioxidant capacity were reduced by PEG 6000 mediated osmotic stress. The highest biochemical response and adaptive reaction was the increase of proline and GB especially by 200 mOsm PEG. While long term molecular analysis will be necessary to fully address the poplar potentials for water stress adaptation, our results on hybrid black poplar suggest that glycine-betaine, proline and PDH enzyme might be the most important markers of poplar on water stress and that future efforts should be focused on these markers and strategies to enhance their concentration in poplar.

Water stress induces changes in polyphenol profile and antioxidant capacity in poplar plants (Populus spp.)

This paper is aimed to characterize young poplar plants under the influence of water stress provoked by polyethileneglycol 6000 (PEG 6000). Three polar genotypes (M1, B229, and PE19/66) were grown in hydroponics and subjected to 100 and 200 mOsm PEG 6000 during six days. Polyphenol characterization, two enzymatic markers and antioxidant capacity in leaves and roots were investigated in stressed plants. Total phenol content, ferric reducing antioxidant capacity (FRAP) and DPPH antiradical power (DPPH ARP) were determined for estimating total antioxidant capacity. Polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were determined as enzymatic markers. Polyphenol characterization of poplar samples was performed by HPLC-PDA analysis. All results were subjected to correlation analysis and principal component analysis (PCA). Inspite of the decrease of total phenol content in investigated genotypes, as well as total antioxidant capacity, some of polyphenols were affected by stress like flavonoids chrysin, myricetine, kaempferol and isoferulic acid in roots of B229 genotype (Populus deltoides). Genotype B229 also showed the increase of antioxidant capacity and PAL activity in root and leaves under stress what could be the indicator of the adaptability of poplar plants to water stress. Significant positive correlations were obtained between PAL, antioxidant capacity as well as phenolic acids among themselves. Chemometric evaluation showed close interdependence between flavonoids, FRAP, DPPH antiradical power and both investigated enzymes of polyphenol metabolism, PAL and PPO.

Comparative study of antioxidant status in androgenic embryos of Aesculus hippocastanum and Aesculus flava

In vivo (leaves and seed embryos) and in vitro (androgenic embryos) antioxidant scavenging activity of Aesculus hippocastanum and Aesculus flava medical plants was examined. Here we report antioxidant enzyme activities of superoxide dismutase, catalase, guaiacol peroxidase and glutathione peroxidase, reduced glutathione quantity, flavonoids, soluble protein contents, quantities of malondialdehyde, and (•)OH radical presence in the investigated plant samples. Total antioxidant capacity of all the samples of A. hippocastanum and A. flava was determined using FRAP, DPPH, and NO(•) radical scavenger capacity. The leaves of A. flava collected from the botanical garden exhibited stronger antioxidant activity (higher activities of SOD, and higher quantities of GSH, TSH, TPC, and scavenging abilities of DPPH and NO(•), and higher FRAP values and lowest quantities of (•)OH and MDA) than in vitro obtained cultures. However, the leaves of A. flava showed higher antioxidant activity than the leaves of A. hippocastanum, and therefore they have a stronger tolerance of oxidative stress. Androgenic embryos of both species had low amount of antioxidants due to controlled in vitro environmental conditions (T, photoperiod, humidity, nutritive factors, and pathogen-free). Our results confirmed that we found optimal in vitro conditions for producing androgenic embryos of both Aesculus species. Also, we assume that horse chestnut androgenic embryos can be used as an alternative source for large-scale aescin production.

Enhancement of antioxidant and isoflavones concentration in gamma irradiated soybean

Serbian soybean genotype Ana was gamma irradiated at doses of 1, 2, 4, and 10 kGy in order to evaluate the influence of gamma irradiation on isoflavone (genistein, daidzein, and their glycosides genistin and daidzin) contents and hydroxyl radical scavenging effect (HRSE). The increase in genistin and daidzin contents as well as antioxidant activities was observed especially at doses of 4 and 10 kGy. Results were also compared with our previous results relating to total phenol content (TPC), DPPH radical scavenger capacity (DPPH RSC), and ferric reducing antioxidant power (FRAP). Our results indicated that doses up to 10 kGy improve the antioxidant activities of soybean and also nutritional quality with respect to isoflavone content. All results were analyzed by multivariate techniques (correlation matrix calculation and autoscaling transformation of data). Significant positive correlations were observed between genistin, daidzin, DPPH RSC, and HRSE.

Antioxidant and scavenging capacity of Anacamptis pyrimidalis L.--pyrimidal orchid from Vojvodina

In the present study we investigated the antioxidative properties of flowers and aboveground part of Anacamptis pyrimidalis L. from Vojvodina. Activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, and glutathione peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the contents of chlorophylls a and b, carotenoids and soluble proteins were determined. Lipofuscin 'plant age pigments', total antioxidant capacity and scavenging activity were also determined. Our results indicated that the aboveground part of the plant exhibited higher antioxidant activity due to low MDA and lipofuscin pigment accumulation (2.82 nmol/mg protein; 92.90%), higher scavenging activity (54.16%) and antioxidant capacity (432.00 micromol Fe(2+)/dm(3)).

Exploring Equisetum arvense L., Equisetum ramosissimum L. and Equisetum telmateia L. as sources of natural antioxidants

The antioxidant and scavenging activities of above ground parts of Equisetum arvense L., Equisetum ramosissimum L. and Equisetum telmateia L. phosphate buffer (pH 7) extracts were investigated. Activities of antioxidant enzymes (superoxide dismutase, catalase, guaiacol peroxidase and glutathione peroxidase), quantities of reduced glutathione, malonyldialdehyde, superoxide and hydroxyl radicals and flavonoid, soluble protein, chlorophyll a, b and carotenoid contents were determined. The total antioxidant capacity was determined by ferric reducing antioxidant power (FRAP) assay. The Equisetum telmateia extract demonstrated scavenging and antioxidant properties better than Equisetum ramosissimum and Equisetum arvense. The ESR signal of DMPO-OH radical adducts in the presence of Equisetum telmateia phosphate buffer (pH 7) extract was reduced by 98.9% indicating that Equisetum telmateia could be a useful source of antioxidants with huge scavenging ability.

Comparative study of antioxidant properties of wild growing and cultivated Allium species

Allium species are cultivated for the edible bulb, which is used mainly as flavoring in foods. Besides that, they could prevent tumor promotion and some processes that are associated with free radicals, such as cardiovascular diseases and aging. Therefore, different Allium species, both cultivated (Allium nutans L., A. fistulosum L., A. vineale L., A. pskemense B. Fedtsch, A. schoenoprasum L., A. cepa L. and A. sativum L.) and wild (A. flavum L., A. sphaerocephalum L., A. atroviolaceum Boiss, A. vineale L., A. ursinum L., A. scorodoprasum L., A. roseum L. and A. subhirsutum L.), were investigated in order to evaluate the antioxidant properties of their bulbs. This study reports on the results obtained for the bulb antioxidant enzyme activities (superoxide dismutase, catalase, guaiacol peroxidase, glutathione peroxidase), the quantities of non-enzymatic plant antioxidants (reduced glutathione and total flavonoids), the contents of soluble proteins, vitamin C, carotenoids, chlorophylls a and b, as well as for the quantities of malonyldialdehyde and .OH and O2.- radicals.

Antioxidant and scavenger activities of Allium ursinum

The antioxidative properties of bulb, leaf and stalk of Allium ursinum were investigated. Activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, glutathione peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the contents of total flavonoids, chlorophylls a and b and carotenoids were determined. The extracts from all plant organs exhibited antioxidant activity, the highest having been observed in the leaves. Furthermore, ESR signal of PBN-OH radical adducts in the presence of leaves phosphate buffer (pH 7) extract was reduced for 87.61%.

Irradiation Effects on Phenolic Content, Lipid and Protein Oxidation and Scavenger Ability of Soybean Seeds

The effect of medium doses of γ-irradiation (1–10 kGy) on total phenolic and tannin contents, lipid peroxidation, protein oxidation intensity and soluble protein content of soybean seeds, (genotype Ana), was investigated. Screening for antioxidant ability was performed using FRAP and DPPH methods. Total phenolic and tannin contents and DPPH scavenger activity were increased, while protein oxidation intensity was decreased by applied doses of γ-irradiation. Gamma irradiation provoked insignificant changes in lipid peroxidation and soluble protein content, while protein oxidation intensity was significantly decreased when dose of 10 kGy was applied. Presented results implicated that increased antioxidant capacity and protein stability of soybean seeds were increased after application of γ-irradiation.

Exploring Allium species as a source of potential medicinal agents

It has been shown that Allium species may help to prevent tumor promotion, cardiovascular diseases and aging; all processes that are associated with free radicals. Therefore the Allium species of both cultivated species (Allium nutans L., Allium fistulosum L., Allium vineale L., Allium psekemense B. Fedtsch, Allium cepa L., Allium sativum L.) and wild species (Allium flavum L., Allium sphaerocephalum L., Allium atroviolaceum Boiss, Allium schenoprasum L., Allium vineale L., Allium ursinum L., Allium scorodoprasum L.) from various locations were investigated for their antioxidative properties. The leaves were examined for activities of antioxidative enzymes (catalase, peroxidase, superoxide-dismutase, glutathione-peroxidase), non-enzymic antioxidants (reduced glutathione and total flavonoids), content of soluble proteins, vitamin C, carotenoids, chlorophylls a and b, as well as the quantities of malonyldialdehyde and *OH and O2*- radicals. Using a contemporary spectroscopic fluorescent method, lipofuscin, 'plant age pigments' were determined. ESR spectroscopy was used to follow the decrease of oxygen radicals in the presence of extracts of Allium species in phosphate buffer (pH 7). The results showed that all Allium species had strong antioxidative properties due to their high concentration of total flavonoids, high content of carotenoids and chlorophylls, and very low concentrations of toxic oxygen radicals. ESR signals of DMPO-OH radical adducts, in the presence of Allium extracts in phosphate buffer (pH 7), were reduced by up to 94.3%.

Evaluation of willow herb's (Epilobium angustofolium L.) antioxidant and radical scavenging capacities

The present study investigated the antioxidative properties of root, leaf and stalk of Epilobium angustofolium L. The activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the content of total flavonoids, chlorophylls a and b, carotenoids, vitamin C and soluble proteins were determined. The results indicate that extracts from all plant organs exhibited antioxidant activity. The highest antioxidant activity was observed in the leaves. Radical scavenging capacity (RSC), determined by DPPH assay, was highest in the leaves as well as total reducing power determined by FRAP assay. Lipofuscin 'plant age pigments' were also determined.

Free radical scavenging activity of three Equisetum species from Fruska gora mountain

The scavenger activities of Equisetum arvense, Equisetum ramosissimum and Equisetum telmateia aboveground parts phosphate buffer (pH 7) extracts were evaluated using three different methods: DPPH assay, ESR and NO radical inhibition assay. Total reducing power was determined by FRAP assay. The E. telmateia extract demonstrated the most relevant scavenger and antioxidant properties. ESR signal of DMPO-OH radical adducts in the presence of E. telmateia phosphate buffer (pH 7) extract was reduced to 98.9% which indicated that E. telmateia could be a useful source of antioxidants with huge scavenger ability.

Screening for antioxidant properties of Allium giganteum

The antioxidative properties of bulb, leaf and stalk of Allium giganteum were investigated. Activities of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, glutathione peroxidase), quantities of malonyldialdehyde, superoxide and hydroxyl radicals and reduced glutathione and also the content of total flavonoids, chlorophylls a and b, carotenoids, vitamin C and soluble proteins were determined. The highest antioxidant activity was observed in the leaves. Furthermore, ESR signal of PBN-OH radical adducts in the presence of leaves phosphate buffer (pH 7) extract was reduced for 74.19%.