Biological activity of blackcurrant Extracts (Ribes nigrum L.) in relation to erythrocyte membranes

Analysis of the Polyphenolic Composition of Vaccinium L. Extracts and Their Protective Effect on Red Blood Cell Membranes

The blueberry fruit of the genus Vaccinium, including high blueberry, low blueberry, and wild bilberry, is consumed for its flavor and medicinal properties. The purpose of the experiments was to investigate the protective effect and mechanism of the interaction of blueberry fruit polyphenol extracts with the erythrocytes and their membranes. The content of polyphenolic compounds in the extracts was determined using the chromatographic UPLC-ESI-MS method. The effects of the extracts on red blood cell shape changes, hemolysis and osmotic resistance were examined. Changes in the order of packing and fluidity of the erythrocyte membrane and the lipid membrane model caused by the extracts were identified using fluorimetric methods. Erythrocyte membrane oxidation was induced by two agents: AAPH compound and UVC radiation. The results show that the tested extracts are a rich source of low molecular weight polyphenols that bind to the polar groups of the erythrocyte membrane, changing the properties of its hydrophilic area. However, they practically do not penetrate the hydrophobic part of the membrane and do not damage its structure. Research results suggest that the components of the extracts can defend the organism against oxidative stress if they are delivered to the organism in the form of dietary supplements.

Ribes nigrum L. Extract-Mediated Green Synthesis and Antibacterial Action Mechanisms of Silver Nanoparticles

Silver nanoparticles (Ag NPs) represent one of the most widely employed metal-based engineered nanomaterials with a broad range of applications in different areas of science. Plant extracts (PEs) serve as green reducing and coating agents and can be exploited for the generation of Ag NPs. In this study, the phytochemical composition of ethanolic extract of black currant (Ribes nigrum) leaves was determined. The main components of extract include quercetin rutinoside, quercetin hexoside, quercetin glucuronide, quercetin malonylglucoside and quercitrin. The extract was subsequently employed for the green synthesis of Ag NPs. Consequently, R. nigrum leaf extract and Ag NPs were evaluated for potential antibacterial activities against Gram-negative bacteria (Escherichia coli ATCC 25922 and kanamycin-resistant E. coli pARG-25 strains). Intriguingly, the plant extract did not show any antibacterial effect, whilst Ag NPs demonstrated significant activity against tested bacteria. Biogenic Ag NPs affect the ATPase activity and energy-dependent H⁺-fluxes in both strains of E. coli, even in the presence of N,N’-dicyclohexylcarbodiimide (DCCD). Thus, the antibacterial activity of the investigated Ag NPs can be explained by their impact on the membrane-associated properties of bacteria.

Targeting interleukin-β by plant-derived natural products: Implications for the treatment of atherosclerotic cardiovascular disease

Inflammation is the main contributing factor to atheroma formation in atherosclerosis. Interleukin-1 beta (IL-1β) is an inflammatory mediator found in endothelial cells and resident leukocytes. Canakinumab is a selective monoclonal antibody against IL-1β which attenuates inflammation and concurrently precipitates fatal infections and sepsis. Natural products derived from medicinal plants, herbal remedy and functional foods are widely used nowadays. Experimental and clinical trial evidence supports that some natural products such as curcumin, resveratrol, and quercetin have potential effects on IL-1β suppression. In this review, we tried to document findings that used medicinal plants and plant-based natural products for treating atherosclerosis and its related diseases through the suppression of IL-1β.

Biochemical composition of black currant berries (Ribes Nigrum L.) for development of new cultivars in Bashkortostan

The paper presents the results of researches of the biochemical composition of black currant berries (Ribes nigrum L.), cultivated in the Republic of Bashkortostan. The objects of the research were cultivars breeding of the Bashkir Research Institute of Agriculture: Valovaya (control), Karaidel, Chishma, Kushnarenkovskaya, Belskaya and Estafeta. Observations have been carried out for 12 years (2006-2017). Differences in the accumulation of components of the biochemical composition are shown in dependence of the varietal peculiarities of the crop. Cultivars that can be used in breeding as sources of individual economically valuable sources are selected.

Influence of the variety on the quality of organic black currant juices

The results of a comparative study of the quality of blackcurrant juices of five varieties of ARSRIFCB breeding suitable for industrial commercial use are presented: Azhurnaya, Orlovskaya Serenada, Orlovsky Vals, Ocharovanye, Chudnoye Mgnovenye. The sensory profiles of juices and their relation to scoring and varietal characteristics were studied. An analysis of the sensory qualities of mono-varietal blackcurrant juices showed that they largely depend on varietal characteristics, such as transparency and thickness, the sensation of acidity and sweetness, and the softness of the taste (absence of harsh acid in the taste). The indicators of the point analysis confirm the results of the descriptor. Sensory analysis data (point and descriptor) showed that preference is given to products with a ruby-red color, typical for blackcurrant juices, bright, not cloudy. Among the studied varieties, of great interest for juice production are the varieties Ocharovanye and Azhurnaya.

Biochemical investigation of the upstream anti-sickling mechanisms of soursop (Annona muricata): 15-acetyl guanacone as an inhibitor of deoxyhaemoglobin polymerisation

Current sickle cell disease (SCD) therapies are limited and inefficient. The ethnomedicinal values of Annona muricata in the treatment of SCD, leading to this present research. Leaves and fruits of Annona muricata were processed using solvent extraction and partitioning; aqueous, chloroform and ethyl acetate fractions. In vitro (anti-oxidant and anti-sickling), in silico, quantitative (amino acids) and kinetic simulation experiments were done. 15-acetyl guanacone, was used, in silico against 2,3-bisphosphoglycerate (2, 3-BPG) mutase and deoxyhaemoglobin. The ethyl acetate and chloroform fractions better NO^● scavengers, iron-chelators and ferric reducing. In vitro unsickling (UT₅₀) had ethyl acetate = 5 h and methanol = 7 h. Chloroform fraction had EC₅₀ 1.00 mg/mL (EC₅₀ = 546 mg/mL) to 10.00 mg/mL (EC₅₀ = 99 mg/mL). EC₅₀ and IC₅₀ of ethyl acetate fraction had steady-decrease. At higher concentration, chloroform fraction had higher Bmax (1.48 × 10²¹ U/mL) and higher Kd (3.66 × 10¹⁹ mg/mL), whereas, at a lower concentration, the ethyl acetate fraction demonstrated higher Bmax (7.23 × 10¹² U/mL) and lower Kd (2.12 × 10¹¹ mg/mL); The relative affinity (BP) of chloroform fraction increased progressively with concentration. The amino acid profile revealed rich concentrations glycine, valine, leucine, lysine, phenylalanine, histidine, arginine, and tryptophan. From the in silico experiments, 15-acetyl guanacone specifically targeted the A and B chains, with greater affinity for the beta subunit. This suggested that 15-acetyl guanacone might be able to prevent the polymerisation of deoxyHbSS, induce an allosteric conformational change that increases the oxygen affinity, and decrease the cellular 2, 3-BPG concentration.Communicated by Ramaswamy H. Sarma.

In vitro hematotoxicity of Vernonanthura polyanthes leaf aqueous extract and its fractions

Vernonanthura polyanthes, popularly known as 'assa-peixe', is widely used in Brazil for therapeutic purpose mainly to treat respiratory tract problems. However, few studies investigated its chemical safety. In this way, we first obtained the V. polyanthes leaf aqueous extract (VpLAE) and three fractions (aqueous; n-butanol, n-BF; and ethyl acetate), and we chemically characterized this material. Then, the cytogenotoxic potential of the VpLAE and its fractions was investigated against human erythrocytes and lymphocytes using Trypan blue exclusion test of cell viability and CometChip. The phytochemical screening of V. polyanthes leaf revealed the presence of total phenolic compounds, flavonoids, tannins, coumarins, terpenic compounds, and cardioactive heterosides. n-BF presented the highest total phenolic, flavonoids, and tannins contents and, consequently, the highest antioxidant activity, according to the DPPH free radical scavenging method. Although the VpLAE and its fractions did not cause death of erythrocytes, the cells acquired an echinocytic form. Regarding lymphocytes, VpLAE and its fractions presented cytotoxicity and genotoxicity. When VpLAE or its fractions were co-treated with doxorubicin (DXR), a recognized cytotoxic drug, we observed an enhancement of DXR cytotoxicity against lymphocytes, but the DXR genotoxicity decreased around 15%. Since the VpLAE and its fractions increased the DXR cytotoxicity and decreased its genotoxicity, further studies should be conducted for the development of an adjuvant drug from this extract to reduce the side effects of chemotherapy. Moreover, the indiscriminate use of 'assa-peixe' by local people should be discouraged.

Valorisation of Ribes nigrum L. Pomace, an Agri-Food By-Product to Design a New Cosmetic Active

The ethical and ecological concerns of today’s consumers looking for both sustainable and efficient ingredients in finished products, put a lot of pressure on the cosmetic market actors who are being driven to profoundly modify the strategies adopted to innovate in terms of actives while notably being urged to switch from petroleum- to plant-based ingredients. To produce such natural cosmetic ingredients, agri-food by-products are advocated as raw material due to their reduced carbon footprint as they actively contribute to the worldwide improvement of waste management. The process to transform plant waste materials into such powerful and objectified “green” cosmetic actives in compliance with circular economy principles is a long-term integrated process. Such a development is thoroughly exemplified in the present paper through the description of the design of liquid anti-age ingredients based on Ribes nigrum L. extract. This was obtained by maceration of blackcurrant pomace. and the embodiment of this extract following its phytochemical analysis notably by HPLC-DAD-ELSD and its bioguided fractionation using in vitro bioassays.

Effects of Polyphenol Compounds and Nitrogen Oxide Donors on Lipid Oxidation, Membrane-Skeletal Proteins, and Erythrocyte Structure under Hypoxia

This study shows that membrane-associated cytoskeletal protein structures and the erythrocyte morphology undergo profound changes during hypoxia. Hypoxia also intensified oxidative processes in the lipid phase of the bilayer of red blood cell membranes. Sodium nitroprusside impaired the morphology of red blood cells and altered quantitative and qualitative composition of membrane-skeletal proteins. The findings suggest that hypoxia causes changes at all levels of red blood cell organization, which can cause the functional disorders of hemoglobin oxygen-transporting properties and, eventually, the complete degradation of red blood cells. The use of flavonoids has a protective effect against hypoxia.

Effect of pre-treatment conditions on the antiatherogenic potential of freeze-dried oyster mushrooms

Oyster mushroom (Pleurotus ostreatus L.) is a valuable food product. It possesses an antiatherogenic potential, which has to be preserved during processing. The paper features the production of oyster mushroom sublimates. It focuses on such pre-treatment conditions as grinding, disinfection, and cryostabilisation, and their effect on the antiatherogenic potential of oyster mushrooms. A set of in vitro experiments was performed to measure the levels of lovastatin and antioxidant, catalase, anti-inflammatory, and thrombolytic properties. Various pre-treatment conditions proved to produce different effects on the biological activity of the freeze-dried oyster mushroom product. The best results were obtained after the mushrooms were reduced to pieces of 0.5 cm, underwent UV disinfection, blanched, treated with hot air, and cryostabilised with a 1.5% apple pectin solution. The best conditions for the antioxidant properties included ozonation, UV disinfection, and cryoprotection with pectin. The critical conditions for the antioxidant properties included homogenisation, blanching, and cryostabilisation with 10% solutions of sucrose and lactose. The catalase properties did not depend on the degree of grinding and were most pronounced after ozonation. The optimal conditions for the anti-inflammatory properties included UV disinfection and cryostabilisation with lactose. Ozonation proved to be critical for anti-inflammatory properties. The optimal conditions for thrombolytic properties included ozonation and cryoprotection with a 5% sorbitol solution, while hot air disinfection proved critical. Therefore, the research provided an experimental substantiation for individual pre-treatment conditions or their combinations that turn sublimated oyster mushrooms into a valuable functional product with antiatherogenic properties.

Antifatigue Activity and Exercise Performance of Phenolic-Rich Extracts from Calendula officinalis, Ribes nigrum, and Vaccinium myrtillus

Calendula officinalis, Ribes nigrum, and Vaccinium myrtillus (CRV) possess a high phenolic compound content with excellent antioxidant activity. Dietary antioxidants can reduce exercise-induced oxidative stress. Consumption of large amounts of phenolic compounds is positively correlated with reduction in exercise-induced muscle damage. Research for natural products to improve exercise capacity, relieve fatigue, and accelerate fatigue alleviation is ongoing. Here, CRV containing a large total phenolic content (13.4 mg/g of CRV) demonstrated antioxidant activity. Ultra-performance liquid chromatography quantification revealed 1.95 ± 0.02 mg of salidroside in 1 g of CRV. In the current study, CRV were administered to mice for five weeks, and the antifatigue effect of CRV was evaluated using the forelimb grip strength test; weight-loaded swimming test; and measurement of fatigue-related biochemical indicators, such as blood lactate, ammonia, glucose, blood urea nitrogen (BUN), and creatine kinase (CK) activity; and muscle and liver glycogen content. The results indicated that in CRV-treated mice, the forelimb grip strength significantly increased; weight-loaded swimming time prolonged; their lactate, ammonia, BUN, and CK activity decreased, and muscle and liver glucose and glycogen content increased compared with the vehicle group. Thus, CRV have antifatigue activity and can increase exercise tolerance.

Marine Spongin: Naturally Prefabricated 3D Scaffold-Based Biomaterial

The biosynthesis, chemistry, structural features and functionality of spongin as a halogenated scleroprotein of keratosan demosponges are still paradigms. This review has the principal goal of providing thorough and comprehensive coverage of spongin as a naturally prefabricated 3D biomaterial with multifaceted applications. The history of spongin's discovery and use in the form of commercial sponges, including their marine farming strategies, have been analyzed and are discussed here. Physicochemical and material properties of spongin-based scaffolds are also presented. The review also focuses on prospects and trends in applications of spongin for technology, materials science and biomedicine. Special attention is paid to applications in tissue engineering, adsorption of dyes and extreme biomimetics.

Antispasmodic Effect of Blackcurrant (Ribes nigrum L.) Juice and Its Potential Use as Functional Food in Gastrointestinal Disorders

OBJECTIVE

The purpose of this study was to investigate the relaxative effects of blackcurrant juice on the gastrointestinal smooth muscle in vitro.

MATERIALS AND METHODS

Berries of the blackcurrant cultivar Ometa were used for the preparation of the juice used. The spasmolytic activity of blackcurrant juice was tested on rat ileum isolated from male Wistar rats by monitoring its influence on spontaneous contractions, as well as contractions induced by potassium chloride (KCl), barium chloride (BaCl2), calcium chloride (CaCl2), and acetylcholine (Ach). The results are expressed as the mean ± standard deviation obtained in 6 measurements and statistical significance was determined by the Student t test, with p < 0.05 taken as significant.

RESULTS

The blackcurrant cultivar Ometa significantly reduced the frequency and the amplitude of spontaneous contractions (57.94 ± 3.44%) and Ach-induced contractions (42.74 ± 5.36%; p < 0.05) of the isolated rat ileum. Cumulative concentrations (0.01-3 mg/mL) of the Ometa juice also reduced contractions of the isolated rat ileum stimulated by KCl (51.46 ± 6.87%), CaCl2 (57.54 ± 6.47%), and BaCl2 (58.54 ± 10.55%). The inhibitory effects of the juice were proportional to the applied concentration.

CONCLUSION

The antispasmodic effect of Ometa cultivar shows that common gastrointestinal disorders could be treated by the functional food.

Radioprotective activity of blackcurrant extract evaluated by in vitro micronucleus and gene mutation assays in TK6 human lymphoblastoid cells

INTRODUCTION

Blackcurrant (Ribs nigrum L.) is a classical fruit that has long been used to prepare juice, jam, liqueur, and sometimes medicines in Europe. Previously, we reported a genome defense effect by the antioxidative activity of several types of blackcurrant extracts (BCEs) in yeast and human cell gene mutation assays. In this study, we determined if BCE exerted radioprotective activity against DNA damage, chromosomal aberration, and gene mutations in the TK6 human lymphoblastoid cell line. We prepared aqueous BCE extracted from mature fruits cultivated in the Aomori Prefecture, Japan.

FINDINGS

In the micronucleus test and TK gene mutation assay, TK6 cells were irradiated with 0, 0.125, 0.250, 0.500, and 1.000 Gy with or without 1.0 mg/mL BCE. Intracellular hydrogen peroxide (H₂O₂) was measured using the fluorescent probe BES-H₂O₂-Ac. Induction of micronuclei and gene mutations by γ-irradiation exposure was suppressed in combination with BCE. In addition, BCE reduced intracellular H₂O₂ levels caused by γ-irradiation.

CONCLUSIONS

Our findings clearly support the genome defense potential of blackcurrant against γ-induced DNA damage. We postulate that these genome defense activities are related to the antioxidant compounds in blackcurrant.

Sweet cherries from Fundão possess antidiabetic potential and protect human erythrocytes against oxidative damage

Cherries are one of the most appreciated summer fruits due to their attractive colour, sweet taste, high water content, low level of calories and composition in bioactive compounds which, in turn, are important to prevent some pathologies like diabetes, cardiovascular diseases and cancer. In this work we evaluated the phenolic profile and biological potential of 5 varieties of sweet cherries from Fundão region (Portugal) (Saco, Sweetheart, Satin, Maring and Hedelfinger). A total of 23 phenolic compounds were identified by LC-DAD and distributed by the several classes: 6 anthocyanins, 1 hydroxybenzoic acid, 8 hydroxycinnamic acids, 3 flavan-3-ols and 5 flavonols. Maring revealed higher contents in anthocyanins, while Hedelfinger was the richest in non-coloured phenolics. The antioxidant capacity was evaluated against DPPH and nitric oxide radicals. Hedelfinger was the most active against DPPH^• (IC₅₀=12.1μg/mL) and Maring against nitric oxide (IC₅₀=140.9μg/mL). Afterwards, antidiabetic capacity was evaluated through the inhibition of α-glucosidase activity, pointing Hedelfinger as the most active (IC₅₀=10.3μg/mL). The capacity of Saco extracts to inhibit the hemoglobin oxidation and the hemolysis of human erythrocytes was also evaluated. Both assays revealed a concentration-dependent inhibitory effect (IC₅₀=38.6μg/mL and IC₅₀=73.0μg/mL, respectively). The results obtained in this study allow us to conclude that sweet cherries possess a great biological potential, and further investigation should be done to promote commercialization and encourage its use in food supplements and in new pharmaceutical and nutraceutical applications.

Cytotoxic and apoptotic activities of extract of Amaranthus spinosus L. in Allium cepa and human erythrocytes

The present study examined the apoptosis inducing effects of Amaranthus spinosus L. aqueous extract in Allium cepa root meristematic cells and human erythrocytes. Cytogenetic assay revealed many apoptosis inducing cytogenetic aberrations viz., cytoplasmic breakage, cytoplasmic disintegration, cytoplasmic shrinkage, receding of cytoplasm, cytoplasmic vacuolation, enucleated cell, ghost cell, nuclear vacuolation, nuclear fragmentation and nuclear disintegration. A remarkable modification of red blood cell surface morphology was observed in the result of RBC assay. The treated RBCs show membrane blebbing and shrinkage, features typical for apoptosis in nucleated cells. Significant induction of cell death was observed in treated Allium root tip cells after Evans blue staining, disclosing the membrane damage potential of the plant extract. TTC assay results in reduced mitochondrial/metabolic activity in Allium root tip cells after treatment, designating the adverse effect of plant extract on mitochondrial respiratory chain. These results confirm the apoptosis inducing potential of A. spinosus extract. Confirming the present results by further in vitro studies, it can be effectively targeted against cell proliferation during cancer treatment by inducing apoptosis. Thus from the present investigation it can be concluded that the aqueous extract of A. spinosus exhibited apoptosis induction and cytotoxic activities.

Nicotine alkaloids as antioxidant and potential protective agents against in vitro oxidative haemolysis

The capacity of eleven nicotine alkaloids to reduce oxidative stress was investigated. In order to provide a structure-activity relationships analysis, new nicotine derivatives with a substituent introduced into the pyrrolidine ring were synthesized and investigated together with nicotine and its known analogs. All newly synthesized compounds were characterized by (1)H, (13)C NMR and EI-MS technique. The antioxidant properties of nicotine, its known analogs and newly produced derivatives, were evaluated by various antioxidant assays such 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH(•)) scavenging, ferrous ions (Fe(2+)) chelating activity and total reducing ability determination by Fe(3+) → Fe(2+) transformation assay. The protective effects of all compounds tested against 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) and tert-butyl hydroperoxide (t-BuOOH)-induced oxidative haemolysis and morphological injury of human erythrocytes, were estimated in vitro. The results showed that nicotine alkaloids exhibited various antiradical efficacy and antioxidant activity in a structure- and a dose-dependent manner. In addition, the capacity of nicotine alkaloids to protect erythrocytes from AAPH- and t-BuOOH-induced oxidative haemolysis, was dependent on its incubation time with cells. Our findings showed that chemical and biological investigations conducted simultaneously can provide comprehensive knowledge concerning the antioxidant potential of nicotine alkaloids. This knowledge can be helpful in better understanding the properties of nicotine alkaloids under oxidative stress conditions.

Physical Effects of Buckwheat Extract on Biological Membrane In Vitro and Its Protective Properties

Buckwheat is a valuable source of many biologically active compounds and nutrients. It has properties that reduce blood cholesterol levels, and so reduces the risk of atherosclerosis, seals the capillaries, and lowers blood pressure. The aim of the study was to determine quantitative and qualitative characteristics of polyphenols contained in extracts from buckwheat husks and stalks, the biological activity of the extracts, and biophysical effects of their interaction with the erythrocyte membrane, treated as a model of the cell. An analysis of the extract’s composition has shown that buckwheat husk and stalk extracts are a rich source of polyphenolic compounds, the stalk extracts showing more compounds than the husk extract. The study allowed to determine the location which incorporated polyphenols occupy in the erythrocyte membrane and changes in the membrane properties caused by them. It was found that the extracts do not induce hemolysis of red blood cells, causing an increase in osmotic resistance of erythrocytes. They affect mainly the hydrophilic region by changing the degree of order of the polar heads of lipids, but do little to change the fluidity of the membrane and its hydration. The results showed also that polyphenolic substances included in the extracts well protect the membranes of red blood cells against oxidation and exhibit anti-inflammatory effect.

Development of reversed-phase high performance liquid chromatography methods for quantification of two isomeric flavones and the application of the methods to pharmacokinetic studies in rats

Isomers 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8 trimethoxy flavone) (flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) (flavone B) have recently demonstrated differential antineoplastic activities against pancreatic cancer in vitro. These studies also indicated that these compounds target highly tumorigenic cells while sparing normal cells. The in vivo antitumor activities of these flavones have not been determined, and detection protocols for these compounds are needed to conduct pre-clinical assays following intravenous dosing. Here, we report methods developed using acetonitrile to extract two flavone isomers and corresponding internal standards, celecoxib and diclofenac, from rat plasma. Separation was achieved using a Shimadzu liquid chromatography system with a C18 column and mobile phase acetonitrile/water (60:40 and 70:30 for flavones A and B, respectively) containing 0.2% acetic acid and 0.05% triethylamine at a flow rate of 0.4mL/min and detection at 245nm. Calibration curves ranging from 250 to 2500ng/mL and 2500 to 100,000ng/mL for both flavones were linear (r(2)≥0.99) with the lower limits of quantification being 250ng/mL. Recovery of concentrations 250, 1000, 2500, 5000, and 100,000ng/mL ranged from 87 to 116% and 84 to 103% (n=3) for flavone A and B, respectively. Stability of both flavones after a freezing/thawing cycle yielded a mean peak ratio ≥0.92 when compared to freshly extracted samples. Intravenous administration of a 20mg/kg dose in rats yielded half-lives of 83.68±56.61 and 107.45±53.31min with clearance values of 12.99±13.78 and 80.79±35.06mL/min/kg for flavones A and B, respectively.

Antiproliferative and antioxidant properties of anthocyanin rich extracts from blueberry and blackcurrant juice

The present study was aimed at evaluating the antiproliferative potential of anthocyanin-rich fractions (ARFs) obtained from two commercially available juices (blueberry and blackcurrant juices) on three tumor cell lines; B16F10 (murine melanoma), A2780 (ovarian cancer) and HeLa (cervical cancer). Individual anthocyanin determination, identification and quantification were done using HPLC-MS. Antioxidant activity of the juices was determined through different mechanism methods such as DPPH and ORAC. For biological testing, the juices were purified through C18 cartridges in order to obtain fractions rich in anthocyanins. The major anthocyanins identified were glycosylated cyanidin derivatives. The antiproliferative activity of the fractions was tested using the MTT assay. The antiproliferative potential of ARF was found to be associated with those bioactive molecules, anthocyanins due to their antioxidant potential. The results obtained indicated that both blueberry and blackcurrants are rich sources of antioxidants including anthocyanins and therefore these fruits are highly recommended for daily consumption to prevent numerous degenerative diseases.

A time-dose model to quantify the antioxidant responses of the oxidative hemolysis inhibition assay (OxHLIA) and its extension to evaluate other hemolytic effectors

The development of a convenient mathematical application for testing the antioxidant potential of standard and novel therapeutic agents is essential for the research community to perform evaluations in a more precise form. The in vitro oxidative hemolysis inhibition assay, despite its relevance for in vivo responses, lacks a proper mathematical model to quantify the responses. In this work, a simple nonlinear time-dose tool to test the effectiveness of antioxidant compounds is presented. The model was verified with available experimental data from the bibliography. The model helps to describe accurately the antioxidant response as a function of time and dose allowing comparisons between compounds. Its advantages are a simple application, provision of parametric estimates that characterize the response, simplification of the protocol, economization of experimental effort, and facilitation of rigorous comparisons among the effects of different compounds and experimental approaches. Finally, other effectors that may obstruct or be of interest for the antioxidant determination are also modeled in similar principles. Thus, the basis of more complex multivariable models is provided. In all experimental data fitted, the calculated parameters were always statistically significant, the equations prove to be consistent, and the correlation coefficient of determination was in all cases higher than 0.98.

Biophysical mechanism of the protective effect of blue honeysuckle (Lonicera caerulea L. var. kamtschatica Sevast.) polyphenols extracts against lipid peroxidation of erythrocyte and lipid membranes

The aim of the present research was to determine the effect of blue honeysuckle fruit and leaf extracts components on the physical properties of erythrocyte and lipid membranes and assess their antioxidant properties. The HPLC analysis showed that the extracts are rich in polyphenol anthocyanins in fruits and flavonoids in leaves. The results indicate that both extracts have antioxidant activity and protect the red blood cell membrane against oxidation induced by UVC irradiation and AAPH. The extracts do not induce hemolysis and slightly increase osmotic resistance of erythrocytes. The research showed that extracts components are incorporated mainly in the external part of the erythrocyte membrane, inducing the formation of echinocytes. The values of generalized polarization and fluorescence anisotropy indicate that the extracts polyphenols alter the packing arrangement of the hydrophilic part of the erythrocyte and lipid membranes, without changing the fluidity of the hydrophobic part. The DSC results also show that the extract components do not change the main phase transition temperature of DPPC membrane. Studies of electric parameters of membranes modified by the extracts showed that they slightly stabilize lipid membranes and do not reduce their specific resistance or capacity. Examination of IR spectra indicates small changes in the degree of hydration in the hydrophilic region of liposomes under the action of the extracts. The location of polyphenolic compounds in the hydrophilic part of the membrane seems to constitute a protective shield of the cell against other substances, the reactive forms of oxygen in particular.