Changes Caused by Fruit Extracts in the Lipid Phase of Biological and Model Membranes

The aim of the study was to determine changes incurred by polyphenolic compounds from selected fruits in the lipid phase of the erythrocyte membrane, in liposomes formed of erythrocyte lipids and phosphatidylcholine liposomes. In particular, the effect of extracts from apple, chokeberry, and strawberry on the red blood cell morphology, on packing order in the lipid hydrophilic phase, on fluidity of the hydrophobic phase, as well as on the temperature of phase transition in DPPC liposomes was studied. In the erythrocyte population, the proportions of echinocytes increased due to incorporation of polyphenolic compounds. Fluorimetry with a laurdan probe indicated increased packing density in the hydrophilic phase of the membrane in presence of polyphenolic extracts, the highest effect being observed for the apple extract. Using the fluorescence probes DPH and TMA-DPH, no effect was noted inside the hydrophobic phase of the membrane, as the lipid bilayer fluidity was not modified. The polyphenolic extracts slightly lowered the phase transition temperature of phosphatidylcholine liposomes. The studies have shown that the phenolic compounds contained in the extracts incorporate into the outer region of the erythrocyte membrane, affecting its shape and lipid packing order, which is reflected in the increasing number of echinocytes. The compounds also penetrate the outer part of the external lipid layer of liposomes formed of natural and DPPC lipids, changing its packing order

Fishroesomes as carriers with antioxidant and anti-inflammatory bioactivities

The great diversity of marine habitats and organisms renders them a high-value source to find/develop novel drugs and formulations. Therefore, herein, sardine (Sardina pilchardus) roe was used as a lipidic source to produce liposomes. This fish product presents high nutritional value, being its lipidic content associated with important health benefits. Consequently, it can be advantageously used to produce therapeutically active delivery devices. Roe lipids were extracted using the Matyash method. After lipid film hydration and extrusion, sardine roe-derived large unilamellar liposomes (LUVs), designated as fishroesomes, presented a size of â 330 nm and a significant negative surface charge (â - 27 mV). Radical scavenging assays demonstrated that fishroesomes efficiently neutralized peroxyl, hydroxyl and nitric oxide radicals. Moreover, fishroesomes significantly reduced the expression of pro-inflammatory cytokines and chemokines by LPS-stimulated macrophages at non-toxic concentrations for L929 and THP-1 cells. Consequently, the developed liposomes exhibit unique properties as bioactive drug carriers for inflammatory diseases treatment.This work was supported by FCT/MCTES (Portuguese Foundation for Science and Technology / Ministry of Science, Technology and Higher Education) or FSE/POCH (European Social Fund through the Operational Program of Human Capital) (grant numbers PD/169/2013, PD/ BD/113795/2015, PD/BD/135246/2017, PTDC/BTM-SAL/28882/ 2017), and the NORTE 2020 Structured Project, co-funded by Norte2020 (NORTE-01-0145-FEDER-000021). Authors also thank the local fisherman for the donation of the samples

Evolving Network Analysis of S&P500 Components: COVID-19 Influence of Cross-Correlation Network Structure

The economy is a system of complex interactions. The COVID-19 pandemic strongly influenced economies, particularly through introduced restrictions, which formed a completely new economic environment. The present work focuses on the changes induced by the COVID-19 epidemic on the correlation network structure. The analysis is performed on a representative set of USA companies—the S&P500 components. Four different network structures are constructed (strong, weak, typically, and significantly connected networks), and the rank entropy, cycle entropy, averaged clustering coefficient, and transitivity evolution are established and discussed. Based on the mentioned structural parameters, four different stages have been distinguished during the COVID-19-induced crisis. The proposed network properties and their applicability to a crisis-distinguishing problem are discussed. Moreover, the optimal time window problem is analysed

Antioxidant activity of polyphenolic extracts from red current and cranberry fruits with regard to erythrocytes membrane

Celem podjętych badań było określenie aktywności przeciwutleniającej wodnych ekstraktów z czerwonej porzeczki i żurawiny w odniesieniu do błony erytrocytów oraz mechanizmu odpowiedzialnego za tę aktywność. Oznaczono skład polifenolowy ekstraktów z zastosowaniem metody chromatografii cieczowej z detektorem diodowym i masowym (UPLC-DAD-MS). Spektrofotometrycznie określono współczynnik podziału związków zawartych w ekstraktach pomiędzy fazę organiczną i wodną. Aktywność przeciwutleniającą ekstraktów wobec błony erytrocytów zbadano metodą fluorymetryczną na podstawie stopnia gaszenia fluorescencji sondy DPH-PA, indukując utlenianie błon erytrocytów związkiem AAPH. Fluorymetrycznie określono również lokalizację w błonie erytrocytów związków polifenolowych zawartych w ekstraktach. Stwierdzono, że owoce czerwonej porzeczki i żurawiny są bogate w związki polifenolowe, szczególnie w antocyjany i procyjanidyny. Wykazano, po zastosowaniu sond fluorescencyjnych, że polifenole zawarte w ekstraktach nie przenikają do części hydrofobowej błony, na co wskazuje brak zmian w anizotropii fluorescencji. Łączą się natomiast z regionem główek polarnych na powierzchni błony, zmieniając ich upakowanie, na co wskazuje zmniejszenie uogólnionej polaryzacji. Dowiedziono, że związki polifenolowe zawarte w ekstraktach skutecznie chronią błonę erytrocytów przed szkodliwym działaniem wolnych rodników indukowanych związkiem AAPH w środowisku wodnym. Ponadto wykazano, że aktywność przeciwutleniająca ekstraktu z czerwonej porzeczki (IC₅₀ = 4,59 μg/ml) jest zbliżona do aktywności standardowego przeciwutleniacza, jakim jest Trolox (IC₅₀ = 3,9 μg/ml), oraz że jest ona wyższa od aktywności ekstraktu żurawiny (IC₅₀ = 12,02 μg/ml).The objective of the research study was to determine the antioxidant activity of aqueous solutions of extracts from red current and cranberry with regard to the erythrocytes membrane, and the mechanism responsible for that activity. The polyphenolic composition of the extracts was determined using an ultraperformance liquid chromatography method with diode array detection and mass analysis (UPLC-DADMS). Spectrophotometrically was determined a partition coefficient for compounds contained in extracts between the organic and aqueous phases. The antioxidant activity of extracts towards the erythrocytes membrane was analyzed using a fluorescence method on the basis of a quenching degree of DPH-PA probe fluorescence, whereas the oxidation of the erythrocytes membranes was induced by an AAPH compound. The fluorescence spectroscopy was also used to determine the location of phenolic compounds, contained in the extracts, in the erythrocyte membrane. It was found that the red currant and cranberry fruits were rich in polyphenols, in particular in anthocyanins and procyanidins. With the use of fluorescence probes, it was proved that polyphenolic compounds contained in the extracts did not penetrate into the hydrophobic region of the membrane; the absence of any changes in the fluorescence anisotropy confirmed it. However, they bound to the region of polar heads on the membrane surface and changed their packing as evidenced by the decrease in the generalized polarization. It was proved that the polyphenols in the extracts efficiently protected the erythrocytes membrane against harmful activity of free radicals induced by the AAPH compound in the aqueous environment. Furthermore, it was proved that the antioxidant activity of red currant extract (IC₅₀ = 4.59 μg/ml) was comparable to that of a standard antioxidant, i.e. of TroloxⓇ (IC₅₀ = 3.9 μg/ml) and that it was better than the activity of cranberry extracts (IC₅₀ = 12.02 μg/ml)

Protection of Erythrocytes and Microvascular Endothelial Cells against Oxidative Damage by <i>Fragaria vesca</i> L. and <i>Rubus idaeus</i> L. Leaves Extracts—The Mechanism of Action

The aim of this work is to determine the biological activity of ellagitannins rich extracts from leaves of raspberry (Rubus idaeus L.) and wild strawberry (Fragaria vesca L.) in relation to cells and cell membranes. Detailed qualitative and quantitative analysis of phenolic compounds of the extract was made using chromatographic methods. Cytotoxic and antioxidant activities of tested extracts in relation to erythrocytes and human vascular endothelial cells (HMEC-1) were determined by using fluorimetric and spectrophotometric methods. In order to establish the influence of the extracts on the physical properties of the membrane, such as osmotic resistance and erythrocytes shapes, mobility and/or hydration of polar heads and fluidity of hydrocarbon chains of membrane lipids, microscopic and spectroscopic methods were used. The results showed that the extracts are non-toxic for erythrocytes and HMEC-1 cells (up to concentration of 50 µg/mL), but they effectively protect cells and their membranes against oxidative damage. The increase in osmotic resistance of erythrocytes, formation of echinocytes and changes only in the polar part of the membrane caused by the extracts demonstrate their location mainly in the hydrophilic part of the membrane. The results indicate that tested extracts have high biological activities and may be potentially used in delaying the ageing process of organisms and prevention of many diseases, especially those associated with oxidative stress

Identifying the Molecular Mechanisms and Types of Cell Death Induced by <i>bio</i>- and <i>pyr</i>-Silica Nanoparticles in Endothelial Cells

The term “nanosilica” refers to materials containing ultrafine particles. They have gained a rapid increase in popularity in a variety of applications and in numerous aspects of human life. Due to their unique physicochemical properties, SiO2 nanoparticles have attracted significant attention in the field of biomedicine. This study aimed to elucidate the mechanism underlying the cellular response to stress which is induced by the exposure of cells to both biogenic and pyrogenic silica nanoparticles and which may lead to their death. Both TEM and fluorescence microscopy investigations confirmed molecular changes in cells after treatment with silica nanoparticles. The cytotoxic activity of the compounds and intracellular RNS were determined in relation to HMEC-1 cells using the fluorimetric method. Apoptosis was quantified by microscopic assessment and by flow cytometry. Furthermore, the impact of nanosilica on cell migration and cell cycle arrest were determined. The obtained results compared the biological effects of mesoporous silica nanoparticles extracted from Urtica dioica L. and pyrogenic material and indicated that both types of NPs have an impact on RNS production causing apoptosis, necrosis, and autophagy. Although mesoporous silica nanoparticles did not cause cell cycle arrest, at the concentration of 50 μg/mL and higher they could disturb redox balance and stimulate cell migration