scholarly journals Polyphenolic Extract from Sambucus ebulus L. Leaves Free and Loaded into Lipid Vesicles

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 56 ◽  
Author(s):  
Ramona-Daniela Păvăloiu ◽  
Fawzia Sha’at ◽  
Corina Bubueanu ◽  
Mihaela Deaconu ◽  
Georgeta Neagu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Radical Scavenging ◽  
Phosphate Buffer Solution ◽  
Entrapment Efficiency ◽  
Lipid Vesicles ◽  
Cytoprotective Effect ◽  
Buffer Solution ◽  
Polyphenolic Extract ◽  
Sambucus Ebulus ◽  
Pre Treatment

The paper deals with the preparation and characterisation of hydroalcoholic polyphenolic extract from Sambucus ebulus (SE) leaves that was further loaded into three-types of lipid vesicles: liposomes, transfersomes, and ethosomes, to improve its bioavailability and achieve an optimum pharmacological effect. For Sambucus ebulus L.-loaded lipid vesicles, the entrapment efficiency, particle size, polydispersity index and stability were determined. All prepared lipid vesicles showed a good entrapment efficiency, in the range of 75–85%, nanometric size, low polydispersity indexes, and good stability over three months at 4 °C. The in vitro polyphenols released from lipid vehicles demonstrated slower kinetics when compared to the free extract dissolution in phosphate buffer solution at pH 7.4. Either free SE extract or SE extract loaded into lipid vesicles demonstrated a cytoprotective effect, even at low concentration, 5 ug/mL, against hydrogen peroxide-induced toxicity on L-929 mouse fibroblasts’ cell lines. However, the cytoprotective effect depended on the time of the cells pre-treatment with SE extract before exposure to a hydrogen peroxide solution of 50 mM concentration, requiring at least 12 h of pre-treatment with polyphenols with radical scavenging capacity.

scholarly journals Encapsulation of Polyphenols from Lycium barbarum Leaves into Liposomes as a Strategy to Improve Their Delivery

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1938
Author(s):  
Ramona-Daniela Păvăloiu ◽  
Fawzia Sha’at ◽  
Georgeta Neagu ◽  
Mihaela Deaconu ◽  
Corina Bubueanu ◽  
...  
Keyword(s):  
Particle Size ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Entrapment Efficiency ◽  
Cytoprotective Effect ◽  
Buffer Solution ◽  
Lycium Barbarum ◽  
Burst Effect ◽  
Pharmaceutical Applications

This study is focused on the encapsulation of polyphenols from Lycium barbarum leaves into liposomes as a strategy to improve their delivery. Liposomes loaded with Lycium barbarum leaves extract were obtained and characterized for particle size, polydispersity, entrapment efficiency, and stability. Liposomes presented entrapment efficiency higher than 75%, nanometric particle size, narrow polydispersity, and good stability over three months at 4 °C. The liposomes containing Lycium barbarum offered a slower release of polyphenols with attenuated burst effect compared with the dissolution of free Lycium barbarum extract in phosphate buffer solution at pH 7.4. Moreover, an in vitro pretreatment of 24 h with loaded liposomes showed a cytoprotective effect against H2O2-induced cytotoxicity on L-929 mouse fibroblasts cells. These preliminary findings imply that liposomes could be successfully employed as carriers for polyphenols in pharmaceutical applications.

Microwave-assisted synthesis of NaA nanozeolite from slag and performance of Ag-doped nanozeolite as an efficient material for determination of hydrogen peroxide

RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 52058-52066 ◽  
Author(s):  
Seyed Naser Azizi ◽  
Shahram Ghasemi ◽  
Mehrnaz Mikhchian
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphate Buffer Solution ◽  
Modified Carbon Paste Electrode ◽  
Microwave Assisted Synthesis ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Microwave Assisted ◽  
And Performance ◽  
Paste Electrode

A new amperometric sensor is prepared based on a Ag doped NaA nanozeolite modified carbon paste electrode (Ag/ACPE) in order to detect hydrogen peroxide (H2O2) in phosphate buffer solution (PBS, pH 7.0).

scholarly journals Effect of Nanoconfinement of Polyphenolic Extract from Grape Pomace into Functionalized Mesoporous Silica on Its Biocompatibility and Radical Scavenging Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 696 ◽  
Author(s):  
Ana-Maria Brezoiu ◽  
Laura Bajenaru ◽  
Daniela Berger ◽  
Raul-Augustin Mitran ◽  
Mihaela Deaconu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Radical Scavenging ◽  
Phosphate Buffer Solution ◽  
Grape Pomace ◽  
Array Detector ◽  
Radical Scavenger ◽  
Radical Scavenger Activity ◽  
Polyphenolic Extract ◽  
Scavenger Activity ◽  
Mcm 41

The aim of this paper is to assess the properties of Mamaia (MM) grape pomace polyphenolic extract loaded onto pristine and functionalized MCM-41 mesoporous silica as potential ingredients for nutraceuticals or cosmetics. The chemical profile of hydroalcoholic polyphenolic extracts, prepared either by conventional extraction or microwave-assisted method, was analyzed by reverse-phase high-performance liquid chromatography with photodiode array detector (HPLC-PDA) analysis, while their radical scavenger activity (RSA) was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl radical) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assays. The extract-loaded materials were characterized by Fourier transform infrared (FTIR) spectroscopy, N2 adsorption-desorption isotherms, thermogravimetric analysis, as well as RSA (DPPH and ABTS assays). The polyphenols release profiles from pristine and functionalized (with mercaptopropyl, propyl sulfonic acid, cyanoethyl and propionic acid moieties) MCM-41-type supports were determined in phosphate buffer solution (PBS) pH 5.7. For selected materials containing embedded phytochemicals, cellular viability, and oxidative stress level on immortalized mouse embryonic fibroblast cell line (NIH3T3) were evaluated. A more acidic functional groups linked on silica pore walls determined a higher amount of phytochemicals released in PBS. The extract-loaded materials showed a good cytocompatibility on tested concentrations. The embedded extract preserved better the RSA over time than the free extract. The polyphenols-loaded MCM-41-type silica materials, especially MM@MCM-COOH material, demonstrated a good in vitro antioxidant effect on NIH3T3 cells, being potential candidates for nutraceutical or cosmetic formulations.

scholarly journals Electrochemical determination of hydrogen peroxide at glassy carbon electrode modified with palladium nanoparticles

2013 ◽  
Vol 78 (5) ◽  
pp. 701-711 ◽  
Author(s):  
Addisu Kitte ◽  
Desalegn Assresahegn ◽  
Refera Soreta
Keyword(s):  
Hydrogen Peroxide ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Palladium Nanoparticles ◽  
Phosphate Buffer Solution ◽  
Reference Electrode ◽  
Electrochemical Determination ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Solution Ph

We report here the modification of glassy carbon electrode (GCE) with palladium nanoparticles and palladium film. The response to hydrogen peroxide on the modified electrode was examined using cyclic voltammetry and amperometry (at -0.2 V vs Ag/AgCl reference electrode in the phosphate buffer solution pH 7.4). The palladium film and palladium nanoparticle modified GCE showed a linear response to hydrogen peroxide in the concentration range between 10 ?M to 14 mM and 1 ?M to 14 mM with detection limit of 6.79 ?M and 0.33 ?M, respectively.

Controlled Release Characteristics of PLA-Pluronic-PLA Nano-Sized Vesicles In Vitro

2013 ◽  
Vol 785-786 ◽  
pp. 493-497
Author(s):  
Yu Ping Li ◽  
Li Zhen Sun ◽  
Xiang Yuan Xiong ◽  
Zi Ling Li ◽  
Ting Kang Xing ◽  
...  
Keyword(s):  
Controlled Release ◽  
Protein Delivery ◽  
Phosphate Buffer Solution ◽  
Entrapment Efficiency ◽  
Poly Lactic Acid ◽  
Oral Insulin ◽  
Buffer Solution ◽  
The Mean ◽  
The Stability

In the present study, controlled release characteristics of new nanosized PLA-Pluronic-PLA block copolymer vesicles comprising of amphiphilic poly (lactic acid) (PLA) and Pluronic block copolymers (PEO-PPO-PEO) have been evaluated as an oral insulin carrier. The mean size of vesicles was 78 nm for PLA-F127-PLA and 165 nm for PLA-P85-PLA copolymer. The mean insulin entrapment efficiency was 59.6% for PLA-P85-PLA and 26.4% for PLA-F127-PLA. The in vitro release characteristics of insulin from vesicles exhibited an initial burst in the range of pH 1.2-7.4 dissolution mediums. The presence of PLA-Pluronic-PLA vesicles improved the stability of insulin in the gastrointestinal fluids than that of the phosphate buffer solution (PBS) of insulin. More importantly, the released insulin from the vesicles maintained their biological activity. The results from this studies demonstrated that biodegradable PLA-Pluronic-PLA can self-assemble with insulin, form insulin-encapsulated vesicles, and is good carrier materials for oral insulin/protein delivery.

A Hydrogen Peroxide Biosensor Based on Peroxidase Activity of Hemoglobin in Polymeric Film

2007 ◽  
Vol 7 (11) ◽  
pp. 4005-4008 ◽  
Author(s):  
A. K. M. Kafi ◽  
Dong-Yun Lee ◽  
Sang-Hyun Park ◽  
Young-Soo Kwon
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphate Buffer Solution ◽  
Amperometric Detection ◽  
Buffer Solution ◽  
Long Term Stability ◽  
Sensor Performance ◽  
Redox Peak ◽  
Relative Standard ◽  
Optimized Conditions

A Hydrogen peroxide (H2O2) biosensor, based on hemoglobin (Hb) and ortho-phenylenediamine (o-PD) gold electrode, was fabricated. Hb was immobilized onto the electrode surface by electrochemical polymerize method with o-PD. The designed biosensor showed a well defined redox peak which was attributed to the direct electrochemical response of Hb. The immobilized Hb exhibited an excellent electrocatalytical response to the reduction of hydrogen peroxide, enabling the sensitivity determination of H2O2. Factors and performances such as pH, potential, influencing the designed biosensor, were studied carefully. The amperometric detection of H2O2 was carried out at −300 mV in phosphate buffer solution (PBS) (0.1 M) with pH 6.0. This biosensor showed a fast amperometric response (less then 5 s) to H2O2. The levels of the (Relative standard deviation) RSDs (<3 5%) for the entire analyses reflected a highly reproducible sensor performance. Using the optimized conditions, the detection limit of the biosensor was 1 × 10−7 M and linear range was from 5 × 10−6 to 1.25 × 10−4 M. In addition, this sensor showed long term stability and good sensitivity.

scholarly journals Cellular Antioxidant Activity of Olive Pomace Extracts: Impact of Gastrointestinal Digestion and Cyclodextrin Encapsulation

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5027
Author(s):  
Kristina Radić ◽  
Ivana Vinković Vrček ◽  
Ivan Pavičić ◽  
Dubravka Vitali Čepo
Keyword(s):  
Matrix Effects ◽  
Cell Damage ◽  
Radical Scavenging ◽  
Raw Material ◽  
Protective Effects ◽  
Olive Pomace ◽  
Gastrointestinal Digestion ◽  
Polyphenolic Extract ◽  
Tert Butylhydroperoxide ◽  
Pre Treatment

Olive pomace is a valuable secondary raw material rich in polyphenols, left behind after the production of olive oil. The present study investigated the protective effect of a polyphenolic extract from olive pomace (OPE) on cell viability and antioxidant defense of cultured human HepG2 cells submitted to oxidative stress induced by tert-butylhydroperoxide (tBOOH). The investigation considered possible matrix effects, impact of gastrointestinal digestion and cyclodextrin (CD) encapsulation. Pre-treatment of cells with OPE prevented cell damage and increased intracellular glutathione but did not affect the activity of glutathione peroxidase and superoxide dismutase. OPE matrix significantly enhanced cell protective effects of major antioxidants, such as hydroxytyrosol (HTS), while cyclodextrin encapsulation enhanced activity of OPE against intracellular reactive oxygen species (ROS) accumulation. The obtained results show that OPE is more potent antioxidant in comparison to equivalent dose of main polyphenols (HTS and TS) and that increasing solubility of OPE polyphenols by CD encapsulation or digestion enhances their potential to act as intracellular antioxidants. Antioxidative protection of cells by OPE was primarily achieved through direct radical-scavenging/reducing actions rather than activation of endogenous defense systems in the cell.

scholarly journals Development of Hydrogen Peroxide Biosensor Based on Immobilization of Hemoglobin on Screen-Printed Carbon Electrode Modified With Silver Nanoparticles

2019 ◽  
pp. 2332-2340
Author(s):  
Ali Saad Elewi ◽  
Shatha Abdul Wadood ◽  
Abdul Kareem Mohammed Ali
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Electron Transfer ◽  
Direct Electron Transfer ◽  
Phosphate Buffer Solution ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Hydrogen Peroxide Biosensor ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

     The direct electron transfer behavior of hemoglobin that is immobilized onto screen-printed carbon electrode (SPCE) modified with silver nanoparticles (AgNPs) and chitosan (CS) was studied in this work. Cyclic voltametry and spectrophotometry were used to characterize the hemoglobin (Hb) bioconjunction with AgNPs and CS. Results of the modified electrode showed quasi-reversible redox peaks with a formal potential of (-0.245V) versus Ag/AgCl in 0.1M phosphate buffer solution (PBS), pH7, at a scan rate of 0.1Vs-1. The charge transfer coefficient (α) was 0.48 and the apparent electron transfer rate constant (Ks) was 0.47s-1. The electrode was used as a hydrogen peroxide biosensor with a linear response over 3 to 240 µM and a detection limit of 0.6 µM. As a result, the modified biosensor here has exhibited a high sensitivity, good reproducibility and stability.

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