In vitro and in vivo antioxidant properties of the plant-based supplement greens+™

Dietary antioxidants play an important role against oxidation, an underlying mechanism in the incidence of chronic diseases. Greens+ is a commercially available preparation containing a variety of plant-derived ingredients. The aim of the current study was to evaluate the antioxidant potential of the methanolic extract of greens+ powder using in vitro and in vivo techniques. In vitro studies were conducted using a liposome model system to simulate biological cell membranes. Total antioxidant potential and polyphenol content of the herbal preparation was measured. For in vivo analysis, 10 healthy human subjects consumed either three or six teaspoons of greens+ per day for four weeks. Blood samples were analyzed at baseline and at the conclusion of the treatment period for total antioxidant capacity, polyphenol content, protein, lipid and LDL oxidation, and the level of glutathione peroxidase. Results showed that greens+ supplementation was well tolerated and increased serum antioxidant potential at higher levels of intake in a dose-dependent manner. HPLC analysis showed the presence of quercetin, apigenin, kaempferol and luteolin in the supplement. Plasma analysis indicated the presence of kaempferol only. A statistically significant (p < 0.05) reduction in protein and lipid oxidation was observed. Based on its antioxidant properties, the results suggest that greens+ might play a role in reducing the risk of chronic diseases involving a burden of oxidative damage.     

In vitro and in vivo antitumor study of folic acid-conjugated carboxymethyl chitosan and phenylboronic acid–based nanoparticles

Folic acid-modified carboxymethyl chitosan was polymerized with N-3-acrylamidophenylboronic acid monomer to prepare tumor-targeting nanoparticles (NPs). Nanoparticles’ size was characterized by dynamic light scattering, while the micromorphology was observed through transmission electron microscopy (TEM) and scanning electronic microscope (SEM). Doxorubicin was then loaded into prepared nanoparticles. The cellular uptake of these NPs was investigated in monolayer cell model and multicellular spheroids. The results revealed that FA-modified nanoparticles possess excellent ability of accumulation and penetration in 2D and 3D cell models. It was also found that these nanoparticles enhanced drug accumulation in tumor, which finally increased antitumor efficiency in H22 tumor-bearing mice.     

Porous β-Ca2SiO4 ceramic scaffolds for bone tissue engineering: In vitro and in vivo characterization

The biodegradable ceramic scaffolds with desirable pore size, porosity and mechanical properties play a crucial role in bone tissue engineering and bone transplantation. A novel porous β-dicalcium silicate (β-Ca₂SiO₄) ceramic scaffold was prepared by sintering the green body consisting of CaCO₃ and SiO₂ at 1300 °C, which generated interconnected pore network with proper pore size of about 300 μm and high compressive strength (28.13±5.37–10.36±0.83 MPa) following the porosity from 53.54±5.37% to 71.44±0.83%. Porous β-Ca₂SiO₄ ceramic scaffolds displayed a good biocompatibility, since human osteoblast-like MG-63 cells and goat bone mesenchymal stem cells (BMSCs) proliferated continuously on the scaffolds after 7 d culture. The porous β-Ca₂SiO₄ ceramic scaffolds revealed well apatite-forming ability when incubated in the simulated body fluid (SBF). According to the histological test, the degradation of porous β-Ca₂SiO₄ ceramic scaffolds and the new bone tissue generation in vivo were observed following 9 weeks implantation in nude mice. These results suggested that the porous β-Ca₂SiO₄ ceramic scaffolds could be potentially applied in bone tissue engineering.     

Preparation of Titanocene–Gold Compounds Based on Highly Active Gold(I)-N-Heterocyclic Carbene Anticancer Agents: Preliminary in vitro Studies in Renal and Prostate Cancer Cell Lines

Heterometallic titanocene-based compounds containing gold(I)-phosphane fragments have been extremely successful against renal cancer in vitro and in vivo. The exchange of phosphane by N-heterocyclic carbene ligands to improve or modulate their pharmacological profile afforded bimetallic complexes effective against prostate cancer, but less effective against renal cancer in vitro. Herein we report the synthesis of new bimetallic Ti–Au compounds by the incorporation of two previously reported highly active gold(I)-N-heterocyclic carbene fragments derived from 4,5-diarylimidazoles. The two new compounds [(η⁵-C₅H₅)₂TiMe(μ-mba)Au(NHC)] (where NHC=1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene, NHC-Bn 2 a ; or 1,3-diethyl-4,5-diphenylimidazol-2-ylidene, NHC-Et 2 b ) with the dual linker (-OC(O)-p-C₆H₄-S-) containing both a carboxylate and a thiolate group were evaluated in vitro against renal and prostate cancer cell lines. The compounds were found to be more cytotoxic than previously described Ti–Au compounds containing non-optimized gold(I)-N-heterocyclic fragments. We present studies to evaluate their effects on cell death pathways, migration, inhibition of thioredoxin reductase (TrxR) and vascular endothelial growth factor (VEGF) in the PC3 prostate cancer cell line. The results show that the incorporation of a second metallic fragment such as titanocene into biologically active gold(I) compounds improves their pharmacological profile.     

Analysis of Protein–Protein Interactions in MCF-7 and MDA-MB-231 Cell Lines Using Phthalic Acid Chemical Probes

Phthalates are a class of plasticizers that have been characterized as endocrine disrupters, and are associated with genital diseases, cardiotoxicity, hepatotoxicity, and nephrotoxicity in the GeneOntology gene/protein database. In this study, we synthesized phthalic acid chemical probes and demonstrated differing protein–protein interactions between MCF-7 cells and MDA-MB-231 breast cancer cell lines. Phthalic acid chemical probes were synthesized using silicon dioxide particle carriers, which were modified using the silanized linker 3-aminopropyl triethoxyslane (APTES). Incubation with cell lysates from breast cancer cell lines revealed interactions between phthalic acid and cellular proteins in MCF-7 and MDA-MB-231 cells. Subsequent proteomics analyses indicated 22 phthalic acid-binding proteins in both cell types, including heat shock cognate 71-kDa protein, ATP synthase subunit beta, and heat shock protein HSP 90-beta. In addition, 21 MCF-7-specific and 32 MDA-MB-231 specific phthalic acid-binding proteins were identified, including related proteasome proteins, heat shock 70-kDa protein, and NADPH dehydrogenase and ribosomal correlated proteins, ras-related proteins, and members of the heat shock protein family, respectively.     

Photocatalytic Degradation of Phenol and Methyl Orange with Titania-Based Photocatalysts Synthesized by Various Methods in Comparison with ZnO–Graphene Oxide Composite

Topics in Catalysis - Photocatalysis is one of the effective methods to treat wastewater and degrade pollutants. Titania (TiO2) is usually chosen based on its superior properties and its high...     

Enzyme-based fluorometric biosensor-based on coffee waste-derived carbon dots modified with APBA and NADP+ cofactor for selective dual detection of γ-aminobutyric acid in in vitro and in vivo models

An enzyme-based fluorescent sensor was developed by adapting carbon dots derived from coffee waste to detect inhibitory neurotransmitters such as γ-aminobutyric acid (GABA). In this study, CDs were synthesized from biomass-derived coffee waste by the facile hydrothermal reaction (i.e., C-CDs). A C-CDs-based enzyme-based sensor was then developed using 3-aminophenyl boronic acid (APBA) and nicotinamide adenine dinucleotide phosphate (NADP⁺) cofactors (i.e., C-CANs). As a result of the addition of the GABase enzyme, the resulting blue-fluorescent C-CANs were effective in detecting GABA. This sensor is capable of sensing GABA in the range of 0–20 μM with a detection limit of 95.09 nM. A distinguished fluorescence quenching was observed in human neuroblastoma (SH-SY5Y) cells where probe (C-CANs-GABase) was able to detect GABA intracellularly. Zebrafish larvae were used to study the sensing potentials of the developed probe against GABA at different concentrations (10 and 20 μM). A validation study was conducted on real samples such as human serum, which showed high recovery values between 97 and 105.6%.     

A Comparison of Catalytic Properties of Cs x H3−x PW12O40 Salts of Various Cesium Contents in Gas Phase and Liquid Phase Reactions

The cesium salts Cs _x H_3?x PW₁₂O₄₀ of Cs content x = 2 up to x = 3 were tested as the catalysts in the gas and liquid phase reactions. Dehydration of ethanol and transesterification of triglycerides with methanol were selected as the catalytic reactions. Apart from the standard preparation, the catalysts were prepared by two-stage procedure with methanol or water as a solvent. The Cs-salts were characterized by FT-IR, XRD, scanning electron microscopy and energy dispersive X-ray techniques. In turn, the influence of Cs-salts composition on the pH and conductivity of their aqueous colloidal solutions was investigated. The results obtained by the latter techniques were also characteristic for acidity of surface layer of colloidal particles because of surface layer-solution equilibrium. It has been shown that the secondary structure of acidic cesium salts existing in crystalline samples (solid solution of H₃PW₁₂O₄₀ in Cs₃PW₁₂O₄₀) changes after contacting with polar medium to the system consisting most probably of Cs₃PW₁₂O₄₀ core with epitaxial layer of heteropolyacid. This is result of the protons migration from bulk to surface layer of primary particles enhanced by polar medium. It strongly influences the surface acidity of primary particles as well as the activity of Cs-salts in transesterification of triglycerides with methanol. In such polar medium, Cs₂HPW₁₂O₄₀ salt becomes the most active catalyst, more active than Cs_2.5H_0.5PW₁₂O₄₀. An accumulation of partial glycerides and in particular glycerol on the surface of primary particles of Cs-salts resulted in relatively low maximum conversion of triglycerides, most probably due to partial blockage of the catalytic centers. This effect and the almost constant activity of Cs-salts under recycling use in the transesterification experiments are considered to be experimental evidences that methanolysis over Cs-salts was accomplished with the participation of surface protons.     

Enhanced gastric retention and drug release via development of novel floating microspheres based on Eudragit E100 and polycaprolactone: synthesis and in vitro evaluation

Eudragit E 100 and polycaprolactone (PCL) floating microspheres for enhanced gastric retention and drug release were successfully prepared by oil in water solvent evaporation method. Metronidazole benzoate, an anti-protozoal drug, was used as a model drug. Polyvinyl alcohol was used as an emulsifier. The prepared microspheres were observed for % recovery, % degree of hydration, % water uptake, % drug loading, % buoyancy and % drug release. The physico-chemical properties of the microspheres were studied by calculating encapsulation efficiency of microspheres and drug release kinetics. Drug release characteristics of microspheres were studied in simulated gastric fluid and simulated intestinal fluid i.e., at pH 1.2 and 7.4 respectively. Fourier transform infrared spectroscopy was used to reveal the chemical interaction between drug and polymers. Scanning electron microscopy was conducted to study the morphology of the synthesized microspheres.     

In Situ Synthesis of Silver Nanoparticles in Novel L-Phenylalanine Based Poly(Amide-Benzimidazole-imide) Matrix Through Metal Complexation Method Using N,N′-Dimethylformamide as a Reaction Medium and Reducing Agent

Silver nanoparticles were obtained in novel optically active poly(amide-benzimidazole-imide) (PABI) matrix through an in situ procedure. Chiral PABI was prepared by polycondensation of amino acid based diacid and benzimidazole containing diamine in the presence of molten tetrabutylammonium bromide. Synthesized PABI was characterized by several techniques, including Fourier transform infrared spectra, ¹H-NMR, elemental analysis, X-ray diffraction, thermogravimetric analysis and field emission scanning electron microscopy (FE-SEM). Then, PABI/Ag nanocomposite was fabricated based on metal complexation route for preparing silver nanoparticles in the PABI matrix and was characterized by various techniques. Microscopic images revealed good dispersion of Ag nanoparticles in the polymer matrix.     

Stereo-Preference in the Degradation of the Erythro and Threo Isomers of β‐O‐4‐Type Lignin Model Compounds in Oxidation Processes: Part 1: In the Reaction with Active Oxygen Species Under Oxygen Delignification Conditions

We examined whether or not active oxygen species (AOS) stereo-preferentially attack the erythro or threo isomer of non-phenolic β-O-4 -type lignin model compounds under oxygen delignification conditions. When AOS were generated in situ by the reaction between O₂ and co-existing 4-hydroxy-3-methoxybenzyl alcohol (vanillyl alcohol), the obtained results could be explained on the basis of the hypothesis that an electrostatic repulsion exists between the negatively charged oxyl anion radical and the side-chain of the erythro isomer carrying the α-alkoxide anion. This repulsion prevents the reaction between the two species and, consequently, the erythro isomer is degraded less than the threo isomer. When 2,4,6-trimethylphenol (TMPh) was used to generate AOS, the reverse stereo-preference was observed. This reversal could be attributed to the neutral nature of a peroxyl radical that is an important AOS in the TMPh system and can attack the side-chain of the erythro isomer carrying the negatively charged α-alkoxide anion.