Antioxidant and antimicrobial emulsions with amphiphilic olive extract, nanocellulose-stabilized thyme oil and common salts for active paper-based packaging.

Anionic cellulose nanofibers (CNFs) were used to stabilize emulsions that combined water-soluble (and oil-soluble), strongly antioxidant extracts with a water-immiscible, notably antimicrobial essential oil. Specifically, the radical scavenging activity was primarily provided by aqueous extracts from olive fruit (Olea europaea L.), while the antimicrobial effects owed eminently to thyme oil (Thymus vulgaris L.). The resulting emulsions were highly viscous at low shear rate (4.4 Pa·s) and displayed yield stress. The addition of edible salts decreased the yield stress, the apparent viscosity and the droplet size, to the detriment of stability at ionic strengths above 50 mM. Once characterized, the antioxidant and antimicrobial emulsions were applied on packaging-grade paper. Coated paper sheets inhibited the growth of Listeria monocytogenes, a common foodborne pathogen, and acted as antioxidant emitters. In this sense, the release to food simulants A (ethanol 10 vol%), B (acetic acid 3 wt%), and C (ethanol 20 vol%) was assessed. A 24-hour exposure of 0.01 m2 of coated paper to 0.1 L of these hydrophilic simulants achieved inhibition levels of the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) in the 15-29 % range. All considered, the bioactive properties of thyme essential oil towards lipophilic food products can be complemented with the antioxidant activity of aqueous olive extracts towards hydrophilic systems, resulting in a versatile combination for active food packaging.

Natural polyphenolic coffee extract administration relieves chronic nociplastic pain in a reserpine-induced fibromyalgia-like female mouse model.

INTRODUCTION: Nociplastic pain involves reflexive and nonreflexive pain responses and it is a core symptom of fibromyalgia (FM). The increasing prevalence of this health condition and the low rates of patients' quality of life, combined with the lack of suitable pharmacologic treatments, evidence the demand to research new alternatives. Polyphenols may be potential therapeutic candidates as they have been reported to exert pathological pain modulation in preclinical models. In that context, this work was aimed to study the antinociceptive effects of a polyphenolic extract obtained from decaffeinated ground roasted coffee, in the RIM6 FM-like mouse model. METHODS: To this end, RIM6 adult ICR-CD1 female mice were administered daily once a week with either 10 or 15 mg/kg of extract, and reflexive pain responses were evaluated for up to 3 weeks. At the end, the depressive-like behavior was assessed as a nonreflexive pain response, and spinal cord and serum samples were collected for immunohistochemical and toxicological analyses. RESULTS: These findings showed that the repeated administration of the coffee polyphenolic extract (CE) modulated reflexive pain responses, depressive-like behavior, and spinal cord gliosis in a dose-dependent manner, without signs of systemic toxicity. CONCLUSION: Thus, the CE may be a potential pharmacological treatment suitable to relieve nociplastic pain responses characteristic of FM.

Pickering emulsions of thyme oil in water using oxidized cellulose nanofibers: Towards bio-based active packaging.

The antioxidant and antimicrobial properties of thyme essential oil (TEO) are useful for active food packaging, but its poor aqueous solubility restricts its applications. This work involves anionic cellulose nanofibers (CNFs) as the sole stabilizing agent for TEO-in-water emulsions, with oil concentrations ranging from 10 mL/L to 300 mL/L. A double mechanism was proposed: the adsorption of CNFs at oil/water interfaces restricted coalescence to a limited extent, while thickening (rheological stabilization) was required to avoid the buoyance of large droplets (>10 µm). Thickening effects comprised both higher viscosity (over 0.1 Pa·s at 10 s-1) and yield stress (approximately 0.9 Pa). Dilute emulsions had good film-forming capabilities, whereas concentrated emulsions were suitable for paper coating. Regarding antimicrobial activity, CNF-stabilized TEO-in-water emulsions successfully inhibited the growth of both Gram-negative (E. coli, S. typhimurium) and Gram-positive bacteria (L. monocytogenes). As for the antioxidant properties, approximately 50 mg of paper or 3-5 mg of film per mL of food simulant D1 were required to attain 50 % inhibition in radical scavenging tests. Nonetheless, despite the stability and the active properties of these bio-based hydrocolloids, providing this antioxidant and antimicrobial activity was incompatible with maintaining the organoleptic properties of the foodstuff unaltered.

Central Neuropathic Pain Development Modulation Using Coffee Extract Major Polyphenolic Compounds in Spinal-Cord-Injured Female Mice.

It was recently shown that coffee polyphenolic extract exerts preventive effects on central neuropathic pain development, but it is unknown whether its beneficial effects are associated with only one of its major polyphenolic compounds or if the whole extract is needed to exert such effects. The main objective of this study was to determine whether the separate administration of major polyphenols from coffee extract exerts preventive effects on the development of central neuropathic pain in mice compared with the effects of the whole coffee extract. Thus, spinal-cord-injured female ICR-CD1 mice were daily treated with either coffee extract or its major polyphenolic compounds during the first week, and reflexive and nonreflexive pain responses were evaluated within the acute phase of spinal cord injury. In addition, the injury-induced gliosis and dorsal horn sprouting were evaluated with immunohistochemistry. The results showed that the coffee extract prevented spinal cord injury-induced neuropathic pain, whereas its major polyphenolic compounds resulted in reflexive pain response attenuation. Both preventive and attenuation effects were associated with gliosis and afferent fiber sprouting modulation. Overall, the results suggested that coffee extract effects may be associated with potential synergistic mechanisms exerted by its major polyphenolic compounds and not by the sole effect of only one of them.

Polyphenolic grape stalk and coffee extracts attenuate spinal cord injury-induced neuropathic pain development in ICR-CD1 female mice.

More than half of spinal cord injury (SCI) patients develop central neuropathic pain (CNP), which is largely refractory to current treatments. Considering the preclinical evidence showing that polyphenolic compounds may exert antinociceptive effects, the present work aimed to study preventive effects on SCI-induced CNP development by repeated administration of two vegetal polyphenolic extracts: grape stalk extract (GSE) and coffee extract (CE). Thermal hyperalgesia and mechanical allodynia were evaluated at 7, 14 and 21 days postinjury. Then, gliosis, ERK phosphorylation and the expression of CCL2 and CX3CL1 chemokines and their receptors, CCR2 and CX3CR1, were analyzed in the spinal cord. Gliosis and CX3CL1/CX3CR1 expression were also analyzed in the anterior cingulate cortex (ACC) and periaqueductal gray matter (PAG) since they are supraspinal structures involved in pain perception and modulation. GSE and CE treatments modulated pain behaviors accompanied by reduced gliosis in the spinal cord and both treatments modulated neuron-glia crosstalk-related biomolecules expression. Moreover, both extracts attenuated astrogliosis in the ACC and PAG as well as microgliosis in the ACC with an increased M2 subpopulation of microglial cells in the PAG. Finally, GSE and CE prevented CX3CL1/CX3CR1 upregulation in the PAG, and modulated their expression in ACC. These findings suggest that repeated administrations of either GSE or CE after SCI may be suitable pharmacologic strategies to attenuate SCI-induced CNP development by means of spinal and supraspinal neuroinflammation modulation.

Green Synthesis of Ag Nanoparticles Using Grape Stalk Waste Extract for the Modification of Screen-Printed Electrodes.

The chemical synthesis of silver nanoparticles (Ag-NPs) by using an environmentally friendly methodology for their preparation is presented. Thus, considering that plants possess components that can act as reducing agents and stabilizers in nanoparticles' production, the synthesis of Ag-NPs by using an extract aqueous solution of grape stalk waste as a reducing and capping agent is studied. First, the total polyphenols and reducing sugars contained in the produced extracts at different conditions are characterized. After that, Ag-NPs are synthesized regarding the interaction of Ag ions (from silver nitrate) and the grape stalk extract. The effect of temperature, contact time, extract/metal solution volume ratio and pH solution in the synthesis of metal nanoparticles are also studied. Different sets of nanoparticle samples are characterized by means of Electron Microscopy coupled with Energy Dispersive X-Ray for qualitative chemical identification. Ag-NPs with an average diameter of 27.7 ± 0.6 nm are selected to proof their suitability for sensing purposes. Finally, screen-printed electrodes modified with Ag-NPs are tested for the simultaneous stripping voltammetric determination of Pb(II) and Cd(II). Results indicate good reproducibility, sensitivity and limits of detection around 2.7 µg L-1 for both metal ions.

Removal of lead(II) and cadmium(II) from aqueous solutions using grape stalk waste.

The sorption of lead and cadmium from aqueous solutions by grape stalk waste (a by-product of wine production) was investigated. The effects of the contact time, pH of the solution, ionic medium, initial metal concentration, other metal ions present and ligands were studied in batch experiments at 20 degrees C. Maximum sorption for both metals was found to occur at an initial pH of around 5.5. The equilibrium process was described well by the Langmuir isotherm model, with maximum grape stalk sorption capacities of 0.241 and 0.248 mmol g(-1) for Pb(II) and Cd(II), respectively, at pH around 5.5. Kinetic studies showed good correlation coefficients for a pseudo-second-order kinetic model. The presence of NaCl and NaClO(4) in the solution caused a reduction in Pb and Cd sorption, the latter being more strongly suppressed. The presence of other metals in the uptake process did not affect the removal of Pb, while the Cd uptake was much reduced. HCl or EDTA solutions were able to desorb lead from the grape stalks completely, while an approximately 65% desorption yield was obtained for cadmium. From the results obtained it seems that other mechanisms, such as surface complexation and electrostatic interactions, must be involved in the metal sorption in addition to ion exchange.

Removal of copper and nickel ions from aqueous solutions by grape stalks wastes.

In the present work, the usefulness of grape stalks wastes generated in the wine production process has been investigated for the removal of copper and nickel ions from aqueous solutions. The sorption process was relatively fast and equilibrium was reached after about 60 min of contact. The influence of pH, sodium chloride and metal concentration on metal removal has been studied. Uptake showed a pH-dependent profile. Maximum sorption for both metals was found to occur at around pH 5.5-6.0. An increase of sodium chloride concentration caused a decrease in metal removal. Langmuir isotherms, at pH 6.0, for each metal were used to describe sorption equilibrium data. Maximum uptake obtained was 1.59x10(-4) mol of copper and 1.81x10(-4) mol of nickel per gram of dry sorbent. Sorption of copper and nickel on grape stalks released an equivalent amount of alkaline and alkaline earth metals (K+, Mg2+, Ca2+) and protons, indicating that ionic exchange is predominantly responsible for metal ion uptake. Fourier transform infrared (FTIR) spectrometry analysis indicated that lignin C-O bond might be involved in metal uptake. Equilibrium batch sorption studies were also performed using a two metal system containing (Cu(II)+Ni(II)). In the evaluation of the two metal sorption system performance, single isotherm curves had to be replaced by three-dimensional sorption isotherm surface. In order to describe the isotherm surface mathematically, the extended-Langmuir model was used. Nickel was found to be much more sensitive to the presence of copper than copper is to the presence of nickel.