Arabinan-rich pectic polysaccharide fraction from Malpighia emarginata fruits alleviates inflammatory pain in mice.

Malpighia emarginata (Malpighiaceae), popularly known as "acerola", is a tropical and subtropical fruit native to the Americas. Despite its high vitamin C content, which gives it a high antioxidant property, soluble dietary fibers, such as polysaccharides, are also abundant constituents of acerola (10% of the dried fruit). The acerola cold-water soluble (ACWS) fraction presented anti-fatigue and antioxidant effects in vivo and in vitro. To infer further systemic effects of ACWS, this study aimed to investigate the antinociceptive, anti-inflammatory, and antioxidant effects of ACWS in murine models of pain. In formalin-induced nociception, ACWS (0.1, 1, and 10 mg/kg) reduced only the inflammatory phase, and also (10 and 30 mg/kg) attenuated the acetic acid-induced writhing and leukocyte migration in the peritoneal cavity. The mechanical allodynia and paw edema induced by intraplantar injection of carrageenan were greatly reduced by ACWS (10 mg/kg). At the inflammatory pick induced by carrageenan (4 h), ACWS significantly reduced myeloperoxidase activity, TNF-α, IL-1ß, and PGE2 levels, and restored IL-10 levels. ACWS also exhibited antioxidant properties by decreasing lipid hydroperoxides content, increasing GSH levels, and restoring superoxide dismutase and catalase activities in the carrageenan model and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. Collectively, these results support the antinociceptive, anti-inflammatory, and antioxidant effects of ACWS and reveal a promising candidate for the treatment of inflammatory pain conditions.

PEDOT: PSS/AuNPs-Based Composite as Voltammetric Sensor for the Detection of Pirimicarb.

An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) and gold nanoparticles (AuNPs) to enhance electrochemical proprieties. Electrode characterizations were performed using scattering electron microscopy (SEM) and cyclic voltammetry (CV). With the SPCE/PEDOT:PSS/AuNPs modified electrode, a new peak at 1.0 V appeared in the presence of PMC related to the PMC oxidation. To elucidate the mechanism of PMC oxidation, Gas Chromatography-Mass Spectrometry (GC-MS), where two major peaks were identified, evidencing that the device can both detect and degrade PMC by an electro-oxidation process. Exploring this peak signal, it was possible the sensor development, performing detection from 93.81-750 µmol L-1, limits of quantification (LOQ) and detection (LOD) of 93.91 µmol L-1 and 28.34 µmol L-1, respectively. Thus, it was possible to study and optimization of PMC degradation, moreover, to perform detection at low concentrations and with good selectivity against different interferents using a low-cost printed electrode based on graphite modified with conductive polymer and AuNPs.

Preparation and Investigation of Thermally Annealed Zein-Propolis Electrospun Nanofibers for Biomedical Applications.

Zein, a corn-derived protein, has a variety of applications ranging from drug delivery to tissue engineering and wound healing. This work aims to develop a biocompatible scaffold for dermal applications based on thermally annealed electrospun propolis-loaded zein nanofibers. Pristine fibers' biocompatibility is determined in vitro. Next, propolis from Melipona quadrifasciata is added to the fibers at different concentrations (5% to 25%), and the scaffolds are studied. The physicochemical properties of zein/propolis precursor dispersions are evaluated and the results are correlated to the fibers' properties. Due to zein's and propolis' very favorable interactions, which are responsible for the increase in the dispersions surface tension, nanometric size ribbon-like fibers ranging from 420 to 575 nm are obtained. The fiber's hydrophobicity is not dependent on propolis concentration and increases with the annealing procedure. Propolis inhibitory concentration (IC50 ) is determined as 61.78 µg mL-1 . When loaded into fibers, propolis is gradually delivered to cells as Balb/3T3 fibroblasts and are able to adhere, grow, and interact with pristine and propolis-loaded fibers, and cytotoxicity is not observed. Therefore, the zein-propolis nanofibers are considered biocompatible and safe. The results are promising and provide prospects for the development of wound-healing nanofiber patches-one of propolis' main applications.

Polyvinyl alcohol-based hydrogel sorbent for extraction of parabens in human milk samples by in-tube SPME-LC-UV.

In this work, we developed an in-tube solid-phase microextraction (SPME) device consisting of a fused silica capillary modified with a polyvinyl alcohol (PVOH) hydrogel. Methylparaben, ethylparaben, propylparaben, and butylparaben were determined in human milk samples by using the in-tube SPME device coupled with liquid chromatography with spectrophotometric detection in the ultraviolet region (LC-UV). The inner surface of the fused silica capillary was silanized to allow covalent modification with the PVOH-hydrogel, using glutaraldehyde as cross-linking agent. The developed device was used up to 250 times with no reduction in the analytes' peak areas or carryover effect, besides having a low production cost. The human milk samples showed a significant matrix effect for parabens with higher logKo/w. Low limits of quantification (LLOQ) between 10.0 and 15.0 ng mL-1 were obtained with RSD values in the range of 1.18 to 18.3%. For the intra- and inter-day assays, RSD values from 5.6 to 16.5% and accuracy from 74.5 to 128.8% were achieved. The PVOH-based hydrogel sorbent allowed the use of water as desorption solvent, eliminating the use of organic solvents, which follows the principles of green chemistry. The results showed a great application potential of the PVOH-based hydrogel sorbent for the extraction of organic compounds from high-complexity samples.

Development of alginate beads with encapsulated jabuticaba peel and propolis extracts to achieve a new natural colorant antioxidant additive.

This work aims to encapsulate anthocyanins and phenolic compounds extracted from a native Brazilian fruit peel - jabuticaba (Plinia cauliflora (Mart.) Kausel) and propolis from Tubuna (Scaptotrigona bipunctata) stingless bees, with great potential benefits for human health. The alginate encapsulation was conducted by the ionotropic gelation through the dripping into the CaCl2 solution. Both raw extracts were characterized by TPC - total phenolic content (Folin-Ciocalteu), AA -antioxidant activity (DPPH and ABTS assays), and TMAC - total monomeric anthocyanin concentration (pH differential method); as well as their resultant mixture (2:1 jabuticaba/propolis). The obtained beads presented highly efficient encapsulation of total polyphenols (~98%) and monomeric anthocyanins (~89%), with spherical morphology and smooth surface obtaining a mean diameter between 200 and 250 µm. In vitro release study showed that JPE/alginate beads were completely disintegrated at pH 7.4 (intestinal pH), but they were resistant to gastric pH (1.2) presenting a slow release of about 40% in 240 min. This is the first report that encapsulates the mixture of jabuticaba and propolis extracts and may contribute to the utilization of a great source of bioactive compounds besides the potential pigment of anthocyanins, an alternative to natural and healthy food/beverage colorants.

Pharmacological potential of alkylamides from Acmella oleracea flowers and synthetic isobutylalkyl amide to treat inflammatory pain.

Acmella oleracea ("jambu") is an Amazonian plant rich in alkylamides. Its flowers are widely used in folk medicine to treat toothache due to tingling, numbness, and local anaesthesia caused in the mouth. Our group previously demonstrated that the intraplantar (i.pl.) injection of an alkylamide-rich hexane fraction (HF) obtained from jambu flowers and a synthetic isobutylalkyl amide (IBA) displayed antinociceptive and anesthetic effects in acute pain models. Thus, here we evaluated the effects of HF and IBA on carrageenan-induced acute inflammation. Mice were pretreated with HF or IBA (0.01, 0.1, and 1 µg/20 µL, i.pl.) 15 min before carrageenan injection (300 µg/20 µL, i.pl.). Mechanical allodynia and paw oedema were evaluated previously (basal) and at 0.5 until 6 h following carrageenan. Both HF and IBA at 0.1 µg promoted effective and long-lasting antiallodynic and anti-oedematogenic activities until 3 and 5 h, respectively, in comparison to the different doses evaluated. At the inflammatory peak, the plantar surfaces were excised for measurement of inflammatory and oxidative stress parameters. HF and IBA (0.1 µg) reduced the myeloperoxidase activity, TNF-α and IL-1ß levels, prevented the production of lipid hydroperoxides, and the decrease of antioxidant agents, namely superoxide dismutase and catalase activities, and glutathione contents. Furthermore, only HF maintained IL-10 levels and decreased PGE2 synthesis. On the basis of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, HF and IBA are devoid of antioxidant activity in vitro. Collectively, our results demonstrated the promising anti-inflammatory effect of local pretreatment with alkylamides, supporting the potential of these molecules to treat acute inflammatory pain conditions.

Potentiality of Epoxy-Montmorillonite Composite for Stir-Bar Sorptive Extraction for Determination of Atrazine

Abstract A new low-cost material is presented for the first time, aiming to study the sorption process for the stir-bar sorptive extraction (SBSE) technique. The bars were made using a composition of a commercial epoxy resin and montmorillonite, under different compositions and a final ratio of 70% (epoxy) and 30% (montmorillonite) was employed, providing the best mechanical and chemical resistance. A PTFE support was developed to hold the bars permitting the magnetic stirring, without turbulent behavior even under long times of stirring at 1000 rpm. The bars were employed to study the sorption of the herbicide atrazine (ATZ), and the best extraction conditions were: sample volume 20.0 mL, pH 6.0, extraction time of 15 min, room temperature, stirring speed of 100 rpm, and 10.0% (w v-1) NaCl. This preliminary evaluation suggests that the modified bars could be employed for ATZ sorption, affording close to 71% of ATZ removal, and presented robust characteristics to be used at least 80 times.

Distinct mechanisms underlying local antinociceptive and pronociceptive effects of natural alkylamides from Acmella oleracea compared to synthetic isobutylalkyl amide.

Acmella oleracea (jambu), is used as ingredient for food and in folk medicine to relief toothache. Jambu edible flowers are rich in alkylamides, mainly spilanthol, which are responsible to evoke chemesthetic sensations. This study aimed to investigate the local effects promoted by the intraplantar injection of the hexanic fraction (HF) rich in alkylamides from jambu flowers and compare to synthetic isobutylalkyl amide (IBA). Swiss male mice were intraplantarly administrated with HF and IBA (0.1-30 µg/20 µL), and the underlying mechanisms associated to the antinociceptive (0.1 µg) and pronociceptive (30 µg) effects were evaluated in chemical and sensorial tests. HF and IBA at 0.1 µg promoted analgesia in neurogenic and inflammatory phases of formalin test, against glutamate-induced nociception and independent of the activation of endogenous opioidergic system and dependent of TRPV1 modulation, whereas only HF reduced both nociception and mast cell degranulation in hindpaw induced by compound 48/80. However, both potentiated the TRPA1-mediated nociception. In contrast, HF and IBA (30 µg)-evoked nociceptive behaviors were reduced by the activation of opioidergic system, by TRPA1 antagonist and TRP nociceptive fibers desensitization. In addition, 30 µg IBA-evoked nociception by activation of TRPV1, and 30 µg HF by mast cell degranulation. Furthermore, on the contrary of IBA, HF elevated both mechanical and thermal paw threshold. Altogether, these results indicate that alkylamides could elicited dual effects, adding new evidences and mechanisms for these opposite actions in different doses. Although further research is needed, we confirmed that alkylamides displays local analgesic and/or anesthetic effects.

Cellulose membrane modified with polypyrrole as an extraction device for the determination of emerging contaminants in river water with gas chromatography-mass spectrometry.

In this study, a simple, efficient, and reusable device based on cellulose membranes modified with polypyrrole was developed to extract 14 emerging contaminants from aqueous matrices. For chemical polymerization, a low-cost cellulose membrane was immersed in 0.1 mol/L pyrrole and 0.5 mol/L ammonium persulfate for 40 min in an ice/water bath. The cellulose membranes modified with polypyrrole were accommodated in a polycarbonate holder suitable for solid-phase extraction disks. Solid-phase extraction parameters that affect extraction efficiency, such as sample volume, pH, flow rate, and desorption were optimized. Subsequently, determination of target compounds was performed by gas chromatography with mass spectrometry. The linear range for analytes ranged from 0.05 to 500 µg/L, with coefficients of determination above 0.990. The limits of quantification varied between 0.05 and 10 µg/L, with relative standard deviations lower than 17%. The performance of the proposed cellulose membranes modified with polypyrrole device for real samples was evaluated after extraction of emerging contaminants from a river water sample from the city of Curitiba, Brazil. Bisphenol A (6.39 µg/L), caffeine (17.83 µg/L), and paracetamol (19.28 µg/L) were found in these samples.

Evaluation of a Hollow-Fiber Liquid-Phase Microextraction Technique for the Simultaneous Determination of PPI Drugs in Human Plasma by LC-DAD.

This study involved the development, validation and application of a three-phase hollow-fiber liquid-phase microextraction (HF-LPME) and liquid chromatography with diode array detection (LC-DAD) method for the simultaneous determination of the proton pump inhibitor (PPI) drugs omeprazole, pantoprazole and lansoprazole in human plasma. The evaluation of the HF-LPME parameters was crucial for the determination of the drugs and the conditions selected were: 1-octanol as solvent; phosphate buffer at pH 5 as donor phase; borate buffer at pH 10 as acceptor phase; extraction time of 15 min; stirring at 750 rpm and NaCl was added at 5% (w/v). Validation of the method according to US-FDA recommendations showed a good linear range (0.2-2.0 µg/mL) for all analytes, with a determination coefficient >0.9910. Precision was evaluated using intra- and inter-day assays, which showed relative standard deviations (RSD), <15% for all concentrations, with a limit of quantification (LOQ) of 0.2 µg/mL. Accuracy was also assessed at these concentration levels and was in the range from 80 to 130%. Finally, the sensitive, selective and reproducible HF-LPME/LC-DAD developed method was successfully applied to human plasma samples from patients undergoing therapy with the PPI drugs.

Evaluation of comprehensive two-dimensional gas chromatography coupled to rapid scanning quadrupole mass spectrometry for quantitative analysis.

Comprehensive two-dimensional gas chromatography (GC×GC) is a powerful technique that provides excellent separation and identification of analytes in highly complex samples with considerable increase in GC peak capacities. However, since second dimension analyses are very fast, detectors with a rapid acquisition rate are required. Over the last years, quite a number of studies have discussed the potential and limitations of the combination GC×GC with a variety of quadrupole mass spectrometers. The present research focuses on the evaluation of qMS effectiveness at a 10,000-amu/s scan speed and 20-Hz scan frequency for the identification (full scan mode acquisition-TIC) and quantification (extracted ion chromatogram) of target pesticide residues in tomato samples. The following MS parameters have been evaluated: number of data points per peak, mass spectrum quality, peak skewing, and sensitivity. The validated proposed GC×GC/qMS method presented satisfactory results in terms of repeatability (coefficient of variation lower than 15%), accuracy (84-117%), and linearity (ranging from 25 to 500 ng/g), while significant enhancement in sensitivity was observed (a factor of around 10) under scan conditions.

Automated analysis of lidocaine and its metabolite in plasma by in-tube solid-phase microextraction coupled with LC-UV for pharmacokinetic study.

A sensitive, selective, and reproducible in-tube solid-phase microextraction and liquid chromatographic (in-tube SPME/LC-UV) method for determination of lidocaine and its metabolite monoethylglycinexylidide (MEGX) in human plasma has been developed, validated, and further applied to pharmacokinetic study in pregnant women with gestational diabetes mellitus (GDM) subjected to epidural anesthesia. Important factors in the optimization of in-tube SPME performance are discussed, including the draw/eject sample volume, draw/eject cycle number, draw/eject flow rate, sample pH, and influence of plasma proteins. The limits of quantification of the in-tube SPME/LC method were 50 ng/mL for both metabolite and lidocaine. The interday and intraday precision had coefficients of variation lower than 8%, and accuracy ranged from 95 to 117%. The response of the in-tube SPME/LC method for analytes was linear over a dynamic range from 50 to 5000 ng/mL, with correlation coefficients higher than 0.9976. The developed in-tube SPME/LC method was successfully used to analyze lidocaine and its metabolite in plasma samples from pregnant women with GDM subjected to epidural anesthesia for pharmacokinetic study.

Determination of fluoxetine and norfluoxetine enantiomers in human plasma by polypyrrole-coated capillary in-tube solid-phase microextraction coupled with liquid chromatography-fluorescence detection.

A sensitive, selective, and reproducible in-tube polypyrrole-coated capillary (PPY) solid-phase microextraction and liquid chromatographic method for fluoxetine and norfluoxetine enantiomers analysis in plasma samples has been developed, validated, and further applied to the analysis of plasma samples from elderly patients undergoing therapy with antidepressants. Important factors in the optimization of in-tube SPME efficiency are discussed, including the sample draw/eject volume, draw/eject cycle number, draw/eject flow-rate, sample pH, and influence of plasma proteins. Separation of the analytes was achieved with a Chiralcel OD-R column and a mobile phase consisting of potassium hexafluorophosphate 7.5mM and sodium phosphate 0.25M solution, pH 3.0, and acetonitrile (75:25, v/v) in the isocratic mode, at a flow rate of 1.0 mL/min. Detection was carried out by fluorescence absorbance at Ex/Em 230/290 nm. The multifunctional porous surface structure of the PPY-coated film provided high precision and accuracy for enantiomers. Compared with other commercial capillaries, PPY-coated capillary showed better extraction efficiency for all the analytes. The quantification limits of the proposed method were 10 ng/mL for R- and S-fluoxetine, and 15 ng/mL for R- and S-norfluoxetine, with a coefficient of variation lower than 13%. The response of the method for enantiomers is linear over a dynamic range, from the limit of quantification to 700 ng/mL, with correlation coefficients higher than 0.9940. The in-tube SPME/LC method can therefore be successfully used to analyze plasma samples from ageing patients undergoing therapy with fluoxetine.

In-tube solid-phase microextraction coupled to liquid chromatography (in-tube SPME/LC) analysis of nontricyclic antidepressants in human plasma.

A sensitive, selective, and reproducible in-tube solid-phase microextraction and liquid chromatographic (in-tube SPME/LC-UV) method for simultaneous determination of mirtazapine, citalopram, paroxetine, duloxetine, fluoxetine, and sertraline in human plasma was developed, validated and further applied to the analysis of plasma samples from elderly patients undergoing therapy with antidepressants. Important factors in the optimization of in-tube SPME efficiency are discussed, including the sample draw/eject volume, draw/eject cycle number, draw/eject flow-rate, sample pH, and influence of plasma proteins. The quantification limits of the in-tube SPME/LC method varied between 20 and 50ng/mL, with a coefficient of variation lower than 10%. The response of the in-tube SPME/LC method for most of the drugs was linear over a dynamic range from 50 to 500ng/mL, with correlation coefficients higher than 0.9985. The in-tube SPME/LC can be successfully used to analyze plasma samples from ageing patients undergoing therapy with nontricyclic antidepressants.