This study aimed to evaluate the antibacterial and antibiofilm activity of a P. peruviana calyx extract. Goldenberry calyx extracts were prepared with 60% (v/v) ethanol. Minimum inhibitory concentration (MIC) analyses were performed by the 96-well plate microdilution method together with the minimum bactericidal concentration (MBC). Biofilm inhibition and destruction was performed in microdilution plates. The P. peruviana calyx extract presented antibacterial activity against the pathogens analyzed (Enterobacter aerogenes ATCC 13048, Klebsiella pneumoniae ATCC 1705, Staphylococcus epidermidis (clinical isolate), Streptococcus pneumoniae ATCC 99619, Pseudomonas aeruginosa PA01, Enterococcus faecalis ATCC 29212, Escherichia coli (clinical isolate), Shigella sonnei (clinical isolate), Acinetobacter baumannii ATCC 19606, Streptococcus agalactie (clinical isolate), Acinetobacter baumannii (clinical isolate), Salmonella sp. (clinical isolate), Salmonella enteritidis (clinical isolate), and Staphylococcus aureus (clinical isolate)). MIC varied from 3.15 to 30 mg/mL extract and showed bacteriostatic activity against eight pathogens and bactericidal activity at 30 mg/mL concentration against six strains. Biofilm tests revealed biofilm formation inhibition, although there was no destruction. According to these results, the potential antibacterial activity of P. peruviana calyx extract was verified. This will enable further studies to be carried out to contribute to its use in the food industry as a preservative of natural origin and other clinical applications.
ABSTRACT: This study produced pectin microcapsules containing Lactobacillus acidophilus by external ionic gelation, followed by the adsorption of whey protein and pectin to form multilayers. The viability of free and microencapsulated lactobacilli was evaluated after in vitro exposure to gastrointestinal conditions. They were also assessed by heat treatment, and stability was examined at -18 °C, 5 °C and 25 °C for 120 days. Exposure to different pHs, simulating passage through the gastrointestinal tract, showed that treatment of the microcapsules with only pectin (LA/P0) and with one and two layers of whey protein (treatments LA/P1 and LA/P3, respectively), were able to protect Lactobacillus acidophilus , with microcapsules increasing the release of probiotics from the stomach into the intestines. Free cells showed a decrease in their counts over the course of the simulated gastrointestinal system. Regarding heat treatments, microcapsules with a layer of whey protein (LA/P1) maintained the viability of their encapsulated Lactobacillus acidophilus (9.57 log CFU/g-1). The best storage viability was at -18 °C, with a count of 7.86 log CFU/g-1at 120 days for microcapsule LA/P1,with those consisting of two layers of whey protein (LA/P3)having a 6.55 log CFU/g-1 at 105 days. This study indicated that external ionic gelation was effective and could be used for the production of pectin microcapsules, with multilayer whey protein promoting greater protection and viability of Lactobacillus acidophilus.
Nanotechnology is increasingly used in food science, and one of the lines of research is the nanoencapsulation of bioactive compounds. While these compounds promote improvements in human health, they are often improperly absorbed. Thus, nanostructured systems improve several characteristics, such as protection against degradation, solubility, stability, and bioavailability, among others. However, the development of nanostructures faces many challenges, from choosing the best method to obtain them to identifying the type of nanomaterial ideal for a bioactive compound of interest. In addition, the characterization of toxicological effects is sought by specific regulation for safety in human consumption and the environment, such as the use of green synthesis.
The aim of this study was to develop and evaluate the physicochemical and antioxidant stability of nanoemulsions containing a Physalis peruviana calyx extract (CPp-NE) and free extracts under different storage conditions (7 and 25 degrees C) and with absence or incidence of light for 120 days. The calyx extracts were prepared with ethanol 60% and characterized for later preparation of the nanoemulsions by spontaneous emulsification. The formulations presented nanometric sizes, low polydispersity index, negative zeta potential, acid pH, rutin content (11 mu g.mL(-1)), and encapsulation efficiency of 85%. Regarding the stability, the droplet size and PdI of the CPp-NE stored at refrigeration temperature in the dark, room temperature in the dark, and refrigeration temperature with light incidence were stable for 120 days and with no visible changes in the formulations. The antioxidant capacity was related to the reducing capacity, and the best results were found for nanoemulsions stored at room temperature and in absence of light. In addition, CPp-NE presented higher antioxidant and reducing capacity in relation to the free extracts.
ABSTRACT: Oil-in-water (O/W) nanoemulsion containing goldenberry extract was elaborated using a high-energy ultrasonic bath method. Physicochemical characterization of the formulation was carried out by determining pH, mean droplet diameter, polydispersity index (PDI) and zeta potential. Nanoemulsion toxicity was assessed using in vitro assays with tumor and non-tumor cell lines, and in vivo using Caenorhabditis elegans. The pH of the nanoemulsion was 3.84, the mean droplet diameter was 268 ± 7 nm, PDI 0.113 and zeta potential -13.94 mV. Results of the cytotoxicity assays employing non-tumor cells indicated that the extract associated or not with nanoemulsion maintained cell viability at different concentrations tested. In the assays using tumor lineage, it is observed that the nanoemulsion containing the extract had higher antitumor activity than the free extract. As for the in vivo tests, there was no change in the survival rate of the worms.
The aim of this study was to investigate the influence of hi-maize, inulin, and rice bran in the survival of Lactobacillus acidophilus LA-5 in pectin microparticles obtained by internal gelation and subjected to freeze-drying. For this, the development of a matrix capable of extending Lactobacillus acidophilus viability to develop new functional foods was emphasized. Microparticle size, encapsulation efficiency, probiotic survivability after gastrointestinal simulation, and storage stability were analyzed. The pectin + inulin encapsulation matrix presented the highest encapsulation efficiency (68.1%) compared to the other treatments. Microparticle sizes ranged from 166 +/- 2 mu m (pectin + hi-maize) to 345 +/- 9 mu m (pectin + inulin). The microparticles added from the different prebiotics showed better microorganism protection when compared to treatment without prebiotics, which presented greater viability in the gastrointestinal simulation. Under storage conditions of 25 degrees C and 18 degrees C, the microparticles containing hi-maize, inulin, and rice bran maintained the probiotic microorganisms viable for longer periods than the pectin microparticles. At 7 degrees C, the pectin + rice bran treatment stood out from the other treatments, as it was able to maintain probiotic stability during 120 days of storage.
Background: Daptomycin (DPT) is the first lipopeptide antibiotic available for commercialization, approved by FDA in 2003 and not included in any official compendia. Introduction: A simple capillary zone electrophoresis method (CZE) to assay DPT injection was developed according to international guidelines. Methods: The method employed a 15 mmol L-1 pH 8.0 phosphate buffer and acetonitrile (85:15) as background electrolyte, with a voltage of 27 kV, hydrodynamic injection (50 mBar/5 s), and detection at 223 nm. The separation was achieved in a fused silica capillary with 40 cm of effective length, at 22 degrees C, and acetylsalicylic acid was used as internal standard. The specificity was evaluated through a stress test combined with the PDA detector. As a result, the method was specific, even in the presence of degradation products. Detection was assessed around 5.5 min and the method was linear in the range of 20-120 mu g mL(-1) (r=0.9989). Results: The results also indicated the precision (RSD values of repeatability and intermediate precision < 2%), and accuracy (mean recovery of 101.26%) of the method. By a full factorial design 2(3), it was observed that none of the single factors or the combination of them affected the DPT assay, confirming the method robust. Conclusion: The method proved to be suitable to determine daptomycin injection, in quality control routine assays or in stability studies, and represents an environmentally friendly method.
Microcapsules containing B. lactis were produced by complex coacervation in gelatin and gum Arabic followed by freeze drying and characterized by optical microscopy and scanning electron microscopy, as well as the resistance of probiotics to the in-vitro release in the simulated gastrointestinal tract and storage under different temperature conditions. Therefore, it formed microcapsules with high encapsulation efficiency (86.04% and 99.52%) and size between 100.12 and 203.32 mu m. In addition, microencapsulated probiotics, both in wet and dry forms, maintained viability against the simulated gastrointestinal conditions. Finally, complex coacervation method was also efficient in maintaining the viability of probiotics during storage at temperatures of -18 degrees C for 120 days, 7 degrees C for 120 days and 25 degrees C for 90 days. Thus, our results demonstrated that complex coacervation method is an appropriate alternative to increase the viability of probiotics.
ABSTRACT: The high intensity ultrasound-assisted extraction (HIU) is one of the most simple, quick and efficient techniques for the extraction of phenolic and other antioxidant compounds from plants. This is the first application of HIU for the extraction of these compounds from goldenberry fruit. The HIU and conventional extraction techniques showed similar results regarding to phenolic compounds and antioxidant capacity. However, the time required for HIU extraction (5min) was 24 times lower than conventional extraction (120min). Phenolic compounds reported were chlorogenic acid, caffeic acid and rutin. In vitro cytotoxicity assays were used for evaluation of extracts and the results showed that in a wide range of concentration, the extract maintains cell viability, thus indicating the possibility to use it as food with safety.
ABSTRACT: Lactobacillus acidophillus La-5 (ML) and Bifidobacterium Bb-12 (MB) microparticles were produced at different temperatures by spray dryer. The influence of different temperatures on the viability, encapsulation efficiency, water activity and moisture were evaluated. Microparticles that presented more viability were submitted to thermal resistance, gastrointestinal simulation, storage stability, morphology and particle size analyses. Drying temperature of 130°C showed higher encapsulation efficiency, 84.61 and 79.73% for Lactobacillus acidophillus (ML) and Bifidobacterium Bb-12 (MB) microparticles, respectively. In the evaluation of thermal resistance and gastrointestinal simulation, the microparticles of Lactobacillus acidophillus La-5 (ML) presented higher survival than Bifidobacterium Bb-12 (MB) under these conditions. In storage viability only the Lactobacillus acidophillus La-5 (ML) microparticles remained viable at all evaluated temperatures during the 120 days. The particle sizes reported were 4.85 for Lactobacillus acidophillus La-5 (ML) and 8.75 for Bifidobacterium Bb-12 (MB), being in agreement with the desired values for products obtained by spray dryer. Finally, the Lactobacillus acidophilus La-5 (ML) microparticles were shown to be more resistant under the conditions evaluated in this study.
This work aimed to develop and validate a simple, fast and low cost analytical method for the quantification of the bioactive piperine in nanoemulsions by high performance liquid chromatography with UV detection. Nanoemulsions were prepared by spontaneous emulsification and their physicochemical properties were evaluated. Considering the chromatographic conditions, the mobile phase was composed by methanol:water (70:30, v/v), Gemini® C18 column, and UV detection at 343 nm. The method was linear in the concentration range of 5-50 μg mL-1 (r = 0.9999), specific, precise (repeatability of RSD 0.38 % and intermediate precision of RSD 1.11 %), accurate (101.3 %) and robust. Nanoemulsions showed nanometric droplet size, polidispersity index below 0.11 and negative zeta potential. The piperine content in the samples was 0.99 ± 0.01 mg mL-1. Regarding these features, the analytical conditions proposed in this work were adequate and effective to determine the piperine content in nanoemulsions.
A lot of effort has been devoted to achieving active targeting for cancer therapy in order to reach the right cells. Hence, increasingly it is being realized that active-targeted nanocarriers notably reduce off-target effects, mainly because of targeted localization in tumors and active cellular uptake. In this context, by taking advantage of the overexpression of transferrin receptors on the surface of tumor cells, transferrin-conjugated nanodevices have been designed, in hope that the biomarker grafting would help to maximize the therapeutic benefit and to minimize the side effects. Notably, active targeting nanoparticles have shown improved therapeutic performances in different tumor models as compared to their passive targeting counterparts. In this review, current development of nano-based devices conjugated with transferrin for active tumor-targeting drug delivery are highlighted and discussed. The main objective of this review is to provide a summary of the vast types of nanomaterials that have been used to deliver different chemotherapeutics into tumor cells, and to ultimately evaluate the progression on the strategies for cancer therapy in view of the future research.
Mimosa (Black wattle) tannin extract is one of the few industrially available natural sources of polyphenols. Even if its composition is rather known, limited attempts for its purification were done until now. A Soxhlet extraction, using various solvents, with single and sequential processes was performed, and the separated fractions were analytically investigated. Yield, molecular mass, phenolic and condensed tannin contents, antioxidant activity and FT-IR spectroscopy have shown that the ethyl acetate fraction strongly contains antioxidants and low molecular mass tannins (also hydrolyzable), while the alcoholic fractions contain purified flavonoids with higher molecular mass; the final residues resulted enriched in carbohydrates and ashes. Sequential extractions optimize the class of compounds extracted according to the specific application. Conforming to statistical analysis, significant correlations have been observed between phenolic content and the antioxidant activity, as well as between molecular masses and ashes content. (C) 2017 Elsevier B.V. All rights reserved.
Emulsification/internal gelation is an encapsulation technique with great potential for protection of probiotics for use in food products. In this study, microparticles containing Bifidobacterium BB-12 produced by emulsification using sodium alginate as wall material with a slow release of calcium ions were evaluated. Probiotics survival was studied for resistance to simulated gastrointestinal conditions and stability during 120 days of storage. The characterization of the microparticles and stability in buffer solutions at different pH (4.5, 6.0, and 7.5) was investigated. Although the free cells presented low resistance, the encapsulated bacteria were resistant to the simulated gastrointestinal conditions, providing protection to Bifidobacterium BB-12. A loss of viability was observed for the encapsulated microorganisms at 7 degrees C and 25 degrees C after 120 days, while the best viability was obtained at frozen storage (-18 degrees C), with a counts of 731 log CFU g(-1) at the end of storage. The microparticles presented stability in buffer pH 4.5 and total release of probiotics at pH 7.5. The study indicates that the emulsification/internal gelation has proven to be a viable technology for protection, application, and controlled release of probiotics. (C) 2016 Elsevier Ltd. All rights reserved.
Microencapsulation is the protection of a compound and modulation of its release and now, several techniques are available and among them there is the complex coacervation. The complex coacervation technique involves the association of two polymers and presents some advantages over other techniques such as the possibility of working with biopolymers, the absence of organic solvent and temperature conditions in mild processing. Functional foods containing probiotic bacteria are becoming increasingly popular in the market due to the beneficial health effects attributed to probiotics. However, these microorganisms are sensitive to various factors found in the environment that are exposed primarily to tratogastrointestinal and storage conditions. Thus, the microencapsulation is an alternative protection and controlled release for probiotics. However, factors such as temperature, pH and concentration of the hydrocolloid, particularly, can influence the formation of microcapsules. For the encapsulation of probiotics, although there are many related studies, however, according to these results, this technique can be regarded as promising for these microorganisms. Thus, this review article aims to address the key technological aspects related to microencapsulation of probiotics by the complex coacervation technique as well as the parameters related to the technique and its application potential.