Microcapsules containing antioxidant molecules as scavengers of reactive oxygen and nitrogen species

Nanofibers of Jussara Pulp: A Tool to Prevent the Loss of Thermal Stability and the Antioxidant Activity of Anthocyanins after Simulated Digestion

Electrospinning can produce a new composite for coating sensitive bioactive compounds, such as anthocyanins, and the product obtained from this process presents characteristics that potentialize the application of natural pigments in foodstuffs. The present work aimed to develop a new nanofiber composite with incorporated anthocyanins from jussara pulp using polyethylene oxide through electrospinning. A decay in the percentage of anthocyanins during digestion was observed. However, the polymeric solution and composites produced maintained the antioxidant activity, showing their protective effect on bioactive compounds; furthermore, both nanofibers and polymer solution improved the thermal stability of the anthocyanins. Thus, the results obtained potentiate electrospinning composites in processed food products since the nanofibers presented superior thermal stability and antioxidant activity, even after the digestion process in vitro.

Scavenging Capacity of Extracts of Arrabidaea chica Leaves from the Amazonia against ROS and RNS of Physiological and Food Relevance

Arrabidaea chica, a medicinal plant found in the Amazon rainforest, is a promising source of bioactive compounds which can be used to inhibit oxidative damage in both food and biological systems. In this study, the in vitro scavenging capacity of characterized extracts of A. chica leaves, obtained with green solvents of different polarities [water, ethanol, and ethanol/water (1:1, v/v)] through ultrasound-assisted extraction, was investigated against reactive oxygen (ROS) and nitrogen (RNS) species, namely superoxide anion radicals (O2•-), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), and peroxynitrite anion (ONOO-). The extract obtained with ethanol-water presented about three times more phenolic compound contents (11.8 mg/g) than ethanol and water extracts (3.8 and 3.6 mg/g, respectively), with scutellarein being the major compound (6.76 mg/g). All extracts showed high scavenging efficiency against the tested ROS and RNS, in a concentration-dependent manner with low IC50 values, and the ethanol-water extract was the most effective one. In addition, all the extracts were five times more efficient against ROO• than Trolox. Therefore, the extracts from A. chica leaves exhibited high promising antioxidant potential to be used against oxidative damage in food and physiological systems.

Green Extraction Process of Food Grade C-phycocyanin: Biological Effects and Metabolic Study in Mice

This study aimed to evaluate different parameters in the green process of organic Spirulina biomass (SB) C-phycocyanin (C-PC) extraction to understand the impact on weight and oral glucose tolerance of C-PC extract in Swiss mice fed with a high-fat diet (HFD). The proximate composition and antioxidant activity were analyzed in Spirulina by-products: SB, C-PC, and Remaining biomass (RB). The protein content on a dry basis was 52.05% in SB and 61.16% in RB and 118.97 μg/g in C-PC. The antioxidant activity was equal for SB and C-PC but higher than RB. However, RB can be considered a promising ingredient, promoting the sustainable use of the whole SB. Swiss mice were distributed in five groups: control diet (CD), HFD, HFD plus Spirulina biomass (HFDS), HFD plus C-PC (HFDC), and HFD plus remaining biomass (HFDR). HFDS increased the delta weight of the animals and showed glucose intolerance compared to the CD and HFDC groups. The results demonstrated that the supplementation of 500 mg/kg of body weight of SB in the HFDS group did not show antiobesogenic potential with an HFD, but it is essential to conduct further studies to bring other interesting responses regarding C-PC biological in vivo effects.

Fermented Jussara: Evaluation of Nanostructure Formation, Bioaccessibility, and Antioxidant Activity

Among the species of plants present in the Atlantic Forest, the jussara (Euterpe edulis Mart.) stands out for the contents of bioactive compounds present in its composition. Fermentation processes can be essential in converting bioproducts and bioactive compounds, improving their biological properties. In addition, the improvement of procedures for the maintenance of the features of bioactive compounds has been a research focus in recent years, and the nanotechnology features that can potentially solve this issue have been highlighted among the most reviewed paths. The present work focused on tailoring nanostructures applying polyethylene oxide, assembling fermented jussara pulp nanofibers, and assessing their characteristics. The results revealed the formation of fermented jussara nanofibers with a diameter of 101.2 ± 26.2 nm. Also, the obtained results allow us to state that it is possible to maintain or even increase the antioxidant activity of anthocyanins and their metabolites after fermentation processes.

Red Propolis as a Source of Antimicrobial Phytochemicals: Extraction Using High-Performance Alternative Solvents

Propolis is a resinous material rich in flavonoids and involved in several biological activities such as antimicrobial, fungicide, and antiparasitic functions. Conventionally, ethanolic solutions are used to obtain propolis phytochemicals, which restrict their use in some cultures. Given this, we developed an alcohol-free high-performance extractive approach to recover antibacterial and antioxidants phytochemicals from red propolis. Thus, aqueous-solutions of ionic liquids (IL) and eutectic solvents were used and then tested for their total flavonoids, antioxidant, and antimicrobial activities. The surface-responsive technique was applied regarding some variables, namely, the time of extraction, the number of extractions, and cavitation power (W), to optimize the process (in terms of higher yields of flavonoids and better antioxidant activity). After that, four extractions with the same biomass (repetitions) using 1-hexyl-3-methylimidazolium chloride [C6mim]Cl, under the operational conditions fixed at 3.3 min and 300 W, were able to recover 394.39 ± 36.30 mg RuE. g-1 of total flavonoids, with total antioxidant capacity evaluated up to 7595.77 ± 5.48 μmol TE. g-1 dried biomass, besides inhibiting the growth of Staphylococcus aureus and Salmonella enteritidis bacteria (inhibition halo of 23.0 ± 1.0 and 15.7 ± 2.1, respectively). Aiming at the development of new technologies, the antimicrobial effect also presented by [C6mim]Cl may be appealing, and future studies are required to understand possible synergistic actions with propolis phytochemicals. Thereby, we successfully applied a completely alcohol-free method to obtain antimicrobials phytochemicals and highly antioxidants from red propolis, representing an optimized process to replace the conventional extracts produced until now.

The Ameliorative Role of Acacia senegal Gum against the Oxidative Stress and Genotoxicity Induced by the Radiographic Contrast Medium (Ioxitalamate) in Albino Rats

Arabic gum (Acacia senegal, AG) is proven effective antioxidant and cytoprotective agent. The present study was designed to test this notion by investigating the possible role of AG against the radiographic contrast medium (Ioxitalamate, Telebrix-35^®, TBX)-induced oxidative stress and genotoxicity. Albino rats were divided into four groups and supplied with either; distilled water, daily 10% (w/v) AG, an intravenous dose of TBX (1600 mg I/kg b.wt) and co-administration of TBX and AG. Rats were sacrificed and blood samples were collected to assess the genotoxicity employing the peripheral blood leucocytes fluorescent double staining; namely the acridine orange/ethidium bromide (AO/EB) staining and alkaline comet assay. Further, chromosomal analyses were done in bone marrow cells. Serum urea and creatinine levels, in addition to malondialdehyde (MDA), nitric oxide (NO), catalase (CAT) and glutathione (GSH) levels in kidney tissues were measured. Liquid chromatography-mass spectrophotometry (LC-MS-MS) was performed to identify the chemical composition of AG extract. Kidney functions, single/double-stranded DNA damage, chromosomal aberrations, mitotic index, MDA and NO levels were significantly (p < 0.001) increased in TBX-treated group compared to the control and AG-treated one. Meanwhile, CAT and GSH activities were significantly diminished and the AG supplementation significantly (p < 0.001) ameliorated these effects compared with the control and AG-treated groups. Five compounds have been identified using GNPS networking including 7,3′,4′-Trihydroxyisoflavone, Noscapine, Tetrahydropapaveroline, Costunolide, Hesperidin. In conclusion, results of the present study suggest that AG exerted a protective role against TBX-induced oxidative stress and genotoxicity which may be attributed to the active metabolites in the gum.

Gum Arabic (Acacia Senegal) Augmented Total Antioxidant Capacity and Reduced C-Reactive Protein among Haemodialysis Patients in Phase II Trial

Background

Oxidative processes might increase in patients with end-stage renal disease (ESRD) according to the current literature. Oxidative stress (OS) is a risk factor of atherosclerosis and cardiovascular complications, which are major causes of mortality among ESRD patients. Haemodialysis (HD) is life-saving procedure, nevertheless it is an active chronic inflammatory status that could augment cardiovascular disease and increase mortality. Gum Arabic (GA) has been claimed to act as an antioxidant and anti-inflammatory agent in experimental studies and clinical trials. Therefore, we assumed GA supplementation among haemodialysis patients would reduce oxidative stress and consequently reduce the state of chronic inflammatory activation associated with haemodialysis.

Methods

Forty end-stage renal failure (ESRF) patients aged 18–80 years who were on regular haemodialysis in Arif Renal Center, Omdurman, Sudan, were recruited. All recruited patients met the inclusion criteria and signed informed consent prior to enrolment. The patients received 30 g/day of GA for 12 weeks. C-reactive protein (CRP) and complete blood count (CBC) were measured as baseline and monthly. Total antioxidant capacity (TAC) and oxidative stress marker malondialdehyde (MDA) levels were measured before and after GA intake. Ethical approval from the National Medicines and Poisons Board was obtained.

Results

Gum Arabic significantly augmented total antioxidant capacity level (P < 0.001) (95% CI, 0.408–0.625) and also attenuated oxidative marker MDA and C-reactive protein (P < 0.001).

Conclusions

GA has revealed potent antioxidative and anti-inflammatory properties in haemodialysis patients. Oral digestion of GA (30 g/day) decreased oxidative stress and inflammatory markers among haemodialysis patients. Trial registration. ClinicalTrials.gov Identifier: NCT03214692, registered 11 July 2017 (prospective registration).

Addition of norbixin microcapsules obtained by spray drying in an isotonic tangerine soft drink as a natural dye

Annatto seeds (Bixa orellana L.) are a natural source of norbixin, a carotenoid with antioxidant activity and an intense yellow-orange color which is a commonly used food and beverage colorant. However, it is susceptible to environmental factors such as light, oxygen, and temperature. Microencapsulation presents an alternative for improving the bioactive compound's stability. In this study, norbixin microcapsules (MCN) were added to isotonic tangerine soft drinks in a quantity not exceeding food additive regulations. The final concentration was 2.86 ± 0.02 µg norbixin/mL, and according to the CIELab system, the beverage acquired the expected orange tonality. The addition of MCN favorably affects beverage stability during storage under accelerated conditions (heat and light), and the half-life time was more significant (29.71 days) than when non-encapsulated norbixin was used (393.39 min). In conclusion, MCN should be considered as an additive with potential use in processed beverage industries instead of synthetic dyes.

Expression patterns of two pal genes of Pleurotus ostreatus across developmental stages and under heat stress

Background

Phenylalanine ammonia-lyase (PAL, EC 4.3.1.24) is the first key enzyme in the phenylpropanoid pathway. The pal gene has been widely studied in plants and participates in plant growth, development and defense systems. However, in Pleurotus ostreatus, the biological functions of pal during organismal development and exposure to abiotic stress have not been reported.

Results

In this study, we cloned and characterized the pal1 (2232 bp) and pal2 (2244 bp) genes from the basidiomycete P. ostreatus CCMSSC 00389. The pal1 and pal2 genes are interrupted by 6 and 10 introns, respectively, and encode proteins of 743 and 747 amino acids, respectively. Furthermore, prokaryotic expression experiments showed that PAL enzymes catalyzed the conversion of L-phenylalanine to trans-cinnamic acid. The function of pal1 and pal2 was determined by constructing overexpression (OE) and RNA interference (RNAi) strains. The results showed that the two pal genes had similar expression patterns during different developmental stages. The expression of pal genes was higher in the reproductive growth stage than in the vegetative growth stage. And the interference of pal1 and pal2 delayed the formation of primordia. The results of heat stress assays showed that the RNAi-pal1 strains had enhanced mycelial tolerance to high temperature, while the RNAi-pal2 strains had enhanced mycelial resistance to H₂O₂.

Conclusions

These results indicate that two pal genes may play a similar role in the development of P. ostreatus fruiting bodies, but may alleviate stress through different regulatory pathways under heat stress.

An in vitro digestion method adapted for carotenoids and carotenoid esters: moving forward towards standardization

In vitro digestion methods are a useful approach to predict the bioaccessibility of food components and overcome some limitations or disadvantages associated with in vivo methodologies. Recently, the INFOGEST network published a static method of in vitro digestion with a proposal for assay standardization. The INFOGEST method is not specific for any food component; therefore, we aimed to adapt this method to assess the in vitro bioaccessibility of carotenoids and carotenoid esters in a model fruit (Byrsonima crassifolia). Two additional steps were coupled to the in vitro digestion procedure, centrifugation at 20 000g for the separation of the aqueous phase containing mixed micelles and exhaustive carotenoid extraction with an organic solvent. The effect of electrolytes, enzymes and bile acids on carotenoid micellarization and stability was also tested. The results were compared with those found with a simpler method that has already been used for carotenoid bioaccessibility analysis. These values were in the expected range for free carotenoids (5-29%), monoesters (9-26%) and diesters (4-28%). In general, the in vitro bioaccessibility of carotenoids assessed by the adapted INFOGEST method was significantly higher (p < 0.05) than those assessed by the simplest protocol, with or without the addition of simulated fluids. Although no trend was observed, differences in bioaccessibility values depended on the carotenoid form (free, monoester or diester), isomerization (Z/E) and the in vitro digestion protocol. To the best of our knowledge, it was the first time that a systematic identification of carotenoid esters by HPLC-DAD-MS/MS after in vitro digestion using the INFOGEST protocol was carried out.

Gum Arabic as novel anti-oxidant agent in sickle cell anemia, phase II trial

Background

Sickle cell anemia patients suffer from oxidative stress due to chronic inflammation and self-oxidation of sickle hemoglobin (Hb S). Chronic oxidative stress contributes to endothelial dysfunction, inflammation and multiple organ damage in sickle cell disease (SCD). Thus, antioxidant medication may favorably influence the disease. Gum Arabic (GA), edible, dried, gummy exudates from Acacia Senegal tree, has been claimed to act as an anti-oxidant and cytoprotective agent, protecting against experimental hepatic, renal and cardiac toxicities in rats. We hypothesized that regular intake of GA increases anti-oxidant capacity and reduce oxidative stress.

Methods

Forty-seven patients (5–42 years) carrying hemoglobin SS were recruited. Patients received 30 g/day GA for 12 weeks. Total anti-oxidant capacity (TAC), malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) levels were measured by spectrophotometric methods before and after GA intake. Complete blood count was measured by sysmex.

Results

Gum Arabic significantly increased TAC level P < 0.001and decreased the oxidative markers MDA (P < 0.05) and H₂O₂ (P < 0.005).

Conclusions

GA has potent anti- oxidative properties in sickle cell anemia. The anti-oxidant effect of GA may thus favorably influence the clinical condition of this and further diseases characterized by oxidative stress.

Trial registration

ClinicalTrials.gov Identifier: NCT02467257. Registered 3rd June 2015. Retrospective registration.

Realgar nanoparticle-based microcapsules: preparation and in-vitro/in-vivo characterizations

Objectives

The aim of this study was to prepare microcapsules for the oral delivery of realgar nanoparticles (RN) that are also capable of improving its stability.

Methods

RN and RN-based microcapsules (RNM) were prepared using ball milling and solvent evaporation techniques, respectively. Properties such as particle size, ζ-potential (ZP), morphology and X-ray diffractometer (XRD) were investigated. In addition, drug release, bioavailability and antitumour studies were also performed.

Key findings

The nanoparticles appeared round or elliptical in shape with a mean size of 85.4 ± 3.5 nm and a ZP of −34.3 ± 1.7 mV. The obtained RNM appeared spherical and not aggregated with a relatively narrow size distribution. XRD analysis revealed that ball milling technique did not change the crystallinity of the realgar powder. RN and RNM exhibited considerable higher release of As2S2, bioavailability and antitumour efficacies compared with crude realgar. Furthermore, RNM could protect RN directly exposed to the air and light, and therefore increased the stability of the RN.

Conclusions

The developed RNM demonstrated a greater potential as a delivery system for realgar.

The Amazonian fruit Byrsonima crassifolia effectively scavenges reactive oxygen and nitrogen species and protects human erythrocytes against oxidative damage

A hydrophilic extract of murici (Byrsonima crassifolia), a fruit native to the North and Northeast regions of Brazil, was evaluated in relation to its phenolic composition and in vitro antioxidant potential against some physiologically relevant reactive oxygen and nitrogen species. Additionally, the protective effect of murici extract against peroxyl radical (ROO)-induced toxicity to human erythrocytes was also determined. The major phenolic compound, determined by HPLC-DAD-MSⁿ, was quercetin (2.72±0.35μg/mL). The extract was able to scavenge ROO (0.30±0.04μmoltroloxequivalent/mg), hypochlorous acid (IC₅₀=10.0±0.1μg/mL), hydroxyl radical (IC₅₀=7±1μg/mL) and peroxynitrite anion (IC₅₀=21.0±0.6μg/mL and 17.0±1.6μg/mL, respectively, in absence and presence of NaHCO₃). Human erythrocytes were subjected to oxidative damage, but murici extract was not able to inhibit hemolysis, even at the highest tested concentration. On the other hand, the extract inhibited hemoglobin oxidation (IC₅₀=271±44μg/mL), lipid peroxidation (1000μg/mL) by 48±5%, depletion of glutathione (100μg/mL) by 49±2% and formation of its oxidized form (100μg/mL) by 96±4%.

Carotenoids and phenolic compounds from Solanum sessiliflorum, an unexploited Amazonian fruit, and their scavenging capacities against reactive oxygen and nitrogen species

The composition of carotenoids and phenolic compounds from mana-cubiu (Solanum sessiliflorum), a fruit native to Amazonia, was determined by high-performance liquid chromatography coupled to diode array and mass spectrometry detectors (HPLC-DAD-MS(n)). The antioxidant capacities of the hydrophilic and carotenoid extracts against some reactive oxygen (ROO(•), H(2)O(2), HOCl, and HO(•)) and nitrogen (ONOO(-)) species were also determined. Seventeen carotenoids and three phenolic compounds were found in mana-cubiu. The major carotenoids were (all-E)-β-carotene (7.15 μg/g of dry weight) and (all-E)-lutein (2.41 μg/g of dry weight). The 5-caffeoylquinic acid (1351 μg/g of dry weight) was the major phenolic compound, representing more than 78% (w/w) of the total phenolic compounds. Moreover, two dihydrocaffeoyl spermidines were found in the hydrophilic extract. Both mana-cubiu extracts were able to scavenge all the tested reactive species. The carotenoid extract was shown to be a potent scavenger of peroxyl radical, while the hydrophilic extract was a potent hydrogen peroxide and hypochlorous acid scavenger.

Scavenging capacity of marine carotenoids against reactive oxygen and nitrogen species in a membrane-mimicking system

Carotenoid intake has been associated with the decrease of the incidence of some chronic diseases by minimizing the in vivo oxidative damages induced by reactive oxygen (ROS) and nitrogen species (RNS). The carotenoids are well-known singlet oxygen quenchers; however, their capacity to scavenge other reactive species, such as peroxyl radical (ROO^•), hydroxyl radical (HO^•), hypochlorous acid (HOCl) and anion peroxynitrite (ONOO⁻), still needs to be more extensively studied, especially using membrane-mimicking systems, such as liposomes. Moreover, the identification of carotenoids possessing high antioxidant capacity can lead to new alternatives of drugs or nutritional supplements for prophylaxis or therapy of pathological conditions related to oxidative damages, such as cardiovascular diseases. The capacity to scavenge ROO^•, HO^•, HOCl and ONOO⁻ of seven carotenoids found in marine organisms was determined in liposomes based on the fluorescence loss of a fluorescent lipid (C₁₁-BODIPY^581/591) due to its oxidation by these reactive species. The carotenoid-bearing hydroxyl groups were generally more potent ROS scavengers than the carotenes, whilst β-carotene was the most efficient ONOO⁻ scavenger. The role of astaxanthin as an antioxidant should be highlighted, since it was a more potent scavenger of ROO^•, HOCl and ONOO⁻ than α-tocopherol.