Garcinia macrophylla: a Promising Underutilized Source of Bioactive Compounds in the Amazonia - A Review

Native species from the Amazonia are still unknown or underutilized and few information about their chemical and biological properties are available in the literature. Among the underutilized plant species in the Amazonia, Garcinia macrophylla can be seen as a promising source of bioactive compounds with relevant biological properties. The stem bark and leaves were the main investigated plant parts, mainly concerning the antioxidant, antibacterial, cytotoxicity and antidiabetic properties. However, the bioactive compounds and biological properties of the edible fruits were not yet reported. Systematic investigations covering the Amazonia biome, concerning plants and vegetables as strategic resources are of paramount importance for the sustainable development of the forest. Therefore, this review gathered the available information in the literature concerning general aspects, chemical profile and biological properties of G. macrophylla, for the first time, which highlighted that systematic and robust in vitro and in vivo research, are still needed to elucidate the phytochemical profiles and associated relevant biological properties.

Amazonian palm tree fruits: From nutritional value to diversity of new food products

The rapid growth of the world population has increased the demand for new food sources, constituting a major challenge concerning the maximum use of existing food resources. The fruits of Amazonian palm trees have excellent nutritional composition and bioactive compounds. This review highlights four fruits of Amazonian palm trees that are still little explored by the food industry: açai (Euterpe oleracea), pupunha (Bactris gasipaes), buriti (Mauritia flexuosa), and tucumã (Astrocaryum aculeatum). This paper aims to inspire new ideas for researching and developing products for the food industry. It also explores the impacts of Amazonian palm fruits on health, highlighting their role in disease prevention through their nutritional effects.

Total and Free Hydrogen Cyanide Content and Profile of Bioactive Amines in Commercial Tucupi, a Traditionally Derived Cassava Product Widely Consumed in Northern Brazil

Tucupi is a broth derived from cassava roots which is produced after the spontaneous fermentation of manipueira (the liquid portion obtained by pressing cassava roots), followed by cooking. This product is widely consumed along with traditional dishes in the Brazilian Amazonia and is already used in different places worldwide. In this study, tucupi obtained from the markets of Belém (Pará, Brazil) and produced using agroindustrial (11 samples) and non-agroindustrial (11 samples) units were investigated to determine their physicochemical characteristics, total and free HCN contents, and free bioactive amine profiles. Most of the samples showed significant variations (p ≤ 0.05) in pH (2.82-4.67), total acidity (0.14-1.36 g lactic acid/100 mL), reducing sugars (up to 2.33 g/100 mL), and total sugars (up to 4.35 g/100 mL). Regarding the amines, four biogenic amines (0.5-4.2 mg/L tyramine, 1.0-23.1 mg/L putrescine, 0.5-66.8 mg/L histamine, and 0.6-2.9 mg/L tryptamine) and one polyamine (0.4-1.7 mg/L spermidine) were identified in the tucupi samples. Even in the tucupi produced using the agroindustrial units, which had quality seals provided by the local regulatory agency, high levels of biogenic amines (4.4-78.2 mg/L) were observed, as well as high dosages of total (8.87-114.66 mg/L) and free (0.80-38.38 mg/L) HCN. These facts highlight the need for better knowledge regarding the product manufacturing process to establish standardization and high-quality conditions for tucupi processing since high contents of biogenic amines and HCN are commonly associated with adverse health effects.

Non-thermal technologies for the conservation of açai pulp and derived products: A comprehensive review

Açai (Euterpe oleracea) is one of the main sustainable extractive crops in the Amazon region, widely consumed by the local population and a significant export product. This review presents the current knowledge regarding nonthermal technologies employed in açai processing. This review aims to discuss and compare the main results attained by the application of HPP, ultrasound, ozone, UV light, cold plasma, and pulsed electric field on microbial inactivation, enzymatic inhibition, and the content of anthocyanin and other bioactive compounds after açai pulp processing. The discussion compares these technologies with pasteurization, the current main technology applied to açai sanitization. This review shows that there are still many gaps to be filled concerning açai processing in thermal and non-thermal technologies. Data analysis allowed the conclusion that pasteurization and HPP are, up to now, the only technologies that enable a 5-log CFU reduction of yeasts, molds, and some bacteria in açai. However, no study has reported the inactivation of Trypanosoma cruzi, which is the major gap found in current knowledge. Other technologies, such as pulsed electric field, cold plasma, and ultrasound, require further development and process intensification studies to be as successful as HPP and pasteurization.

Sustainable Applications of Nanopropolis to Combat Foodborne Illnesses

Propolis has numerous biological properties and technological potential, but its low solubility in water makes its use quite difficult. With the advent of nanotechnology, better formulations with propolis, such as nanopropolis, can be achieved to improve its properties. Nanopropolis is a natural nanomaterial with several applications, including in the maintenance of food quality. Food safety is a global public health concern since food matrices are highly susceptible to contamination of various natures, leading to food loss and transmission of harmful foodborne illness. Due to their smaller size, propolis nanoparticles are more readily absorbed by the body and have higher antibacterial and antifungal activities than common propolis. This review aims to understand whether using propolis with nanotechnology can help preserve food and prevent foodborne illness. Nanotechnology applied to propolis formulations proved to be effective against pathogenic microorganisms of industrial interest, making it possible to solve problems of outbreaks that can occur through food.

Açai Seeds (Euterpe oleracea Mart) Are Agroindustrial Waste with High Potential to Produce Low-Cost Substrates after Acid Hydrolysis

Açai seeds have been discarded improperly around the Amazonia region, but they can be seen as promising low-cost substrates for fermentation processes. The structural carbohydrates and physicochemical characterization of açai seeds from the Amazonia were assessed followed by the determination of the optimal hydrolysis conditions using H3PO4 (phosphoric acid) and H2SO4 (sulfuric acid) to obtain a liquor with high contents of simple carbohydrates and low levels of potential microbial inhibitors usually generated during acid hydrolysis of carbohydrates. A central composite rotational design was carried out varying the concentrations of diluted acid (0-5%, w/v), solids (0.1-25%, w/v), and hydrolysis time (9.5-110 min). Acid hydrolysis with H2SO4 was more effective in producing reducing sugars (15.9-103.1 g/L) than H3PO4 (2.9-33.9 g/L) during optimization. The optimal hydrolysis conditions with H2SO4 were 3.5% of acid (w/v), 25% of solids during 70 min at 121 °C, which provided a liquor with 55 g/L of reducing sugars and low levels of microbial inhibitors: acetic acid (1.8 g/L), hydroxymethyl furfural (338 mg/L), and furfural (10 mg/L). Thus, açai seeds were characterized as promising agroindustrial waste with high potential to be used as a low-cost substrate in biotechnological processes, comprising relevant environmental and bioeconomic aspects for the development of the Amazonia.

Extracts of Eryngium foetidum Leaves from the Amazonia Were Efficient Scavengers of ROS and RNS

Eryngium foetidum L. is an edible plant widespread in Amazonian cuisine and its leaves have high levels of promising phenolic compounds for the production of extracts to be used as natural antioxidant additives. In this study, the in vitro scavenging capacity of three freeze-dried extracts of E. foetidum leaves, obtained by ultrasound-assisted extraction using green solvents [water (H₂O), ethanol (EtOH), and ethanol/water (EtOH/H₂O)], was investigated against the most common reactive oxygen species (ROS) and reactive nitrogen species (RNS) generated in both physiological and food systems. Six phenolic compounds were identified, chlorogenic acid (2198, 1816 and 506 μg/g) being the major compound for EtOH/H₂O, H₂O, and EtOH extracts, respectively. All E. foetidum extracts were efficient in scavenging all the ROS and RNS (IC₅₀ = 45-1000 µg/mL), especially ROS. The EtOH/H₂O extract showed the highest contents of phenolic compounds (5781 μg/g) and showed the highest efficiency in scavenging all the reactive species, with high efficiency for O₂^•- (IC₅₀ = 45 μg/mL), except for ROO^•, for which EtOH extract was the most efficient. Therefore, E. foetidum leaf extracts, especially EtOH/H₂O, showed high antioxidant potential to be used as natural antioxidants in food formulations and are promising for nutraceuticals products.

Ultrasound-assisted extraction using ethanol efficiently extracted carotenoids from peels of peach palm fruits (Bactris gasipaes Kunth) without altering qualitative carotenoid profile

Peach palm (Bactris gasipaes Kunth) is an amazonian fruit in which its peel has been appointed as a carotenoid-rich byproduct with biological properties. For analytical purposes, carotenoids are frequently extracted by non-green (use of toxic organic solvents) and time-consuming methods, which can affect the quality (carotenoid profile) and safety of extracts for direct food applications. We investigated herein the effect of different extraction methods on the individual carotenoid profile of extracts of peach palm peels by HPLC-DAD. Carotenoid extractions were carried out by maceration in mortar with pestle (with acetone or ethanol), magnetic stirring, shaker and ultrasound-assisted extraction (UAE) using ethanol. UAE provided the highest carotenoid contents (67 mg/100 g), followed by maceration with acetone and ethanol (63 and 52 mg/100 g, respectively), while the lowest contents were observed for the magnetic stirring and shaker extractions (44 mg/100 g), being (all-E)-β-carotene and a Z-isomer of γ-carotene accounted 54-73% of the carotenoid composition. HPLC-DAD data showed the same carotenoid profile regardless the extraction method, yet the percentage of Z-isomers of β-carotene was higher for the shaking (18%), UAE (17%) and magnetic stirring (15%) than for both maceration methods (7 and 8%, with acetone and ethanol, respectively). Thus, the tested extraction methods affected the total carotenoid contents, whereas the chromatographic profile did not change. Furthermore, a carotenoid-rich extract was effectively obtained by using ethanol associated with ultrasound technique (less time-consuming) instead of toxic and non-safe solvents.

Thermal Degradation of Carotenoids from Jambu Leaves (Acmella oleracea) during Convective Drying

Jambu (Acmella oleracea) is a vegetable used in human food. Drying is an alternative to increase the shelf life of the product. High temperatures can induce the degradation of carotenoids and reduce the health benefits of these compounds. This study investigated the effect of the Jambu leaves' drying temperature on the carotenoid composition. It was performed previously by screening 16 plants from different localities based on the total carotenoid content. The process of drying by convection was carried out at temperatures of 35, 40, 50, and 60 °C in an air circulation oven, at an air velocity of 1.4 m/s^-1 and a processing time of ~20 h. The drying data were fitted to six mathematical models and the quantification of the carotenoid retention was determined by HPLC-DAD. The study demonstrates that the carotenoid content among the samples collected from the 16 producers varied by 72% (lower-175 ± 16 μg/g, higher-618 ± 46 μg/g). Among the models, the Page model was found to be the most suitable model to explain the variation of the experimental data. The drying process at 40 °C reduces the Jambu leaves' carotenoid content significantly (p < 0.05) (All-trans-β-carotene-86 ± 2 μg/g, All-trans-lutein-141 ± 0.2 μg/g) but does not alter the carotenoid profile. The occurrence of similar reduction behavior was observed for the different carotenoids at all the temperatures studied. The drying process at 35 °C was the condition that ensured the highest retention of carotenoids, and also a product classified as a very high source of carotenoids (total carotenoids-748 ± 27 μg/g, vitamin A-17 ± 1 μg RAE/g). Thus, this study concludes that a temperature of 35 °C for 14 h (air velocity-1.4 m/s^-1) is the best drying condition for Jambu leaves using a low-cost dryer and as a possibility for the preservation and marketing of this Amazonian raw material.

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.

Use of wildlife as an alternative protein source: Collared peccary meat

Knowledge on the nutritional and sensory characteristics of wild meat provides a better basis for its use as food, ultimately expanding studies in gastronomy areas and stimulating the development of new products. This review aims to present information on the use of wild meat, with a focus on collared peccaries (Pecari tajacu). The biological characteristics of collared peccaries are discussed, with a focus on the main aspects of their meat. Collared peccary meat has excellent nutritional value due to its high protein levels (18.25%), unsaturated fatty acids (51.6-57.8%), and tenderness, similar to other domestic animals, thereby stimulating the interest of a new product market. Despite the demand for this product, collared peccary meat is scarce and not readily available for commercialization. Further, public policies are needed to encourage the management of this species to add value to the development of a production chain.

Lactic Acid Bacteria and Bioactive Amines Identified during Manipueira Fermentation for Tucupi Production

There is scarce information regarding lactic acid bacteria (LAB) and the production of biogenic amines during manipueira fermentation for tucupi. Thus, the objective of this study was to isolate and identify LAB, and to determine their impact on bioactive amine formation. Spontaneous fermentation of manipueira was carried out at laboratory scale and selected LAB colonies were isolated and identified by sequencing techniques and comparison with sequences from a virtual database. Only two LAB species of the genus Lactobacillus were identified during fermentation: Lactobacillus fermentum and Lactobacillus plantarum. L. fermentum was the predominant, whereas L. plantarum was only detected in manipueira prior to fermentation. Spermidine and putrescine were detected throughout fermentation, whereas histamine was produced at the final stage. There was positive correlation between LAB counts and putrescine and histamine levels, suggesting that the identified LAB are responsible for the synthesis of these amines during manipueira fermentation. Genetic assays are needed to verify whether the LAB identified have the genes responsible for decarboxylation of amino acids.

Encapsulation of bioactive compounds extracted from plants of genus Hibiscus: A review of selected techniques and applications

The genus Hibiscus includes more than 250 species, and many studies showed that these plants contain bioactive compounds with technological potential to be used in the development of functional foods. However, the instability of these compounds during typical food processing conditions, such as exposure to high temperatures, pH changes and presence of light and oxygen have stimulated the use of encapsulation techniques to increase their stability and applicability. Among the existing Hibiscus species, only H. sabdariffa, H. cannabinus, and H. acetosella have been investigated in encapsulation studies, being spray drying the most common method approached. Considering the high technological potential offered by the incorporation of encapsulated bioactive compounds from plants of the genus Hibiscus in food formulations, this review discusses key information of selected encapsulation techniques, which represents promising alternatives to increase food systems' stability and stimulate the design of new functional foods. Relevant gaps in the literature were also noticed, mainly the lack of systematic studies regarding the composition of bioactive compounds after encapsulation, instead of total determinations, and biological activities in different analytical systems, such as antioxidant, antimicrobial and anti-inflammatory properties as well as bioaccessibility and bioavailability.

Antrocaryon amazonicum: An unexploited Amazonian fruit with high potential of scavenging reactive oxygen and nitrogen species

Antrocaryon amazonicum fruits are unexploited sources of bioactive compounds found in the Amazonia region of Brazil. In this study, for the first time, the carotenoid and phenolic compound profiles of the pulp and peel of A. amazonicum fruits, from two varieties at two harvest periods, were determined by LC-MS. Additionally, the potential of the peel and pulp extracts to scavenge physiologically relevant reactive oxygen species (ROS) and reactive nitrogen species (RNS) was assessed. The major carotenoids in both parts of the fruits were lutein, accounting for ≈42% of the identified carotenoids in the peel and ≈25% in the pulp, whereas catechin and hydroxybenzoic acid derivatives were the major phenolics in both parts. The peel extract, which presented the highest bioactive compound contents, was more efficient to scavenge ROS than the pulp. The peel extract showed high scavenging efficiency (IC₅₀ ) for singlet oxygen (¹ O₂ ; 16 µg/ml), hypochlorous acid (HOCl; 20 µg/ml), peroxynitrite (ONOO^- ; 38 µg/ml), and superoxide radical (O₂ ^•- ; 47 µg/ml), whereas the pulp extract exhibited high efficiency for ONOO^- (13 µg/ml), followed by HOCl (30 µg/ml), ¹O₂ (76 µg/ml), and less efficient for O₂ ^•- (44 µg/ml). Therefore, A. amazonicum fruits can be seen as an expressive source of bioactive compounds with high antioxidant potential to be further investigated to inhibit or delay oxidative processes both in food and physiological systems triggered by ROS and RNS. PRACTICAL APPLICATION: Bioactive compound extracts of Antrocaryon amazonicum fruits have high potential to be exploited for inhibiting or delaying oxidative processes and increase food stability.

Peach palm flour: production, hygroscopic behaviour and application in cookies

In this work, two types of flour from peach palm fruits (Bactris gasipaes) were prepared to be used to produce cookies: one with the whole fruit (pulp + peel) and another one with only the pulp. Analyses of proximate composition, physicochemical and hygroscopic behaviour were carried out in both flour, as well as sensory analysis of the produced cookies. Both the types of flour did not differ statistically in total lipids, total carbohydrates and ashes (p > 0.05). Among the mathematical models tested for the prediction of the hygroscopic behaviour of both flour, Halsey model showed the best fit to the experimental data (R2 = 0.99 and P<10%). The cookies produced with both types of peach palm flour presented low moisture (4.9-6.2%), high lipid content (25.56-26.37%) and total carbohydrates (59.10-61.84%), resulting in a product with high total energetic value (501.8-502.8 kcal/100 g). Based on the results of acceptance test, both cookie formulations presented good sensory acceptance (>70%). The purchase intention inquiry showed that the cookie prepared with the whole fruit flour presented the highest percentage of purchase intention (85%), which demonstrate that the use of peach palm peels in the development of new food products represent an excellent alternative for the use of by-products.

Peels of tucumã (Astrocaryum vulgare) and peach palm (Bactris gasipaes) are by-products classified as very high carotenoid sources

Tucumã (Astrocaryum vulgare) and peach palm (Bactris gasipaes) are Amazonian fruits with high potential to be used as source of carotenoids due to the remarkable yellow-orange colour of their pulp and peel. In this study, for the first time, both the extraction of carotenoids from the peel of tucumã and peach palm fruits and their carotenoid profile were investigated. The carotenoid contents of the peel of both fruits were higher than those found in the pulp. The highest yield of carotenoids from both fruit peels were obtained at the solid-liquid ratio of 1:7 (w/v), 80 min of shaking and by adding 30% of ethyl acetate in acetone, being β-carotene the major carotenoid (7.8 and 7.3 mg/100 g for tucumã and peach palm, respectively), followed by γ-carotene and δ-carotene. Thus, peels of tucumã and peach palm fruits were classified as very high carotenoid sources to be used by any potential interested industry.

Phenolic compounds are highly correlated to the antioxidant capacity of genotypes of Oenocarpus distichus Mart. fruits

This research aimed to evaluate 32 genotypes of Oenocarpus distichus fruits regarding the contents of total phenolic compounds, flavonoids, flavanols, monomeric anthocyanins, antioxidant capacity (ABTS and DPPH assays), and the phenolic compound profiles of the five genotypes that presented the highest yields of bioactive compounds. The genotypes were harvested in three different locations in Pará State, Northern Brazil, (Belém, São João do Araguaia and Marabá). Among the 32 genotypes, the highest bioactive compound contents and antioxidant capacity were found for three genotypes harvested in Belém (B-3, B-7 and B-8) and two harvested in São João do Araguaia (SJ-1 and SJ-4), and the total phenolic compounds varied from 131.97 to 363.01 mg gallic acid equivalent/100 g, total flavonoids from 24.23 to 38.19 mg quercetin equivalent/100 g, total flavanols from 72.29 to 259.18 mg catechin equivalent/100 g, and monomeric anthocyanins from 21.31 to 67.76 mg cyanidin 3-rutinoside/100 g. The main phenolic compounds tentatively identified in the five selected genotypes were cyanidin 3-O-rutinoside (48.47 to 196.51 μg/g), which could be identified and quantified as the major phenolic compound in Oenocarpus distichus fruits, for the first time, followed by chlorogenic acid (0.71 to 64.56 μg/g) and rutin (13.98 to 56.76 μg/g).

Anthocyanins of Jambolão (Syzygium cumini): Extraction and pH-Dependent Color Changes

Jambolão fruits are promising sources of anthocyanins, and in this study, the jambolão fruit from the Brazilian Amazonian region was characterized and the efficiency of six ethanol-based solutions to extract anthocyanins was determined. Moreover, the color changes of anthocyanin extracts, as influenced by different pH conditions (pH from 1.0 to 8.0), were evaluated. The fruits exhibited high contents of total anthocyanins (296 mg/100 g) and the CIELAB parameters characterized jambolão as a purple-red colored fruit (a* = 20.30, b* = -4.17, and hab∘= 348.39). Among the six different ethanol-based solutions, ethanol 95% with 1% of HCl (v/v) was the most efficient solution to extract anthocyanins from jambolão fruits. Furthermore, the CIELAB parameters were characterized as useful tool to monitor the color changes of anthocyanins of jambolão over the tested pH range. Therefore, jambolão fruits from Amazonian region have technological potential for the application by food, pharmaceutical, and cosmetic industries.

PRACTICAL APPLICATION

Jambolão fruits are great source of anthocyanins and the incorporation of these natural pigments as food colorants is not only valuable to improve overall appearance, but it is also beneficial to human health. The production of natural extracts with high levels of anthocyanins from jambolão can be considered a very useful approach to the food, pharmaceutical and cosmetic industries.

Solanum diploconos fruits: profile of bioactive compounds and in vitro antioxidant capacity of different parts of the fruit

Solanum diploconos is an unexploited Brazilian native fruit that belongs to the same genus of important food crops, such as tomato (Solanum lycorpersicum) and potato (Solanum tuberosum). In this study, we determined, for the first time, the profile of bioactive compounds (phenolic compounds, carotenoids, ascorbic acid and tocopherols) of the freeze-dried pulp and peel of Solanum diploconos fruits, as well as of an extract obtained from the whole fruit. Additionally, the antioxidant potential of the whole fruit extract was evaluated in vitro, against reactive oxygen species (ROS) and reactive nitrogen species (RNS). Eighteen phenolic compounds were identified in the peel and pulp and 6 compounds were found in the whole fruit extract. Coumaric, ferulic and caffeic acid derivatives were revealed to be the major phenolic constituents. All-trans-β-carotene was the major carotenoid (17-38 μg g(-1), dry basis), but all-trans-lutein and 9-cis-β-carotene were also identified. The peel and pulp presented <2 μg per mL of tocopherols, and ascorbic acid was not detected. The whole fruit extract exhibited scavenging capacity against all tested ROS and RNS (IC50 = 14-461 μg mL(-1)) with high antioxidant efficiency against HOCl. Thus, Solanum diploconos fruits may be seen as a promising source of bioactive compounds with high antioxidant potential against the most physiologically relevant ROS and RNS.

Biodistribution of polyacrylic acid-coated iron oxide nanoparticles is associated with proinflammatory activation and liver toxicity

Iron oxide nanoparticles (IONs) have physical and chemical properties that render them useful for several new biomedical applications. Still, so far, in vivo safety studies of IONs with coatings of biomedical interest are still scarce. The aim of this study, therefore, was to clarify the acute biological effects of polyacrylic acid (PAA)-coated IONs, by determining their biodistribution and their potential proinflammatory and toxic effects in CD-1 mice. The biodistribution of PAA-coated IONs in several organs (liver, spleen, kidneys, brain, heart, testes and lungs), the plasma cytokines, chemokine and aminotransferases levels, white blood cell count, oxidative stress parameters, adenosine triphosphate and histologic features of liver, spleen and kidneys were evaluated 24 h after a single acute (8, 20 or 50 mg kg(-1) ) intravenous administration of PAA-coated IONs in magnetite form. The obtained results showed that these IONs accumulate mainly in the liver and spleen and, to a lesser extent, in the lungs. Although our data showed that PAA-coated IONs do not cause severe organ damage, an inflammatory process was triggered in vivo, as evidenced by as evidenced by increased neutrophils and large lymphocytes in the differential blood count. Moreover, an accumulation of iron in macrophages of the liver and spleen was observed and hepatic lipid peroxidation was elicited, showing that the IONs are able to induce oxidative stress. The effects of these nanoparticles need to be further investigated regarding the mechanisms involved and the long-term consequences of intravenous administration of PAA-coated IONs. Copyright © 2016 John Wiley & Sons, Ltd.

Size-dependent cytotoxicity of silver nanoparticles in human neutrophils assessed by multiple analytical approaches

AIMS

Silver nanoparticles (AgNPs) have emerged as an important class of nanomaterials with a wide range of industrial and medical applications. The assessment of AgNPs' biological effects in the human organism is therefore essential to evaluate the impact of these nanomaterials in public health and reassure the ratio benefit/risk. In the present study, the effect of polyvinyl pyrrolidone (PVP)-coated AgNPs with distinct sizes (10 and 50nm) on neutrophils' oxidative burst and toxicity were tested.

MAIN METHODS

The effect of AgNPs on human neutrophils viability was evaluated by trypan blue, neutral red and propidium iodide methods. The measurement of neutrophils' oxidative burst was performed using the probe dihydrorhodamine 123. The cytomorphological alterations of human neutrophils exposed to AgNPs were evaluated by optical microscopy and transmission electron microscopy.

KEY FINDINGS

It was observed that PVP-coated AgNPs are toxic to human neutrophils being the 10nm AgNPs more toxic than the 50nm AgNPs. The smallest AgNPs lead to membrane damage, impaired lysosomal activity and induce neutrophils' oxidative burst. Despite the production of reactive species, the toxicity of AgNPs is not NADPH oxidase-dependent.

SIGNIFICANCE

These data indicate that AgNPs are toxic to human neutrophils in concentration-, time- and size-dependent manner, but independent of NADPH oxidase activation.

Uncovering novel 3-hydroxy-4-pyridinone metal ion complexes with potential anti-inflammatory properties

Ligands of the 3-hydroxy-4-pyridinone (3,4-HPO) type, with one (Hmpp) or two methyl groups (Hdmpp), have been reported to possess biomedical, chemical and analytical applications. In this first screening study aiming to uncover new promising agents to mitigate the oxidative damage highly present in several metabolic disorders, such as diabetes mellitus, we assessed the potential of twelve 3,4-HPO metal ion complexes to modulate oxidative burst in human neutrophils. Metal ion 3,4-HPO complexes of Ni, Fe, V, Co, Cu and Zn were synthesized and tested up to 15μM. Among all the compounds, [Cu(mpp)2] and [Cu(dmpp)2] exhibited the highest scavenging capacity against superoxide radical (O2(-)) (IC50=0.36±0.07 and 0.30±0.06μM, respectively) and against hypochlorous acid (HOCl) (IC50=0.6±0.3 and 0.4±0.1μM, respectively). In the particular case of O2(-), [Fe(mpp)3] and [Fe(dmpp)3] (both at 15μM) presented 35% and 22% of inhibition, respectively, while all the other compounds were neither able to scavenge O2(-) nor stimulate its production. Regarding the scavenging capacity against hydrogen peroxide (H2O2), all the compounds showed low efficiency (from 6-39%). Finally, with exception of [VO(mpp)2] and [VO(dmpp)2], all compounds exhibited scavenging activity against HOCl (39-81%) and the most efficient compounds were Cu(II) and Zn(II) complexes. Thus, these preliminary results uncover promising new metal ion complexes, inhibitors of neutrophil's oxidative burst, with potential anti-inflammatory properties, which may be seen as an useful strategy for further studies in the treatment of a number of diseases where oxidative damage is a serious issue.

Stem bark and flower extracts of Vismia cauliflora are highly effective antioxidants to human blood cells by preventing oxidative burst in neutrophils and oxidative damage in erythrocytes

CONTEXT

Vismia cauliflora A.C.Sm. [Hypericaceae (Clusiaceae)] is an Amazonian plant traditionally used by indigenous population to treat dermatosis and inflammatory processes of the skin. Previous research on V. cauliflora extracts suggests its potential to neutralize cellular oxidative damages related to the production of reactive oxygen and nitrogen species.

OBJECTIVE

To determine the activity of stem bark and flower extracts of V. cauliflora on the modulation of oxidative burst in human neutrophils, as well as its potential to inhibit oxidative damage in human erythrocytes.

MATERIALS AND METHODS

The modulation of neutrophil's oxidative burst by the ethanolic extracts (0.3-1000 µg/mL) was determined by the oxidation of specific probes by reactive species. Additionally, the potential of these extracts to inhibit oxidative damage in human erythrocytes was evaluated by monitoring its biomarkers of oxidative stress.

RESULTS

Vismia cauliflora extracts presented remarkable capacity to prevent the oxidative burst in activated human neutrophils (IC50 < 15 µg/mL). However, the maximum percentage of inhibition achieved against hydrogen peroxide was 45%. Concerning the oxidative damage in human erythrocytes, the extracts were able to minimize the tert-butyl hydroperoxide-induced hemoglobin oxidation and lipid peroxidation in a very low concentration range (2.7-18 μg/mL). Furthermore, only stem bark extract (100 µg/mL) was able to inhibit the depletion of glutathione (13%).

DISCUSSION AND CONCLUSION

These results reinforce the therapeutic potential of stem bark and flower extracts of V. cauliflora to heal topical skin disease, namely in the treatment of neutrophil-related dermatosis and skin conditions related to oxidative stress, including skin aging.

Bioactive compounds and scavenging capacity of extracts from different parts of Vismia cauliflora against reactive oxygen and nitrogen species

CONTEXT

Vismia cauliflora A.C.Sm. [Hypericaceae (Clusiaceae)] is a plant from Amazonian forest. It is used by Amerindians to treat dermatosis and inflammatory processes in the skin and has been considered an interesting source of bioactive compounds.

OBJECTIVE

We evaluated the scavenging capacity of extracts from V. cauliflora (leaf, branch, stem bark, flower, and whole fruit) against reactive oxygen (ROS) and nitrogen species (RNS), namely, superoxide radical ([Formula: see text]), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), singlet oxygen ((1)O2), nitric oxide ((•)NO), and peroxynitrite (ONOO(-)). In addition, for the first time, the profile of phenolic compounds and carotenoids was determined.

MATERIALS AND METHODS

The scavenging capacities of each extract were determined using specific probes (fluorescent, colorimetric, and chemiluminescent) to detect different reactive species ((1)O2, HOCl, H2O2, [Formula: see text], (•)NO, and ONOO(-)). The identification and the quantification of phenolic compounds and carotenoids were carried out by HPLC-DAD-ESI-MS/MS and HPLC-DAD, respectively.

RESULTS

(-)-Epicatechin and proanthocyanidin dimers and trimer were the major phenolic compounds tentatively identified in leaf, branch, stem bark, and flower extracts, while dihydroxybenzoic acids were the major compounds in whole fruit extracts. All-trans-zeinoxanthin and all-trans-β-carotene were the major carotenoids tentatively identified in leaf extracts. All extracts of V. cauliflora showed high efficiency against all tested ROS and RNS, although flower and stem bark extracts exhibited the most remarkable scavenging capacity, especially for (•)NO and ONOO(-).

DISCUSSION AND CONCLUSION

Vismia cauliflora has great potential to be used in the development of phytopharmaceutical products due to its characteristic of being a promising source of bioactive compounds with high antioxidant properties.

The seed of the Amazonian fruit Couepia bracteosa exhibits higher scavenging capacity against ROS and RNS than its shell and pulp extracts

Couepia bracteosa is an interesting source of bioactive compounds which may be investigated for protecting human health against oxidative damage.

Stem bark and flower extracts of Vismia cauliflora: modulation of oxidative burst in human neutrophils' and inhibition of oxidative damage in human erythrocytes

Vismia cauliflora is an Amazonian plant traditionally used to treat dermatosis and inflammatory processes of the skin by indigenous population. Our research group showed that stem bark and flower extracts of V. cauliflora are efficient in vitro scavengers of reactive oxygen and nitrogen species. In this study, we determined the activity of stem bark and flower extracts of V. cauliflora plant on the modulation of in vitro oxidative burst in human neutrophils and their potential to inhibit the oxidative damage in human erythrocytes. The oxidative burst in activated neutrophils were monitored by specific probes to detect the oxidizing effect of superoxide anion radical (MCLA), hydrogen peroxide (amplex red) and hypochlorous acid (APF), and both extracts were efficient to neutralize the oxidative burst (IC50 from 3 to 15µg/mL). These same extracts were also effective against oxidative damage in erythrocytes by inhibiting hemoglobin oxidation (IC50=18µg/mL) and lipid peroxidation (IC50=2.7 and 7.5µg/mL, flower and stem bark, respectively). In addition, stem bark extract (100µg/mL) inhibited the depletion of glutathione by 13%. These extracts have similar phenolic composition, but flower presents quercetin (14%) in its composition. Therefore, these results reinforce the potential therapeutic of stem bark and flower extracts of V. cauliflora to heal topical skin disease and requires further research targeted effectively to develop phytopharmaceutical drug based on this plant.

Identification and quantification, by HPLC-DAD-MS/MS, of carotenoids and phenolic compounds from the Amazonian fruit Caryocar villosum

The Amazonian region from Brazil has a wide variety of native and wild noncommercially cultivated fruits. This article reports for the first time the composition of carotenoids and phenolic compounds from Caryocar villosum fruit pulp, and, in addition, its proximate composition and antioxidant capacity (ORAC assay) were determined. According to the nutritional composition, water (52%) and lipids (25%) were the major components found in the pulp, and the total energetic value was 291 kcal/100 g. The major phenolic compounds identified by HPLC-DAD-ESI-MS/MS were gallic acid (182.4 μg/g pulp), followed by ellagic acid rhamnoside (107 μg/g pulp) and ellagic acid (104 μg/g pulp). The main carotenoids identified by HPLC-DAD-APCI-MS/MS were all-trans-antheraxanthin (3.4 μg/g pulp), all-trans-zeaxanthin (2.9 μg/g pulp), and a lutein-like carotenoid (2.8 μg/g pulp). The antioxidant capacity of the pulp (3.7 mMol Trolox/100 g pulp) indicates that it can be considered a good peroxyl radical scavenger.

Antigenotoxic effects of piquiá (Caryocar villosum) in multiple rat organs

This study investigated the in vivo genotoxicity of piquiá pulp (Caryocar villosum) and its potential antigenotoxicity on doxorubicin (DXR)-induced DNA damage by comet assay and micronucleus test. In addition, the phytochemicals present in piquiá pulp were determined. Piquiá fruit pulp (75, 150 or 300 mg/kg b.w.) was administered by gavage to Wistar rats for 14 days, and the animals received an injection of saline or DXR (15 mg/kg b.w., i.p.) 24 h before they were euthanized. The phytochemical analysis revealed the presence of carotenoids; phenolic compounds, including flavonoids; tannins and α-tocopherol in piquiá pulp. No statistically significant differences were observed in the evaluated parameters, demonstrating the absence of cytotoxic and genotoxic effects of piquiá pulp at all tested doses. In liver, kidney, cardiac and bone marrow cells, piquiá significantly reduced the DNA damage induced by DXR. Our results showed that the lowest piquiá dose caused the largest decrease in DNA damage and the highest dose caused the smallest decrease, demonstrating an inverse dose-response of piquiá pulp. Furthermore, we observed a difference in the potential antigenotoxic effects in several tissues. In conclusion, our results demonstrated that piquiá pulp was not genotoxic and inhibited the genotoxicity induced by DXR, but some of the protective effects that were observed depended on the doses and experimental conditions. Therefore, further investigations are needed to clarify how piquiá pulp positively affects human health.