O conhecimento sobre a composição de alimentos regionais é de suma importância para a orientação nutricional da população. Os frutos de Mauritia flexuosa L. f. são fonte alimentar que vem gerando ...interesse devido sua composição química e farmacológica. O objetivo desse estudo foi avaliar a composição centesimal e a atividade antioxidante dos frutos de M. flexuosa do Cariri cearense. Sua polpa foi submetida às análises de umidade, acidez total, pH, proteínas, glicídios redutores e não redutores, cinzas, lipídios e vitamina C. Foram realizados os testes de DPPH e FRAP com as frações obtidas da polpa. Todas as análises foram realizadas em triplicata, sendo determinadas a média e desvio-padrão. A polpa apresentou teores de 21,68% de umidade, 12,29% de acidez total, 3,84 de pH, 58,48% de proteínas, glicídios redutores e não redutores de 39,10% e 8,40%, respectivamente, bem como valores de 3,82% de cinzas, 5,91% de lipídios e 60,63 mg/100g de vitamina C. A fração acetato de etila mostrou potencial antioxidante em ambas as análises. Assim, pelo seu teor nutricional, o consumo do fruto do buriti pode ser encorajado, tanto no aproveitamento industrial como em enriquecimento de produtos.
The aim of this study was to assess the impact of ferrous (Fe2+) or ferric (Fe3+) iron on the antioxidant capacity and the ability to bind iron of bovine spermatozoa at specific time intervals (0h, ...2h, 8h, 16h and 24h) during an in vitro culture. 35 semen samples were collected from 7 adult breeding bulls and diluted in physiological saline solution supplemented with different concentrations (0, 1, 5, 10, 50, 100, 200, 500, 1000 μmol/L) of FeCl2 or FeCl3. Spermatozoa motility was assessed using the SpermVisionTM CASA (Computer aided sperm analysis) system. The ferric reducing ability of plasma (FRAP) assay was applied to study the antioxidant capacity of the samples, while the ability of the sample to bind excess iron was determined using the Total iron-binding capacity (TIBC) test. Both ferrous and ferric iron exhibited a dose- and time-dependent impact on the spermatozoa motility. Concentrations ≥50 µmol/L FeCl2 and ≥100 µmol/L FeCl3 led to a significant decrease of spermatozoa motion (P<0.001), while concentrations below 10 µmol/L FeCl2 and 50 µmol/L FeCl3 proved to preserve the parameter (P<0.001). The FRAP assay revealed that both ferrous as well as ferric iron had a similar effect on the FRAP marker of the samples: high concentrations led to a dramatic and significant (P<0.001) increase of the parameter, followed by a notable decrease of the reducing ability in the subsequent time periods, whose intensity was dependent upon the time, oxidation state of iron, as well as the time of analysis. Furthermore, supplementation of FeCl2 and FeCl3 had an impact on the capacity of the sperm culture to bind free iron, reflected in a significant decrease of the parameter (P<0.001) early on (Time 2h) in case of high doses of both oxidative states of this biometal. In a direct comparison, ferrous iron has been shown to be more toxic than ferric iron. Results from this in vitro study show that high concentrations of both forms of iron are toxic, while their low concentrations may have spermatozoa activity-promoting properties. 50 µmol/L FeCl2 and 100 µmol/L FeCl3 could be regarded as critical in vitro concentrations of ferrous or ferric iron when it critically accumulates with toxic outcomes.
BCL-2-associated X (BAX) protein acts as a gatekeeper in regulating mitochondria-dependent apoptosis. Under cellular stress, BAX becomes activated and transforms into a lethal oligomer that causes ...mitochondrial outer membrane permeabilization (MOMP). Previous studies have identified several structural features of the membrane-associated BAX oligomer; they include the formation of the BH3-in-groove dimer, the collapse of the helical hairpin α5–α6, and the membrane insertion of α9 helix. However, it remains unclear as to the role of lipid environment in determining the conformation and the pore-forming activity of the BAX oligomers. Here we study molecular details of the membrane-associated BAX in various lipid environments using fluorescence and ESR techniques. We identify the inactive versus active forms of membrane-associated BAX, only the latter of which can induce stable and large membrane pores that are sufficient in size to pass apoptogenic factors. We reveal that the presence of CL is crucial to promoting the association between BAX dimers, hence the active oligomers. Without the presence of CL, BAX dimers assemble into an inactive oligomer that lacks the ability to form stable pores in the membrane. This study suggests an important role of CL in determining the formation of active BAX oligomers.
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•Membrane-associated BAX can exist in either inactive or active form.•Cardiolipin is crucial to promoting the activated BAX oligomers.•Cardiolipin is important to promote BAX to induce large membrane pores.•In a PC-only environment, BAX associates with lipids to form an inactive oligomer.
Halophytes, distributed from coastal regions to inland deserts have traditionally been used for medicinal and nutritional purposes. Living in sub-optimal conditions, these plants synthesize stress ...associated bioactive molecules, which are still remain largely unexplored. In search of natural antioxidant sources, antioxidant capacity (AC) and total phenolic content (TPC) of 100 medicinal plants (halophytes vs non-halophytes), commonly used as herbal teas, were investigated. Nutrients and phytochemical composition, especially phenolic metabolites in selected medicinal plants with higher AC were also determined. Most of the medicinal plants analysed for the first time showed considerable AC. In general, halophytes displayed higher AC and TPC than non-halophytes. High correlation indicated a major contribution of TPC in AC of these plants. Five medicinal halophytes i.e., Thespesia populneoides, Salvadora persica, Ipomoea pes-caprae, Suaeda fruticosa, and Pluchea lanceolata displayed significantly higher AC than synthetic antioxidants (BHT and BHA). Presence of bioactive phytochemicals including phenols (42.3–63.9mgGAEg−1), flavonoids (12.3–37.1mgQEg−1), tannins (8.7–20mgTAEg−1), proanthocyanidins (15.8–22.4mgCEg−1), carotenoids (0.07–0.84mgg−1), alkaloids (0.64–1.1mgg−1), and saponins (11.2–28.4mgDAEg−1) reflected therapeutic benefits of these plants. HPLC analyses showed that the hydrolysed extracts contained chlorogenic acid, gallic acid, catechin, and quercetin as abundant phenolic metabolites which may be responsible for higher AC. These plants were also found to contain suitable amounts of proteins (8.5–17%), carbohydrates (2.6–11.4%), fibre (31.6–41.2%), and minerals (2.1–9.7%) showing their nutritional potential that has already been exploited by rural communities. The present study highlights the potential of medicinal halophytes as a source of natural antioxidants, valuable phytochemicals, and essential nutrients for pharmaceutical, nutraceutical, and chemical industries.
•Medicinal halophytes have higher antioxidant capacity than synthetic antioxidants.•Phenolic content is strongly correlated with antioxidant capacity.•Halophytes have high content of nutrients and phenolic metabolites.
In the present research effects of gamma irradiation (5–20 kGy) on the physicochemical, antioxidant and thermal properties of brown rice starch were studied. Scanning electron microscopy displayed ...mostly polyhedral shapes with no surface fractures. XRD displayed characteristic A type pattern and decrease in per cent crystallinity (22.53–20.41%) was observed as the dose increased from 5 to 20 kGy. DPPH % inhibition and FRAP values were increased in a dose dependent manner. Pasting properties (peak, final and setback viscosity) decreased with irradiation. Pasting temperature also significantly decreased with irradiation for all the irradiated starches. The transition temperatures, enthalpy of gelatinization, pH and apparent amylose content of starch decreased significantly with increase in irradiation dose.
•Swelling index and apparent amylose content decreased.•Total per cent crystallinity of the starches decreased.•No surface cracking of the starch granules was seen.•Pasting temperature was decreased.•FTIR pattern did not change.
This study determined the total phenolic and flavonoid contents, ascorbic acid and phenolic composition and evaluated antioxidant properties and metal chelating activity of five peach cultivars, ...separately for pulp and peel. Identification and quantification of ascorbic acid and phenolic compounds were performed using HPLC method. The antioxidant and metal chelating activities are evaluated by means of several in vitro methods, such as the β-carotene/linoleate model system, radical scavenging, reducing power, and iron and copper ion chelation. The results showed that the peach peels have the highest antioxidant capacities, reflecting their highest content of total phenolics, flavonoids, ascorbic acid and phenolic compounds. In addition, the predominant phenolic compounds in peaches was found to be chlorogenic acid, followed by neo-chlorogenic acid, (+)-catechin, quercetin-3-rutinoside and protocatechuic acid. The results indicated that peach peels are good sources of bioactive and antioxidant compounds, and can be explored for their health promoting values in food products.
•Five representative peaches from China were analyzed separately for peel and pulp.•Peel contained higher contents of TPs, TFs, ascorbic acid and phenolics than pulp.•Peel presented higher antioxidant capacity and metal chelating capacity than pulp.•Antioxidant and metal chelating properties were correlated both to TPs, TFs and ascorbic acid.
Antioxidants are substances that can slow down the oxidation process of free radicals. Limpasu plant (Baccaurea lanceolata (Miq) Muell. Arg), an indigenous plant of Borneo, is a natural antioxidant ...source. The purpose of this study was to determine the antioxidant activity of the limpasu pericarpium extract. The extraction of the limpasu pericarpium was done by maceration method using solvents with increasing polarity ranging from n-hexane, ethyl acetate, and methanol. Antioxidant activities of the three extracts were measured by the DPPH and FRAP methods. The IC50 values of n-hexane, ethyl acetate, and methanol extracts, as well as quercetin using the DPPH method were 517,45 µg/mL, 530,64 µg/mL, 10,63 µg/mL and 6,83 µg/mL, respectively. Meanwhile, the IC50 values obtained from FRAP method were 198,96 µg/mL, 190,07 µg/mL, 661,36 µg/mL, and 7,09 µg/mL, respectively. The results revealed that the methanol extract is more potent than other extracts tested for antioxidant activity.
In the current study, ultrasonic assisted ethanolic extract of propolis was discussed in detail, including their total phenolic content, total antioxidant capacity and radical scavenging capacity. ...For this purpose, we determined the total antioxidant capacity of propolis extract by CUPRAC and FRAP) assay. At the same time, the free radical scavenging capacity of propolis extracts was investigated via the DPPH• and CUPRAC- hydroxyl radical scavenging (HRS) methods. The chemical constituents of propolis extract were characterized by ATR-FTIR. The results revealed that propolis is rich in total phenolic components (189 mg GAE /g extract). According to the CUPRAC assay, the total antioxidant capacity of propolis extract was calculated to be 2.43 ± 0.07 mmol TE/g-propolis extract. FRAP value of propolis extract was determined as 1.11 mmol TE/g-propolis extract. DPPH• scavenging activity of propolis extract was calculated to be 0.71± 0.002 mmol TE / g - extract. On the other hand, according to the CUPRAC method, HRS capacity of propolis extract at different concentrations (5-10 μg/mL) was determined as 68.1% and 77.64 %, respectively. Research findings showed that propolis extract has a strong radical scavenging potential. The FTIR spectra of the functional groups originating from the phenolic compounds in the propolis extract were as expected.
In the current study, ultrasonic assisted ethanolic extract of propolis was discussed in detail, including their total phenolic content, total antioxidant capacity and radical scavenging capacity. For this purpose, we determined the total antioxidant capacity of propolis extract by CUPRAC and FRAP) assay. At the same time, the free radical scavenging capacity of propolis extracts was investigated via the DPPH• and CUPRAC- hydroxyl radical scavenging (HRS) methods. The chemical constituents of propolis extract were characterized by ATR-FTIR. The results revealed that propolis is rich in total phenolic components (189 mg GAE /g extract). According to the CUPRAC assay, the total antioxidant capacity of propolis extract was calculated to be 2.43 ± 0.07 mmol TE/g-propolis extract. FRAP value of propolis extract was determined as 1.11 mmol TE/g-propolis extract. DPPH• scavenging activity of propolis extract was calculated to be 0.71± 0.002 mmol TE / g - extract. On the other hand, according to the CUPRAC method, HRS capacity of propolis extract at different concentrations (5-10 μg/mL) was determined as 68.1% and 77.64 %, respectively. Research findings showed that propolis extract has a strong radical scavenging potential. The FTIR spectra of the functional groups originating from the phenolic compounds in the propolis extract were as expected.
Apigenin is a common bioactive flavonoid found in a variety of fruits, plants and vegetables. Many pharmacological activities of apigenin have been identified, but its low water solubility limits ...clinical evidence on its oral bioavailability. This study estimated the antioxidant activity of apigenin and its potassium salt derivative (apigenin-K) and the intestinal permeability of both compounds in Caco-2 cell monolayers.
The antioxidant activity was evaluated with different methods: trolox equivalent antioxidant capacity (TEAC) and ferric reducing-antioxidant power (FRAP). Intestinal permeability coefficient was estimated in Caco-2 cell monolayer model with the addition of apigenin or apigenin-K to the apical (AP) or basolateral (BL) site.
Apigenin exhibited a higher antioxidant activity than apigenin-K. Intestinal absorption evaluation corroborated the low permeability of both apigenin and apigenin-K.
These results indicate that apigenin and apigenin-K may be considered as antioxidant ingredients for oral administration. Their low absorption estimation suggests that encapsulation may be necessary to enhance apigenin bioavailability for oral applications.
Senyawa antioksidan berperan dalam menghambat atau menunda reaksi oksidasi molekul dengan cara memperlambat proses inisiasi atau propagasi reaksi oksidasi berantai. Hasil pengujian aktivitas ...antioksidan dapat bervariasi karena perbedaan struktur kimiawi antioksidan, sumber radikal bebas, dan sifat fisikokimia dari sampel yang diuji. Senyawa yang mengandung radikal bebas memiliki satu atau lebih elektron yang tidak berpasangan dan bersifat reaktif sehingga dapat merusak sel dan jaringan bila terakumulasi dalam tubuh manusia. Terdapat antioksidan alami dan sintetis yang berfungsi untuk menghambat reaksi oksidasi dan mencegah terbentuknya radikal bebas. Namun, perlu diperhatikan bahwa antioksidan sintetis dapat memodifikasi senyawa menjadi karsinogenik. Oleh karena itu, eksplorasi antioksidan alami dan pengujian aktivitas antioksidannya penting dilakukan. Salah satunya adalah pengujian aktivitas antioksidan teh hitam (Camellia sinensis). Teh merupakan salah satu minuman yang paling populer di dunia dan merupakan tanaman yang banyak ditemukan di daerah pegunungan Asia. Teh diketahui memiliki manfaat kesehatan karena mengandung polifenol yang merupakan antioksidan alami. Antioksidan polifenol berperan dalam melawan radikal bebas yang berbahaya bagi tubuh. Penentuan aktivitas antioksidan dilakukan dengan uji penangkapan radikal DPPH (2.2-difenill-1-pikrilhidrazil), ABTS (3-ethyl-benzothiazoline-6-sulfonic acid) dan FRAP (Ferric Reducing Antioxidant Power). Ketiga metode uji antioksidan berbeda dalam mekanisme reaksinya. Hasil pengujian antioksidan pada teh hitam dengan metode DPPH sebesar 208.83 mgTE/g, ABTS sebesar 217.83 mgTE/g dan FRAP sebesar 42.15 mgTE/g, dimana TE adalah Trolox Ekuivalen.
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