Navegando por Assunto "ROS Espécies reativas de oxigênio"

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Acesso aberto (Open Access)
Arrabidaea chica(Humb. & Bonpl.) Verlot: Identificação de compostos bioativos e avaliação do potencial antioxidante por métodois químicos (in vitro)
(Universidade Federal do Pará, 2022-04-28) SIQUEIRA, Francília Campos de; CHISTÉ, Renan Campos; http://lattes.cnpq.br/0583058299891937; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191
Arrabidaea chica is a medicinal plant from the Bignoniaceae family, which occurs in tropicalAmerica and it is widely distributed in the Brazilian Amazonia. This plant can be seen as apromising source of bioactive compounds, such as phenolic compounds and carotenoids,which are secondary plant metabolites that can be used to delay oxidative damage in bothfood and biological systems. In this study, the composition of carotenoids and phenoliccompounds of A. chica leaves were identified and quantified by HPLC-DAD-MS/MS, inaddition to the ascorbic acid content. The main phenolic compounds identified werescutellarin and scutellarein (aglycone); while lutein, β-carotene and α-carotene were the maincarotenoids. Regarding the in vitro antioxidant capacity, the hydromethanolic extract of A.chica leaves was characterized as an efficient ABTS radical scavenger, in addition to protecttryptophan against oxidation by singlet oxygen in a concentration-dependent manner (IC 50 =177 μg/mL). These results stimulated the next study to further investigate the antioxidantpotential of extracts of A. chica, obtained through ultrasound-assisted extraction, using“green” solvents, against reactive oxygen (ROS) and nitrogen (RNS) species of physiologicaland food relevance. The antioxidant capacity of three extracts of A. chica leaves obtained withsolvents of different polarities (water, ethanol and ethanol/water (1:1, v/v) were tested againstsuperoxide anion radical (O 2 •- ), hydrogen peroxide (H 2 O 2 ), hypochlorous acid (HOCl), theperoxynitrite radical (ONOO−), the oxigênio singleto 1 O 2 and peroxyl radical (ROO • ). The A.chica extract prepared with ethanol/water presented the highest phenolic contents (11.80 mg/gextract), being scutelarein (flavone) the major compound (57%), while ethanol and wateralone were less efficient resulting in changes in the individual profile of phenolic compounds,highlighted by the absence of scutelarein and by the high levels of phenolic acids. All extractswere able to scavenge the tested ROS/RNS in a concentration-dependent manner with lowIC 50 values, being the extract obtained with ethanol/water the most effective for all theROS/RNS (IC 50 from 0.34 to 35.66 μg/mL). Regarding the antioxidant capacity against ROO • ,all the extracts showed the same antioxidant behavior, with scavenging efficiency about fivetimes higher than Trolox. Therefore, A. chica leaves proved to be a promising source ofbioactive compounds with high antioxidant properties to be used as natural antioxidants to inhibit oxidative damage in both food and physiological systems.
Acesso aberto (Open Access)
Potencial antioxidante de compostos bioativos da chicória (eryngium foetidum L.) por métodos químicos (in vitro)
(Universidade Federal do Pará, 2022-04-29) LEITÃO, Deusa do Socorro Teixeira Costa; CHISTÉ, Renan Campos; http://lattes.cnpq.br/0583058299891937; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191
Amazonian chicory (Eryngium foetidum L.), a native plant to the Amazon and Central America, is one of the main unconventional vegetables (PANCs) grown in Brazil and considered as apromising source of bioactive compounds. The main objective of this work was to determine the composition of phenolic compounds and carotenoids in amazonian chicory leaves using high performance liquid chromatography coupled to diode array detectors and mass spectrometer (HPLC-DAD-MS /MS), as well as the evaluation of the in vitro antioxidant potential. The leaves of Amazonian chicory presented high contents of water (87%), low contents of lipids (2.8%), proteins (1.99%) and low total energy value (52.23 kcal/100 g). The main phenolic compounds in the leaves were chlorogenic acid (4328 μg/g), followed by ferrulic acid derivative (3892 μg/g), while the main carotenoids were lutein (204.86 μg/g), followed by β-carotene (161 μg/g leaves). Regarding the evaluation of the in vitro antioxidant capacity, the hydromethanolic extract of Amazonian chicory leaves was able to eliminate DPPH●(91.6%, at 5 mg/mL), ABTS●+ (15.77 μM Trolox equivalent/g of extract) and exhibited high efficiency to protect tryptophan against 1O2 in a concentration-dependent manner (IC50 = 343 μg/mL). Furthermore, Amazonian chicory leaf extracts were obtained using green solvents with different polarities [H2O, EtOH/H2O, EtOH (1:1, v/v)], through ultrasound-assisted extraction. The scavenging capacity of the extracts against the main reactive oxygen (ROS) and nitrogen (RNS) species was evaluated, namely the superoxide anion radical (O2•-), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), and the peroxynitrite anion (ONOO−). The EtOH/H2O extract presented the highest phenolic compound contents (5781.00 mg/g extract) and the highest scavenging efficiency, being chlorogenic acid the major compound (38%). All the extracts were efficient in scavenging all the tested ROS and RNS in a concentration-dependent manner. The EtOH/H2O extract was the most effective (IC50 of 45.00 – 1000 μg/mL) for almost all species, with the exception of 1O2. Regarding ROO•-scavenging capacity, the most efficient extract was EtOH. Based on the results of this study, the green solvents used in this study were promising for obtaining amazonian chicory leaf extracts with a high content of bioactive compounds and antioxidant capacity. Therefore, such information have great relevance for the food, cosmetic and pharmaceutical industries, since amazonian chicory is a natural rich source of bioactive compounds to be used as potential raw material for obtaining extracts against oxidative damage both in food and physiological systems.