Potencial antioxidante de compostos bioativos da chicória (eryngium foetidum L.) por métodos químicos (in vitro)

Abstract

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.