ABSTRACT Hepatic disorders such as steatosis and alcoholic steatohepatitis are common diseases that affect thousands of people around the globe. This study aims to identify the main phenol compounds using a new HPLC-ESI+-MS/MS method, to evaluate some oxidative stress parameters and the hepatoprotective action of green dwarf coconut water, caffeic and ascorbic acids on the liver and serum of rats treated with ethanol. The results showed five polyphenols in the lyophilized coconut water spiked with standards: chlorogenic acid (0.18 µM), caffeic acid (1.1 µM), methyl caffeate (0.03 µM), quercetin (0.08 µM) and ferulic acid (0.02 µM) isomers. In the animals, the activity of the serum γ-glutamyltranspeptidase (γ-GT) was reduced to 1.8 I.U/L in the coconut water group, 3.6 I.U/L in the ascorbic acid group and 2.9 I.U/L in the caffeic acid groups, when compared with the ethanol group (5.1 I.U/L, p<0.05). Still in liver, the DNA analysis demonstrated a decrease of oxidized bases compared to ethanol group of 36.2% and 48.0% for pretreated and post treated coconut water group respectively, 42.5% for the caffeic acid group, and 34.5% for the ascorbic acid group. The ascorbic acid was efficient in inhibiting the thiobarbituric acid reactive substances (TBARS) in the liver by 16.5% in comparison with the ethanol group. These data indicate that the green dwarf coconut water, caffeic and ascorbic acids have antioxidant, hepatoprotective and reduced DNA damage properties, thus decreasing the oxidative stress induced by ethanol metabolism.

A água de coco contém várias substâncias não caracterizadas e é amplamente utilizada na alimentação humana. Neste estudo, foram detectados e quantificados ácido ascórbico e ácido cafeico e polifenóis totais em diversas variedades de coco, e usando HPLC-MS-MS (25,8 ± 0,6 µg-mL, 1,078 ± 0,013 µg-mL and 99,7 µg-mL, respectivamente, em água de coco do anão verde, ou 10 mg, 539 µg e 39,8 mg por unidades de coco consumido, 500 ± 50 mL). O potencial antioxidante da água de coco das quatro variedades de coqueiro (anão verde, anão amarelo, anão vermelho e amarelo malasiano) foi comparada com água de coco industrializada e água liofilizada da variedade anão verde. Todas as variedades foram eficazes - com destaque para as propriedades antioxidantes do anão verde, uma vez que é o mais comum usado – no sequestro do radical DPPH (IC50=73 µL), óxido nítrico (0,1 mL com IP de 29,9%) e inibindo a produção de espécies reativas com o ácido tiobarbitúrico (1 mL com IP de 34,4%) in vitro. Em cultura de células, a água de coco da variedade anão verde foi eficiente na proteção contra danos oxidativos induzidos por peróxido de hidrogênio.

Coconut water contains several uncharacterized substances and is widely used in the human consumption. In this paper we detected and quantified ascorbic acid and caffeic acid and total phenolics in several varieties of coconut using HPLS-MS-MS (25.8 ± 0.6 µg-mL and 1.078 ± 0.013 µg-mL and 99.7 µg-mL, respectively, in the green dwarf coconut water, or 10 mg and 539 µg and 39.8 mg for units of coconut consumed, 500 ± 50 mL). The antioxidant potential of four coconut varieties (green dwarf, yellow dwarf, red dwarf and yellow Malaysian) was compared with two industrialized coconut waters and the lyophilized water of the green dwarf variety. All varieties were effective in scavenging the DPPH radical (IC50=73 µL) and oxide nitric (0.1 mL with an IP of 29.9%) as well as in inhibiting the in vitro production of thiobarbituric acid reactive substances (1 mL with an IP of 34.4%), highlighting the antioxidant properties of the green dwarf which it is the most common used. In cell culture, the green dwarf water was efficient in protecting against oxidative damages induced by hydrogen peroxide.

O excesso de óxido nítrico (NO) produzido por indução da enzima óxido nítrico sintase (iNOS) participa do desenvolvimento de inúmeras desordens que conduzem à perda da homeostasia. O estresse oxidativo gerado pelo aumento da produção endógena de NO pode levar a efeitos de toxidade induzida, tais como peroxidação lipídica, nitração de proteínas e danos ao DNA. Compostos que sejam capazes de sequestrar o radical NO podem diminuir a toxicidade das espécies reativas de nitrogênio (RNS), atuando na modulação de processos inflamatórios. Trabalhos realizados com alga da espécie Bryothamnion triquetrum (Gmelin) Howe, demonstraram que a mesma apresenta ação antioxidante, tendo sido eficiente no sequestro do radical DPPH, além de inibição da peroxidação lipídica, com uma atividade comparável ao ácido ascórbico e ao α-tocoferol. Este estudo objetivou avaliar a capacidade de sequestro do radical NO in vitro pelo extrato metanólico da Bryothamnion triquetrum. Os resultados obtidos revelaram a presença de polifenóis sendo que todas as concentrações testadas (1,0; 2,5; 7,5; 10,0 mg/mL) foram capazes de inibir a formação de nitrito a partir de uma solução de nitroprussiato de sódio 5 mM sendo a concentração de 7,5 mg/mL a que apresentou maior percentual de inibição com 46,6%.

The excess of nitric oxide (NO) produced by induction of nitric oxide sintase enzyme (iNOS) participates in the development of countless disorders that lead to the loss of homeostasis. The oxidative stress generated by the increase of endogenous production of NO can lead to some effects of induced toxicity, such as fatty per oxidation, nitration of proteins and DNA damages. Compounds that scavenge the NO radical can reduce the toxicity of reactive nitrogen species (RNS), and act in the modulation of inflammatory processes. Works accomplished with the alga species Bryothamnion triquetrum (Gmelin) Howe demonstrated that it presents an antioxidant action, and it is efficient in the scavenging of DPPH radical and in the inhibition of fatty per oxidation, with activity comparable to the ascorbic acid and α-tocoferol. This study aimed to evaluate the capacity of NO radical scavenging in vitro for the methanol extract of the alga Bryothamnion triquetrum. The results revealed that the presence of poliphenol in all tested concentrations (1,0; 2,5; 7,5; 10,0 mg/mL) was capable to inhibit the nitrite formation, starting from a solution of sodium nitroprussiate 5 mM whose concentration of 7,5 mg/mL presented the largest inhibition percentage of 46,6%.