Evaluation of chemical constituents and antioxidant activity of coconut water (Cocus nucifera L.) and caffeic acid in cell culture.

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.

Avaliação do sequestro do óxido nítrico (NO) pelo extrato metanólico da alga Bryothamnion triquetrum (Gmelin) Howe / Evaluation of nitric oxide (NO) scavenging for the metanol extract of the alga Bryothamnion triquetrum (Gmelin) Howe

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 por cento.

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 percent.