Avaliação do sequestro do óxido nítrico (NO) pelo extrato metanólico da alga Bryothamnion triquetrum (Gmelin) Howe

Abstract

RESUMO: 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%.Unitermos: óxido nítrico, Bryothamnion triquetrum, estresse oxidativo.ABSTRACT: "Evaluation of nitric oxide (NO) scavenging for the metanol extract of the alga Bryothamnion triquetrum (Gmelin) Howe". 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%.

Antinociceptive and Anti-Inflammatory Activities of Crude Methanolic Extract of Red Alga Bryothamnion triquetrum

“…Some studies have demonstrated an antioxidant action [76,77,78,79,80] and nitric oxide (NO) scavenging for B. triquetrum [79]. ROS, including molecules such as hydrogen peroxide, superoxide, hydroxyl radicals and NO, have been implicated in tissue damage and development of the inflammatory and pain response.…”

Phytochemical screening, antioxidant and cytotoxic activities of Cordia verbenacea extracts

“…It is related to several pathological processes, including inflammatory processes and induced toxicity (ADEGBOLA et al, 2017;FÖRSTERMANN et al, 2017;MITTAL et al, 2014;SILVA, DELGADO, 2020). Thus, the search for natural substances capable of scavenging free radicals can be of great value in the therapeutic field, helping to reduce the toxicity caused by reactive species, acting as a modulator of inflammatory processes (MAIA et al, 2010).…”