Composição química e avaliação da atividade antioxidante dos frutos de Schinus terebinthifolius Raddi

Abstract

Secondary metabolites are chemical substances present in medicinal plants known to have antioxidant activity. The neutralization of reactive oxygen species by these substances can prevent the appearance of several chronic diseases linked to oxidative stress, as well as being used for their treatment. Among the medicinal plants native to the Cerrado is Schinus terebinthifolius Raddi, known as pimento-rosa or aroeira- vermelha. This study aimed to evaluate the chemical composition and antioxidant potential of the methanolic extract of the fruits of S. terebinthifolius (ExSt). For this, the methanolic extract of the fruits was prepared and the chemical composition was investigated by spectrophotometry as to the presence of β-Carotene, lycopene, ascorbic acid, phenolic compounds (tartaric esters, flavonoids and condensed tannins). Then, the antioxidant activity was evaluated by the methods of (I) free radicals scavenging (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)) and 2,2-diphenyl-1- picrylhydrazyl DPPH); (II) iron reducing power, and (III) the 2,2'-azobis (2- amidinopropane) -induced oxidative hemolysis inhibition assay (AAPH) followed by evaluation of lipid peroxidation by the dosage of malondialdehyde (MDA) in humans erythrocytes. Except ascorbic acid (AA), all phytochemicals investigated are present in the extract. The required concentration of ExSt to inhibit 50% of free radicals DPPH and ABTS (IC50) was 14.58 ± 2.16 and 9.96 ± 1.04 μg / mL, respectively, being similar to the BHT control and superior to the AA control. The iron reducing capacity of ExSt was lower than AA. No hemolysis was observed in erythrocytes treated with ExSt at concentrations of 10-75 μg / mL, however, ExSt was hemolytic at the highest concentrations (100 and 250 μg / mL). In the presence of the oxidizing agent AAPH, ExSt protected the erythrocytes from oxidative hemolysis and reduced the MDA generated. In this context, the results indicate that the ExSt has chemical compounds that are linked to the observed antioxidant activity. Future perspectives for the development of biotechnological products from the Brazilian biodiversity for the prevention and / or treatment of diseases associated with oxidative stress are broadened.