Avaliação da composição química, atividade antioxidante e toxicidade oral aguda de Jatropha gossypiifolia L. (Euphorbiaceae)

Abstract

The Jatropha gossypiifolia L. is popularly known as a purple-backed or purple-pine, belonging to the family Euphorbiaceae, of the genus Jatropha. It is distributed in Brazil predominantly in the Amazon region, Caatinga and Mata Atlântica (FÉLIX-SILVA et al. 2014). In popular medicine it is used for the treatment of peptic ulcers, diabetes, neoplasias, diarrhea, as cicatrizante and diuretic (MARIZ et al., 2006). The main secondary metabolites identified in its chemical constitution are: phenolic acids, alkaloids, terpenes, steroids, flavonoids, lignans and tannins. The biological activities evidenced in the species were: antioxidant, antidiarrheal, antimalarial, antimicrobial, antiviral, sedative, anticonvulsant, besides hypotensive and vasorelaxant potential (MARIZ et al., 2010). The objective of this study was to characterize and quantify the phenolic compounds and terpenoids as analytical markers, using ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS / MS), as well as to investigate antioxidant activity in vitro against superoxide anion, hydroxyl and peroxyl radicals and to evaluate the acute oral toxicity of the hydroethanolic extract of the leaves of J. gossypiifolia. The extracts were obtained by infusion and maceration of the dry plant material (leaves and fruits) in the thrEHE different crops, and the infusion was not used for the toxicity test. After the maceration, the obtained hydroethanolic extract was lyophilized and resuspended in water for the fractionation with solvents in the increasing order of their polarities: hexane, chloroform, ethyl acetate and n-butanol. The presence of the major phenolic compounds, such as catechin, p-coumaric acid, ferulic acid and luteolin, were found in the hydroethanolic extract and infusion. Also in the hydroethanolic extract, the presence of three triterpene compounds (α-amirin, β-amirin and lupeol) was identified. The anti-radical activity tested in the infusion, hydroethanolic extract and ethyl acetate and butanol fractions, showed a higher in vitro antioxidant activity in the hydroethanolic extract (96.6 ± 3.0) and infusion (99.7 ± 13.9) in the concentrations of 0.1% w / v and 1.0% w / v, respectively. The hydroethanolic extract from the leaves of J. gossypiifolia, tested in acute oral toxicity, had an LD50 of between 2000-5000 mg / kg and was characterized as low toxicity, according to the Organization for Economic Cooperation and Development (OECD 423., 2001) guideline. No significant changes (p> 0.05, ANOVA) were observed in the biochemical and hematological parameters of the test group analyzed, in relation to the control group. Thus, the study suggests that the presence of catechin, as the major compound in the infusion, may be related to the hypotensive effect and that the pharmacological properties of the flavonoids and phenolic acids found may be associated with the popular use of this medicinal plant.