Análise do perfil químico e investigação da atividade hepatoprotetora in vivo e da citotoxidade e das atividades anti-inflamatória e antibacteriana in vitro de Vernonia condensata Baker (Asteraceae Bencht. & Presl)

Abstract

Vernonia Condensata Baker (Asteraceae), traditionally used for the relief of several diseases, such as gastric and hepatic disorders, and also in inflammatory processes, was the focus of this study, which sought to deepen the knowledge about the biological potential of this species. The leaves were subjected to cold extraction with ethanol. The extract (EE) thus obtained was dried and resuspended, passing through a liquid-liquid partitioning process with solvents in increasing order of polarity, giving the partitions: hexane (PH), dichloromethane (PD) and ethyl acetate (PA). Hepatoprotective activity was evaluated in vivo. Three models of hepatic injury induction were applied: acetaminophen, acetaminophen, acetaminophen, acetaminophen and acetaminophen. For the first model the ethanolic extract and its partitions were tested, inhibition of hepatic damage was observed for the animals treated with PA at the concentrations 50, 100 and 200 mg / kg, with the reduction of hepatic transaminases levels, lipid parameters and antioxidant action observed by the lipid peroxidation assays and the activity of catalase and reduced glutathione enzymes performed in hepatic tissue. For the paracetamol model in repeated doses the animals were treated with PA at concentrations 100 and 200 mg / kg, given the treatment profile no significant differences were observed between the biochemical parameters of the different groups, however it was possible to verify the antioxidant activity of the partition for this model. For induction of acute hepatic injury by ethanol, significant differences were observed for hepatic transaminase levels for the groups treated simultaneously and after induction with BP at the concentration of 200 mg / kg. In vitro anti-inflammatory activity was also tested against RAW (macrophages) PA cells and levels of NO, IL-6 and TNF-α were measured and a significant reduction of these pro-inflammatory mediators was observed. The antibacterial activity of the samples was verified by tests of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), checkerboard, growth curve analysis, cell viability and inhibition of biofilm adhesion. The results of CIM for PA indicated moderate antibacterial activity for S. aureus strains with results equal to or less than 625 μg / mL, presenting bacteriostatic activity. PA led to a decrease in the growth rate of S. aureus strains as well as to inhibit biofilm adhesion. In PA, which was more promising for the tests performed, the flavonoids luteolin, apigenin and the chlorogenic acid phenolic compound were identified and quantified by means of high performance liquid chromatography coupled to diode array with external standards. PA was further fractionated and one of the fractions obtained was isolated, identified and quantified 1,5 - o - dicyclohexylic acid. The presence of these may justify, in part, the activities observed in this study.