ABSTRACT Eriosema campestre var. macrophylum (Grear) Fortunato, Fabaceae, is a native plant of the Brazilian Cerrado and the decoction of its roots has been used by folk medicine for the therapy of inflammatory diseases. In this study we aimed to investigate the effect of the dichloromethane–ethanolic extract of E. campestre roots on the proliferative response of lymphocytes and to examine the profile of IL-2 production. The effect of dichloromethane–ethanolic extract of E. campestre on the proliferation of phytohemagglutinin-stimulated lymphocytes was evaluated by using flow cytometry and the cell supernatants were assayed for IL-2 concentrations by using an enzyme-linked immunosorbent assay. The phytochemical screening of E. campestre roots was performed to determine the main secondary metabolites through chromogenic and precipitation reactions and by using HPLC-PAD. In addition to the presence of subclasses of flavonoids (flavones and flavonols) in dichloromethane–ethanolic extract of E. campestre, we observed that the extract induced a concentration-dependent decrease in IL-2 levels on the supernatant of the cell cultures as well as an antiproliferative effect on T lymphocytes, including CD4+ and CD8+ cells. The anti-inflammatory effects attributed to E. campestre by folk medicine may partly be explained by its antiproliferative action on T lymphocytes.

Abstract Ageratum fastigiatum (Gardner) R.M. King & H. Rob., a member of the Asteraceae family popularly known in Brazil as "matapasto", is indicated in folk medicine as anti-inflammatory and analgesic. Despite its popular use, little is known about its potential effect on the parameters involved in an inflammatory response. The objective of this study was to characterize the chemical composition of the essential oil from A. fastigiatum and to evaluate the frequency of tumor necrosis factor alpha and interferon gamma producing cells in peripheral blood lymphocytes stimulated with phorbol myristate acetate in the presence of essential oil from A. fastigiatum. Non-toxic concentrations of essential oil from A. fastigiatum were evaluated in cultures of peripheral blood leucocytes using the trypan blue exclusion assay by flow cytometry. GC–MS analysis revealed that the prevalent compounds identified in the essential oil from A. fastigiatum sample were α-pinene, limonene, trans-caryophyllene, α-humulene, caryophyllene oxide, 1,2-humulene-epoxide, 1,6-humulanodien-3-ol, and α-cadinol. Results showed that exposure to essential oil from A. fastigiatum at concentrations of 0.5 × 10−2 and 1 × 10−2 µl/ml caused no alterations in leukocyte viability as compared to the control group. Both concentrations lowered the percentage of tumor necrosis factor alpha (+)-lymphocytes and neutrophils. There were no changes in the percentage of lymphocytes positive for the interferon gamma cytokine. Our results suggest that part of the anti-inflammatory activity attributed to A. fastigiatum may be due to the effect of some of its components in decreasing the number of cells that produce the pro-inflammatory cytokine tumor necrosis factor alpha.

Control of Chagas disease is based on insecticide spraying in domiciles in order to exterminate triatomine populations. However, since the vectors differ in susceptibility to currently used insecticides, the screening of the toxic potential of Brazilian flora may identify new molecules lethal to triatomines. This study evaluated the toxicity of ethanolic extract of Ageratum fastigiatum (Gardner) R.M. King & H. Rob., Asteraceae, on Rhodnius nasutus, a known vector of Chagas disease. Ethanolic extracts of the aerial parts of A. fastigiatum were prepared at 25 and 50 mg/mL concentrations, and 5 µL was applied to fifth-instar nymphs of R. nasutus (n=30). Controls included nymphs that were treated with 5 µL ethanol (n=30) or left untreated (n=30). The percentage of dead insects in each group was observed at 24, 48, 72, 96 and 120 h after application. The extracts of A. fastigiatum showed a mortality rate of about 37% and 77% after 120 h, at concentrations of 25 and 50 mg/mL, respectively. In control groups, the mortality rate remained under 7%. The extract of A. fastigiatum contains a coumarin, a molecule with recognized toxicity in insects, and which may be responsible for killing the triatomines.