Phytochemical profile and antiproliferative activity of human lymphocytes of Gomphrena virgata Mart. (Amaranthaceae).

Gomphrena virgata Mart. popularly known as 'Cangussu-branco', is used in Brazilian folk medicine to treat inflammations and infections. This work aimed to carry out phytochemical analysis and evaluate the anti-inflammatory potential of Gomphrena virgata. In the phytochemical investigation, in addition to the presence of two ecdysteroids, 20 R-dihydroxyecdysone and 20-hydroxyecdysone, identified by HPLC-PDA-MS and NMR, 22 compounds were identified by GC-MS. In the cytotoxicity study, the aqueous extract of the roots of this species did not show in vitro toxicity of PBMCs in the concentrations of 250, 500 and 1000 µg/mL when analyzed by the trypan blue exclusion method. Also, it was effective in reducing lymphocyte proliferation, stimulated with the mitogen PHA, by 26.02%, 48.57% and 50.49% when compared to dexamethasone, respectively. In this work we present information about the phytochemicals of G. virgata, showing that the species is promising in obtaining compounds with medicinal potential mainly anti-inflammatory potential.

Background autofluorescence induced by plant extracts in human lymphocytes: A flow cytometric analysis of a critical bias.

The presence of background autofluorescence sources is considered as an important problem when performing fluorometric methods, due to the possible spectral overlap between it and the fluorescence emission of probes. Regarding that, we evaluated the presence of background autofluorescence in human lymphocytes after the treatment with extracts from three medicinal plants, including ethanolic extract from aerial parts of Ageratum fastigiatum, ethanolic extract from aerial parts of Eriosema campestre and the ethanolic extract from stem of Pseudobrickellia brasiliensis. Human peripheral blood mononuclear cells were treated with each extract in vitro during 24 h, followed by flow cytometric analysis. Additionally, the fluorescence emission of plant extracts was evaluated by fluorometry, using the same concentrations used in cell cultures. We identified that plant extracts treatment on lymphocytes induced background autofluorescence detectable in several wavelength ranges. Isolated extracts showed no expressive fluorescence emission in fluorometric analyses, suggesting that background autofluorescence was induced in lymphocytes by interactions between cellular components and extracts compounds. Here we discuss the importance to perform previous tests to evaluate a possible background autofluorescence induction after cell treatments with plant extracts or any other substance. In spite of being mandatory, background autofluorescence analysis of cells after treatments and stimulations is still underestimated on literature. In summary, following the precautions herein established should help to reduce the incidence of false positive results.