Effect of essential oil from Ageratum fastigiatum on beta-integrin (CD18) expression on human lymphocytes stimulated with phorbol myristate acetate in vitro.

Agareratum fastigiatum is a Brazilian medicinal plant used as anti-inflammaroty and for wound healing by the folk medicine. In vitro and in vivo studies involving A. fastigiatum essential oil (EOAF) showed indications of anti-inflammatory activity, however, its effect on membrane integrins involved on cell migration is still unclear. Hence, it was evaluated in the present study the effect of EOAF on CD18 frequency on human lymphocytes. By using gas chromatography/mass spectrometry it was identified 9 compounds on EOAF: α-pinene; ß-pinene; ß-myrcene; d-limonene; ß-ocimene; sesquiterpenes; α-copaene; 4,8-ß-epóxi-caryophyllene; germacrene and bicyclogermacrene. On in vitro tests, 6.25 × 10-3 and 12.5 × 10-3 µL/mL EOAF reduced CD18 frequency on phorbol-12-myristate-13-acetate (PMA)-stimulated lymphocytes. Such cells were obtained from peripheral blood of healthy volunteers, and were treated or not with EOAF. They were stained with fluorescent anti-CD18 monoclonal antibodies, after 24 hours incubation. Our data corroborates previous findings, indicating a possible anti-inflammatory activity of EOAF.

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.

Dimethyl Sulfoxide (DMSO) Decreases Cell Proliferation and TNF-α, IFN-γ, and IL-2 Cytokines Production in Cultures of Peripheral Blood Lymphocytes.

Dimethylsulfoxide (DMSO) is an amphipathic molecule composed of a polar domain characterized by the sulfinyl and two nonpolar methyl groups, for this reason it is able to solubilize polar and nonpolar substances and transpose hydrophobic barriers. DMSO is widely used to solubilize drugs of therapeutic applications and studies indicated that 10% v/v concentration did not modify culture viability when used to treat human peripheral blood mononuclear cells (PBMC). However, some DMSO concentrations could influence lymphocyte activation and present anti-inflammatory effects. Therefore, the objective of this study was to evaluate the effect of DMSO on lymphocyte activation parameters. Cell viability analysis, proliferation, and cytokine production were performed on PBMC from six healthy subjects by flow cytometry. The results indicated that 2.5% v/v DMSO concentrations did not modify lymphocytes viability. DMSO at 1% and 2% v/v concentrations reduced the relative proliferation index of lymphocytes and at 5% and 10% v/v concentrations reduced the percentage of total lymphocytes, cluster of differentiation 4⁺ (CD4⁺) T lymphocytes and CD8⁺ T lymphocytes interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2) producers. Thus, it was concluded that DMSO has an in vitro anti-inflammatory effect by reducing lymphocyte activation demonstrated with proliferation reduction and the decrease of cytokine production.

Dental wear estimation using a digital intra-oral optical scanner and an automated 3D computer vision method.

The objective of this work was to propose an automated and direct process to grade tooth wear intra-orally. Eight extracted teeth were etched with acid for different times to produce wear and scanned with an intra-oral optical scanner. Computer vision algorithms were used for alignment and comparison among models. Wear volume was estimated and visual scoring was achieved to determine reliability. Results demonstrated that it is possible to directly detect submillimeter differences in teeth surfaces with an automated method with results similar to those obtained by direct visual inspection. The investigated method proved to be reliable for comparison of measurements over time.