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

Autor: Ottoni MHF; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Graduate Program in Pharmaceutical Sciences, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Santos MGD; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Multicenter Graduate Program in Physiological Sciences/UFVJM, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Almeida VG; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil., Costa LA; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Multicenter Graduate Program in Physiological Sciences/UFVJM, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Meireles AB; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Graduate Program in Pharmaceutical Sciences, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Avelar-Freitas BA; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Laboratory of Cellular Biology, Institute of Science and Technology, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Santos JATD; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Multicenter Graduate Program in Physiological Sciences/UFVJM, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Pereira WF; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Graduate Program in Pharmaceutical Sciences, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil., Brito-Melo GEA; Laboratory of Immunology, Department of Pharmacy, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-00, Brazil; Graduate Program in Pharmaceutical Sciences, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil; Multicenter Graduate Program in Physiological Sciences/UFVJM, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, Minas Gerais 39100-000, Brazil. Electronic address: gustavomelo@ufvjm.edu.br.
Jazyk: angličtina
Zdroj: Journal of immunological methods [J Immunol Methods] 2019 May; Vol. 468, pp. 1-9. Date of Electronic Publication: 2019 Feb 22.
DOI: 10.1016/j.jim.2019.02.007
Abstrakt: 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.
(Copyright © 2019. Published by Elsevier B.V.)
Databáze: MEDLINE
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