Open AccessChemical composition, immunostimulatory, cytotoxic and antiparasitic activities of the essential oil from Brazilian red propolis
Author(s) -
Ângela Sena-Lopes,
Francisco Silvestre Brilhante Bezerra,
Raquel Nascimento das Neves,
Rodrigo Barros de Pinho,
Mara Thaís de Oliveira Silva,
Lucielli Savegnago,
Tiago Collares,
Fabiana Kömmling Seixas,
Karine R. Begnini,
João Antônio Pêgas Henriques,
Mariana Roesch Ely,
Luciane Corbellini Rufatto,
Sidnei Moura,
Thiago Barcellos,
Francine Ferreira Padilha,
Odir A. Dellagostin,
Sibele Borsuk
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0191797
Subject(s) - propolis , antiparasitic , essential oil , biology , cytotoxicity , antiparasitic agent , chemistry , eugenol , food science , microbiology and biotechnology , biochemistry , in vitro , pharmacology , medicine , organic chemistry , pathology
Most studies of Brazilian red propolis have explored the composition and biological properties of its ethanolic extracts. In this work, we chemically extracted and characterized the essential oil of Brazilian red propolis (EOP) and assessed its adjuvant, antiparasitic and cytotoxic activities. The chemical composition of EOP was analyzed using gas chromatography with mass spectrometry (GC-MS). EOP was tested for in vitro activity against Trichomonas vaginalis (ATCC 30236 isolate); trophozoites were treated with different concentrations of EOP (ranging from 25 to 500 μg/mL) in order to establish the MIC and IC 50 values. A cytotoxicity assay was performed in CHO-K1 cells submitted to different EOP concentrations. BALB/c mice were used to test the adjuvant effect of EOP. The animals were divided in 3 groups and inoculated as follows: 0.4 ng/kg BW EOP (G1); 50 μg of rCP40 protein (G2); or a combination of 0.4 ng/kg BW EOP and 50 μg of rCP40 (G3). Total IgG, IgG1 and IgG2a levels were assessed by ELISA. The major constituent compounds of EOP were methyl eugenol (13.1%), (E)-β-farnesene (2.50%), and δ-amorphene (2.3%). Exposure to EOP inhibited the growth of T . vaginalis , with an IC 50 value of 100 μg/mL of EOP. An EOP concentration of 500 μg/mL was able to kill 100% of the T . vaginalis trophozoites. The EOP kinetic growth curve showed a 36% decrease in trophozoite growth after a 12 h exposure to 500 μg/mL of EOP, while complete parasite death was induced at 24 h. With regard to CHO-K1 cells, the CC 50 was 266 μg/mL, and 92% cytotoxicity was observed after exposure to 500 μg/mL of EOP. Otherwise, a concentration of 200 μg/mL of EOP was able to reduce parasite proliferation by 70% and was not cytotoxic to CHO-K1 cells. As an adjuvant, a synergistic effect was observed when EOP was combined with the rCP40 protein (G3) in comparison to the administration of each component alone (G1 and G2), resulting in higher concentrations of IgG, IgG1 and IgG2a. EOP is constituted by biologically active components with promising antiparasitic and immunostimulatory activities and can be investigated for the formulation of new vaccines or trichomonacidal drugs.