Chemical composition, immunostimulatory, cytotoxic and antiparasitic activities of the essential oil from Brazilian red propolis

Abstract

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 IC50 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 IC50 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 CC50 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.

Brazilian Red Propolis: Extracts Production, Physicochemical Characterization, and Cytotoxicity Profile for Antitumor Activity

“…This technique is usually employed to separate compounds that have low polarity and high volatility. These characteristics, associated with the availability of a large library of mass spectra information of each substance, allow the identification of the chemical compounds present in the samples [16,36]. Due to the advantages of this separation technique, and the low polarity of the extracts, gas chromatography coupled with mass spectrometry (GC/MS) was used in this study.…”

“…In addition to the phenolic compounds often extracted with high-polar solvents, low-polar chemical constituents have also been described in samples of red propolis, including terpenes and others [6]. Some of these chemical compounds, such as methyl eugenol, a methylated ether previously reported as one the major constituents of the essential oil of red propolis, have been demonstrated to induce anticancer activity [16]. Furthermore, other substances of lower polarity present in samples of red propolis, such as sesquiterpenes, have also exhibited antitumor activity in vitro [17,18].…”

Supercritical Extraction of Red Propolis: Operational Conditions and Chemical Characterization

“…Previous studies have also reported higher concentrations of phenolic compounds, such as formononetin, in extracts of red propolis, which is identified as its major component [ 4 , 15 , 22 ]. López et al [ 64 ], when evaluating samples of red propolis from different regions by mass spectrometry, identified the presence of formononetin ( m / z 267.06, retention time, rt 4.5 min) in all analyzed samples.…”

“…Numerous studies have demonstrated its antioxidant [ 3 , 4 ], antimicrobial [ 5 , 6 ], anti-inflammatory [ 7 , 8 ] and antitumor [ 7 , 8 ] activities, among others [ 9 , 10 , 11 , 12 ]. These activities are attributed to the bioactive chemical compounds in propolis, such as phenolic acids, flavonoids, terpenes and sesquiterpenes [ 13 , 14 , 15 ]. Given this context, research has intensified on different extracts from natural matrices that have a wide variety of compounds with beneficial effects on health, such as propolis [ 16 , 17 , 18 , 19 ].…”

Phytochemical Screening and Antiprotozoal Effects of the Methanolic Berberis Vulgaris and Acetonic Rhus Coriaria Extracts

“…In addition to that, β-guaiene and caryophyllene show antiprotozoal activity against P. falciparum, T. brucei, T. cruzi, L. amazonensis, and L. infantum with IC 50 values ranging from 2.2 to 56.6 µg/mL [40]. Sena-Lopes et al [41] investigated the antiprotozoal effect of methyleugenol, β-caryophyllene and α-curcumene against the growth of T. vaginalis, with an IC 50 value of 100 µg/mL. The GC-MS analysis of Syzygium (S.) aromaticum documented the presence of eugenol, β-guaiene, caryophyllene, and α-ylangene which showed potent antipiroplasmic effect in vitro and in vivo [9,42].…”