Display omitted
•L. gracilis EO and terpenes was tested on susceptible and OP resistant R. microplus.•Essential oils of both genotypes were more effective against OP resistant tick.•Carvacrol was 3.2 ...times more toxic to OP resistant strain than to susceptible strain.•Thymol was equally toxic to resistant and susceptible tick strains.
Plant-derived natural products can serve as an alternative to synthetic compounds for control of ticks of veterinary and medical importance. Lippia gracilis is an aromatic plant that produces essential oil with high content of carvacrol and thymol monoterpenes. These monoterpenes have high acaricidal activity against Rhipicephalus (Boophilus) microplus. However, there are no studies that show efficacy differences of essential oils between susceptible and organophosphate resistant strains of R. (B.) microplus. The aim of the present study was to compare acaricidal effects of essential oils extracted from two different genotypes of L. gracilis and the main monoterpenes on larvae of both susceptible and organophosphate resistant R. (B.) microplus larvae. The efficacy of the essential oil of two genotypes of L. gracilis (106 and 201) and their monoterpenes carvacrol and thymol was measured using the larval immersion test on coumaphos-resistant and susceptible strains of R. (B.) microplus. Lethal concentrations were calculated using GraphPad Prism 6.0. Chemical analysis was performed by GC–MS and FID. Thymol and carvacrol were observed to be major constituents in 106 and 201L. gracilis genotype essential oils, respectively. Essential oils of both genotypes were more effective against organophosphate-resistant tick strain than susceptible tick strain. Carvacrol was 3.2 times more toxic to organophosphate resistant strain than to susceptible strain. Thymol was equally toxic to resistant and susceptible tick strains. The significantly higher efficacy monoterpene carvacrol against resistant ticks may lead to development of new natural product acaricide formulations for use to control organophosphate resistant R. (B.) microplus populations.
is a trypanosomatid phytoparasite, found in a great variety of species, including tomato plants. It is a significant problem for agriculture, causing high economic loss. In order to reduce the ...vegetal infections, different strategies have been used. The biological activity of molecules obtained from natural sources has been widely investigated to treat trypanosomatids infections. Among these compounds, chalcones have been shown to have anti-parasitic and anti-inflammatory effects, being described as having a remarkable activity on trypanosomatids, especially in
species. Here, we evaluated the antiprotozoal activity of the chalcone derivative (NaF) on
promastigotes, while also assessing its mechanism of action. The results showed that treatment with the derivative NaF for 24 h promotes an important reduction in the parasite proliferation (IC
/24 h = 23.6 ± 4.6 µM). At IC
/24 h concentration, the compound induced an increase in reactive oxygen species (ROS) production and a shortening of the unique flagellum of the parasites. Electron microscopy evaluation reinforced the flagellar phenotype in treated promastigotes, and a dilated flagellar pocket was frequently observed. The treatment also promoted a prominent autophagic phenotype. An increased number of autophagosomes were detected, presenting different levels of cargo degradation, endoplasmic reticulum profiles surrounding different cellular structures, and the presence of concentric membranar structures inside the mitochondrion. Chalcone derivatives may present an opportunity to develop a treatment for the
infection, as they are easy to synthesize and are low in cost. In order to develop a new product, further studies are still necessary.
BACKGROUND: Dengue fever is a severe public health problem for several countries. In order to find effective larvicides to aid control programs, the structure‐activity relationships of eugenol ...derivatives against Aedes aegypti (Diptera: Culicidae) larvae were evaluated. Additionally, the composition and larvicidal activity of Syzygium aromaticum essential oil was assessed. RESULTS: Four compounds representing 99.05% of S. aromaticum essential oil have been identified. The essential oil was active against Ae. aegypti larvae (LC50 = 62.3 and 77.0 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity of eugenol, the major compound of the essential oil, was further evaluated (LC50 = 93.3 and 71.9 ppm, field‐collected and Rockefeller larvae respectively). The larvicidal activity and structure‐activity relationships of synthetic derivatives of eugenol were also assessed. The larvicidal activity of the derivatives varied between 62.3 and 1614.9 ppm. Oxidation of eugenol allylic bond to a primary alcohol and removal of the phenolic proton resulted in decreased potency. However, oxidation of the same double bond in 1‐benzoate‐2‐methoxy‐4‐(2‐propen‐1‐yl)‐phenol resulted in increased potency. CONCLUSION: Structural characteristics were identified that may contribute to the understanding of the larvicidal activity of phenylpropanoids. The present approach may help future work in the search for larvicidal compounds.
Five chalcone-based molecules denominated by C-3 ((E)-1-(4-methoxyphenyl)-3-phenylprop-2-en-1-one), C-4 ((E)-1,3-bis(4-methoxyphenyl)prop-2-en-1-one), C-5 ...((E)-1-(benzod1,3dioxol-5-yl)-3-(4-methoxyphenyl)prop-2-en-1-one), C-6 ((E)-3-(naphthalen-1-yl)-1-phenylprop-2-en-1-one) and C-7 ((E)-1-(4-methoxyphenyl)-3-(naphthalen-1-yl)prop-2-en-1-one) were synthesized by Claisen-Schmidt reaction in solution of NaOH in water/ethanol 2:1. The aldehydes used were benzaldehyde, anisaldehyde, and β-naphthaldehyde, while the used ketones were acetophenone, p-methoxyacetophenone, and 3,4-methylenedioxyacetophenone. Z-scan and hyper-Rayleigh scattering techniques were used to study the nonlinear optical properties of these compounds in dichloromethane medium. By using Z-scan technique with femtosecond pulses, two-photon absorption cross-sections (σTPA) were determined, while the first molecular electronic hyperpolarizabilities (βHRS) were evaluated by the hyper-Rayleigh scattering technique, with picosecond pulses. From the recorded two-photon absorption spectra, it was identified that compound C-7 presented the highest σTPA, regarding the HOMO-LUMO transition, with a value of 40 GM, while C-6 achieved the lowest value for the same transition with 13 GM. Concerning the values of the first molecular hyperpolarizability, compound C-4 presented the highest value, 38 × 10−30 cm4 statvolt−1, while C-3 presented the lowest βHRS value of about 16 × 10−30 cm4 statvolt−1. Time-dependent density functional theory calculations were used to simulate the one- and two-photon absorption spectra, as well to predict the theoretical value of βHRS in dichloromethane and vacuum medium.
Display omitted
•Synthesis and structural characterization of five chalcone-based molecules;•Experimental two-photon absorption spectra obtained with the Z-scan technique by using femtosecond pulses;•Experimental first molecular hyperpolarizability obtained with the HRS technique by using picosecond pulses;•Simulation of the one- and two-photon absorption spectra by using Gaussian 09;•Simulation of the first molecular hyperpolarizability by using Gaussian 09.
Display omitted
•Extraction of Piper hispidum dried leaves was conducted with supercritical CO2 and co-solvents addition.•The use of 5 % of co-solvent increased up to 47 % the extract yield compared ...to only CO2.•Four cinnamoyl pyrrolidine amides were isolated from SC−CO2 extracts.•The cinnamoyl pyrrolidine amides (up to 74.11 %) were the major compounds identified at supercritical extracts.
Supercritical carbon dioxide (SC−CO2) extraction of dry leaves of Piper hispidum was employed to optimize the selective extraction of cinnamoyl pyrrolidine amides. Taguchi L-9 method and 32 factorial experiments were used in the methodology optimization. The extraction yield (1.92 %, 353 K/ and 20 MPa) was improved significantly to 3.62 % with organic solvents addition (5 % of methanol in the extraction). The chemical composition investigation of supercritical extracts led to the isolation of four compounds, not initially identified by GC–MS. The compound 2 (Z,E) and 3 (E,Z) were identified as the major cinnamoyl pyrrolidine amides (up to 74.11 %). Antioxidant activity assay of the extract obtained at 333 K/ 20 MPa presented an IC50 of 228 μg/mL and AAI of 0.087. The amide 2 and 5 % co-solvent extracts were also capable of inhibiting HL-60 cells grow up to 73 %. The newly developed methodology was suitable to obtain selectively metabolites with biological potential.
Plant essential oils are potential sources of insecticidal compounds, but have rarely been explored for their effect on termites. In the present study, we assessed the chemical composition of ...essential oils of Lippia sidoides Cham. (pepper‐rosmarin; Verbenaceae) and Pogostemon cablin (Blanco) Benth. (patchouli; Lamiacaeae) and evaluated their toxicity, behavioral impairment, and repellence to termite species of the genera Amitermes and Microcerotermes (Isoptera: Termitidae: Termitinae). The main components of essential oils of L. sidoides and P. cablin were thymol (44.6%) and patchouli alcohol (36.6%), respectively. The essential oil of P. cablin was most potent against Amitermes cf. amifer Silvestri and had the lowest LD50 (0.63 μg mg−1). There was no difference in toxicity for Microcerotermes indistinctus Mathews between the essential oils of L. sidoides (LD50 = 1.49 μg mg−1) and P. cablin (LD50 = 1.67 μg mg−1). Pogostemon cablin essential oil was the most toxic to M. indistinctus (LC50 = 0.32 μl ml−1) and A. cf. amifer (LC50 = 0.29 μl ml−1). The essential oils analyzed exhibited high toxicity and repellence to the termites, in addition to reducing behavioral interactions among individuals, thus constituting potential termiticides.
Plants of the genus
have been frequently reported as important medicinal plants. Despite their high bioactive potential, to date, there are no reports of their effects on leaf-cutting ants. ...Therefore, the present study aimed to evaluate the insecticidal activity of the essential oil of
and its major components on
and
, two species of leaf-cutting ants. The bioassays were performed regarding routes of exposure, acute toxicity, binary mixtures of the major components and behavioral effects. Twenty-five components were identified in the essential oil of
using a gas chromatographic system equipped with a mass spectrometer and a flame ionization detector. The components found in higher proportions were sulcatyl acetate, limonene,
-cymene and linalool. The essential oil of
and its individual major components were efficient against
and
workers when applied by fumigation. These components showed fast and efficient insecticidal activity on ants. The components acted synergistically and additively on
and
, respectively, and caused a strong repellency/irritability in the ants. Thus, our results demonstrate the great potential of the essential oil of
and its major components for the development of new insecticides.
Different parts of
Annona muricata
L., Annonaceae, are widely used for their biological activities. The fruit of this plant, called “graviola,” is recognized for its nutritional value, but its seeds ...are usually discarded, despite their potential as a source of substances with anti-inflammatory properties. This study investigated the effect of graviola seed oil in models of cutaneous inflammation after topical administration. Graviola seed oil was characterized regarding its fatty acid composition and evaluated
in vitro
for cytotoxicity in L929 fibroblasts. Acute cutaneous inflammation was induced by topical administration of 12-
O
-tetradecanoilphorbol-13-acetate, phenol, or capsaicin in the right ears of Swiss mice. Concomitantly, ears were treated with graviola seed oil (0.3, 1, and 3 mg/ear), oleic acid (0.3, 0.1, and 3 mg/ear), or dexamethasone (control). After the induction, inflammatory parameters were analyzed. The main fatty acids found in graviola seed oil were oleic (43.37%), linoleic (29.86%), palmitic (21.94%), and stearic acids (4.82%). Seed oil (10–150 μg/ml) did not alter L929 fibroblasts’ viability after 24 h of exposure. Treatment with seed oil, or dexamethasone reduced ear edema, myeloperoxidase activity, histological alterations, lipid peroxidation, and interleukin-1β and 6 levels induced by 12-
O
-tetradecanoilphorbol-13-acetate. Treatment with oleic acid reduced ear edema and lipid peroxidation, but not myeloperoxidase activity, in 12-
O
-tetradecanoilphorbol-13-acetate model. Treatment with seed oil and oleic acid reduced edema formation, but only treatment with seed oil reduced myeloperoxidase activity in phenol-induced ear inflammation. Administration of seed oil and oleic acid did not affect capsaicin-induced ear edema. These findings demonstrate the anti-inflammatory activity of graviola seed oil after skin injury, which is partially related to the presence of oleic acid.
Graphical Abstract
The essential oils obtained by hydrodistillation from fresh leaves of Vitex agnus-castus and Ocimum campechianum, and from fresh inflorescences of Ocimum carnosum were analysed by GC-FID and GC-MS. ...The major components of V. agnus-castus essential oil were identified as 1,8-cineole (47.9%), terpinyl α-acetate (11.6%), sabinene (11.2%) and caryophyllene oxide (9.7%), while in the O. campechianum essential oil were eugenol (72.1%), β-elemene (6.8%), (E)-caryophyllene (6.4%) and bicyclogermacrene (5.2%). Linalool (79.0%), α-epi-cadinol (5.4%), terpinen-4-ol (3.2%) and 1,8-cineole (2.8%) were the major constituents in the O. carnosum essential oil. The essential oils were subsequently evaluated for their larvicidal and cytotoxic activities. Larval bioassay against Aedes aegypti of V. agnus-castus, O. campechianum and O. carnosum essential oils showed LC50 values of 97.55 ± 0.35, 81.45 ± 0.35 and 109.49 ± 0.35 μg/mL, respectively. The in vitro cytotoxic activities of the essential oils has been evaluated on breast adenocarcinoma (MCF-7), lung carcinoma (NCI-H292), pro-myelocytic leukemia (HL-60), and cervical adenocarcinoma (HEP-2) human cell lines, and pro-myelocytic leukemia cells lines (HL-60) were found to be the most sensitive to all the essential oils tested than the others. This is the first report on larvicidal and cytotoxic activities of these essential oils.
PDF
