Publications by authors named "Geanne K N Santos"

9 Publications

  • Page 1 of 1

Anti-Inflammatory Activity of Babassu Oil and Development of a Microemulsion System for Topical Delivery.

Evid Based Complement Alternat Med 2017 21;2017:3647801. Epub 2017 Dec 21.

Núcleo de Plataformas Tecnológicas, Instituto Aggeu Magalhães, FIOCRUZ, Av. Prof. Moraes Rego S/N, Cidade Universitária, 50740-465 Recife, PE, Brazil.

Babassu oil extraction is the main income source in nut breakers communities in northeast of Brazil. Among these communities, babassu oil is used for cooking but also medically to treat skin wounds and inflammation, and vulvovaginitis. This study aimed to evaluate the anti-inflammatory activity of babassu oil and develop a microemulsion system with babassu oil for topical delivery. Topical anti-inflammatory activity was evaluated in mice ear edema using PMA, arachidonic acid, ethyl phenylpropiolate, phenol, and capsaicin as phlogistic agents. A microemulsion system was successfully developed using a Span® 80/Kolliphor® EL ratio of 6 : 4 as the surfactant system (S), propylene glycol and water (3 : 1) as the aqueous phase (A), and babassu oil as the oil phase (O), and analyzed through conductivity, SAXS, DSC, TEM, and rheological assays. Babassu oil and lauric acid showed anti-inflammatory activity in mice ear edema, through inhibition of eicosanoid pathway and bioactive amines. The developed formulation (39% A, 12.2% O, and 48.8% S) was classified as a bicontinuous to o/w transition microemulsion that showed a Newtonian profile. The topical anti-inflammatory activity of microemulsified babassu oil was markedly increased. A new delivery system of babassu microemulsion droplet clusters was designed to enhance the therapeutic efficacy of vegetable oil.
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http://dx.doi.org/10.1155/2017/3647801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5753019PMC
December 2017

Evaluation of the Activity of the Essential Oil from an Ornamental Flower against Aedes aegypti: Electrophysiology, Molecular Dynamics and Behavioral Assays.

PLoS One 2016 29;11(2):e0150008. Epub 2016 Feb 29.

Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.

Dengue fever has spread worldwide and affects millions of people every year in tropical and subtropical regions of Africa, Asia, Europe and America. Since there is no effective vaccine against the dengue virus, prevention of disease transmission depends entirely on regulating the vector (Aedes aegypti) or interrupting human-vector contact. The aim of this study was to assess the oviposition deterrent activity of essential oils of three cultivars of torch ginger (Etlingera elatior, Zingiberaceae) against the dengue mosquito. Analysis of the oils by gas chromatography (GC)-mass spectrometry revealed the presence of 43 constituents, of which α-pinene, dodecanal and n-dodecanol were the major components in all cultivars. Solutions containing 100 ppm of the oils exhibited oviposition deterrent activities against gravid Ae. aegypti females. GC analysis with electroantennographic detection indicated that the oil constituents n-decanol, 2-undecanone, undecanal, dodecanal, trans-caryophyllene, (E)-β-farnesene, α-humulene, n-dodecanol, isodaucene and dodecanoic acid were able to trigger antennal depolarization in Ae. aegypti females. Bioassays confirmed that solutions containing 50 ppm of n-dodecanol or dodecanal exhibited oviposition deterrent activities, while a solution containing the alcohol and aldehyde in admixture at concentrations representative of the oil presented an activity similar to that of the 100 ppm oil solution. Docking and molecular dynamics simulations verified that the interaction energies of the long-chain oil components and Ae. aegypti odorant binding protein 1 were quite favorable, indicating that the protein is a possible oviposition deterrent receptor in the antenna of Ae. aegypti.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0150008PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4771710PMC
July 2016

Thiosemicarbazones as Aedes aegypti larvicidal.

Eur J Med Chem 2015 Jul 28;100:162-75. Epub 2015 May 28.

Quantum Theory Project, University of Florida, 2234 New Physics Building, Gainesville, PO Box 118435, Florida, USA.

A set of aryl- and phenoxymethyl-(thio)semicarbazones were synthetized, characterized and biologically evaluated against the larvae of Aedes aegypti (A. aegypti), the vector responsible for diseases like Dengue and Yellow Fever. (Q)SAR studies were useful for predicting the activities of the compounds not included to create the QSAR model as well as to predict the features of a new compound with improved activity. Docking studies corroborated experimental evidence of AeSCP-2 as a potential target able to explain the larvicidal properties of its compounds. The trend observed between the in silico Docking scores and the in vitro pLC50 (equals -log LC50, at molar concentration) data indicated that the highest larvicidal compounds, or the compounds with the highest values for pLC50, are usually those with the higher docking scores (i.e., greater in silico affinity for the AeSCP-2 target). Determination of cytotoxicity for these compounds in mammal cells demonstrated that the top larvicide compounds are non-toxic.
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http://dx.doi.org/10.1016/j.ejmech.2015.04.061DOI Listing
July 2015

Effects of α,β-unsaturated lactones on larval survival and gut trypsin as well as oviposition response of Aedes aegypti.

Exp Parasitol 2015 Sep 1;156:37-41. Epub 2015 Jun 1.

Departamento de Química Fundamental-CCEN, Universidade Federal de Pernambuco, Av. Jornalista Aníbal Fernandes, s/n - Cidade Universitária, Recife, PE 50740-560, Brazil.

Lactones are organic cyclic esters that have been described as larvicides against Aedes aegypti and as components of oviposition pheromone of Culex quinquefasciatus. This work describes the effect of six α,β-unsaturated lactones (5a-5f) on survival of A. aegypti fourth instar larvae (L4). It is also reported the effects of the lactones on L4 gut trypsin activity and oviposition behavior of A. aegypti females. Five lactones were able to kill L4 being the lactones 5a (LC50 of 39.05 ppm), 5e (LC50 of 36.30 ppm) and 5f (LC50 of 40.46 ppm) the most promising larvicides. Only the lactone 5a inhibited L4 gut trypsin activity, with an IC50 of 115.15 µg/mL. Lactones 5a, 5c, 5d and 5e did not exert deterrent or stimulatory effects on oviposition, whereas lactone 5b exhibited a strong deterrent oviposition activity. In conclusion, this work introduces new α,β-unsaturated lactones as promising alternatives to control A. aegypti dissemination. The larvicidal mechanism of the lactone 5a can involve the disruption of proteolysis at larval gut.
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http://dx.doi.org/10.1016/j.exppara.2015.05.017DOI Listing
September 2015

Extract of Bowdichia virgilioides and maackiain as larvicidal agent against Aedes aegypti mosquito.

Exp Parasitol 2015 Jun 24;153:160-4. Epub 2015 Mar 24.

Departamento de Química Fundamental, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.

The larvicidal activities of extracts of three hardwood species (Hymenaea stigonorcapa, Anadenanthera colubrina and Bowdichia virgilioides) against 4th instar larvae of Aedes aegypti were evaluated using WHO guidelines. Extracts of H. stignocarpa and A. colubrina showed weak activity. The highest larvicidal effect was obtained with the cyclohexane extract of the heartwood of B. virgilioides, which caused 100% mortality at concentrations at 50 and 100 µg/mL. Fraction toluene/EtOAc (8:2) from this extract showed larvicidal activity (LC₅₀ = 34.90 ± 1.27 µg/mL). A mixture of two compounds identified as medicarpin and maackiain exhibited a very good larvicidal activity (sub-fraction 2, LC₅₀ = 17.5 ± 1.87 µg/mL) and maackiain showed to be a strong larvicidal compound (LC₅₀ = 21.95 ± 1.34 µg/mL). This result can be of value in the search for new natural larvicidal compounds from other hardwood plant extracts and presents the first report of B. virgilioides being used to control a mosquito vector.
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http://dx.doi.org/10.1016/j.exppara.2015.03.018DOI Listing
June 2015

Effects of Croton rhamnifolioides essential oil on Aedes aegypti oviposition, larval toxicity and trypsin activity.

Molecules 2014 Oct 14;19(10):16573-87. Epub 2014 Oct 14.

Laboratório de Ecologia Química, Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.

Although numerous reports are available concerning the larvicidal potential of essential oils, very few investigations have focused on their mechanisms of action. In the present study, we have investigated the chemical composition of the leaf oil of Croton rhamnifolioides during storage and its effects on oviposition and survival of larvae of the dengue fever mosquito Aedes aegypti. In addition, we have established a possible mechanism of action for the larvicidal activity of the essential oil. GC-MS analyses revealed marked differences in the composition of oil that had been freshly isolated and that of a sample that had been stored in a sealed amber-glass vial under refrigeration for three years. However, both fresh and stored oil exhibited substantial larvicidal activities with LC50 values of 122.35 and 89.03 ppm, respectively, and oviposition deterrent effects against gravid females at concentrations of 50 and 100 µg·mL-1. These results demonstrate that the larvicidal effect of the essential oil was unchanged during three years of storage even though its chemical composition altered. Hence, the essential oil could be used in the preparation of commercial products. In addition, we observed that the trypsin-like activity of mosquito larvae was inhibited in vitro by the essential oil of C. rhamnifolioides, suggesting that the larvicidal effect may be associated with inhibition of this enzyme.
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http://dx.doi.org/10.3390/molecules191016573DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6271117PMC
October 2014

The enzyme 3-hydroxykynurenine transaminase as potential target for 1,2,4-oxadiazoles with larvicide activity against the dengue vector Aedes aegypti.

Bioorg Med Chem 2013 Nov 20;21(22):6996-7003. Epub 2013 Sep 20.

Department of Fundamental Chemistry, Federal University of Pernambuco, Recife 50740-560, Brazil.

The mosquito Aedes aegypti is the vector agent responsible for the transmission of yellow fever and dengue fever viruses to over 80 million people in tropical and subtropical regions of the world. Exhaustive efforts have lead to a vaccine candidate with only 30% effectiveness against the dengue virus and failure to protect patients against the serotype 2. Hence, vector control remains the most viable route to dengue fever control programs. We have synthesized a class of 1,2,4-oxadiazole derivatives whose most biologically active compounds exhibit potent activity against Aedes aegypti larvae (ca. of 15 ppm) and low toxicity in mammals. Exposure to these larvicides results in larvae pigmentation in a manner correlated with the LC50 measurements. Structural comparisons of the 1,2,4-oxadiazole nucleus against known inhibitors of insect enzymes allowed the identification of 3-hydroxykynurenine transaminase as a potential target for these synthetic larvicides. Molecular docking calculations indicate that 1,2,4-oxadiazole compounds can bind to 3-hydroxykynurenine transaminase with similar conformation and binding energies as its crystallographic inhibitor 4-(2-aminophenyl)-4-oxobutanoic acid.
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http://dx.doi.org/10.1016/j.bmc.2013.09.020DOI Listing
November 2013

Larvicidal isoxazoles: Synthesis and their effective susceptibility towards Aedes aegypti larvae.

Bioorg Med Chem 2013 Feb 13;21(4):940-7. Epub 2012 Dec 13.

Departamento de Química Fundamental, Universidade Federal de Pernambuco, Cidade Universitária, 50740-560 Recife, PE, Brazil.

Twenty 3,5-disubstituted isoxazoles have been synthesized and tested against fourth instar Aedes aegypti larvae. In the synthesis of title compounds, modifications have been made in the C-5 side-chain with a view to test their larvicidal activity. These isoxazoles have been obtained by 1,3-dipolar cycloaddition of arylnitrile oxides to terminal alkynes which furnished the desired products in 20% to 79% yields. A comparative study of the larvicidal activity between 3-(3-aryl-isoxazol-5-yl)-propan-1-ols and 3-(3-aryl-isoxazol-5-yl)-propionic acids clearly demonstrated that the latter compounds possess much better larvicidal activity than the former. We also tested two esters, viz., methyl 3-[3-(phenyl)-isoxazole-5-yl] propionate and methyl 3-[3-(4-chlorophenyl)-isoxazole-5-yl] propionate, where the latter presented an excellent larvicidal profile.
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http://dx.doi.org/10.1016/j.bmc.2012.12.006DOI Listing
February 2013

Differential vulnerability of substantia nigra and corpus striatum to oxidative insult induced by reduced dietary levels of essential fatty acids.

Front Hum Neurosci 2012 30;6:249. Epub 2012 Aug 30.

Laboratório de Neurofisiologia, Departamento de Fisiologia e Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Pernambuco Recife, Brazil.

Oxidative stress (OS) has been implicated in the etiology of certain neurodegenerative disorders. Some of these disorders have been associated with unbalanced levels of essential fatty acids (EFA). The response of certain brain regions to OS, however, is not uniform and a selective vulnerability or resilience can occur. In our previous study on rat brains, we observed that a two-generation EFA dietary restriction reduced the number and size of dopaminergic neurons in the substantia nigra (SN) rostro-dorso-medial. To understand whether OS contributes to this effect, we assessed the status of lipid peroxidation (LP) and anti-oxidant markers in both SN and corpus striatum (CS) of rats submitted to this dietary treatment for one (F1) or two (F2) generations. Wistar rats were raised from conception on control or experimental diets containing adequate or reduced levels of linoleic and α-linolenic fatty acids, respectively. LP was measured using the thiobarbituric acid reaction method (TBARS) and the total superoxide dismutase (t-SOD) and catalase (CAT) enzymatic activities were assessed. The experimental diet significantly reduced the docosahexaenoic acid (DHA) levels of SN phospholipids in the F1 (~28%) and F2 (~50%) groups. In F1 adult animals of the experimental group there was no LP in both SN and CS. Consistently, there was a significant increase in the t-SOD activity (p < 0.01) in both regions. In EF2 young animals, degeneration in dopaminergic and non-dopaminergic neurons and a significant increase in LP (p < 0.01) and decrease in the CAT activity (p < 0.001) were detected in the SN, while no inter-group difference was found for these parameters in the CS. Conversely, a significant increase in t-SOD activity (p < 0.05) was detected in the CS of the experimental group compared to the control. The results show that unbalanced EFA dietary levels reduce the redox balance in the SN and reveal mechanisms of resilience in the CS under this stressful condition.
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http://dx.doi.org/10.3389/fnhum.2012.00249DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3431008PMC
October 2012
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