Efeitos de combinações entre o ácido anacárdico derivado da casca da castanha do caju (Anacardium occidentale) e o óleo de açaí (Euterpe oleracea Mart.), livres ou nanoestruturados, no tratamento de células de câncer de pele não melanoma, in vitro

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Pós-Graduação em Nanociência e Nanobiotecnologia, 2017.O Câncer de Pele Não Melanoma (CNPM) o tipo de câncer que possui maior incidência no Brasil e no mundo. O ácido anacárdico (AA) é um composto proveniente da casca da castanha do caju (Anacardium occidentale) que vem atraindo grande interesse nos últimos anos devido ás suas propriedades antitumorais, antibióticas, gastroprotetoras e antioxidantes. O açaí (Euterpe oleracea Mart.) também vem atraindo a atenção de pesquisadores, por ser rico em polifenóis com atividades como supressão tumoral, antiproliferativo e pró-apoptótica. Grande parte desses fitoquímicos que possuem atividades terapêuticas são pouco solúveis em soluções aquosas, o que dificulta sua administração e absorção no organismo. Desta forma, a encapsulação desses compostos em nanoestruturas se torna uma alternativa plausível para potencializar seus efeitos biológicos. Diante do exposto, o presente projeto de pesquisa tem como objetivo avaliar os efeitos de combinações entre o ácido anacárdico (AA) derivado da casca da castanha do caju (Anacardium occidentale) e o óleo de açaí (Euterpe oleracea Mart.), livres ou nanoestruturados, no tratamento de câncer de pele não melanoma in vitro. Os testes de estabilidade mostraram que a nanoemulsão à base de óleo de açaí (AçNE) apresentaram gotículas com diâmetro hidrodinâmico de ± 140 nm, com índice de polidespersão de 0,229, potencial de superfície de ± 17,6 mV e pH 7 por 120 dias. Foi possível modificar a superfície das AçNE adicionando polímeros de quitosana (CH), polietileno glicol (PEG) e fosfolipídios catiônicos DOTAP (1,2-Dioleoiloxi-3-(trimetilamónio) propano). Tais formulações não apresentaram efeito citotóxico nas linhagens A431 e HaCaT, independentemente do tipo de superfície. Os tratamentos AçNE associado ao AA provocaram uma significativa redução na viabilidade das células A431, porém não foi observado efeito de sinergismo entre os mesmos. Em contrapartida, quando ambos compostos foram adicionados na forma não-nanoestruturada, observou-se redução de 90% da viabilidade de células A431 em 24 horas. Dados de citometria de fluxo indicam que a combinação dos compostos livres resulta em morte celular por apoptose e bloqueio do ciclo celular. O presente estudo sugere que a combinação de óleo de açaí e AA é uma promissora alternativa terapêutica antitumoral a ser mais explorada em estudos futuros.Non-Melanoma Skin Cancer (CNPM) is the type of cancer that has the highest incidence in Brazil and worldwide. Anacardic acid (AA) is a compound derived from cashew nuts (Anacardium occidentale) that has attracted great interest in recent years due to its antitumor, antibiotic, gastroprotective and antioxidant properties. Açaí (Euterpe oleracea Mart.) has also attracted the attention of researchers, because it is rich in polyphenols which shows great activity as a tumor suppressor, antiproliferative and pro-apoptotic. Most of these phytochemicals that have therapeutic activities are poorly soluble in aqueous solutions, which hinders their administration and absorption in the body. In this way, the encapsulation of these compounds in nanostructures becomes a plausible alternative to enhance their biological effects. Thus, the present research project has the objective of evaluating the effects of anacardic acid (AA) derived from cashew nut shell (Anacardium occidentale) and açaí oil (Euterpe oleracea Mart.), free or nanostructured, in the treatment of non-melanoma skin cancer in vitro. The stability tests showed that the açaí oil-based nanoemulsion (AçNE) showed droplets with a hydrodynamic diameter of ± 140 nm, with a polydispersion index of 0.229, surface potential of ± 17.6 mV and pH 7 for 120 days. It was possible to modify the surface of the AçNE by adding polymers of chitosan (CH), polyethylene glycol (PEG) and cationic phospholipids DOTAP (1,2-Dioleoyloxy-3- (trimethylammonium) propane). Such formulations showed no cytotoxic effect on the A431 and HaCaT cell lines, regardless of surface type. The AçNE treatments associated with AA caused a significant reduction in the viability of A431 cells, but no synergism was observed between them. On the other hand, when both compounds were added in the non-nanostructured form, a 90% reduction in the viability of A431 cells was observed in 24 hours. Flow cytometry data indicate that the combination of the free compounds results in cell death by apoptosis and cell cycle block. The present study suggests that the combination of acai oil and AA is a promising alternative antitumor therapy to be further explored in future studies

Population dynamics of female-specific RIDL and autosomal X-shredders.

<p>A: Initial population suppression following 30 consecutive releases of males homozygous for the female-specific RIDL allele (no fitness cost) into an isolated population. Results depicted are a single run of the stochastic simulation. B: Sustained population suppression achieved through regular releases of 5,000 males homozygous for the female-specific RIDL allele into population C at each half generation following 20 initial releases of 10,000 transgenic males (bi-directional migration rate of 1% per generation). C: Initial population suppression following 30 consecutive releases of males homozygous for the autosomal X-shredder allele (no fitness cost, transgenic males have 90% male offspring) into an isolated population. D: Sustained population suppression achieved through regular releases of 2,500 males homozygous for the autosomal X-shredder allele into population C at each generation following 20 initial releases of 10,000 transgenic males (bi-directional migration rate of 1% per generation).</p

<i>Medusa</i> dynamics in two partially-isolated populations.

<p>A: Bi-directional migration model in which mosquitoes carrying the <i>Medusa</i> system are introduced into population C, and populations C and D exchange a fraction, <i>m</i>, of their individuals at each generation. B: Confined population suppression following six consecutive releases of 10,000 <i>Medusa</i> males (no fitness cost) into population C (bi-directional migration rate of 1% per generation). Results depicted are a single run of the stochastic simulation. C: Confined population suppression and a wild-type rebound for the same release scenario as in panel B, but a smaller bi-directional migration rate of 0.03% per generation. D: The frequency of a wild-type rebound occurring within 100 generations of a super-threshold release (no <i>Medusa</i> fitness cost) as a function of migration rate. E: Sustained population suppression achieved through regular releases of 180 <i>Medusa</i> males into population C at each generation following six initial releases of 10,000 <i>Medusa</i> males into the same population.</p

Components and inheritance pattern of the <i>Medusa</i> system.

<p><i>Medusa</i> consists of four components – two at a locus on the X chromosome and two at a locus on the Y chromosome. The action of the maternally-expressed, X-linked toxin is suppressed in zygotes that inherit the Y-linked antidote. The effects of the zygotically-expressed, Y-linked toxin are suppressed in zygotes inheriting the X-linked antidote.</p

Engineered Reciprocal Chromosome Translocations Drive High Threshold, Reversible Population Replacement in Drosophila

Replacement of wild insect populations with transgene-bearing individuals unable to transmit disease or survive under specific environmental conditions using gene drive provides a self-perpetuating method of disease prevention. Mechanisms that require the gene drive element and linked cargo to exceed a high threshold frequency in order for spread to occur are attractive because they offer several points of control: they bring about local, but not global population replacement; and transgenes can be eliminated by reintroducing wildtypes into the population so as to drive the frequency of transgenes below the threshold frequency required for drive. Reciprocal chromosome translocations were proposed as a tool for bringing about high threshold population replacement in 1940 and 1968. However, translocations able to achieve this goal have only been reported once, in the spider mite <i>Tetranychus urticae,</i> a haplo-diploid species in which there is strong selection in haploid males for fit homozygotes. We report the creation of engineered translocation-bearing strains of <i>Drosophila melanogaster</i>, generated through targeted chromosomal breakage and homologous recombination. These strains drive high threshold population replacement in laboratory populations. While it remains to be shown that engineered translocations can bring about population replacement in wild populations, these observations suggest that further exploration of engineered translocations as a tool for controlled population replacement is warranted

The monthly number of imported cases for 2013, 2014, and the mean, median, and range of 2001 to 2014.

<p>The monthly number of imported cases for 2013, 2014, and the mean, median, and range of 2001 to 2014.</p

Climate and the Timing of Imported Cases as Determinants of the Dengue Outbreak in Guangzhou, 2014: Evidence from a Mathematical Model

<div><p>As the world’s fastest spreading vector-borne disease, dengue was estimated to infect more than 390 million people in 2010, a 30-fold increase in the past half century. Although considered to be a non-endemic country, mainland China had 55,114 reported dengue cases from 2005 to 2014, of which 47,056 occurred in 2014. Furthermore, 94% of the indigenous cases in this time period were reported in Guangdong Province, 83% of which were in Guangzhou City. In order to determine the possible determinants of the unprecedented outbreak in 2014, a population-based deterministic model was developed to describe dengue transmission dynamics in Guangzhou. Regional sensitivity analysis (RSA) was adopted to calibrate the model and entomological surveillance data was used to validate the mosquito submodel. Different scenarios were created to investigate the roles of the timing of an imported case, climate, vertical transmission from mosquitoes to their offspring, and intervention. The results suggested that an early imported case was the most important factor in determining the 2014 outbreak characteristics. Precipitation and temperature can also change the transmission dynamics. Extraordinary high precipitation in May and August, 2014 appears to have increased vector abundance. Considering the relatively small number of cases in 2013, the effect of vertical transmission was less important. The earlier and more frequent intervention in 2014 also appeared to be effective. If the intervention in 2014 was the same as that in 2013, the outbreak size may have been over an order of magnitude higher than the observed number of new cases in 2014.The early date of the first imported and locally transmitted case was largely responsible for the outbreak in 2014, but it was influenced by intervention, climate and vertical transmission. Early detection and response to imported cases in the spring and early summer is crucial to avoid large outbreaks in the future.</p></div

Climate file and intervention used in each scenario.

<p>Climate file and intervention used in each scenario.</p

Trajectories for daily new cases of the 637 passing parameter sets in Cycle 5.

<p>Black dots indicate the number of daily new cases from Guangzhou CDC, while gray lines are model outputs and red line is the median for all outputs. Blue and red vertical dash lines stand for washout and intervention days, respectively. Blue shaded area for the 90 percent interval for all 637 simulations.</p

Mosquito submodel patterns.

<p>The scaled 637 simulated results and field data for (a) larva and (b) adults. Gray lines show model output, red lines median output, and dark blue points show mosquito surveillance data acquired from Guangzhou CDC.</p