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Estudos fitoquímicos e avaliação da atividade antitumoral de extratos vegetais de Casearia sylvestris nanoencapsulados
(Universidade Federal de São Carlos, 2013-03-26) Santos, Karen Cristina dos; Forim, Moacir Rossi; https://lattes.cnpq.br/1234565160573730; https://lattes.cnpq.br/8077173096185048
The term cancer refers to neoplasias that are characterized by uncontrolled growth of cells that have some kind of genetic mutation. Prostate cancer is the cancer with the highest incidence in men. In its initial phase, the prostate cancer is hormone dependent, so current therapy is based on blocking the biosynthesis of hormones, but after the initial treatment, neoplastic cells grow back inordinately becoming resistant to treatment. Although there are drugs in clinical trials, it´s still necessary the search for molecules that exhibit activity against prostate cancer cells. Natural products have a great importance in cancer treatment. Due to its past history of beneficial effects on human health and especially its cytotoxic activity on cancer cells, the plant Casearia sylvestris was studied. However, the insolubility and low bioavailability in aqueous media hamper the use of these compounds. In an attempt to reduce this limitation, nanostructured systems for drug delivery have been recognized as promising vehicles. Polymeric nanoparticles have been used to overcome problems of solubility, bioavailability and aiming the target cells (tumor). The purpose of this work was the preparation of formulations of polymeric nanoparticles containing plant extract of C. sylvestris and evaluation of cytotoxic activity in cell lines and healthy prostate carcinoma. Thus, 3 factorial 22 designs were developed, and parameters as solution stability, recovery and encapsulation efficiency were considered. The nanoparticles were prepared by the method of nanoprecipitation, and the stability, recovery and encapsulation efficiency were satisfactory. In biological tests, the nanoparticles formulations showed selectivity up to 23 % on healthy and neoplastic cells, decreasing the viability of prostate carcinoma cells by 45%. Therefore, plant extracts of C. sylvestris shown to be active in cancer cells, and polymeric nanoparticle delivery systems may be promising in the treatment of prostate carcinoma.
Filogeografia de Bubulcus ibis (Linnaeus, 1758) na África e o processo de colonização do continente americano por essa espécie
(Universidade Federal de São Carlos, 2013-03-26) Castillo, Carlos Congrains; Del Lama, Sílvia Nassif; https://lattes.cnpq.br/7893772074091604; https://lattes.cnpq.br/6507370808858197
The cattle egret (Bubulcus ibis [Ardeidae]) was first reported in the New World in the late nineteenth century and has been found scattered throughout the Americas since the 1950s. The aim of the present study was to analyze the distribution of genetic diversity in African and Brazilian populations of the cattle egret to understand the process of colonization of the non-native area in the Brazil. Genetic variation in the mitochondrial DNA (mtDNA) Control Region (CR) (n = 412 African and 177 Brazilian individuals), in ATPase 6 and 8 genes (n = 108 African and 49 Brazilian individuals) and in the intron 5 of the nuclear transforming growth factor beta-2 gene (n = 96 African and 50 Brazilian individuals) were evaluated. Genetic diversity across regions of Africa was similar, except for the lesser diversity found in South Africa. Neutrality tests, mismatch distributions and Bayesian skyline plots revealed demographic expansion in the overall African population, dated by the latter method as 15000 years before the present, occurred after the last glacial maximum. The findings were discussed hypothesizing that past climatic events have shaped the current distribution of genetic diversity. AMOVA and pairwise Fst tests revealed a lack of differentiation among nearly all African populations. The few cases of differentiation involved the South African and/or Nigerian populations. Brazilian populations exhibited no genetic structure or effective size deviations over time. Mitochondrial and nuclear DNA genetic variability demonstrated similar levels of genetic variation between the Brazilian and African populations, suggesting multiple introduction events. Based on historical and genetic data (differentiation levels and shared haplotypes), we propose a likely migration route between both continents departing from West Africa, passing through oceanic islands and archipelagos, such as Cape Verde, and finally arriving in the Americas on the northern and/or southern coast of Brazil.
Síntese de complexos semi-sanduíche n6-p-cimeno- Ru(II) contendo ligantes binitrogenados, interação com o DNA e potenciais atividades farmacológicas / Legna Andreina Colina Vegas
(Universidade Federal de São Carlos, 2013-03-26) Colina Vegas, Legna Andreina; Batista, Alzir Azevedo; https://lattes.cnpq.br/6469642481998660; https://lattes.cnpq.br/6588460663135481
The synthesis, spectroscopic characterization, crystal structures and electrochemistry of π-arene piano-stool ruthenium (II) complexes with pyridine or derivatives as nitrogen donor ligands are described. A series of six organometallic compounds of formulae [RuCl(η6-p-cymene)(N∩N)]PF6 [N∩N=1,10’-phenantroline (phen), 4,7’-diphenil-1,10’-phenantroline (phphen), 2,2’-bipyridine (bipy), 5,5’-dimethyl-2,2’-bipyridine (mebipy), 4,4’-dimethoxi-2,2’-bipyridine (meobipy) and 4,4’-di-t-buthyl-2,2’-bipyridine (butbipy)]were synthesized and fully characterized. The solid state structures of the six complexes were determined by X-ray crystallography and their characterization was completed by FT-IR spectroscopy, molar conductivity and NMR studies (1H and 13C). Electrochemical experiments were performed by cyclic voltammetry to estimate the redox potential of the Ru(II)/Ru(III) couple and this potential does not vary significantly between the complexes. Additionally, spectroscopic titration with DNAct were done, to estimate interaction constants between the metal complex and this macromolecule. The values of the constants indicate a reversible interaction with DNA, which is in concordance with the literature.