Plantas e constituintes químicos empregados em Odontologia: revisão de estudos etnofarmacológicos e de avaliação da atividade antimicrobiana in vitro em patógenos orais

Produtos derivados de plantas podem representar estratégia promissora na odontologia. Desse modo, o objetivo deste trabalho foi levantar na literatura os estudos sobre o uso popular de plantas em afecções orais, bem como os estudos de avaliação da atividade antimicrobiana in vitro de extratos vegetais e compostos isolados sobre patógenos orais, no período de 1996 a 2011. Quarenta e sete famílias botânicas foram referidas, com maior número de citações para Anacardiaceae, sendo Anacardium occidentale L., a espécie mais citada. O levantamento sobre estudos de avaliação antimicrobiana relacionou extratos de sessenta e seis espécies vegetais pertencentes a trinta e oito famílias botânicas, destacando-se Anacardiaceae, com pesquisas realizadas de forma predominante com as folhas, investigadas pelo método de difusão em ágar. Cinquenta e oito substâncias isoladas de plantas foram avaliadas, demonstrando que Terminalia chebula Retz (Combretaceae) representa a espécie vegetal com atividade antimicrobiana in vitro mais significativa, apresentando halo de inibição de 32,97 mm contra Staphylococcus aureus, microrganismo encontrado em infecções orais; enquanto ácido tetra iso-alfa isolada de Humulus lupulus L. (Canabinaceae) apresentou maior halo de inibição para Streptococcus mutans (26,0 mm). Os resultados apresentados devem estimular o desenvolvimento dos estudos de validação na garantia do uso seguro e eficaz de espécies vegetais em odontologia

Thioglycollate-elicited murine macrophages are cytotoxic to Mycoplasma arginini-infected YAC-1 tumor cells

Macrophages are important components of natural immunity involved in inhibition of tumor growth and destruction of tumor cells. It is known that these cells can be activated for tumoricidal activity by lymphokines and bacterial products. We investigated whether YAC-1 tumor cells infected with Mycoplasma arginini stimulate nitric oxide (NO) release and macrophage cytotoxic activity. Thioglycollate-elicited macrophages from male BALB/c mice were co-cultured for 20 h with YAC-1 tumor cells infected or not with Mycoplasma arginini. The cytotoxic activity was evaluated by MTT assay and nitrite levels were determined with the Griess reagent. Thioglycollate-elicited macrophages co-cultured with noninfected YAC-1 cells showed low cytotoxic activity (34.7 ± 8.6%) and low production of NO (4.7 ± 3.1 µM NO2-). These macrophages co-cultured with mycoplasma-infected YAC-1 cells showed significantly higher cytotoxic activity (61.4 ± 9.1%; P<0.05) and higher NO production (48.5 ± 13 µM NO2-; P<0.05). Addition of L-NAME (10 mM), an inhibitor of NO synthesis, to these co-cultures reduced the cytotoxic activity to 37.4 ± 2% (P<0.05) and NO production to 3 ± 4 µM NO2- (P<0.05). The present data show that Mycoplasma arginini is able to induce macrophage cytotoxic activity and that this activity is partially mediated by NO

Factor analysis applied to genome prediction for high-dimensional phenotypes in pigs

The aim of the present study was to propose and evaluate the use of factor analysis (FA) in obtaining latent variables (factors) that represent a set of pig traits simultaneously, for use in genomewide selection (GWS) studies. We used crosses between outbred F2 populations of Brazilian Piau X commercial pigs. Data were obtained on 345 F2 pigs, genotyped for 237 SNPs, with 41 traits. FA allowed us to obtain four biologically interpretable factors: “weight”, “fat”, “loin”, and “performance”. These factors were used as dependent variables in multiple regression models of genomic selection (Bayes A, Bayes B, RR-BLUP, and Bayesian LASSO). The use of FA is presented as an interesting alternative to select individuals for multiple variables simultaneously in GWS studies; accuracy measurements of the factors were similar to those obtained when the original traits were considered individually. The similarities between the top 10% of individuals selected by the factor, and those selected by the individual traits, were also satisfactory. Moreover, the estimated markers effects for the traits were similar to those found for the relevant factor

A method for multiple sequential analyses of macrophage functions using a small single cell sample

Microbial pathogens such as bacillus Calmette-Guérin (BCG) induce the activation of macrophages. Activated macrophages can be characterized by the increased production of reactive oxygen and nitrogen metabolites, generated via NADPH oxidase and inducible nitric oxide synthase, respectively, and by the increased expression of major histocompatibility complex class II molecules (MHC II). Multiple microassays have been developed to measure these parameters. Usually each assay requires 2-5 x 10(5) cells per well. In some experimental conditions the number of cells is the limiting factor for the phenotypic characterization of macrophages. Here we describe a method whereby this limitation can be circumvented. Using a single 96-well microassay and a very small number of peritoneal cells obtained from C3H/HePas mice, containing as little as <=2 x 10(5) macrophages per well, we determined sequentially the oxidative burst (H2O2), nitric oxide production and MHC II (IAk) expression of BCG-activated macrophages. More specifically, with 100 µl of cell suspension it was possible to quantify H2O2 release and nitric oxide production after 1 and 48 h, respectively, and IAk expression after 48 h of cell culture. In addition, this microassay is easy to perform, highly reproducible and more economical