In vitro Effects of Four Native Brazilian Medicinal Plants in CYP3A4 mRNA Gene Expression, Glutathione Levels, and P-Glycoprotein Activity.

Erythrina mulungu Benth. (Fabaceae), Cordia verbenacea A. DC. (Boraginaceae), Solanum paniculatum L. (Solanaceae) and Lippia sidoides Cham. (Verbenaceae) are medicinal plant species native to Brazil shortlisted by the Brazilian National Health System for future clinical use. However, nothing is known about their effects in metabolic and transporter proteins, which could potentially lead to herb-drug interactions (HDI). In this work, we assess non-toxic concentrations (100 μg/mL) of the plant infusions for their in vitro ability to modulate CYP3A4 mRNA gene expression and intracellular glutathione levels in HepG2 cells, as well as P-glycoprotein (P-gp) activity in vincristine-resistant Caco-2 cells (Caco-2 VCR). Their mechanisms of action were further studied by measuring the activation of human pregnane X receptor (hPXR) in transiently co-transfected HeLa cells and the inhibition of γ-glutamyl transferase (GGT) in HepG2 cells. Our results show that P-gp activity was not affected in any case and that only Solanum paniculatum was able to significantly change CYP3A4 mRNA gene expression (twofold decrease, p < 0.05), this being correlated with an antagonist effect upon hPXR (EC50 = 0.38 mg/mL). Total intracellular glutathione levels were significantly depleted by exposure to Solanum paniculatum (-44%, p < 0.001), Lippia sidoides (-12%, p < 0.05) and Cordia verbenacea (-47%, p < 0.001). The latter plant extract was able to decrease GGT activity (-48%, p < 0.01). In conclusion, this preclinical study shows that the administration of some of these herbal medicines may be able to cause disturbances to metabolic mechanisms in vitro. Although Erythrina mulungu appears safe in our tests, active pharmacovigilance is recommended for the other three species, especially in the case of Solanum paniculatum

Características microbiológicas do suco de laranja in natura Microbiological characteristics of orange juices

Sucos de laranja frescos são amplamente consumidos, devido ao seu sabor agradável e por representar uma importante fonte de vitamina C, minerais e carboidratos. Essas características tornam o suco um meio propício ao desenvolvimento de microrganismos, incluindo patógenos capazes de sobreviver em ambientes ácidos, como E. coli, Salmonella e Listeria monocytogenes. A qualidade microbiológica do suco de laranja pode ser avaliada pela contagem de bactérias mesófilas heterotróficas totais, bactérias ácido-láticas (BAL), bolores e leveduras, coliformes totais e fecais, além da detecção direta de patógenos. Neste trabalho foi realizado o acompanhamento dessas características para 50 amostras de suco fresco de marcas comercializadas no Rio de Janeiro. As amostras foram adquiridas e mantidas sob refrigeração a 4ºC, até o momento das análises. Além das contagens mencionadas, foi realizada a pesquisa de E. coli e Salmonella sp. As contagens de microorganismos mesófilos heterotróficos e BAL, para a maioria das amostras, mostraram-se em níveis elevados. O nível de coliformes fecais em 15% das amostras foi acima do permitido pela legislação. Os perfis de susceptibilidade a antimicrobianos de coliformes isolados estavam dentro do previsto para amostras ambientais ou fecais não submetidas a grande pressão seletiva.<br>Fresh orange juices are very popular as a source of vitamin C, minerals and carbohydrates. However, for the same reasons, they are a suitable environment for the microorganism growth, including pathogens that are able to survive in such conditions, as E. coli, Salmonella and Listeria monocytogenes. To assure the quality of these products, microbiological safety monitoring is needed, through measuring lactic acid bacteria (LAB), moulds and yeasts, total and fecal coliforms and total plate counts. These parameters were monitored for 50 fresh juice samples commercialized in Rio de Janeiro, Brazil. The samples were acquired and maintained under refrigerated conditions. Tests were also made for the detection of E. coli and Salmonella sp. The LAB and total plate counts were, for the most of the samples, higher than the expected. The fecal coliforms levels of 15% of the samples were above those permitted by law. The susceptibility patterns for fecal coliforms isolates were as the expected to environmental or fecal samples that were not under selective pressure

Structures of the alkaloids from <i>E. mulungu</i>.

<p>Structures of the alkaloids from <i>E. mulungu</i>.</p

Screening of the <i>Erythrina</i> alkaloids.

<p>A. Hippocampal neurons constitutively expressing α7* nicotinic receptors. Currents elicited by 0.5-s pulses of acetylcholine 100 µM (blue bars) were partially and reversibly blocked by co-application with 100 µM of (+)-11α-hydroxyerysotrine, (+)-erythravine and (+)-11α-hydroxyerythravine (red bars). Membrane potentials were fixed at –67 mV. <b>B.</b> HEK 293 cells heterologously expressing α4β2 nicotinic receptors. Currents elicited by 2-s pulses of acetylcholine 50 µM (blue bars) were partially and reversibly blocked by co-application with 10 µM of (+)-11α-hydroxyerysotrine, (+)-erythravine and (+)-11α-hydroxyerythravine (red bars). Membrane potentials were fixed at –87 mV. <b>C.</b> PC12 cells constitutively expressing α3* nicotinic receptors. Currents elicited by 0.5 s pulses of acetylcholine 100 µM (blue bars) were partially and reversibly blocked by co-application with 50 µM of (+)-11α-hydroxyerysotrine, (+)-erythravine and (+)-11α-hydroxyerythravine (red bars). Membrane potentials were fixed at –87 mV. All experiments were performed in the presence of 0.15 µM of TTX (only in experiments with neurons) and 0.5 µM of atropine sulfate. Traces are representative of 3 to 5 independent cells and the mean responses are shown in the bar graphs to the right as the percentages of the current obtained from the first acetylcholine pulse, with error bars being the SEM. Black bars represent the current at peak and grey bars represent the area under the trace for a period of 1.5 s for α4β2 HEK 293 cells and PC12 cells and 1 s for hippocampal neurons, starting at the beginning of the agonist pulse. HEt, (+)-11α-hydroxyerysotrine; Ev, (+)-erythravine; HEv, (+)-11α-hydroxyerythravine.</p

Concentration dependence of the blockade of nicotinic receptor-mediated currents by (+)-erythravine.

<p>A. Currents elicited by 2-s pulses of acetylcholine 50 µM (blue bars) in a representative HEK 293 cell expressing α4β2 receptors in the presence of increasing concentrations of (+)-erythravine (0.003 to 1 µM; red bars). <b>B.</b> Currents elicited by 0.5 s pulses of acetylcholine 300 µM (blue bars) in a representative hippocampal neuron expressing α7* receptors in the presence of increasing concentrations of (+)-erythravine (0.3 to 100 µM; red bars). The alkaloid was pre-applied on the bathing solution and was in equilibrium during the agonist pulse. <b>C</b>. Concentration-response curves showing the area under the current traces obtained as in <b>A</b> and <b>B</b>. Non-linear regression using the Hill equation yielded an IC₅₀ of 4 nM and a Hill coefficient of ­–0.6 for α4β2 receptors (empty circles) and an IC₅₀ of 6 µM and a Hill coefficient of ­–0.5 for native α7* receptors (filled triangles). Data are presented as means ± SEM (n  =  3 cells).</p