Antioxidant and antifungal activities of Camellia sinensis (L) Kuntze leaves obtained by different forms of production / Atividade antioxidante e antifúngica das folhas de Camellia sinensis (L) Kuntze, obtidas por diferentes formas de produção

Abstract The antioxidant and anticandidal activities of leaves obtained from Camellia sinensis by non-fermentation (green and white teas), semi-fermentation (red tea) and fermentation method (black tea) were investigated. It was evaluated the total phenolic content by Folin-Ciocalteau assay; antioxidant capacities were evaluated in vitro using DPPH and ABTS radicals, hypochlorous acid and superoxide anion scavenger assays, induced hemolysis, lipid peroxidation by conjugated diene formation and myeloperoxidase activity. Anticandidal activity was performed on three strains of Candida spp. The results showed that non-fermented teas have a higher concentration of phenolic compounds, and then presented the best inhibitory activity of AAPH-induced hemolysis, the best inhibition of conjugated diene formation and more pronounced antioxidant activity in all tests. The highest anticandidal activity was obtained from fermented tea, followed by non-fermented tea. These results indicate that the antioxidant activity demonstrated has no direct relation with the anticandidal activity.

Resumo A atividade antioxidante e antifúngica das folhas obtidas da Camellia sinensis pelos métodos de não-fermentação (chás verde e branco), semi-fermentação (chá vermelho) e fermentação (chá preto) foram investigadas. Foi avaliado o conteúdo total de compostos fenólicos pelo método de Folin-Ciocalteau; a capacidade antioxidante foi avaliada in vitro usando os radicais artificiais DPPH e ABTS, o ácido hipocloroso, ensaios do ânion superóxido, hemólise induzida, peroxidação lipídica por formação de dienos conjugados e atividade da Mieloperoxidase. A atividade antifúngica foi obtida sobre três cepas de Candida spp. Os resultados obtidos mostram que os chás não fermentados apresentam a maior concentração de compostos fenólicos e também, apresentam a melhor atividade inibitória, sobre hemólise induzida por APPH, sobre a formação de dienos conjugados e a mais pronunciada atividade antioxidante sobre todos os testes. A maior atividade antifúngica foi obtida pelo chá fermentado, seguido pelo semi-fermentado e não-fermentados. Os resultados obtidos demonstram que a atividade antioxidante observada não apresenta relação com a atividade antifúngica.

Genome features of Leptospira interrogans serovar Copenhageni

We report novel features of the genome sequence of Leptospira interrogans serovar Copenhageni, a highly invasive spirochete. Leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in mammals. Genomic sequence analysis reveals the presence of a competent transport system with 13 families of genes encoding for major transporters including a three-member component efflux system compatible with the long-term survival of this organism. The leptospiral genome contains a broad array of genes encoding regulatory system, signal transduction and methyl-accepting chemotaxis proteins, reflecting the organism's ability to respond to diverse environmental stimuli. The identification of a complete set of genes encoding the enzymes for the cobalamin biosynthetic pathway and the novel coding genes related to lipopolysaccharide biosynthesis should bring new light to the study of Leptospira physiology. Genes related to toxins, lipoproteins and several surface-exposed proteins may facilitate a better understanding of the Leptospira pathogenesis and may serve as potential candidates for vaccine.