RESUMEN
An antioxidant activity of the water-alcohol extracts of leaves of ten herbs from Western Siberia was studied. In vivo the capability of extracts to protect cells of Escherichia coli against the bacteriostatic action of H2O2 and the influence of the extracts on the expression of the antioxidant gene katG coding catalase-hydroperoxidase I were investigated. In vitro the radical-binding activity with DPhPG (1,1-diphenyl-2-picrylhydrazyl radical), the chelating capability with ferrozine, and total composition of flavonoids and tannins were determined. The extracts of Filipendula stepposa and Limonium gmelinii were characterized by the highest antioxidant activity. According to data, the test extracts could have an antioxidant effect on bacteria in different ways at once including the direct inhibition of ROS (reactive oxygen species), iron ion chelation and antioxidant gene induction.
Asunto(s)
Antioxidantes/farmacología , Escherichia coli/crecimiento & desarrollo , Filipendula/química , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Plantas Medicinales/química , Plumbaginaceae/química , Antioxidantes/química , Catalasa , Escherichia coli/enzimología , Escherichia coli/genética , Proteínas de Escherichia coli , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica/genética , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/genética , Estrés Oxidativo/genética , Extractos Vegetales/química , SiberiaRESUMEN
Treatment of Escherichia coli K-12 cells aerobically grown in M9 glucose salt medium (H2O2) and non-penetrating (ferricyanide) oxidants resulted in similar inhibition of growth and decrease in intracellular K+ pool by 15%. Only H2O2 inhibited growth of auxotrophic strains grown in M9 medium supplemented with protein hydrolysate. Ferricyanide reduction was associated with decrease in low-molecular-weight thiols, whereas the treatment of cells with H2O2 increased their level. Pretreatment of cells with ferricyanide enhanced the H2O2-induced expression of katG gene encoding for catalase HPI; this gene is a member of the gene family controlled by the oxyR gene. Pretreatment with ferricyanide inhibited H2O2-induced expression of the sfiA gene which is the member of the gene family controlled by the recA and lexA genes. Glutathione is the major low-molecular-weight thiol in E. coli, and it can play different roles in cellular responses to H2O2 and ferricyanide.
Asunto(s)
Proteínas de Escherichia coli , Escherichia coli/efectos de los fármacos , Ferrocianuros/farmacología , Peróxido de Hidrógeno/farmacología , Antioxidantes/metabolismo , Proteínas Bacterianas/genética , Catalasa/metabolismo , Escherichia coli/enzimología , Escherichia coli/genética , Escherichia coli/metabolismo , Genes Bacterianos , Glutatión/metabolismo , NADH NADPH Oxidorreductasas/metabolismo , Estrés Oxidativo , Peroxidasas/genéticaRESUMEN
In 2-3 weeks after the oral immunization of rabbits, made in one or two administrations, with attenuated two-marker S. dysenteriae 1 strain VS-12 and recombinant S. dysenteriae VS-12/S. sonnei NR-18 and S. flexneri y433/S. sonnei NR-18 pronounced immunological reaction developed in the mucous membrane of the small intestine: blast transformation follicles of Peyer's patches, an increase in the number of lymphoblasts and plasmocytes in the cupolae of follicles and in intestinal villi, and an increase in the number of lymphocytes and macrophages in the intestinal epithelium with their release into the lumen of the intestine after challenge with virulent shigellae. The protective potency of these recombinants after challenge with massive doses of virulent shigellae was found to be high, which was shown by quantitative evaluation of the decrease of adhesion, invasiveness and cytotoxicity, suppression of epithelial lesions and development of inflammation in the intestinal mucosa.
Asunto(s)
Vacunas Bacterianas/inmunología , Disentería Bacilar/patología , Disentería Bacilar/prevención & control , Shigella dysenteriae/inmunología , Shigella flexneri/inmunología , Shigella sonnei/inmunología , Animales , Evaluación Preclínica de Medicamentos , Disentería Bacilar/inmunología , Inmunización , Inmunogenética , Intestino Delgado/inmunología , Intestino Delgado/patología , Conejos , Recombinación Genética , Shigella dysenteriae/genética , Shigella dysenteriae/patogenicidad , Shigella flexneri/genética , Shigella flexneri/patogenicidad , Shigella sonnei/genética , Shigella sonnei/patogenicidad , Factores de Tiempo , Vacunas Atenuadas/inmunología , VirulenciaRESUMEN
Radioreceptor investigations showed that it is impossible to interpret changes in the activity of opioid receptor ligands of mu and delta types in plasma of mice under footshock stress (FSS) as activation or depletion of opioid system (OS). There occurred qualitative changes characterized by interstrain differences (ID). These are also typical for dynamics of development of FSS effects on blood corticosterone levels. Administration of dalargin diminishes qualitative and quantitative changes in OS function at different periods after FSS preventing early rise of corticosterone levels after the exposure. In spite of common features in dalargin action on opioid and steroid metabolism in mice of both strains, ID are also present.