Reactive oxygen species (ROS) originating from mitochondria are perceived as a factor contributing to cell aging and means have been sought to attenuate ROS formation with the aim of extending the cell lifespan. Silybin and dehydrosilybin, two polyphenolic compounds, display a plethora of biological effects generally ascribed to their known antioxidant capacity. When investigating the cytoprotective effects of these two compounds in the primary cell cultures of neonatal rat cardiomyocytes, we noted the ability of dehydrosilybin to de-energize the cells by monitoring JC-1 fluorescence. Experiments evaluating oxygen consumption and membrane potential revealed that dehydrosilybin uncouples the respiration of isolated rat heart mitochondria albeit with a much lower potency than synthetic uncouplers. Furthermore, dehydrosilybin revealed a very high potency in suppressing ROS formation in isolated rat heart mitochondria with IC(50) = 0.15 μM. It is far more effective than its effect in a purely chemical system generating superoxide or in cells capable of oxidative burst, where the IC(50) for dehydrosilybin exceeds 50 μM. Dehydrosilybin also attenuated ROS formation caused by rotenone in the primary cultures of neonatal rat cardiomyocytes. We infer that the apparent uncoupler-like activity of dehydrosilybin is the basis of its ROS modulation effect in neonatal rat cardiomyocytes and leads us to propose a hypothesis on natural ischemia preconditioning by dietary polyphenols.
- MeSH
- analýza rozptylu MeSH
- benzimidazoly MeSH
- fluorescenční barviva MeSH
- inhibiční koncentrace 50 MeSH
- karbocyaniny MeSH
- kardiomyocyty metabolismus MeSH
- krysa rodu rattus MeSH
- mitochondrie metabolismus MeSH
- molekulární struktura MeSH
- potkani Wistar MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rotenon toxicita MeSH
- silymarin chemie farmakologie MeSH
- spotřeba kyslíku účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVES: Different probiotic strains used in clinical trials have shown prophylactic properties in different inflammatory diseases of the gastrointestinal tract. This study was aimed to investigate the influence of Escherichia coli strain Nissle 1917 (EcN) components on the integrity of the Caco-2 cell monolayer (human adenocarcinoma cell line). METHODS: The effect of supernatant of EcN suspension and lipopolysaccharide (LPS) isolated from EcN (in concentrations from 0.001 to 1 000 µg/ml) on paracellular transport of 14C-mannitol marker through epithelial cell monolayer was estimated. RESULTS: Both LPS and EcN supernatant exerted almost the same effect; whereas no effect was shown using high concentrations (100 and 1 000 µg/ml), low concentrations (0.001, 0.1 and 1 µg/ml) significantly decreased permeability of 14C-mannitol. Concentration (0.001 µg/ml) decreased 14C-mannitol permeability approximately about 20% (LPS) and 30% (EcN supernatant). To elucidate the observed changes in monolayer permeability ("tighter monolayer") induced by concentrations of LPS or supernatant, media able to open epithelial intercellular junctions were used. The effects of Ca2+-free transport medium and of medium containing 5, 10, 20, 50, and 100% of Ca2+ on the 14C-mannitol transport in the presence of the lowest (0.001 µg/ml) and high (100 µg/ml) concentrations of LPS were studied. Using Ca2+-free medium both concentrations of LPS significantly decreased apparent permeability coefficient (Papp) of 14C-mannitol indicating that changes of 14C-mannitol permeability are independent of dimensions of paracellular spaces. CONCLUSION: The decrease of 14C-mannitol permeability caused by EcN LPS indicates the ability of components of probiotic EcN strain to restore disrupted epithelial barrier.
- MeSH
- adenokarcinom metabolismus patologie MeSH
- Caco-2 buňky MeSH
- Escherichia coli MeSH
- lidé MeSH
- lipopolysacharidy farmakologie MeSH
- mannitol metabolismus MeSH
- nádory tračníku metabolismus patologie MeSH
- permeabilita buněčné membrány účinky léků MeSH
- probiotika farmakologie MeSH
- radioizotopy uhlíku MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Dental caries is a highly prevalent multifactorial disease that can result in serious health impairment. It was shown that oral bacteria play a significant role in caries development. Point-of-care (POC) salivary microbial tests for detection of cariogenic species have been investigated as a potential tool for caries risk assessment. This review aims to evaluate clinical relevance of these tests in the light of recent scientific evidence. Methodology involved PubMed search using key words salivary microbial tests, cariogenic bacteria and caries risk prediction. Articles obtained by the search were cross-referenced to obtain further sources. Specificity and negative-predictive value of these tests are higher than their sensitivity and positive value. Predictive power of the POC salivary microbial tests as a single predictor is generally weak, although it increases when included in multifactorial models for caries prediction. Literature findings support the use of these tests for screening of at-risk individuals in a population of young preschool children without visible caries and for motivation of subjects on individual level. POC salivary microbial tests are simple and inexpensive and, therefore, may be advantageous from public health perspective.
- MeSH
- Bacteria izolace a purifikace klasifikace patogenita MeSH
- bakteriální infekce diagnóza komplikace mikrobiologie MeSH
- bakteriologické techniky metody MeSH
- financování organizované MeSH
- lidé MeSH
- sliny mikrobiologie MeSH
- vyšetření u lůžka MeSH
- zubní kaz mikrobiologie prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
