Search results for "Complement"
showing 10 items of 2113 documents
Cloning and characterization of PRA1, a gene encoding a novel pH-regulated antigen of Candida albicans.
1998
ABSTRACT Candida albicans is an opportunistic fungal pathogen of humans. The cell wall of the organism defines the interface between the pathogen and host tissues and is likely to play an essential and pivotal role in the host-pathogen interaction. The components of the cell wall critical to this interaction are undefined. Immunoscreening of a lambda expression library with sera raised against mycelial cell walls of C. albicans was used to identify genes encoding cell surface proteins. One of the positive clones represented a candidal gene that was differentially expressed in response to changes in the pH of the culture medium. Maximal expression occurred at neutral pH, with no expression d…
Identification of a mannoprotein present in the inner layer of the cell wall of Saccharomyces cerevisiae.
1997
Cell wall extracts from the double-mutant mnn1 mnn9 strain were used as the immunogen to obtain a monoclonal antibody (MAb), SAC A6, that recognizes a specific mannoprotein--which we have named Icwp--in the walls of cells of Saccharomyces cerevisiae. Icwp runs as a polydisperse band of over 180 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of Zymolyase extracts of cell walls, although an analysis of the secretory pattern of the mannoprotein shows that at the level of secretory vesicles, it behaves like a discrete band of 140 kDa. Immunofluorescence analysis with the MAb showed that Icwp lies at the inner layer of the cell wall, being accessible to the antibody on…
Role of the virulence plasmid pR99 and the metalloprotease Vvp in resistance of Vibrio vulnificus serovar E to eel innate immunity
2007
Vibrio vulnificus biotype 2 serovar E (VSE) is a bacterial pathogen that produces a haemorrhagic septicaemia called vibriosis in eels. Its ability to grow in blood is conferred by a recently described virulence plasmid [Lee CT, Amaro C, Wu KM, Valiente E, Chang YF, Tsai SF, et al. A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid. Journal of Bacteriology, submitted for publication.]. In this study, we analyzed the role of this plasmid together with the role played by the metalloprotease (Vvp) in the interaction between bacteria and eel innate immunity. To this end, we compared and statistically analyzed the differences in resistance …
Antioxidant activity and cardioprotective effect of a nonalcoholic extract of Vaccinium meridionale Swartz during ischemia-reperfusion in rats
2013
Our objective was to assess the antioxidant properties and the effects against the reperfusion injury of a nonalcoholic extract obtained by fermentation from the Colombian blueberry, mortiño (Vaccinium meridionale Swartz, Ericaceae). Antioxidant properties were assessed by in vitro systems. To examine the postischemic myocardial function, isolated rat hearts were treated 10 min before ischemia and during the first 10 min of reperfusion with the extract. To analyze the participation of nitric oxide (NO), other experiments were performed in the presence of nitric oxide synthase (NOS) inhibition with NG-nitro-L-arginine methyl ester (L-NAME). In cardiac tissue thiobarbituric acid reactive subs…
Dietary polyphenols in chemoprevention and synergistic effect in cancer: Clinical evidences and molecular mechanisms of action
2020
Abstract Background Epidemiological studies has revealed that a diet rich in fruits and vegetables could lower the risk of certain cancers. In this setting, natural polyphenols are potent anticancer bioactive compounds to overcome the non-target specificity, undesirable cytotoxicity and high cost of treatment cancer chemotherapy. Purpose The review focuses on diverse classifications of the chemical diversity of dietary polyphenol and their molecular targets, modes of action, as well as preclinical and clinical applications in cancer prevention. Results The dietary polyphenols exhibit chemo-preventive activity through modulation of apoptosis, autophagy, cell cycle progression, inflammation, …
The neuroprotective potential of carotenoids in vitro and in vivo.
2021
Abstract Background Despite advances in research on neurodegenerative diseases, the pathogenesis and treatment response of neurodegenerative diseases remain unclear. Recent studies revealed a significant role of carotenoids to treat neurodegenerative diseases. The aim of this study was to systematically review the neuroprotective potential of carotenoids in vivo and in vitro and the molecular mechanisms and pathological factors contributing to major neurodegenerative diseases (Alzheimer's disease, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, and stroke). Hypothesis Carotenoids as therapeutic molecules to target neurodegenerative diseases. Results Aggregation of …
Ursolic acid ameliorates stress and reactive oxygen species in C. elegans knockout mutants by the dopamine Dop1 and Dop3 receptors.
2020
Abstract Background Depression and stress-related disorders are leading causes of death worldwide. Standard treatments elevating serotonin or noradrenaline levels are not sufficiently effective and cause adverse side effects. A connection between dopamine pathways and stress-related disorders has been suggested. Compounds derived from herbal medicine could be a promising alternative. We examined the neuroprotective effects of ursolic acid (UA) by focusing on dopamine signalling. Methods Trolox equivalent capacity assay was used to determine the antioxidant activities of UA in vitro. C. elegans N2 wildtype and dopamine receptor-knockout mutants (dop-1-deficient RB665 and dop-3-deficient LX70…
The triterpenoid ursolic acid ameliorates stress in Caenorhabditis elegans by affecting the depression-associated genes skn-1 and prdx2.
2021
Abstract Introduction Depression is one of the leading causes of death worldwide. Lower antioxidant concentrations and increased oxidative stress levels contribute to the development of depression. Effective and tolerable medications are urgently needed. Nrf2 and PRDX2 are promising targets in the treatment of oxidative stress and, therefore, promising for the development of novel antidepressants. Ursolic acid (UA), a natural triterpenoid found in various plants is known to exert neuroprotective and antioxidant effects. Skn-1 (which corresponds to human Nrf2) and prdx2 deficient mutants of the nematode Caenorhabditis elegans are suitable models to study the effect of UA on these targets. Ad…
Flavonoids from Erythrina schliebenii
2017
Prenylated and O-methylflavonoids including one new pterocarpan (1), three new isoflavones (2–4), and nineteen known natural products (5–23) were isolated and identified from the root, stem bark, and leaf extracts of Erythrina schliebenii. The crude extracts and their constituents were evaluated for antitubercular activity against Mycobacterium tuberculosis (H37Rv strain), showing MICs of 32–64 μg mL–1 and 36.9–101.8 μM, respectively. Evaluation of their toxicity against the aggressive human breast cancer cell line MDA-MB-231 indicated EC50 values of 13.0–290.6 μM (pure compounds) and 38.3 to >100 μg mL–1 (crude extracts).