11 research outputs found
In vitro biosynthesis of 1,4-beta-galactan attached to a pectin-xyloglucan complex in pea
Effects of partial enzymic degradation of sugar beet pectin on oxidative coupling of pectin-linked ferulates in vitro
The antioxidant and anti-proliferative activity of the Lebanese 'Olea europaea' extract
It is becoming increasingly evident that certain phytochemicals possess cancer chemopreventive properties. In this study, the anti-proliferative activity of plant extracts from olive (Olea europaea L.) leaves was tested on human leukemic cell line (Jurkat). Cytotoxicity of various concentrations of plant extracts was examined and the IC(50) was determined. Olive leaf extracts showed concentration-dependent anti-proliferative effect as determined by the WST-1 proliferation kit and [(3)H]-thymidine incorporation method. To study whether cell death was due to apoptosis, cells were stained with Annexin V-FITC and PI and the expression of important regulatory proteins (Bcl-2, Bax, and p53) involved in apoptosis were examined by Western blot. The antioxidant activity of olive leaves (SC(50) = 0.1 mg dry weight) was studied using the DPPH scavenging method. Present findings suggest that olive leaves extracts exhibit anti-proliferative effect on leukemic cells by inducing apoptosis
Galactosyl- and fucosyltransferases in etiolated pea epicotyls: product identification and sub-cellular localisation
Nascent pectin formed in Golgi apparatus of pea epicotyls by addition of uronic acids has different properties from nascent pectin at the stage of galactan elongation
Identification of antitumoral agents against human pancreatic cancer cells from Asteraceae and Lamiaceae plant extracts
Polysaccharide microarrays for high-throughput screening of transglycosylase activities in plant extracts
Polysaccharide transglycosylases catalyze disproportionation of polysaccharide molecules by cleaving glycosidic linkages in polysaccharide chains and transferring their cleaved portions to hydroxyl groups at the non-reducing ends of other polysaccharide or oligosaccharide molecules. In plant cell walls, transglycosylases have a potential to catalyze both cross-linking of polysaccharide molecules and grafting of newly arriving polysaccharide molecules into the cell wall structure during cell growth. Here we describe a polysaccharide microarray in form of a glycochip permitting simultaneous high-throughput monitoring of multiple transglycosylase activities in plant extracts. The glycochip, containing donor polysaccharides printed onto nitrocellulose-coated glass slides, was incubated with crude plant extracts, along with a series of fluorophore-labelled acceptor oligosaccharides. After removing unused labelled oligosaccharides by washing, fluorescence retained on the glycochip as a result of transglycosylase reaction was detected with a standard microarray scanner. The glycochip assay was used to detect transglycosylase activities in crude extracts from nasturtium (Tropaeolum majus) and mouse-ear cress (Arabidopsis thaliana). A number of previously unknown saccharide donor-acceptor pairs active in transglycosylation reactions that lead to the formation of homo- and hetero-glycosidic conjugates, were detected. Our data provide experimental support for the existence of diverse transglycosylase activities in crude plant extracts.Ondřej Kosík, Richard P. Auburn, Steven Russell, Eva Stratilová, Soňa Garajová, Maria Hrmova and Vladimír Farka