98%
921
2 minutes
20
Alpha-tocopherol has been shown to increase nitric oxide (NO)-dependent relaxation but the underlying mechanisms have not been fully characterized. The present study investigates the effect of alpha-tocopherol and its derivative trolox on the synthesis of NO in human umbilical vein endothelial cells. NO was assayed as citrulline (co-product of NO) and cGMP (product of the NO-activated soluble guanylate cyclase) on ionomycin stimulation of cells. Ionomycin induced citrulline and cGMP formation partially through phosphorylation of endothelial NO synthase (eNOS) at its serine residue 1177, which was mediated mainly by calmodulin-dependent kinase II. Preincubation of cells with alpha-tocopherol or trolox increased eNOS activity in a concentration-dependent manner without changing eNOS expression. The effect of the water-soluble trolox was due to chemical stabilization of the eNOS cofactor tetrahydrobiopterin. On the contrary, alpha-tocopherol, located mainly in cellular membranes, did not affect tetrahydrobiopterin but increased ionomycin-induced eNOS phosphorylation at serine 1177. The effects of alpha-tocopherol on citrulline and cGMP formation and eNOS phosphorylation were amplified by co-incubation with ascorbate, which is suggested to regenerate oxidized alpha-tocopherol and to act synergistically with alpha-tocopherol. Our data describe a new vasoprotective function of alpha-tocopherol that may contribute to the prevention of endothelial dysfunction in vivo.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.freeradbiomed.2004.05.017 | DOI Listing |
Front Immunol
September 2025
Bacterial Scientific Area, GSK Vaccine, Siena, Italy.
Background: Protein-polysaccharide conjugate vaccines rely on the induction of T-cell-dependent responses that support germinal center (GC) reactions to potentiate the expansion of antigen-specific memory B-cell (MBC) populations and high-avidity antibody responses. The effects of adjuvants on B-cell and antibody responses are well described for protein antigens but remain largely unexplored for conjugated polysaccharidic antigens.
Methods: We assessed the effects of five adjuvants present in licensed vaccines (AS01, AS03, AS04, and aluminum hydroxide [Alum]) or under clinical evaluation (AS37) on the magnitude and quality of antigen-specific antibody responses and local/systemic B-cell responses.
J Food Sci Technol
October 2025
Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, 141004 Punjab India.
Unlabelled: Tocopherol content and composition (, ) in seeds are normally determined using wet chemistry methods, which are time-consuming, labor-intensive, and hazardous to human health. We attempted the development and validation of the first near-infrared reflectance spectroscopy (NIRS) model as a quick alternative. A total of 356 seed samples were collected from a germplasm diversity set of 178 genotypes.
View Article and Find Full Text PDFPoult Sci
September 2025
Laboratory of Chemical Research and Instrumental Analysis, Faculty of Animal Breeding and Biology, Bydgoszcz University of Science and Technology, Mazowiecka 28, 85-084, Bydgoszcz, Poland.
The objective of this study was to evaluate the effect of dietary inclusion of different carrot forms on production results, carcass traits, meat quality, fatty acid (FA) composition, vitamin content, and feed costs in Cherry Valley broiler ducks. A total of 240 one-day-old males (initial body weight of 55.2 g) were allocated to 4 treatments (n = 60; 6 replicates of 10 birds): control (CD; 100 % commercial diet), CFL (CD + 2 % carrot flakes), RAWC (80 % CD + 20 % raw carrot), and CPOW (CD + 2 % carrot powder).
View Article and Find Full Text PDFWorld J Methodol
December 2025
Third Academic Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki 56403, Greece.
Background: Massive rotator cuff tears (RCTs) result in impaired shoulder function and quality of life. These tears lead to structural changes in the rotator cuff muscles, which compromise recovery after repair and increase re-tear rates.
Aim: To investigate the potential inhibitory effects of alpha-tocopherol (vitamin E) and OTR-4131 on muscle atrophy, fatty infiltration, and fibrosis in rotator cuff muscles following a massive RCT using a Wistar rat model, and establish a standardized methodology for evaluating potential therapeutic agents.
Mol Ther
September 2025
Pediatric Intensive Care Unit, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences); Department of Immunology, School of Basic Medical Sciences; Department of Clinical Laboratory, the Third Affiliated Hospital of Southern Medical University, Southern Medical University, Gua
Dietary immunization plays a pivotal role in modulating allergic airway inflammation mediated by group 2 innate lymphoid cells (ILC2s). This study identifies α-tocopherol (α-Toc), a component of vitamin E, as a key regulator of allergic airway inflammation. Transcriptomic analysis of lung ILC2s from mice treated with α-Toc reveals reduced expression of scavenger receptor class B type 1 (SCARB1) and inhibition of the liver kinase B1 (LKB1)-AMPK/mTOR signaling pathway.
View Article and Find Full Text PDF