Thiol compounds such as cysteine (Cys) and reduced glutathione (GSH) play an important role in human aging and age-related diseases. In erythrocytes, GSH is synthesized by glutamic acid, cysteine, and glycine, but the rate of GSH synthesis is determined only by the availability of L-cysteine. Cysteine supplementation has been shown to ameliorate several parameters that are known to degenerate during human aging. We have studied L-cysteine efflux in vitro in human erythrocytes as a function of age by suspending cells in solution containing 10 mM L-cysteine for uptake; later cells were re-suspended in phosphate-buffered saline (PBS)-glucose to allow efflux. Change in the free sulfhydryl (-SH) concentration was then measured to calculate the rate of efflux. The GSH/oxidized glutathione (GSSG) ratio was taken as a control to study the oxidation/reduction state of the erythrocyte. The total anti-oxidant potential of plasma was measured in terms of ferric reducing ability of plasma (FRAP) values. We have shown a significant (p<0.0001) decline in the efflux of L-cysteine in erythrocytes during human aging, and the GSH/GSSG ratio decreases as a function of human age. The decline in L-cysteine efflux during aging correlates with the decrease in GSH and the FRAP value. This finding may help to explain the shift in the redox status and low GSH concentration that might determine the rate of L-cysteine efflux observed in erythrocytes and an important factor in the development of oxidative stress in erythrocytes during aging.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1089/rej.2012.1394 | DOI Listing |
Phytomedicine
January 2025
School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, PR China. Electronic address:
Background: Cinnamomum cassia Presl (Lauraceae) is widely used as a medicinal plant in the folk medicine and pharmaceutic industry, for its promising anti-inflammatory, anti-oxidative, and anti-bacterial function. However, the major bioactive components were still in debate, and their underlying molecular mechanism was not yet fully understood.
Purpose: This study aimed to identify the bioactive ingredients of C.
NPJ Biofilms Microbiomes
December 2024
Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, 2200, Denmark.
The evolution of antimicrobial resistance (AMR) in biofilms, driven by mechanisms like oxidative stress, is a major challenge. This study investigates whether antioxidants (AOs) such as N-acetyl-cysteine (NAC) and Edaravone (ED) can reduce AMR in Pseudomonas aeruginosa biofilms exposed to sub-inhibitory concentrations of ciprofloxacin (CIP). In vitro experimental evolution studies were conducted using flow cells and glass beads biofilm models.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Chemistry, SRM Institute of Science and Technology, SRM Nagar, Potheri, Kattankulathur, Tamil Nadu 603203, India.
The nitrogen mustard alkylating agent chlorambucil (CBL) is a critical component of chemotherapeutic regimens used in the treatment of chronic lymphocytic leukemia. The cancer cell-killing actions of CBL are limited by glutathione (GSH) conjugation, a process catalyzed by the GSH transferase hGSTA1-1 that triggers CBL efflux from cells. In the cancer cell microenvironment, intracellular GSH levels are elevated to counterbalance oxidative stress generated due to the high glycolytic demand.
View Article and Find Full Text PDFProtein Sci
January 2025
Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
Efflux is one of the mechanisms employed by Gram-negative bacteria to become resistant to routinely used antibiotics. The inhibition of efflux by targeting their regulators is a promising strategy to re-sensitize bacterial pathogens to antibiotics. AcrAB-TolC is the main resistance-nodulation-division efflux pump in Enterobacteriaceae.
View Article and Find Full Text PDFBiomaterials
April 2025
Department of Ultrasound and Chongqing Key Laboratory of Ultrasound Molecular Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400010, PR China. Electronic address:
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!