s‐Ethyl Cysteine and s‐Methyl Cysteine Protect Human Bronchial Epithelial Cells Against Hydrogen Peroxide Induced Injury

Abstract

Protective effects and actions from s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) for BEAS-2B cells were examined. BEAS-2B cells were pretreated with SEC or SMC at 4, 8, or 16 μmol/L, and followed by hydrogen peroxide (H2 O2 ) treatment. Data showed that H2 O2 enhanced Bax, caspase-3 and caspase-8 expression, and declined Bcl-2 expression. However, SEC or SMC dose-dependently decreased caspase-3 expression and reserved Bcl-2 expression. H2 O2 increased reactive oxygen species (ROS) production, and lowered glutathione level, glutathione peroxide, and glutathione reductase activities in BEAS-2B cells. SEC or SMC pretreatments reduced ROS generation, and maintained glutathione redox cycle in those cells. H2 O2 upregulated the expression of both p47(phox) and gp91(phox) . SEC and SMC downregulated p47(phox) expression. SEC or SMC at 8 and 16 μmol/L decreased H2 O2 -induced release of inflammatory cytokines. H2 O2 stimulated the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase. SEC and SMC pretreatments dose-dependently downregulated NF-κB p65 and p-p38 expression. Pyrrolidine dithiocarbamate or SB203580 inhibited NF-κB activation and p38 phosphorylation; thus, SEC or SMC pretreatments failed to affect protein expression of these factors. These novel findings suggest that SEC or SMC could protect bronchial cells and benefit respiratory epithelia stability and functions.

RETRACTED: Post-Intake of S-Ethyl Cysteine and S-Methyl Cysteine Improved LPS-Induced Acute Lung Injury in Mice

“…Our previous cell line study revealed that pre-treatments of SEC or SMC, two cysteine-containing compounds, protected human bronchial cells against H 2 O 2 -induced damage [16]. The results from our present animal study further found that post-intake of SEC or SMC markedly improved LPS-induced inflammatory, oxidative and apoptotic lung injury through decreasing MPO activity and neutrophil counts, and declining NF-κB, MAPK and NADPH oxidase pathways.…”

“…Our previous animal study found that dietary intake of SEC or SMC displayed anti-oxidative and anti-inflammatory protection against ethanol-induced liver injury in mice [15]. Our other study indicated that SEC or SMC ameliorated H 2 O 2 -induced apoptotic, oxidative and inflammatory injury in human BEAS-2B cells (bronchial cells) through preserving Bcl-2 expression, decreasing ROS formation and limiting protein expression of NAPDH oxidase, NF-κB and MAPK [16]. Those previous studies suggest that SEC and SMC are agents with anti-oxidative and anti-inflammatory activities, and may be able to protect the lung.…”

Therapeutic Role of Functional Components in Alliums for Preventive Chronic Disease in Human Being

“…The antiwrinkle for skin aging of caffeic acid, S -allyl cysteine, and uracil associated with antioxidation and anti-inflammation by modulating MMP via NF- κ B signaling [ 28 ]. The S -ethyl cysteine or S -methyl cysteine can protect bronchial cells and respiratory epithelia [ 29 ]. Chemical constituents of garlic were alliin (0.320%), allicin (0.273%), and allitride (0.357%) [ 30 ].…”