title: 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.
authors.affiliation: Dept. of Respiratory Therapy, China Medical Univ, Taichung City, Taiwan.|Dept. of Internal Medicine, China Medical Univ. Hospital, Taichung City, Taiwan.
authors.forename: Te-chun
authors.initials: TC
authors.lastname: Hsia
authors.affiliation: Dept. of Health and Nutrition Biotechnology, Asia Univ, Taichung City, Taiwan.|Dept. of Nutrition, China Medical Univ, Taichung City, Taiwan.
authors.forename: Mei-chin
authors.initials: MC
authors.lastname: Yin
mesh_terms: D000490:Allium / Q000737:chemistry*; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D001980:Bronchi / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000627:therapeutic use; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013859:Thiocarbamates / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D016207:Cytokines; D018836:Inflammation Mediators; D016328:NF-kappa B; D010936:Plant Extracts; D019253:Proto-Oncogene Proteins c-bcl-2; D011759:Pyrrolidines; D017382:Reactive Oxygen Species; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; C031752:ethyl cysteine; C026826:S-ethylcysteine; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D020169:Caspases; D005978:Glutathione; D003545:Cysteine; C017507:mecysteine
keywords: MAPK; NF-κB; bronchial epithelial cells; s-ethyl cysteine; s-methyl cysteine