title: The effects of S-carboxymethylcysteine and N-acetylcysteine on the adherence of Moraxella catarrhalis to human pharyngeal epithelial cells.
abstract: We investigated the effects of two mucoregulating drugs, S-carboxymethylcysteine (S-CMC) and N-acetylcysteine (NAC), on the attachment of Moraxella catarrhalis (M. catarrhalis) to pharyngeal epithelial cells. The attachment of M. catarrhalis decreased (33-57%) significantly (P<0.01) in a dose-dependent manner in cells treated with mucoregulating drugs as compared to the control. There was a significant (P<0.01) decrease (35-45%) in the attachment of M. catarrhalis to pharyngeal cells after oral administration of S-CMC. By electron microscopic observation, it was found that there was a fine, granular, electron-dense, ruthenium red-positive layer on the surface of pharyngeal epithelial cells; this layer was absent on cell surfaces treated with mucoregulating drugs. Possibly, this layer contained the portion of M. catarrhalis receptor which is responsible for the attachment of this bacteria to pharyngeal epithelial cells. From the above results, it may be concluded that one of the mechanisms of mucoregulating drugs to decrease the episode of respiratory infections in patients with chronic respiratory diseases is by inhibiting the attachment of bacteria to the upper respiratory tract.
authors.affiliation: Department of Internal Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: C H
authors.initials: CH
authors.lastname: Zheng
authors.forename: K
authors.initials: K
authors.lastname: Ahmed
authors.forename: N
authors.initials: N
authors.lastname: Rikitomi
authors.forename: G
authors.initials: G
authors.lastname: Martinez
authors.forename: T
authors.initials: T
authors.lastname: Nagatake
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D001249:Asthma / Q000473:pathology; D001422:Bacterial Adhesion / Q000187:drug effects*; D001987:Bronchiectasis / Q000473:pathology; D001991:Bronchitis / Q000473:pathology; D002233:Carbocysteine / Q000378:metabolism / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects / Q000382:microbiology / Q000648:ultrastructure; D005100:Expectorants / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D001936:Moraxella catarrhalis / Q000187:drug effects* / Q000502:physiology; D010614:Pharynx / Q000166:cytology / Q000382:microbiology*; D011656:Pulmonary Emphysema / Q000473:pathology; D013183:Sputum / Q000378:metabolism
chemical_list: D005100:Expectorants; D002233:Carbocysteine; D000111:Acetylcysteine