title: Inhibition of mouse liver cytochrome P-450 by gram-negative bacteria lipopolysaccharides.
abstract: The ability of bacterial endotoxins, of different origin, to modify the level of mouse liver cytochrome P-450 was investigated. Endotoxins, (lipopolysaccharides, LPSs) were isolated from Proteus, Escherichia, Salmonella, Bacteroides and Coxiella strains. The most potent inhibitor of cytochrome P-450 activity was S. typhi 0101 LPS, which at a dose of 1 microgram/mouse reduced the cytochrome P-450 activity to 59%. E. coli O55:B5, S. typhimurium, P. mirabilis O3, and C. burnetii LPSs, at dose 10 micrograms/mouse, decrease cytochrome P-450 level from 56 to 69%. B. ovatus LPS significantly suppressed the expression of cytochrome P-450 only at the highest dose used-100 micrograms/mouse. The comparison of inhibitory activity of P. mirabilis complete, S and R types of LPSs indicate that lipid A portion of LPSs are sufficient to decrease the cytochrome P-450 level. However, the core oligosaccharide of LPS significantly enhance that inhibition. The isolated O-specific polysaccharide part of P. mirabilis O3 LPS did not decrease cytochrome P-450 level. The comparison of biological activity of Proteus LPSs, tested by chromogenic Limulus amebocyte lysate (LAL) test, demonstrated the enhancement effect of O-polysaccharide part of tested LPSs.
authors.affiliation: Institute of Microbiology and Immunology, University of Lódź, Banacha, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Kaca
authors.forename: M
authors.initials: M
authors.lastname: Mara
authors.forename: J
authors.initials: J
authors.lastname: Ocenaskova
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D065607:Cytochrome P-450 Enzyme Inhibitors; D004305:Dose-Response Relationship, Drug; D005260:Female; D006090:Gram-Negative Bacteria / Q000737:chemistry*; D007274:Injections, Intraperitoneal; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008099:Liver / Q000201:enzymology*; D051379:Mice; D019081:O Antigens / Q000494:pharmacology; D009844:Oligosaccharides / Q000494:pharmacology; D013045:Species Specificity
chemical_list: D001427:Bacterial Toxins; D065607:Cytochrome P-450 Enzyme Inhibitors; D008070:Lipopolysaccharides; D019081:O Antigens; D009844:Oligosaccharides