Inhibition of mouse liver cytochrome P-450 by gram-negative bacteria lipopolysaccharides.

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.

Prolonged survival of AVN Wistar rats with transplanted Yoshida sarcoma and increase of granular lymphocytes after administration of Bacillus firmus and their crude lipids.

Bacillus firmus is a Gram-positive, aerobic, sporulating, nonpathogenic air contaminant which, according to earlier findings, is a strong polyclonal activator of B lymphocytes. The crude lipids of this microbe induced significant resistance of mice against listerial infection. The administration of bacterin, like that of crude lipids obtained by the extraction of cell suspension with chloroform-methanol to rats, strain AVN Wistar, transplanted later with Yoshida sarcoma, significantly prolonged the survival of the animals in comparison with the control group. At the same time the number of granular lymphocytes was increased. The destruction of tumor cells in the peritoneal exudate of immunostimulated rats was also determined.

The influence of Propionibacterium acnes (Corynebacterium parvum) fractions on immune response in vivo.

Bacterin of Propionibacterium acnes (Corynebacterium parvum), its cellular fractions (lipids, fractions obtained by mechanical disruption and differential centrifugation, by phenol-water and pyridine extractions), and a polysaccharide from culture filtrate were prepared and tested in mice. The activation of RES by splenomegaly and hepatomegaly, prevention of listerial infection, prevention of the lethal effect of sarcoma 180, and depression of liver microsomal cytochrome P-450 were employed. The bacterin was effective in all tests. Lipid-free cells were less active, in particular in the activation of RES and in the listerial infection model. Fractions prepared by the disruption and differential centrifugation lost their activity in all tests along with a decrease in molecular weight. Lipids extracted by ethanol caused pronounced splenomegaly and decreased the cytochrome P-450 content. The residue left after the phenol-water extraction was very active, its delipidation did not destroy the activity. Pyridine extraction provided a completely inactive extract, but a very active residue. The possibility of reducing the complexity of bacterin while preserving immunomodulatory effect is demonstrated.

Depression of cytochrome P-450 in mouse liver induced by fractions from Nocardia opaca.

We measured the liver cytochrome P-450 content of mice 24 h after they had been injected with the following immunoadjuvants: Nocardia opaca derivatives and peptidoglycans from several bacterial strains. The cell wall fraction was not active, the others diminished liver cytochrome P-450 levels. The dose-response activity varied with the bacterial origin of the peptidoglycans. These findings indicate that the toxicity and efficiency of immunochemotherapeutic protocols can be modified by altering drug metabolism.

Resistance to infection and activation of the monocyto-macrophage system caused by Bacillus firmus and its fractions.

Crude lipids isolated from Bacillus firmus, but not from other bacilli, were previously found to induce significant resistance against Listeria monocytogenes infection in mice. In this study, formaldehyde- and heat-killed bacterins of eight Bacillus species and some cellular fractions of B. firmus were prepared and tested for further immunomodulatory activities. Crude lipids, their aqueous extract, LTA, Protodyne and Pex-residue preparations exhibited a strong anti-infection activity, whereas Pextract, P40 and all bacterins tested had no effect. Formaldehyde-killed bacterins, live bacteria and the P40 preparation of both B. firmus strains, as well as bacterins of both B. subtilis strains, induced pronounced splenomegaly in mice. Peptidoglycan and Pex-residue induced significant depression of cytochrome P-450 in mouse liver microsomes after application of 0.1 mg per mouse. Optimal conditions for obtaining a bacterial suspension exhibiting these immunomodulatory properties were elaborated.

Effect of crude bacterial lipids on the course of Listeria infection in mice.

Crude lipids from 37 strains belonging to 32 bacterial species were isolated. By injecting mice with lipids 5 d prior to challenge with a virulent strain of Listeria monocytogenes, immunostimulatory activity in 19 preparations was found. In general, lipids of Gram-negative bacteria appeared to be more effective. As to bacilli, an extraordinary activity was found in the lipids of Bacillus firmus. Lipids of various species of the genus Listeria were found to be active in approximately one-half of cases. Among other Gram-positive bacteria, significant activity of lipids was found in Corynebacterium xerosis, Propionibacterium acnes and BCG. The composition of fatty acids in the lipids did not differ significantly from that reported in the literature and their mutual differences could not explain the different biological activity. In selected strains of Gram-negative bacteria lipids were repeatedly purified with anhydrous chloroform; these preparations were found to be inactive as compared with original chloroform-methanol lipids.

Effect of cytochrome P-450 inhibition and stimulation on intensity of polyethylene degradation in microsomal fraction of mouse and rat livers.

Polyethylene (PE) is degraded in microsomal fractions of mouse and rat livers with the formation of carbonyl groups. Infrared spectroscopy demonstrated formation of predominantly ketone groups and to a lesser degree ester and aldehyde groups. The inhibition and stimulation of cytochrome P-450 in mouse livers affected the formation of oxidative groups on PE. Phenobarbital doses of 3 x 0.05 mg per mouse increased the concentration of cytochrome P-450 and ketone groups on PE, whereas the vaccine Propionibacterium acnes (0.5 mg) and its pyridine fraction (0.5 and 1 mg) had the opposite effect. The coherence of cytochrome P-450 with oxidative changes on PE is compared and discussed with findings on implants in man.

The immunological properties of listerial complex Ei.

Factor Ei, besides exerting toxic reactions, is amphipathic, antigenic, chemotaxinogenic, causes blastic transformation, adjuvant effect, hypersensitivity (MIF, skin test), activates the RES (splenomegaly), increases the macrophage production, prevents listerial infection in mice, mycobacterial infection in guinea pigs and enhances the effect of BCG experimental tuberculosis and neoplasia in mice (Sa 180).

Acute and chronic vitamin C deficiency in guinea-pigs: its effect on ceruloplasmin and cytochrome P 450 and b5 levels.

Serum and liver ceruloplasmin levels rose markedly in guinea pigs with acute scurvy and with chronic latent scurvy. Their increase in the former condition can be attributed to the general stress reaction, but the increase in ceruloplasmin levels in concentration may have a stimulant effect on the ceruloplasmin, when the oxidation of Fe2+ to Fe3+ is potentiated, may obstruct the binding of iron to protoporphyrin and prevent formation of the haeme of cytochrome P 450 and b5.