Biomedical subjects

N Ivanovska

Publications and source records attributed to N Ivanovska.

25 records · Page 2Linked to original sources

PubMed1994

Antiinflammatory effect of superoxide dismutase (SOD). Comparison between yeast and bovine SOD on some complement-mediated reactions in vitro and in vivo.

The effect of CulZn superoxide dismutases from yeast cells (SODy) and commercial SOD from bovine erythrocytes (SODb) on zymosan-induced inflammation in mice and on complement activity in normal human serum (NHS) was studied. Zymosan-induced oedema formation was moderately suppressed by SODb. The alternative pathway (AP) activity in mouse serum was strongly inhibited after i.p. treatment with SODy. Comparison between the two enzymes showed different mode of action on the classical pathway (CP) as compared to the AP of complement activation. The inhibitory effect caused by SODy was more pronounced and strongly time- and temperature-dependent. SODy affected several activation steps in the complement cascade, while the inhibition caused by SODb was mainly directed to C1 of the complement activity. The powerful action of SODy on AP activity may be attributed to the oligosaccharide moiety in the enzyme molecule from yeast origin.

Animals↗

PubMed1992

Polyphenols from Bulgarian medicinal plants with anti-infectious activity.

Three Bulgarian medicinal plants--Geranium macrorrhizum L. and G. sanguineum L. (Geraniaceae), and Epilobium hirsutum L. (Onagraceae) were analyzed phytochemically. Different polyphenols like flavonoids and tannis have been found to be principal constituents of the plants. A series of water or alcohol extracts was obtained, and their anti-infectious activity was tested. A significant inhibitory effect of water-alcohol extract and of four fractions from the polyphenolic mixture of E. hirsutum on the reproduction of influenza viruses in vitro, in ovo, and in vivo was established. Four extracts from G. macrorrhizum and three extracts from G. sanguineum were studied for in vitro inhibition of the growth of some Gram-negative bacteria (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa), Gram-positive bacterium (Staphylococcus aureus), and fungus (Candida albicans). Some geranium extracts caused a strong increase of the survival rate in an infection with K. pneumoniae in mice. Augmentation of the nonspecific host resistance in relation to the influence of the extracts on the classical complement activation pathway was also studied.

Animals↗

PubMed1992

Immunomodulatory action of propolis: IV. Prophylactic activity against gram-negative infections and adjuvant effect of the water-soluble derivative.

The efficacy of the water-soluble derivative (WSD) of natural propolis (bee glue) was examined for augmentation of host resistance against experimental infections caused by Gram-negative pathogens (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa). The substance was found to induce significant non-specific protection, but did not inhibit the in vitro growth of the same strains. Pretreatment with WSD prior to the standard scheme for tumour necrosis factor (TNF) induction (BCG and two weeks later lipopolysaccharide (LPS)) provoked an interval-dependent reduction in the lytic capacity of serum against L 929 target cells. The replacement of the triggering or priming signal with WSD markedly increased TNF production. In vivo administration of WSD led to a rapid and route-dependent change in the alternative complement pathway haemolysis. The alteration in C1q complement component and total protein synthesis, and also in nitroblue tetrazolium reduction, suggests that macrophage activation makes a major contribution to the capacity of WSD to prevent infections.

Adjuvants, Immunologic↗

PubMed1990

[The immunomodulating properties of a macro glycopeptide isolated from serum. II. The activation of macrophages and polymorphonuclear cells].

The stimulating properties of three fractions of a glucomacropeptide consisting of different carbohydrate and peptide components were studied. The phagocytic activity of polymorphonuclears was increased on the 24th hour and of macrophages on the 3rd day after application of the preparations to mice. In vitro fraction 3 stimulates the lysozyme activity and the synthesis of proteins and Clq of the macrophages complement. These properties of the cells are collaborated by the established ultrastructural changes. The different composition of the fractions determines their immunostimulating effect.

Adjuvants, Immunologic↗

PubMedDate not supplied

Correlation between inhibited alternative complement activity and the protective effect induced by Nocardia lysozyme digest (NLD) during Klebsiella pneumoniae infection in mice.

Nocardia lysozyme digest (NLD) was administered intraperitoneally (i.p.) at a dose of 500 micrograms/kg to normal and immunosuppressed mice for 3 consecutive days prior to inoculation with Klebsiella pneumoniae. A protective effect was observed when the pathogen was injected subcutaneously and intravenously, as opposed to an aggravating effect obtained in the case of intraperitoneal inoculation The i.p. administration of NLD partially restored the immunosuppression caused by cyclophosphamide but did not change cobra venom-induced deterioration of the infection. The results obtained could be regarded as a consequence of the lowered alternative pathway serum complement activity and the crucial role of the diminished level of complement in the peritoneal cavity.

Adjuvants, Immunologic↗

PubMedDate not supplied

Phytochemical study and antiinflammatory properties of Lobelia laxiflora L.

Three new piperidine alkaloids were isolated from stems, leaves and flowers of Lobelia laxiflora L. (Campanulaceae). The structures of racem. cis-8,10-diethyl-3,4-dehydrolobelidiol (1), racem. trans-8-ethyl-10-phenyl-3,4-dehydrolobelidiol (2) and racem. cis-8-ethyl-10-phenyl-3, 4-dehydrolobelidiol (3) were established by spectral analyses. The residues obtained from the ethanol extracts from stems (S), leaves (L), and flowers (F) were applied in carrageenan (Car)- and cobra venom (CV)-induced acute inflammation in mice. A suppression of paw edema formation at a dose of 100 mg kg-1 was established. In this study the antiinflammatory potential of Lobelia l. was regarded in connection with the complement system. The sequential activation and assembly into functional units of complement components can proceed via two different pathways, named classical (CP) and alternative (AP). The ability of the residues, nonalkaloid fractions, alkaloid fractions and the three alkaloids at a concentration from 0.125 to 1.0 mg ml-1 to inhibit complement activation and thus to prevent inflammatory process was estimated in vitro in human serum via both pathways. All of them inhibited complement activity with a predominant action on CP.

Alkaloids↗

PubMedDate not supplied

Anticomplement activity of lysine complexes of propolis phenolic constituents and their synthetic analogs.

Several phenolic constituents of propolis and their synthetic analogs were derivatized with L-lysine. The ability of these complexes to alter complement activity was estimated in vitro in human serum. The influence of selected complexes on C3 hemolytic activity via classical pathway (CP) and alternative pathway (AP) and on zymosan-induced AP activation was determined. The results suppose that the anticomplement effect of the complexes might be related to the interaction with C3 complement component.

Complement Inactivator Proteins↗