Antimutagenic effect of the plant triterpenoid miliacin was studied, in order to characterize its protective properties in a model of acute irradiation immunosuppression using outbred male mice. Ionizing irradiation at different doses (0.5; 1.0; 2.0; 4.0 Gy) was used for experimental (miliacin-treated), and control animals that received the miliacin solvent. Miliacin was administered three times intraperitoneally at a single dose of 4.0 mg/kg with 24-hour intervals between injections. The last dose was applied 1 day before irradiation. Myelokaryocytes served as test objects, the analysis of which was carried out 24 hours after irradiation. Miliacin had a certain protective effect by limiting the post-radiation myeloablation, reducing the number of aberrant cells and the total number of aberrations. Protective effect of triterpenoids showed inverse relation to the radiation dose, being most pronounced at the dose of 0.5 Gy. Higher values of chromatid aberrations at radiation doses of 1.0 and 2.0 Gy in animals from the experimental group versus control mice, probably, due to anti-apoptotic effect of the triterpenoid, thus ensuring higher survival rates of mutated cells with severe damage to their genome. The protective effect of miliacin at 24 hours after radiation exposure may indicate its effect on the primary radiochemical stage of radiation injury. It is suggested that the mechanism of protective action of triterpenoid is mediated by its previously shown antioxidant activity, due to its ability to stabilize membranes and normalize expression of genes encoding antioxidant protection enzymes. Thus, the antimutagenic activity of miliacin after irradiation is an important characteristic of its immunoprotective effect during the radiation-induced immunosuppression. With respect to its ability to limit the mutagenic effect, miliacin may be classified as a weak radioprotective antimutagen with a protection efficiency of 20-40% at the dose range of 0.5 to 1.0 Gray.

Triterpenoid miliacin-related anti-mutagenic effect aftert exposure to isonizing radiation was studied to assess its protective properties against radiation-induced immunosuppression. (CBAxC57Bl6)F1 mice were subdivided into four groups: 1) intact mice; 2) irradiated mice; 3) miliacin-pretreated irradiated mice; and 4) miliacin-solvent-pretreated irradiated mice. Irradiation of animals was performed on the X-ray device “RUST-M1” (4 Gy; exposure time 288 sec.). Twenty four hours post irradiation myelokaryocytes were isolated for analysis. Chromosome preparations were examined by light microscopy. Injections of miliacin (4 mg/kg daily for 3 consecutive days) attenuated the irradiation-triggered mutagenic effect assessed by counting cells with chromosomal aberrations as well as number of aberrations per 100 metaphase plates. Miliacin exerted a protective effect on radiation-induced chromosomal aberrations, although degree of protection was less pronounced compared to chemically induced mutagenesis. These data indicate about limited potential for miliacin to protect central immune organs such as red bone marrow upon radiation exposure.

Acute generalized infection caused by P aerugenosa in mice (CBAxC 57 Bl 6 )Fj, is characterized by more severe morphological and functional disorders than the same infection caused by K. pneumoniae. The use of miliacin has a protective effect in case of sepsis, makes structural disorders less severe and modulates functional activity of immune peritoneal macrophages.

Aim. The comparative estimation of miliacine influence on the biofilm formation of bacteria. Materials and methods. The objects of investigation were the clinical isolates of Salmonella enteritidis (28), Salmonella typhimurium (24), Klebsiella pneumoniae (8), Pseudomonas aeruginosa (8) and reference strains of lactobacilli (5) and bifidobacteria (3). Miliacin was obtained from crystals of millet oil. Antibacterial activity of miliacin was detected by the method of serial dilutions. For investigation of biofilms miliacin in 100 and 50 mkg/ml concentrations was used. Miliacin was diluted in Twin-21. Biofilm formation was studied by method of O'Toole G.A., Kolter R. (1998) using spectrophotometer Elx 808 (BioTek, USA). The morphometry of biofilms was conducted by atomic force microscopy with the use of scanning probe microscope SMM-2000. Results. Miliacin and its solvent did not influence the growth of bacteria. Maximum sensivity of biofilms to miliacin was detected in K. pneumoniae and P. aeruginosa, minimal - in S. enteritidis. Miliacin did not influence the biofilm formation in strains of lactobacilli and bifidobacteria. Conclusion. Miliacin in addition to immunotropic activity, detected earlier, can inhibit the biofilms of opportunistic and pathogenic bacteria without influence on the biofilm formation of representatives of usual flora.

AIM:Evaluate the effect of miliacin on the intensity of endotoxinemia and features of cytokine production in experimental salmonella infection.MATERIALS AND METHODS:The studies were carried out in 128 male mice (CBAxC57Bl6)F1 divided into 4 groups: I--intact; II--infected; III--infected after administration of miliacin solvent: tween-21; IV--infected after administration of miliacin. Determination of the endotoxin in blood plasma was carried out by using chromogenic LAL-test. Cytokine production was studied in splenocyte culture by EIA method.RESULTS:Miliacin reduced the intensity of endotoxinemia in mice of group IV. Salmonella infection increased spontaneous (IFNγ) and induced (IL-12, IFNγ, IL-17) cytokine production. Miliacin ensured the most significant increase of spontaneous IL-10, IL-12 and IFNγ production compared with groups II and III. At the same time it limited the increase of induced IL-17 production compared with groups II and III.CONCLUSION:Protective effect of miliacin is determined by the reduction of endotoxinemia, mobilization of Th-1 response, stimulation of IL-10 production and limitation of IL-17 participation in the development of the inflammatory reaction.

AIM:Evaluation of influence of triterpenoid miliacin on the development of experimental salmonellosis infection.MATERIALS AND METHODS:Studies were carried out in 330 male mice (CBAxC57Bl6)F1. Miliacin was administered 3 times intraperitoneally with the interval of 3 days between administrations at a single dose of 2 mg/kg. The animals were infected intraperitoneally by hospital origin Salmonella enteritidis strain (2x10(6) bacteria per mice). 4 groups of mice were used: I - intact; II - infected; III - infected after administering solvent for miliacin 3 times (tween 21 at final concentration of 1.6x 10(-7) mol/kg); IV - infected after administration ofmiliacin.RESULTS:Miliacin reduced the mortality of mice compared with groups II and III. Microbial contamination of mice spleen in group IV was significantly lower compared with group II at all the periods of the study, and liver - at days 10 and 15. Triterpenoid weakened cell depletion of bone marrow, thymus and limited hyperplasia of spleen compared with animals of groups II and III. Its protective effect did not correlate with increase of antibody titers.CONCLUSION:Miliacin weakens the severity of salmonellosis infection course.

We studied the role of the natural triterpenoid miliacin (3-3-methoxy-Al8-oleanene) in the regulation of oxidative stress in the liver of (CBAxC57B1(6))F1 mice exposed to methotrexate. Miliacin attenuated methotrexate-induced lipid peroxidation as determined by an attenuation of thiobarbituric acid-reacting products in the liver. Furthermore, miliacin normalized the expression of genes encoding the 2e1 isoform of cytochrome P-450 and glutathione reductase that were dramatically dysregulated by methotrexate. These results established the role of miliacin in modulation of redox genes, thereby providing evidence for a new mechanism of organ protection by this triterpenoid.

The State Education Institution of Higher professional education "The Orenburg State Medical Academy of Federal Agency in Public Health and Social Development". In the experiment on mice (CBA x C57Bl6) F1 and Wistar rats is shown the protective effect of triterpenoid plant--miliatsina (3-beta-methoxy-delta18-oleanena) in relation to the humoral immune response and clearance macrophage function hepatic xenobiotic conditions of use--methotrexate. The results define the term as used miliatsina immunoprotector with adverse effects on the body of environmental and industrial chemical factors that form the secondary immunodeficiency.

In the experiment on mice (CBA x C57Bl6) F1 and Wistar rats is shown the protective effect of triterpenoid plant — miliatsina (3-β-methoxy-Δ18-oleanena) in relation to the humoral immune response and clearance macrophage function hepatic xenobiotic conditions of use methotrexate. The results define the term as used miliatsina immunoprotector with adverse effects on the body of environmental and industrial chemical factors that form the secondary immunodeficiency.

Morphological changes in lymphoid organs induced by antitumor drug methotrexate were studied in 219 male (CBA×C57Bl/6)F 1 mice. Plant triterpenoid miliacin attenuated the lymphotoxic effect of this drug.

A plant triterpenoid miliacin prevented stress-induced activation of LPO and accumulation of LPO products in the blood. The inhibitory effect of miliacin was not related to direct inhibition of reactive oxygen species generation.

Naloxone hydrochloride, an opioid receptors blocker, was administered to chick embryos. Morphological analysis of femoral bones of embryos showed an appreciable increase in the thickness of the perichondral bone cuff in the tubular bone diaphyses and increased mitotic activity in the zone of proliferating young cartilage of the epiphyseal plate.

We studied the effect of plant triterpenoid miliacin on dexamethasone-induced apoptosis in thymocytes and splenocytes. Miliacin produced a protective effect on splenocytes by decreasing the degree of DNA fragmentation due to blockade of the cascade cell death distally to the intramembrane phosphatidylserine translocation.