[Study of membranotropic and antioxidant activity of flavonoids and their complexes with ferric iron].

We studied the interaction with liposomes and the antioxidant activity of flavonoid (quercetin, catechin, taxifolin) complexes with iron (III). It was found that the lipophilicity of complexes depends on an iron:flavonoid ratio and grows at a ratio of 1 to 1, while complexes in a 2:1 ratio were the most effective to slow down the lipid peroxidation and restore radical 2,2-diphenyl-1-pic: rylhydrazyl. Thus, the stoichiometry of complexes formed in aqueous solution, may differ from the stoichiometry of complexes that most effectively protect membranes from.peroxidation.

[Thermodynamic behaviour and conformational changes of alcohol oxidase of yeasts Hansenula polymorpha].

We studied influence of heating, ethanol and sodium azide on the structural and conformational changes of the alcohol oxidase from yeast Hansenula polymorpha. The increase of fluorescence of alcohol oxidase -cofactor, flavin adenine dinucleotide, was revealed when heated to 60 degrees C while the enzymatic activity of alcohol oxidase remained unchanged. Differential scanning microcalorimetry revealed that ethanol stabilized the protein structure and increased the temperature of melting, Based on the data of circular dichroism, we concluded that the percentage of helicities in the secondary structure of alcohol oxidase was not influenced by both ethanol and sodium azide, however ethanol significantly modified the circular dichroism spectrum associated with the tertiary structure of alcohol oxidase.

[Biological activity of water-soluble nanostructures of dihydroquercetin with cyclodextrins].

The biological properties of dihydroquercetin (DHO) modified by including it into the ring of beta-cyclodextrin (beta-CD) to give it more water-soluble properties have been investigated. It was shown that the peroral administration of the DHQ/beta-CD complex provides a long increase of DHQ concentration in rat blood (up to 7.5 h), and, unlike pure DHQ, the complex does not accumulate in the liver. As DHQ is released from the complex, it penetrates into liposome membranes, changing their thermodynamic characteristics. DHQ decreases the specific heat absorption, enthalpies, and temperature maximum of lipid melting and increases the transition half-width. This property is used to estimate the stability of the DHQ/beta-CD complex. It was shown that complex DHQ/beta-CD is not stable, and DHQ molecules slowly leave the complex in water environment. Seven and a half hours after the peroral injection of drugs, DHQ was found in the blood plasma of rats to which water-soluble complex DHQ/betaCD was injected and in the liver of rats to which free DHQ was injected. Thus, DHQ/betaCD not only is a more water-soluble complex but also it slowly releases DHQ, supporting long a low concentration of the free form of DHQ and providing the penetration of DHQ into the blood stream. After several weeks of feeding old mice with antioxidants, the activity of mitochondrial enzymes was restored to the level observed in young animals.

[Interaction of taxifolin (dihydroquercetin) with dimyristoylphosphatidylcholine multilamellar liposomes].

Differential scanning calorimetry was used to study the influence of the flavonoid taxifolin (dihydroquercetin) on the temperature-dependent phase transition of dimyristoylphosphatidylcholine multilamellar liposomes. Taxifolin was added to organic solution of the lipid during the procedure of liposomes preparation (addition from-within) or to a suspension of prepared liposomes (addition from-without). In the first case, liposomes contained from 2 to 50 mol% of taxifolin added from-within; in the second case, lyposomes were treated with 0.001% or 0.01% taxifolin. In both cases, the effect was similar. When the concentration of taxifolin increased, the temperature of lipid melting decreased while the width of transition considerably enlarged. Freeze-fracture electron microscopy revealed that taxifolin did not rupture multilamellar liposomes, while the formation of ripple-phase was retarded in all bilayers even when the liposomes were treated from without. This suggested the ability of taxifolin to penetrate through numerous bilayers of multilamellar liposomes.

[Specific modification of the alpha-subunit of Escherichia coli Rna polymerase by monomercuric derivative of fluorescein mercuric acetate]. / Spetsificheskaia modifikatsiia alpha-sub''edinitsy RNK-polimerazy Escherichia coli monortutnym proizvodnym fluorestseinmerkuratsetata.

The method for specific modification of Escherichia coli RNA polymerase by a monomercuric derivative of fluorescein--fluoresceinmonomercuracetate (FMMA)--a specific reagent for SH-groups of proteins is suggested. It is shown, that in conditions of equimolar FMMA/enzyme ratio the fluorescent label interacts preferantially with a single sulfhydryl group in alpha-subunit of RNA polymerase. The mercaptide bonding formation is followed by significant alterations of all spectral parameters of FMMA, but has no effect on the kinetic parameters (KB and k2) of RNA synthesis initiation nor does it lead to inhibition of the total RNA synthesis. The modification presented may be used in structural and topological investigations of RNA polymerase functioning.

[The effect of low intensity electromagnetic irradiation on hydration of DNA film]. / Ussledovanie vliianiia EMI maloi intensivnosti na gidratatsiiu plenok DNK.

By using the IR-spectroscopy it has been shown that electromagnetic radiation (frequency 8.15-10.0 GHz, energy flux density 5 microWt/cm2) reduces the rate of water desorption from DNA films. It was found that the irradiation of samples with high humidity did not change spectral characteristics of DNA molecules in the range of 900-4000 cm-1, that means their molecular structure remains intact. At the same time the irradiation changed conformation liability of these biopolymeric molecules, that is their ability of conformational transformations under the influence of outer factors. Drying of non-irradiated humid films induced rapid (for a few minutes) transition of DNA from B to A conformational state, whereas in the irradiated films this transition took several hours after humidity reducing.

[Structural changes in lipid membranes and collagen irradiated with UV light and the protective effect of plant extracts]. / Strukturnye izmeneniia lipidnykh membran i kollagena, obluchennye UF-svetom, i zashchitnoe deistvie rastitel'nykh ékstraktov.

The results of experimental studies on the effect of UV irradiation on collagen, artificial lipid membranes, and rat skin, as well as the protective effect of plant extracts from UV radiation are presented. The irradiation of collagen and lipid membranes with solar and artificial UV light leads to structural changes in these objects. In particular, collagen molecules denature and transfer into a new conformational state. The effect of UV light on lipid membranes and liposomes leads to a disturbance of membrane structure, which is connected with a decrease in the number of lipid molecules involved in the cooperative transition from gel into a liquid crystal state. The components of plant extracts (mainly flavonoids) absorb UV radiation in the erythem-forming spectral area and block the destructive processes occurring in collagen and lipids.

[Mechanism of the formation of paramagnetic centers in proteins exposed to UV-radiation]. / Mekhanizm obrazovaniia paramagnitnykh tsentrov v belkakh pri deistvii UF-sveta

It is shown that the process of formation of paramagnetic centres in UV-irradiated at 77degreesK protein solutions in a biquantum one. The protein molecule in triplet state is an intermediate product.

[Accumulation of paramagnetic centers in protein solutions exposed to UV-radiation]. / Issledovanie nakopleniia paramagnitnykh tsentrov v rastvorakh belkov pri deistvii UF-sveta

It is shown that concentration of paramagnetic centres (PC) in UV-irradiated protein solutions at 77degreesK approximates the limiting value. The limiting number of PC (n) per one molecule is in direct proportion to that of aromatic amino acid residues in it n(sigma)=2+0,1 sigma. The formation of PC slopps because all the energy absorbed by aromatic amino acid residues is transfered to the radicals formed.

[Effect of electromagnetic radiation of radio frequency (340 and 800 MHz) on liposomes from dimyristoyl lecithin]. / Vliianie élektromagnitnykh izluchenii radiochastotnogo diapazona (340 i 800 MGts) na liposomy iz dimiristoilletsitina.

Using the liposomes prepared from dimyristoyl lecithin at temperature below that of phase transition, its was shown that the annealing of liposomes by 340- and 800-MHz microwave radiation required less integral heating of the samples, than it should be expected from the experiments on heating the samples in a thermostat.

[K+,H+ and Cl- fluxes across erythrocyte membrane irradiated with radio frequency electromagnetic fields]. / Issledovanie potokov K+,H+ i Cl- cherez membranu éritrotsitov, obluchennykh élektromagnitnym izlucheniem radiochastotnogo diapazona.

The effect of 460 MHz microwave radiation on the ion-transporting properties of the isolated rat erythrocytes was studied with the use of K+, H+ and Cl(-)-selective electrodes. In comparison with the control cells kept at 0 degree C the most significant changes were observed in the K+ transport system. Particularly, microwave radiation (specific absorbed rate 280 W/kg) caused an increased loss of K+ during treatment and 2-fold decrease in the rate of K+ efflux from the irradiated erythrocytes, when the latter were incubated in the isoosmotic, unbuffered sucrose. The same changes were observed when the erythrocytes were conventionally heated up to 39 degrees C for 20 minutes. It is concluded that high levels of microwave radiation cause temperature-induced changes of the membrane structure resulting in alterations in potassium transport across the membrane.

[Action of triterpene glycosides of the dammarane series and their aglycones on lipid membranes]. / Deistvie triterpenovykh glikozidov dammaranovogo riada i ikh aglikonov na lipidnye membrany.

The action of the dammarane triterpene glycosides Rb1 and Rg1 and their aglycones 20(S) protopanaxatriole and 20(S) protopanaxadiole from Korean ginseng on permeability of bilayer lipid membranes formed of monolayers was studied. RgI, protopanaxatriole and protopanaxadiole in concentrations of 3, 0.5 and 30 micrograms/ml respectively formed single ionic channels in the water phase on the membrane side containing cholesterol. The channel conductivity was 5 to 30 pSm in 1 M KCl. The ionic channels were more selective with respect to K+ as compared to Cl-. Rb1 was also able to increase the conductivity of the lipid membranes. However, no jumps in the current characteristics of the single channels were detected. All the substances in high concentrations on one side of the membrane independently of the cholesterol content induced fluctuation of the high amplitude current (from several tens of pSm to several hundreds of nSm).

[Effect of ginseng ginsenosides on phase transitions of dipalmitoylphosphatidylcholine membranes]. / Issledovanie vliianiia ginzenozidov zhen'shenia na fazovye perekhody membran iz dipal'mitoilfosfatidilkholina.

The influence of dammaran triterpene glycosides (ginsenosides Rb1 and Rg1) from Panax Ginseng C.A. Meyer and their aglycones on the phase transfers of multilayer vesicles of dipalmitoylphosphatidyl choline was studied. Ginsenosides Rb1 and Rg1 and aglycone 20(S) protopanaxatriol insignificantly modified the lipid gel phase and only in concentrations close to the equimolar ones insignificantly damaged the lipid covers and decreased the size of the cooperative unit. Aglycone 20(S) protopanaxadiol (PD) induced the formation of the second phase with a more solid cover of the lipids but a lower size of the cooperative unit by comparison with that of the pure lipid. The presence of cholesterol in an amount up to 5 mol per cent slightly influenced the interaction of the agents with the gel phase except for PD. In the presence of cholesterol PD did not induce the formation of the two phases and in an amount of 100 mol per cent eliminated the major transfer. The study suggested that PD interacted with the gel phase and did not penetrate into the bilayer deeper than the glycerol skeleton of the lipid molecule.

[Action of triterpene glycosides of the dammarane series and their aglycones on the K+ and H+ ion currents in erythrocytes, induced by the ionophore A23187 and divalent ions]. / Deistvie triterpenovykh glikozidov dammaranovogo riada i ikh glikonov na ionnye potoki K+ i H+ v éritrotsitakh, indutsirovannye ionoforom A23187 i dvukhvalentnymi ionami.

The influence of the dammarane triterpene glycosides Rb1, Rb2, Rg1 and Rf and their aglycones 20(S) protopanaxatriol and 20(S) protopanaxadiol on fluctuation of the K+ and H+ flows in erythrocytes induced by ionophore A23187 and Ca2+ was studied. It was shown that glycoside Rb1 (10 to 50 micrograms/ml) and 20(S) protopanaxatriol (30 micrograms/ml) had a property of inducing fluctuation of the K+ and H+ flows in erythrocytes. In case of Rb1 the system entirely reversed to the initial state whereas in case of the protopanaxatriol use after the fluctuation the system did not reverse to the initial state. Glycosides Rb2 (10 to 30 micrograms/ml), Rg1 (5 to 20 micrograms/ml) and Rf (10 to 100 micrograms/ml) and 20(S) protopanaxadiol (30 micrograms/ml) in the concentrations used did not initiate the fluctuations. The above substances increased the extracellular concentration of K+ and pH without the system reversion to the initial state.

[Mechanism of activation of Ehrlich ascites carcinoma cells using the total fraction of saponins from Korean ginseng]. / Mekhanizm aktivatsii kletok astsitnoi kartsinomy Erlikha obshchei fraktsiei saponinov iz koreiskogo zhen'sheniia.

Molecular mechanisms of action of the total fraction of saponins from Red Korean Ginseng on the elements of the intracellular signalling system of the cells of ascitic Ehrlich carcinoma (AEC) were studied. The action of the total fraction of the saponins on the AEC cells was compared with that of the classic activator of such cells i.e. ATP. It was shown that the action of the total fraction of the saponins was similar to that of ATP. In concentrations of 10(-6) to 10(-3) per cent saponin induced an increase of [Ca2+]j mobilizing Ca2+ from the endoplasmic reticulum (ER) and activating the Ca2+ inlet to the cells. The same as in case with the use of ATP the Ca2+ mobilization from ER was reversible. In comparison to ATP saponin induced higher activation of the Ca2+ inlet to ER and the cells. The same as ATP saponin activated the Na+/H+ exchange and the Ca2+ - dependent K+-channels. Out of all the mention-ed parameters only the activation of the Ca2+ inlet to the cells was probably the direct result of the saponin action. The changes in the other parameters were mediated by nonspecific activation of the purine receptor. The analysis of the kinetic data demonstrated that unlike the ATP-dependent activation of the purine receptor the saponins first of all activated the inlet of Ca2+ to the cells and only after that the mobilization of the latter from ER.

[Treatment of late radiation-induced skin ulcers with laser radiation]. / Lechenie pozdnikh luchevykh iazv kozhi lazernym izlucheniem.

The authors presented the results of laser stimulation of reparation processes in 25 patients with late radiation skin ulcers. Short-term therapeutic results turned out to be favorable in 18 (72%) patients, a complete cicatrization of ulcers was observed in 9 patients, significant improvement in 9.

[Study of the effect of tegalide and bithionol on biological membranes using fluorescent probes]. / Issledovanie deistviia tegalida i bitionola na biologicheskie membrany s pomoshch'iu fluorestsentnykh zondov.

Fluorescent probes were used to study structural changes in different membranes affected by gamma-radiation, protonophores and radioprotective agents, tegalide and bithionol. The preparations of the defined concentrations decreased the microviscosity of membranes, lowered the peaks and changed the temperature of phase transitions in liposomes from dipalmitoyl lecithin, and induced the output of Ca2+ from mitochondria. The effects depended on the radiation dose, the structure, concentration and lipophilicity of the preparation; protonophores produced a specific effect.