Antitumor Properties of Aqueous Extracts from Inonotus rheades Mycelium and Their Evaluation under Various Cultivation Conditions.

The antitumor properties of aqueous extracts of Inonotus rheades basidiomycete mushrooms were evaluated when the fungi were cultured on wood discs and wood shavings (birch) at 25 ± 1°C in the dark and under constant illumination with blue light (12.8 W/m2). The aqueous fraction containing water-soluble polysaccharides was isolated and analyzed: WS-5 fraction cultured on wood discs under blue light illumination, WS-8 fraction grown under similar conditions on wood shavings; WS-6 fraction grown in the dark on wood discs; and WS-7 fraction grown under similar conditions on wood shavings. The antitumor effects of the extracts were studied on the model of Ehrlich ascites carcinoma in mice. It was found that the extracts isolated from the basidial fungus Inonotus rheades exhibit antitumor properties and that their accumulation during growth is determined by different cultivation conditions.

[Impossible mechanisms of germatranol influence on the thermal stability of wheat germs].

The influence of biologically active substance germatranol in low and very low doses on the respiration rate and the content of reactive oxygen species (ROS) in wheat roots under conditions of high stress was investigated. The results showed that solutions of the studied substance in concentrations of from 10­5 M to 10­10 M (depending on the temperature) increase the thermotolerance of wheat germs and affect the ROS content and respiration rate. It is assumed that germatranol can have a positive impact on plant growth and development and act as antioxidants in plant cells.

Mitochondrial energy-dissipating systems (alternative oxidase, uncoupling proteins, and external NADH dehydrogenase) are involved in development of frost-resistance of winter wheat seedlings.

Gene expression, protein synthesis, and activities of alternative oxidase (AOX), uncoupling proteins (UCP), adenine nucleotide translocator (ANT), and non-coupled NAD(P)H dehydrogenases (NDex, NDPex, and NDin) were studied in shoots of etiolated winter wheat (Triticum aestivum L.) seedlings after exposure to hardening low positive (2°C for 7 days) and freezing (-2°C for 2 days) temperatures. The cold hardening efficiently increased frost-resistance of the seedlings and decreased the generation of reactive oxygen species (ROS) during further cold shock. Functioning of mitochondrial energy-dissipating systems can represent a mechanism responsible for the decrease in ROS under these conditions. These systems are different in their response to the action of the hardening low positive and freezing temperatures. The functioning of the first system causes induction of AOX and UCP synthesis associated with an increase in electron transfer via AOX in the mitochondrial respiratory chain and also with an increase in the sensitivity of mitochondrial non-phosphorylating respiration to linoleic and palmitic acids. The increase in electron transfer via AOX upon exposure of seedlings to hardening freezing temperature is associated with retention of a high activity of NDex. It seems that NDex but not the NDPex and NDin can play an important role in maintaining the functional state of mitochondria in heterotrophic tissues of plants under the influence of freezing temperatures. The involvement of the mitochondrial energy-dissipating systems and their possible physiological role in the adaptation of winter crops to cold and frost are discussed.

[Branched glucan from the fruiting bodies of Piptoporus betulinus (Bull.:Fr.) Karst].

A new glucan, namely, piptoporane I, with a molecular mass of 270 kDa was isolated from fruiting bodies of Piptoporus betulinis (Bull.:Fr.) Karst. (Fomitopsidacaeae). Using a combination ofphysicochemical methods, it was established that piptoporane I was a branched glucan with a backbone consisting of alpha-( 1->3)-glucopyranose residues substituted at the C-6 position by single residues of beta-D-glucopyranose by 17.3%. A polysaccharide with such a structure was isolated for the first time from the fungus genus Piptoporus.

Effect of amiodarone on thermotolerance and Hsp104p synthesis in the yeast Saccharomyces cerevisiae.

Amiodarone (AMD) is known to induce a transient increase in cytosolic Ca2+ level in cells of the yeast Saccharomyces cerevisiae. In the present study the effect of AMD on the thermotolerance and Hsp104p synthesis of the yeast was studied. AMD induced Hsp104p synthesis and increased survival of the yeast after a severe heat shock (50°C). The development of thermotolerance to a considerable extent depended on the presence of Hsp104p. The same effect was achieved by treatment with the classical uncoupler CCCP, which is also known to increase the cytosolic Ca2+ level. It is supposed that the change in intracellular Ca2+ concentration plays an important role in activation of the HSP104 gene expression and in increasing the thermotolerance of the yeast. The possible link between mitochondrial activity and calcium homeostasis is discussed.

Dependence of blood levels of HSP70 and HSP90 on genotypes of HSP70, GSTT1, and GSTM1 gene polymorphism in individuals chronically exposed to mercury.

The relationship between blood levels of HSP72, HSP72+HSP73, and HSP90 and genotypes of three polymorphisms of the HSP70 family, HSPA1L (2437T/C) and HSPA1B (2074G/C and 1267A/G) as well as GSTT1 and GSTM1 polymorphisms was studied in 82 men chronically exposed to mercury. Of these, 40 men were exposed to mercury for more than 10 years (group 1) and 42 developed chronic mercuric intoxication (group 2). The groups differed significantly by TT (p=0.004) and TC (p=0.007) genotypes of HSPA1L gene locus 2437T/C. Differences in the heat shock protein content associated with HSP70 gene polymorphism were detected only for HSPA1B gene locus 2074G/C and consisted in reduction of HSP90 (p=0.020) and HSP72 (p=0.056) for GG genotype in group 2 in comparison with group 1. Combination of GSTT1(+)/GSTM1(0/0) genotypes was associated with reduction of the protein levels, while variants including GSTT1(0/0) were associated with a significant elevation thereof.

Effect of cell transplantation on induction of heat shock proteins in damaged heart.

Variations in the amount of heat shock proteins of various classes in the damaged myocardium of rats were studied after xenogeneic transplantation of heart cells.

[Water-soluble endopolysaccharides from the fruiting bodies of Laetiporus sulphureus (Bull.: Fr.) Murr].

Endopolysaccharides represented by glucans, galactans, and glycoproteins were isolated from the fruiting bodies of the sulfur shelf (Laetiporus sulphureus (Bull.:Fr.) Murr), which were obtained by the natural-plantation method. The study of the major 56-kDa polysaccharide, laetiporan A, the content of which accounted for 0.28% of the fruiting body weight, showed that it is a beta-1,3-glucan containing mannose, galactose, fucose, xylose, and rhamnose residues at position C-6. An antioxidant effect of laetiporan A was discovered.

[Alkali-soluble polysaccharides of Laetiporus sulphureus (Bull.: Fr.) Murr fruit bodies].

Alkali-soluble polysaccharides have been extracted from Laetiporus Sulphureus (Bull.: Fr.) Murr fruit bodies with a yield of 42.7%. The structure of the dominant polymer (16.05% of fruit bodies' mass), named latiglucan I, has been determined. It is linear beta-1,3-glucan (molecular weight 1.8 x 10(5) Da, [alpha]D-17 degrees).

[Induction of synthesis of Hsp104 of Saccharomyces cerevisiae in heat shock is controlled by mitochondria]. / Induktsiia sinteza Hsp104 Saccharomyces cerevisiae pri teplovom shoke nakhoditsia pod kontrolem mitokhondrii.

Heat shock protein Hsp104 of Saccharomyces cerevisiae functions as a protector of cells against heat stress. When yeast are grown in media containing nonfermentable carbon sources, the constitutive level of this protein increases, which suggests an association between the expression of Hsp104 and yeast energy metabolism. In this work, it is shown that distortions in the function of mitochondria appearing as a result of mutation petite or after exposure of cells to the mitochondrial inhibitor sodium azide reduce the induction of Hsp104 synthesis during heat shock. Since the addition of sodium azide suppressed the formation of induced thermotolerance in the parent type and in mutant hsp104, the expression of gene HSP104 and other stress genes during heat shock is apparently regulated by mitochondria.