Biochemistry (Moscow), Supplement Series B: Biomedical Chemistry (v.7, #2)

Computer modeling of blood brain barrier permeability for physiologically active compounds by O. A. Raevsky; S. L. Solodova; A. A. Lagunin; V. V. Poroikov (95-107).
The review considers the current level of computer modelling of the relationship between structure of organic compounds and drugs and their ability to penetrate the blood brain barrier (BBB). All descriptors that influence BBB permeability within classification and regression QSAR models have been summarized and analyzed. Special attention is paid to the crucial role of H-bond for processes of both passive and active transport across the BBB. It is concluded that subsequent progress in computer modelling of the BBB penetration capacity for drug substances will be achieved after characterization of a spatial structure of the full-size P-glycoprotein molecule with high resolution and the creation of QSAR models describing quantitative relationship between structure and active transport of substances across the BBB.
Keywords: blood brain barrier; QSAR; passive transport; active transport; descriptors; Pgp; permeability

The review discusses the functional role of sphingolipids in the pathogenesis of Alzheimer’s disease (AD). Certain evidence exists that the imbalance of sphingolipids such as sphingomyelin, ceramide, sphingosine, sphingosine-1-phosphate and galactosylceramide in the brain of animals and humans, in the cerebrospinal fluid and blood plasma of AD patients plays a crucial role in neuronal function by regulating growth, differentiation and cell death in CNS. Activation of sphingomyelinase (Smase), which leads to the accumulation of the proapoptotic agent, ceramide, can be considered as a new mechanism for AD and may be a prerequisite for the treatment of this disease by using drugs that inhibit SMase activity. The role of sphingolipids as biomarkers for the diagnosis of the early stage of Alzheimer’s disease and monitoring the effectiveness of treatment with new drugs is discussed.
Keywords: Alzheimer’s disease; sphingolipids (sphingomyelin, ceramide, sphingosine, sphingosine-1-phosphate, sulphatides); mass spectrometry of sphingolipids; brain; cerebrospinal fluid; blood plasma; biomarkers

Modern methods of cytochrome P450 analysis by N. E. Moskaleva; V. G. Zgoda (124-135).
The review describes recent approaches used for evaluation of cytochrome P450 concentration and activity. It considers employment of modern methods of proteomic analysis including electrophoresis and chromatography/mass-spectrometry (MS) for investigation of the particular group of proteins. Special attention is paid to targeted quantitative MS analysis of cytochromes P450 in biological samples. Finally, we analyze methods used for assay of cytochromes P450 activities and problems of correlation between content of certain P450 isoforms and their specific enzymatic activities.
Keywords: quantitative proteomics; mass-spectrometry; cytochrome P450

Imiquimod: The biochemical mechanisms of immunomodulatory and anti-inflammatory activity by S. V. Bozrova; V. A. Levitsky; S. A. Nedospasov; M. S. Drutskaya (136-145).
Imidazoquinolines are a new group of compounds that recently have been introduced into clinical practice as antitumor and antiviral immunomodulators. Structurally, they are low molecular weight synthetic guanosine-like molecules. Although imiquimod, the most widely used imidazoquinoline, has been recommended for treatment of several forms of skin cancer and papillomas, its molecular mechanisms of action are not fully understood. In particular, imiquimod is known as a specific agonist of Toll-like receptor 7 (TLR7) and this capacity is widely used in a large number of experimental studies and clinical trials. Nevertheless, detailed analysis of the published data suggests that the biological activity of imiquimod can not be explained only by its interaction with TLR7. Certain evidence exists that imiquimod directly interacts with adenosine receptors and other molecules that regulate synthesis of cyclic adenosine monophosphate. A detailed understanding of the biochemical basis of immunomodulating and antitumor effects of imiquimod will increase its clinical effectiveness and accelerate the development of new drugs with similar but improved pharmaceutical characteristics. This review summarizes the published data about effects of imiquimod on various intracellular biochemical processes and signaling pathways.
Keywords: imidazoquinolines; imiquimod; tumor necrosis factor; anti-inflammatory drug; cAMP

The study of complex formation of human recombinant HSP70 with tumor-associated peptides by V. A. Chernikov; N. V. Gorokhovets; L. V. Savvateeva; S. E. Severin (146-153).
Molecular chaperones of the HSP70 family (70 kDa heat shock proteins) are involved in presentation of exogenous antigenic peptides by antigen-presenting cells (APC). HSP70 complexes with tumor-associated peptides are powerful immunotherapeutic agents, inducing an adaptive cytotoxic T-cell mediated immune response. Several clinical trials have shown that HSP-based autological anticancer vaccines possess high efficiency and safety. However, sometimes it is impossible to isolate sufficient amount of such vaccines and so human recombinant HSP are used for in vitro loading with tumor-associated peptides. In this study we have investigated binding of two human recombinant proteins HSP70HYB and HSC70 with antigenic peptides of different origin and optimized conditions for complex formation. The proposed method for complex formation increases the repertoire of HSP70 bound peptides compared with in vivo formed complexes.
Keywords: heat shock proteins; HSP70; tumor-associated antigenic peptide; peptide binding

Study into possible molecular targets of a neuroprotective compound dimebon using a transgenic mouse line by T. A. Shelkovnikova; A. A. Ustyugov; V. S. Kokhan; T. V. Tarasova; V. K. Medvedeva; I. V. Khrytankova; S. O. Bachurin; N. N. Ninkina (154-159).
In the present study we have used a transgenic mouse line overexpressing an amyloidogenic protein, gamma-synuclein, in the nervous system to address the effect of dimebon on proteinopathy progression. Chronic dimebon administration increased lifespan in these transgenic mice, furthermore, using histological and biochemical approaches we have demonstrated that dimebon reduced the number of amyloid inclusions in the spinal cord of transgenic animals and decreased the content of ubiquitinated proteins in the detergent-insoluble fraction of the spinal cord. These effects are likely to occur at the level of aggregated protein species, since transgene expression remained unaltered during dimebon administration. Thus, pathological protein aggregation serves as one of dimebon targets in neurodegeneration.
Keywords: neurodegeneration; neuroprotection; protein aggregation; transgenic models; dimebon

The effect of antioxidants on electrocatalytic activity of cytochrome P450 3A4 by V. V. Shumyantseva; A. A. Makhova; T. V. Bulko; E. V. Shich; V. G. Kukes; S. A. Usanov; A. I. Archakov (160-164).
The electrochemical analysis of cytochrome P450 3A4 catalytic activity has shown that vitamins C, A and E influence reduction of cytochrome P450 3A4. These data suggest a possibility of cross effects and interference of vitamins-antioxidants with drugs metabolised by cytochrome P450 3A4, during complex therapy of patients. These vitamins demonstrate antioxidant properties that lead to the increase of the cathodic current corresponding to heme reduction of this functionally significant hemoprotein. Ascorbic acid (0.028–0.56 mM) stimulated the cathodic peak (an electrochemical signal) of cytochrome P450 3A4. In the presence of diclofenac (Voltaren), a typical substrate of cytochrome P450 3A4, the increase in the catalytic current suggesting electrocatalysis and stimulating action of ascorbic acid was observed. In the presence of vitamins A and E the dose-dependent increase in the catalytic current of cytochrome P450 3A4 was observed in the range of vitamin concentrations from 10 to 100 μM. The maximal increase of 229 ± 20 and 162 ± 10% was observed at 100 μM vitamin A and vitamin E, respectively. In contrast to vitamin A, vitamin E in the presence of the cytochrome P450 inhibitor itraconazole did not increase the catalytic current. The latter implies existence of some substrate properties in vitamin E. The electrochemical approach for the analysis of catalytic activity of cytochrome P450 3A4 and studies of the effect of biologically active compounds on electrocatalysis is the sensitive and effective sensor approach, allowing to use low concentration of protein on an electrode (up to 10–15 mol/electrode), to carry out the analysis without involvement of protein redox partners, and to reveal drug-drug or drug-vitamins interaction in pre-clinical experiments.
Keywords: cytochrome P450 3A4; diclofenac; antioxidants; electrochemistry; enzyme electrodes; vitamins A; C; E; interaction

The antiradical activity of plant extracts and their health-improving and prophylactic combinations with a phosholipid complex by V. S. Baranova; I. F. Rusina; D. A. Guseva; N. N. Prozorovskaya; O. M. Ipatova; O. T. Kasaikina (165-174).
Using the chemiluminescence method, the effective concentration of antioxidants (AO) and their antiradical activity (ARA) have been measured for 13 plant extracts. All extracts demonstrated higher ARA than that of the synthetic antioxidant ionol. The highest ARA was found in extracts from Larix dahurica, Hypericum perforatum, Potentilla fruticosa, Aronia melanocarpa, and Rhaponticum carthamoides. Synergistic action was found for combinations of extracts from Aronia + Rhaponticum, Larix + Hibiscus, and Schizandra + Aronia; the synergistic effect β was 38, 33, and 22%, respectively. This effect may be attributed to compounds present in these extracts. Phospholipids (the phospholipid complex Lipoid S40) lacking any antioxidant effect alone, showed a potent synergistic effect in combination with the Aronia extract (β = 60%) and the Silybum extract (β = 41%). Combinations of plant extracts with the phospholipids complex potentiated their inhibitory activity by increasing the induction period. Clinical trials have demonstrated, the combinations used may be recommended as an additional component in the complex therapeutic treatment of such chronic diseases as cardiovascular and hepatobiliary and also as an individual prophylactic agent.
Keywords: phytoextract; antioxidants; antiradical activity; chemiluminescence technique; synergism; prophylactic combinations

The use of real-time PCR for quantitative determination of some propionic bacteria inhabiting the human skin by A. G. Globa; Ya. I. Alekseev; V. G. Arzumanyan; V. A. Zaborova; A. A. Guridov (175-177).
A test system has been developed for determination of propionic bacterial species inhabiting the human skin. This system developed in the real time PCR format is applicable for quantitative determination and also detection of genomes of the following Propionibacterium species: P. acnes, P. granulosum, and P. avidum. This system was used for analysis of wash samples from the skin of 17 pentathlon sportsmen and 16 students. All three species of propionic bacteria were found in all skin wash samples. However, contamination with P. acnes was two times higher in the control group than in the group of pentathlon sportsmen.
Keywords: polymerase chain reaction; propionic bacteria; microbiota