[The effect of combination of glycyrrhizic acid with alpha-glutamyl-tryptophan on the experimental adenoviral infection].

In this work, the activity of glycyrrhizic acid (GL) and dipeptide alpha-glutamyl-tryptophane (EW) as single preparations or in combination (GL+EW) against experimental adenoviral infection in the syrian hamsters was studied. Application of gl and GL+EW was shown to decrease the level of the adenovirus replication in liver tissue by 0.6 - 1.2 lgTCID50 depending on the composition and time point of the post infection. It was also demonstrated that normalization of the structure of the liver tissue was required, which was shown on the level of both optical and electron microscopy. The results obtained in this work suggest that gl and GL+EW may be considered as potential component of the complex therapy of adenoviral infection.

Broad range of inhibiting action of novel camphor-based compound with anti-hemagglutinin activity against influenza viruses in vitro and in vivo.

Influenza virus continues to remain one of the leading human respiratory pathogens causing significant morbidity and mortality around the globe. Due to short-term life cycle and high rate of mutations influenza virus is able to rapidly develop resistance to clinically available antivirals. This makes necessary the search and development of new drugs with different targets and mechanisms of activity. Here we report anti-influenza activity of camphor derivative 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene-aminoethanol (camphecene). In in vitro experiments it inhibited influenza viruses A(H1, H1pdm09, H3 and H5 subtypes) and B with EC50's lying in micromolar range. Due to low cytotoxicity it resulted in high selectivity indices (74-661 depending on the virus). This effect did not depend on susceptibility or resistance of the viruses to adamantane derivatives amantadine and rimantadine. The compound appeared the most effective when added at the early stages of viral life cycle (0-2h p.i.). In direct hemagglutinin inhibition tests camphecene was shown to decrease the activity of HA's of influenza viruses A and B. The activity of camphecene was further confirmed in experiments with influenza virus-infected mice, in which, being used orally by therapeutic schedule (once a day, days 1-5 p.i.) it decreased specific mortality of animals infected with both influenza A and B viruses (highest indices of protection 66.7% and 88.9%, respectively). Taken together, these results are encouraging for further development of camphecene-based drug(s) and for exploration of camphor derivatives as highly prospective group of potential antivirals.

[Anti-viral activity of a complex of the glycyrrhizic acid-alpha-glutamyltryptophan against the experimental lethal influenza infection in white mice caused by the oseltamivir-resistant strain of the virus].

Influenza virus is a leading causing factor of infectious respiratory human pathology. The search and development of novel anti-influenza drugs with a wide spectrum of activity is an important goal for medical science. In addition to specific anti-viral activity of the compound, its way of application is of great importance. In this work, we present the results of the study of the activity of a combination of glutamyl-tryptophan with glycirrhyzic acid (GTGA) against oseltamivir-resistant strain of the virus A/Vladivostok/2/09 (H1N1) at per os application on the model of the lethal influenza infection in white mice. The application of the GTGA was shown to decrease the specific mortality of animals (index of protection 43-50%), to increase the mean day of death to 2.5-3.9 days, and to reduce the infectious titer of the virus in the lung tissue to 1.5-1.9 Ig EID50/20 mg. The corresponding values for the reference compound oseltamivir were 14-25%, 1.1-1.9 days and 0.7 Ig EID50/20 mg, respectively, depending on the dose of the virus. The use of the GTGA also led to a reliable increase of the titers of interferon in the blood from 44.3 to 66.3 ME/mL. Morphological analysis revealed that GTGA lead to normalization of the structure of the lung tissue restricting the level of the cytodestruction and inflammation. The results obtained in this work allow the combination studied to be suggested as a promising anti-influenza drug that is active against the drug-resistant virus strains and can be applied orally.

[The anti-viral activity of the complex glycyrrhizic acid-alpha-glutamyl-tryptophan against experimental lethal influenza infection in white mice caused by oseltamivir-resistant strain of the virus].

Influenza virus is a leading causing factor of infectious respiratory human pathology. The ability to implement the antigenic drift and development of drug resistance makes it important to develop novel anti-influenza drugs of wide spectrum of activity. In this work, we present the results of the study of the activity of a combination of glycyrrhizic acid with dipeptide alpha-glutamyl-tryptophan against oseltamivir-reistant strain of the virus Al Vladivostok/2/09 (H1 N1) on the model of lethal influenza infection in white mice. Application of Orvilax was shown to decrease the specific mortality of animals (index of protection 39-67% depending on the dose of the virus and drugs combination), to increase the mean day of death to 3.7-5.0 days and decrease the infectious titer of the virus in lung tissue to 1.3 Ig EID50/20 mg. The corresponding figures for the reference compound Tamiflu were 8-11%, 0.5-1.5 days, and 0.6 Ig EID50/20 mg. The use of Orvilax also led to reliable increase of the titers of interferon in the blood from 30.4 to 56.5 ME/mL. The results obtained allow the drug to be considered as a promising anti-influenza remedy that is active against the drug-resistant virus strains.

[Ingavirin treatment of experimental parainfluenza pneumonia in Syrian hamsters].

Parainfluenza viruses affect the upper respiratory tract in all age group patients, in children aged 6 months to 3 years in particular. The most urgent task is to design drugs to treat parainfluenza. This investigation studied the antiviral activity of Ingavirin (2-(imidazole-4-yl) ethanamide of pentandioic-1,5 acid) on a model of parainfluenza infection in Syrian hamsters. The drug was shown to restrict the infectious process in animal lung tissue. This restriction manifested itself as reductions in the infectious titer of parainfluenza virus in the lung tissue, in the degree of pulmonary edema and tissue cell infiltration, and in virus-specific lesion of bronchial epithelial cells. The in vitro experiments demonstrated the ability of Ingavirin to diminish the infective activity of viral descendants. The finding allows one to consider Ingavirin to be a promising antiviral agent that is active against parainfluenza infection in vivo.

[Development of novel drugs against influenza virus based on synthetic and natural compounds].

Recent progress of the laboratory in the area of the search and development of novel remedies for prophylaxis and treatment of influenza is reviewed in this work. The data of the study of the anti-viral activity of compounds from the chemical groups of azolo-adamantanes, triterpenes, derivatives of benzimidazole, usnic acid, and other heterocyclic substances are presented. The protective properties of the plant antioxidants at lethal influenza infection of animals are discussed. High virus-inhibiting activity of natural polysaccharides and their complexes with silver ions is shown against influenza virus. The data presented allow listed groups of compounds to be suggested as promising candidates for further development of anti-influenza drugs.

[Effect of antiviral drugs with various mechanisms of action on morphogenesis of infection caused by extremely pathogenic influenza virus strains in animals].

The effect of meglumine salt of acridonoacetic acid (cycloferon) on the in vivo morphogenesis of influenza infection caused by viruses of different origin (avian, swine and human) and variable susceptibility to antivirals (rimantadine and oseltamivir) has been studied. The administration of cycloferon results in stimulation of the immune response, restriction of the foci of post-influenza pneumonia, and normalization of the structure of respiratory zones independently of the susceptibility or resistance of infectious virus to the drugs. Among virions formed in the lungs of cycloferon-treated mice, prevalence of irregular-shaped virions with defects of surface glycoproteins was observed. The data obtained suggest that cycloferon is a drug with the complex mechanism of activity.

[Protective activity of Ingavirin in experimental lethal influenza due to pandemic influenza virus A (H1N1)v in albino mice].

Despite obvious success in the vaccine development and chemotherapy of influenza, it remains a poorly controlled infection leading to emergence of new pandemic variants of the virus with high morbidity and mortality. We investigated the protective activity of Ingavirin against the lethal influenza A (H1N1) 2009 virus infection on albino mice. Oral use of Ingavirin resulted in sharp decreasing of the mortality (index of protection up to 57%), slight decreasing of the infectious titer of the virus in the lungs (up to 40-fold), normalizing of the body weight dynamics and the lung tissue structure vs. the placebo-treated control. The degree of the bronchial epithelium damage was also strongly decreased. The results allow to consider Ingavirin as an effective antiviral against the current pandemic influenza virus.

[Antiviral activity of Ingavirin in experimental lethal influenza due to influenza virus B in albino mice].

The protective activity of Ingavirin against experimental infection caused by influenza B virus was studied on albino mice vs. Arbidol. Oral use of Ingavirin was shown to decrease the infectious titers of the virus in the animal lung tissue, to normalize the body weight dynamics, to lower the mortality and to increase the average lifespan vs. the placebo-treated animals. The activity of Ingavirin was higher than that of the reference drug. The results allowed to consider Ingavirin as a prospective agent for the treatment of influenza infection in humans.

[The role of oligomeric structure of human serum albumin during its interaction with polyalbumin receptors in blood serum of patients with viral hepatitis B]. / Rol' oligomernosti syvorotochnogo al'bumina cheloveka pri ego vzaimodeistvii s retseptorami polial'bumina v syvorotke krovi bol'nykh virusnym gepatitom B.

Several oligomers of human blood serum albumin modified by glutaraldehyde differ in their binding ability to polyalbumin receptors in blood serum of patients with viral hepatitis B. Erythrocytes containing the albumin tetramer are able to agglutinate, while the red blood cells coated with dimer or monomer are deprived of this property. At the same time, the albumin dimers and monomers neutralize agglutination of the erythrocytes containing the complete pool of modified albumin in membranes although their effect is distinctly lower than that of tetramer. The albumin tetramer may have two or more sites of binding to erythrocytes or to the surface antigen of hepatitis B virus, bearing polyalbumin receptors, whereas the protein dimer or monomer contained only one site of binding.