The study of the neuraminidase and interferon inducing activity of Altabor substance

Abstract

Influenza is acute respiratory disease of viral etiology characterized by the phenomena of general intoxication and respiratory tract lesions.Hemagglutinin and neuraminidase, surface antigen of influenza virus are the factors of aggression. Hemagglutinin is a polypeptide, a surface protein of the viral envelope, due to it the virus attaches to the surface of the host cell.Neuraminidase is an enzyme, a glycoproteid complex that determines the enzymatic activity and is responsible for the ability of a viral virion to penetrate the host cell and leave it after propagation.In other words, neuraminidase helps viral particles to penetrate the secretions of the mucous membranes to achieve epithelial cells of the respiratory tract by virions.In addition, the properties of hemagglutinin determine the intensity of intoxication in disease, and neuraminidase exhibits a marked immunosuppressive effect.Therefore, for prevention and treatment of influenza diseases it is advisable to use two schemes, which would affect two elements of the infectious process, namely the use of drugs that would affect influenza virus destroying it, and medicines for strengthening the body's defences by stimulating the interferon inducing activity.Thus, the search for drugs that would have a combined scheme of action is appropriate and promising.The aim of the workwas to study the anti-influenza activity of Altabor substance obtained from the collective fruit of black alder (Alnus glutinosa) and grey alder (Alnus incana) in order to determine its effect on the virion of influenza virus concerning its destruction and on a human in relation to increase of the body defences. The research of the antiviral activity of Altabor substance was conducted by studying its effects on isolated neuraminidase and different strains of the influenza virus. The effect of the drug on interferon production was also studied.The antineuraminidase activity of Altabor substance was studied on the example of inhibition of neuraminidases of different types of influenza viruses (A/Hong Kong/68/H3N2/, A/Victoria/75/H3N2, A/Khabarovsk/H1N1/) and neuraminidase isolated from Astrobacter ureafaciens 1 unit Calbiochem, Hoest in the concentrations of 105 and 51.5 γ/ml/min with Altabor solution in the concentration of 1 mg/ml.The interferon inducing activity of Altabor was studied in the culture of human leukocytes. The solution of the drug in different doses was added to 3 mln of human leukocytes and cultured at 37^о С for 24 hours. After that the supernatant was collected, and the pH value was adjusted to 2.0, left at 4 ^оС for 48-72 h, then the pH of the liquid was restored to 7.3, and the level of interferon was determined.Thus, based on the results it can be concluded that Altabor substance in the dose of 1 mg/ml completely inhibited 1/6 enzyme units or 51.5 γ/ml/min of neuraminidase (Astrobacter ureafaciens 1 unit Calbiochem, Hoest), and there is 84.2 and 85.0 % reduction in the activity of neuraminidase of A/Hong Kong/68/H3N2/, A/Victoria/75/H3N2, A/Khabarovsk/H1N1/ influenza viruses.These data show that Altabor dose-dependently stimulates the production of interferon in human leukocytes indicating the activity of the drug and its prospects as an interferon inducer.The results of the studies conducted on the antiviral activity of Altabor substance have shown that this substance effectively inhibits the reproduction of influenza viruses.The mechanism of the anti-influenza action of Altabor is due to inhibition of the neuramidase activity of influenza viruses with simultaneous induction of interferon by human cells.