Influence of saponin tauroside Sx1 on lifespan and expression of vitamin D receptors in the liver tissue of mice with influenza infection

Introduction. Respiratory infections, including influenza, are often accompanied by hepatitis in humans which pathogenesis is not fully understood. According to the available datan D deficiency is presumably a risk factor in the occurrence of acute respiratory viral infections due to its modulation of immune response. Recent studies indicate that several plant compounds can interact with vitamin D receptors (VDRs) and modulate the activity of VDRs. The biologically active components saponins have found widespread use in clinical practice due to their wide range of biological and pharmacological effects which mechanisms are still largely unclear. Aim. To study the effect of oral administration of saponin tauroside Sx1, obtained from Crimean ivy, on life expectancy and activation of vitamin D receptors in the liver of mice during experimental viral infection of varying severity. Materials and methods. The 11 subgroups were formed from male BALB/c mice, were used in the experiment depending on the infectious dose of influenza virus, 5 LD 50 virus or 10 LD 50 virus, respectively, including control. Saponin tauroside Sx1 was used as a corrector. Immunohistochemical studies were carried out automatically in a BOND-MAX immunohistainer (Leica, Germany). Primary rabbit polyclonal antibodies to the vitamin D receptor were used. Results and discussion. Due to the administration of tauroside Sx1 at a dose of 200 μg/mouse/day increases the average life expectancy of animals receiving saponin by 4.6 days. Reducing the infectious dose of IV from 10 LD 50 to 5 LD 50 also changed the onset of death of animals by 2 days in both groups. With different infectious doses of the virus, on the 10th day of the experiment in the subgroups, the expression of vitamin D receptors changes without correction. In subgroup 2V, the number of total positive cells was lower than the control group. Moreover, in the 2Vir subgroup, VDR expression was significantly higher than the control group. Conclusion. The saponin tauroside Sx1 at a dose of 200 µg/mouse/day has a fairly pronounced antiviral effect during experimental infection of mice with the influenza A/H1N1 virus, which is manifested by an increase in the average life expectancy of animals (for 4.6 days) and a decrease in the mortality rate during severe influenza infection, compared with the control group, where 100 % mortality was observed by the 14th day of the experiment. The introduction of saponin on the 4th day of the experiment in all subgroups reduces the total number of immune cells that intensively express VDR.