Investigation of the inhibitory activity of extracts, fractions and secondary metabolites of <i>Silene</i> spp. (<i>Caryophyllaceae</i>) and <i>Serratula cupuliformis</i> (<i>Asteraceae</i>) on the replication of SARS-CoV-2 coronavirus

Aim. In vitro analysis of the inhibitory activity of extracts, fractions and secondary metabolites of plants of the genus Silene [Caryophylaceae] and Serratula cupuliformis [Asteraceae) on the replication of SARS-CoV-2.

Material and Methods. Silene spp. and Serratula cupuliformis of the Siberian Botanical Garden of National Research Tomsk State University were used. Ethanol extracts and butanol fractions of Silene spp. were prepared. The flavonoid shaftoside and the ecdysteroid 20-hydroxyecdysone from Lychnis chalcedonica were isolated. Analysis of BAS was carried out by the HPLC method. In vitro analysis of the inhibitory activity of extracts on SARS-CoV-2 replication was performed in Vero cell culture by direct inactivation [neutralization) of virions. Comparison samples were dry ethanol extracts of chaga [Inonotus obliquus, Basidiomycota), spices of cloves [Syzygium aromaticum, Myrtaceae) and root of licorice [Glycyrrhiza glabra L., Fabaceae).

Results. The inhibitory activity of ethanol extracts and butanol fractions of Silene spp., as well as individual compounds [shaftozide and 20-E) was revealed in the range of 50% effective concentrations [EC50) when dissolved in water from 339.85±83.92 pg/ml to 1.59±0.39 pg/ml and when dissolved in DMSO from 119.34±26.34 pg/ml to 2.22±0.57 pg/ml, respectively. The butanol fraction of Serratula cupuliformis was active with EC50=21.74±4.80 and 27.42±6.05 pg/mL. These results for some samples of Silene spp. and Serratula cupuliformis are comparable to the EC50 values of the comparators.

Conclusion. The results obtained suggest the presence of biologically active substances in the herbal preparations studied that act destructively on virions of SARS-CoV-2 and affect one of the main stages of its "life" cycle - on the attachment to receptors of sensitive cells.

[Expansion of the functional domain of chicken alpha-globin genes]

The transcriptional domain of chicken alpha-globin genes was shown to contain the non-globin coding erythroid-specific TMEM8 gene inducible upon terminal differentiation of erythroblasts. Acquirement by the chicken TMEM8 gene of the erythroid-specific expression correlates with its approachment to the cluster of alpha-globin genes as a result of inversion of a 170-kb chromosomal segment. The human TMEM8 gene is located far from the globin genes and is not expressed in erythroblasts. Transcription of the TMEM8 gene and adult globins in differentiated chicken erythroid cells is controlled by alternative activatory hubs sharing two regulatory elements (including the erythroid enhancer). A conclusion is made that in mature erythroblasts these regulatory elements shuttle between two different activatory hubs.

[Protein kinases abundantly expressed in undifferentiated human ESC lines and derived embryoid bodies]

The ability of human embryonic stem cells (ESCs) to unlimited proliferation and huge differentiation potential makes them very attractive tool both for basic research and biological medicine. There are still little known about mechanisms that govern their differentiation or keep them in a pluripotency state. A variety of signaling events determines gene expression profiles responsible for such mechanisms activation. Protein kinases are key components of the signaling cascades. The knowledge about protein kinases expression profile in undifferentiated ESCs and embryoid bodies (EBs) will allow to understand early differentiation events. We constructed cDNA libraries containing fragments of protein kinases catalytic domain that were expressed in undifferentiated cells or EB of hESM01, hESM02 cell lines. We detected high level of MAK-V expression using Northern-blot hybridization. Semi-quantitative RT-PCR was used to compare the level of abundantly expressed kinases MAK-V, A-RAF-1, MARK3, IGF1R, NEK3 and NEK7 in undifferentiated ESCs or derived EBs.

Characteristics of human bone marrow mesenchymal stem cells isolated by immunomagnetic selection

Immunophenotype of human bone marrow mesenchymal stem cells was studied after several culturing passages and after cryopreservation. Immunocytochemical analysis showed that bone marrow mesenchymal stem cells acquired homogeneity during in vitro culturing, but initially contained heterogeneous populations.