Investigation of the inhibitory activity of extracts, fractions and secondary metabolites of Silene spp. (Caryophylaceae) and Serratula cupuliformis (Asteraceae) on the «entry» of herpes simplex type 2 into sensitive cells of the Vero line

In vitro analysis of the inhibitory activity of extracts, fractions and secondary metabolites of plants of the genus Silene (Caryophylaceae) and Serratula cupuliformis (Asteraceae) to the «entry» of herpes simplex type 2 (HSV‐2) into sensitive cells of the Vero line.Ethanol extracts and butanol fractions of Silene spp. and Serratula cupuliformis were prepared. The flavonoid shaftoside and the ecdysteroid 20‐hydroxyecdysone from Lychnis chalcedonica were isolated. For analysis of biologically active substances (BAS) the HPLC method was used. The samples were dissolved in distilled water or DMSO. The laboratory strain MS HSV‐2 was grown on Vero cell culture. In vitro analysis of the inhibitory activity of the herbal preparations on «entry» of HSV‐2 was performed in Vero cell culture by direct inactivation (neutralisation) of virions with 103 PFU /ml.Effective concentrations (EC50) have been identified in the range of 50 % from 2.12±0.47 to 180.99±49.24 μg/ml when preparations were dissolved in water and from 1.99±0.44 to 57.42±14.74 μg/ml when they were dissolved in DMSO. Such results for some samples is comparable to the EC50 of comparison preparations (dry ethanol extracts of spice of cloves, chaga and licorice root). The results obtained suggest the presence of BAS in the herbal preparations studied that act destructively on HSV‐2 virions and affect one of the main stages of its «life» cycle – the «entry» of the virus into sensitive cells.