Screening Active Substances Of Potentilla Freyniana In Vitro Against Herpes Simplex Vims Type Ⅰ

Herpes simplex virus type Ⅰ(HSV-1) infect human mainly through the human respiratory tract or close contact on skin and mucous membranes, the infection often occurs in the mouth, pharynx, eyes and skin, a few occur in other parts including the genital. After herpes infection being cured, the remnants often transfer to the trigeminal ganglia and other parts which remain there for long time. When the body’s resistance become weaken or encounter certain stimuli such as heat, cold, infection, menstruation, gastrointestinal disorders, trauma, the potential virus will be activated and then implicate themselves, which cause secondary infection. In China, the infected population by HSV-l has showed an increasing trend. So study the prevention and treatment of anti-HSV-1 infection drug has some theoretical significance and practical value.In this study,the rhizome of Potentilla freyniana were extracted with 80%ethanol,the ethanol extract was soluted with water and then extracted with ethyl acetate, n-butyl alcohol, respectively. The ethyl acetate extract, n-butyl alcohol extract and water extract were abtained after the solvent were evaporated from the extracts and residues were made to dryness. The toxicity to Hep-2 cells of the 80% ethanol extract and the three extracts were measured with the MTT assay,dividely.The results show that the half toxic concentration(TC50) to Hep-2 cells of 80% ethanol extract, ethyl acetate extract, n-butyl alcohol extract and water extract were 39.78, 47.64, 43.62, 254.60 μg· mL-1,respectively.With acyclovir(ACV) as the positive control drug, the anti-HSV-1bioactivity of 80% ethanol extract, ethyl acetate extract, n-butyl alcohol extract and water extract were screened by the method of cytopathic effect(CPE) and plaque reduction experiment(PRA). The results show that Potentilla freyniana 80% ethanol extract and ethyl acetate extract have theability to resistant HSV-1, half of its inhibitory concentration(IC50) were 4.78,7.16μg·mL-1, treatment index(TI) were 8.32, 6.65; The IC50 of n-butyl alcohol extract and water extract were not determinated, which indicated that n-butyl alcohol extract and water extract have little ability to anti-HSV-1. These results suggest that Potentilla freyniana have ability against HSV-1 virus infection and the ethyl acetate extract was the major antiviral active fraction.By the method of cytopathic effect, the bioactivity of six compounds which named as Y4, Y5, Y7, Y9, Y10, Y11 from Potentilla freyniana ethyl acetate extract were screened, respectively. The results showed that no IC50 were detected among the all six components at the given concentration range,which implied that Y4, Y5, Y7, Y9, Y10, Y11 should not be the anti-HSV-1 virus active ingredients of Potentilla freyniana...