Putranjivain A from Euphorbia jolkini inhibits both virus entry and late stage replication of herpes simplex virus type 2 in vitro.
OBJECTIVE
To investigate the in vitro antiviral properties of putranjivain A, isolated from the whole plant of Euphorbia jolkini Bioss (Euphorbiaceae).


RESULTS
Herpes simplex virus (HSV)-2 strain 196-infected Vero cells were used. It was shown that putranjivain A exhibited antiviral activity with an IC50 of 7.9 +/- 1.2 micro M using the XTT assay, with the IC50 value increasing with increasing multiplicity of infection. Using the plaque reduction assay, the IC50 and IC90 were 6.3 +/- 0.8 and 14.5 +/- 3.1 micro M, respectively. Putranjivain A showed no cytotoxic effect on cell multiplication at concentrations that achieved antiviral activity. The 50% cell cytotoxic concentration (CC50) was 80.3 +/- 14.7 microM, and the selectivity index (SI) (ratio of CC50 to IC50) for the XTT and plaque reduction assays was 10.2 and 12.7, respectively. When tested for virucidal activity, putranjivain A significantly reduced viral infectivity at concentrations of 75 and 100 micro M, but not at 50 microM or below. The results of the time-of-addition studies suggested that putranjivain A affected the late stage of HSV-2 replication at 25 microM. Interestingly, putranjivain A also showed inhibition of viral attachment and cell penetration. The combination of putranjivain A and aciclovir produced no interaction.


CONCLUSIONS
Putranjivain A possesses antiviral activity, inhibiting viral attachment and penetration, and also interfering with the late stage of viral replication.
Graduate Institute of Pharmaceutical Sciences, College of Pharmacy, Kaohsiung Medical University, Kaohsiung.
Hua-Yew
HY
Cheng
Ta-Chen
TC
Lin
Chien-Min
CM
Yang
Kuo-Chih
KC
Wang
Liang-Tzung
LT
Lin
Chun-Ching
CC
Lin
D000818:Animals; D000998:Antiviral Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002522:Chlorocebus aethiops; D004305:Dose-Response Relationship, Drug; D028481:Euphorbia; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000302:isolation & purification / Q000494:pharmacology*; D005960:Glucosides / Q000302:isolation & purification / Q000494:pharmacology*; D018258:Herpesvirus 2, Human / Q000187:drug effects* / Q000502:physiology*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018514:Plant Structures; D014709:Vero Cells; D014779:Virus Replication / Q000187:drug effects*
D000998:Antiviral Agents; D005960:Glucosides; D010936:Plant Extracts; C479122:putranjivain A; D005707:Gallic Acid