Abstract
Betulin, a pentacyclic triterpenoid, was isolated from the bark of Betula papyrifera. The antiviral efficacies of betulin on herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) were evaluated using viral plaque reduction assays on Vero cells. The results indicate that betulin is active against both HSV-1 and HSV-2 infections with the 50% effective concentrations (EC50) of 0.40 and 4.15 μg/ml, respectively. The cytotoxicity of betulin was examined on Vero cells using a neutral red uptake assay. The 50% cytotoxic concentration (CC50) of betulin was 73.1 μg/ml. A synergistic antiviral effect between betulin and acyclovir (ACV) was determined by drug combination studies. Strong and moderate synergistic antiviral effects were observed for betulin and ACV against HSV-1 when the concentrations of ACV and betulin were higher than 0.068 and 0.4 μg/ml, respectively. At the concentrations lower than these, additive effect was found. Synergistic antiviral effects were also found against HSV-2 at higher concentrations than for HSV-1, i.e. 0.45 μg/ml of ACV combined with 8.4 μg/ml of betulin.
Original language | English (US) |
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Pages (from-to) | 127-130 |
Number of pages | 4 |
Journal | Antiviral Research |
Volume | 64 |
Issue number | 2 |
DOIs | |
State | Published - Nov 2004 |
Bibliographical note
Copyright:Copyright 2013 Elsevier B.V., All rights reserved.
Keywords
- Acyclovir.
- Betulin
- Drug combination
- Herpes simplex viruses
- Synergistic