The in vitro activity of geraniin and 1,3,4,6-tetra-O-galloyl-β-d-glucose isolated from Phyllanthus urinaria against herpes simplex virus type 1 and type 2 infection

Phyllanthus urinaria Linnea (Euphorbiaceae) is a widely used traditional medicinal plant by oriental countries and has been reported to possess various biological activities. Previously, the acetone extract from Phyllanthus urinaria was found to inhibit herpes simplex virus (HSV) infection. In this study, geraniin and 1,3,4,6-tetra-O-galloyl-β-d-glucose (1346TOGDG), both of which were isolated from the acetone extract of Phyllanthus urinaria, were examined for their activity against HSV-1 and HSV-2 in vitro. Results showed that geraniin actively suppressed HSV-2 infection, whereas 1346TOGDG effectively inhibited HSV-1 infection. The 50% inhibitory concentration (IC50) was 18.4 ± 2.0 μM for geraniin against HSV-2 infection, and 19.2 ± 4.0 μM for 1346TOGDG against HSV-1. No toxic effect towards the host cell was observed at the antiviral concentrations. In conclusion, geraniin and 1346TOGDG were found to inhibit HSV-1 and HSV-2 multiplication at different magnitudes of potency.