Hippomanin A from acetone extract of Phyllanthus urinaria inhibited HSV-2 but not HSV-1 infection in vitro.

Phyllanthus urinaria Linnea (Euphorbiaceae) is a commonly used traditional medicinal plant in oriental countries and has been reported to possess various biological activities. Previously, the acetone extract and some pure compounds from P. urinaria were found to suppress herpes simplex virus (HSV). In this study, another two pure compounds were isolated from acetone extract of P. urinaria and were tested for their in vitro anti-HSV-1 and HSV-2 activities. The results showed that hippomanin A impeded HSV-2 but not HSV-1 infection. Corilagin, however, inhibited neither HSV-1 nor HSV-2 replication. The similarity between corilagin and hippomanin A in structure, but difference in antiviral activity, therefore, merit further investigation.