Evaluation of the antiviral activity of an aqueous extract from Phyllanthus orbicularis

The antiviral and cytotoxic activity of Phyllanthus orbicular is, a member of the Euphorbiaceae, was evaluated in tissue culture. An aqueous extract m ade from leaves and stems of this plant exhibited selective antiviral index es of 12.3 and 26 against bovine herpesvirus type 1 and herpes simplex viru s type 2, respectively, showing no selective antiviral activity against ade novirus type 5 and mengovirus. Incubation with this plant extract during ce ll culture infection, impaired the productive replication of both herpes vi ruses in an extract concentration-dependent manner, also depending on the m ultiplicity of infection (MOI) used. The results obtained suggested that th e P. orbicularis antiviral activity might be partially due to a direct inte raction with virus particles or their entry into the cell, instead of inter fering with intracellular virus-specific macromolecular synthesis. (C) 2000 Elsevier Science Ireland Ltd. Ail rights reserved.