Blackberry extract ≥ 56 μg/ml inhibited HSV-1 replication in oral epithelial cells by >
99% (p < 0.005). Concentrations ≥ 280 μg/ml were antiviral when the extract was added after
virus adsorption and entry. Exposure of cell-free virus to ≥ 280 μg/ml blackberry extract for 15
minutes at room temperature was virucidal (p = 0.0002). The virucidal effects were not due to pH
changes at concentrations up to 1500 μg/ml