Antiviral effects of blackberry extract against herpes simplex virus type 1

Objective. The aim of this study was to evaluate antiviral properties of blackberry extract against herpes simplex virus type 1 (HSV-1) in vitro. Study design. HSV-infected oral epithelial (OKF6) cells and cell-free virus suspensions were treated with blackberry extract (2.24-1,400 mu g/mL), and virus yield and infectivity were quantified by direct plaque assay. Results. Blackberry extract >= 56 mu g/mL inhibited HSV-1 replication in oral epithelial cells by >99% (P < .005). Concentrations >= 280 mu g/mL were antiviral when the extract was added after virus adsorption and entry. Exposure of cell-free virus to >= 280 mu g/mL blackberry extract for 15 minutes at room temperature was virucidal (P = .0002). The virucidal effects were not due to pH changes at concentrations up to 1,500 mu g/mL. Conclusions. Blackberry extract inhibited the early stages of HSV-1 replication and had potent virucidal activity. These properties suggest that this natural fruit extract could provide advantage as a topical prophylactic/therapeutic agent for HSV infections. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112:e31-e35)