Antiviral activity of Quercus persica L.: High efficacy and low toxicity

BACKGROUND: Drug-resistant strain of Herpes simplex virus type 1 (HSV-I) has increased the interest in the use of natural substances. AIMS: This study was aimed to determine minimum inhibitory concentration of hydroalchoholic extract of a traditionally used herbal plant, Quercus persica L., on HSV-1 replication on baby hamster kidney (BHK) cells. SETTING: The study was conducted in Shahrekord University of Medical Sciences, Iran. DESIGN: This was an experimental study. MATERIALS AND METHODS: BHK cells were grown in monolayer culture with Dulbecco's modified Eagle's medium (DMEM) supplemented with 5% fetal calf serum and plated onto 48-well culture plates. Fifty percent cytotoxic concentration (CC50%) of Q. persica L. on BHK cells was determined. Subsequently, 50% inhibitory concentration (IC50%) of the extract on replication of HSV-1 both in interacellular and exteracellular cases was assessed. STATISTICAL ANALYSIS: Statistic Probit model was used for statistical analysis. The dose-dependent effect of antiviral activity of the extracts was determined by linear regression. RESULTS: Q. persica L. had no cytotoxic effect on this cell line. There was significant relationship between the concentration of the extract and cell death (P<0.01). IC50s of Q. persica L. on HSV-1, before and after attachment to BHK cells were 1.02 and 0.257 μg/mL, respectively. There was significant relationship between the concentration of this extract and inhibition of cytopathic effect (CPE) (P<0.05). Antioxidant capacity of the extract was 67.5%. CONCLUSIONS: The hydroalchoholic extract of Q. persica L. is potentially an appropriate and promising anti herpetic herbal medicine.