The Antiinfluenza Virus Activity of Hydroalcoholic Extract of Olive Leaves

The influenza viruses are major etiologic agents of human respiratory infections,and inflict a sizable health and economic burden. this study examines theantiinfluenza virus activity of hydroalcoholic extract of olive leaves (olhe). oliveleaves were collected from gardens around the city of shiraz, characterized, dried,ground to powder, and its hydroalcoholic extract was prepared. the influenza viruseswere isolated from patients and characterized by standard antiinfluenza sera.virucidal effects of olhe (10-1 to 103 ىg/ml) were examined in pretreatment,treatment and incubation protocols using quantal assay after incubation for 72 h. allexperiments were performed three times in quadruplicates. pretreatment of thecell line with olhe for one hour followed by the addition of the virus wasassociated with virucidal effects (1 to 1000 ىg/ml). olhe added one hour afterincubation of the virus with cell did not show antiviral effects. olhe incubated withthe virus for one hour, and then added to the cell line did have antiviral activity (1to 1000 ىg/ml). the findings indicate that antiviral activity of olhe occurred extracellularly,probably by changing the properties of membrane of the virus, rather thanthat of the cell, to prevent the virus from attaching and penetrating the cell line.