Antiviral effect of mangiferin and isomangiferin on herpes simplex virus

Using tissue culture technique the present study for the first time indicated the antiviral effect of mangiferin and isomangiferin against type I herpes simplex virus (HSV-I). 4 methods were used for evaluating drug effectiveness (i.e., in vitro drug-on-virus direct action, simultaneous addition of drug-virus-inoculum to cell bottle, virus inoculation preceding drug addition, and drug addition followed by virus inoculation), it was readily found by log determination of HSV-I inhibition that isomangiferin somewhat exceeded such control drugs as acyclovir, idoxuridine, and cyclocytidine in log by 0.27-0.50, and that mangiferin was lower than isomangiferin in log by 0.53. The average plaque reduction rates of mangiferin and isomangiferin were 56.8% and 69.5% respectively. The antiviral effect of mangiferin and isomangiferin was presumably due to their capability of inhibiting virus replication within cells.