&ITIn vitro&IT anti-herpes simplex virus activity, antioxidant potential and total phenolic compounds of selected Iranian medicinal plant extracts

Abstract Drug resistant strains of herpes simplex virus-1 (HSV-1) have been increased recently. Essentially, medicinal plant-based new antiviral agents that are effective against HSV-1 infections are urgently required. Therefore, this research was conducted to evaluate in vitro anti HSV-1 activity of 25 plant extracts. In this study, the hydroalchoholic extracts of different parts of 25 medicinal plants belonging to 16 different families were prepared. Anti-HSV-1 activity was evaluated on Vero cell line using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The 50 % effective concentration (EC50) and 50 % cytotoxicity concentration (CC50) of the extract were determined using regression analysis. The inhibitory effect of the plant materials on adsorption and/or post-adsorption stages of HSV-1 replication cycle was determined. Antioxidant activity, total phenolic content, and total flavonoid content of the extracts were determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, Folin-Ciocalteu reagent, and aluminum chloride colorimetric method, respectively. Results showed that Pistacia atlantica Desf, Equisetum arvense L., Melissa officinalis L., Anthyllis vulneraria L., Punica granatum L., Syzygium aromaticum (L.) Men. & L.M. Perry, Camellia sinensis (L.) Kuntze, and Crataegus azarolus L., were active against HSV-1. There was a significant association of total phenolic contents (R = 0.773, p < 0.001) and the free radical scavenging property (R = -0.684, p < 0.01) with the antiviral activity of the extracts. Some of the Iranian plant extracts studied showed potent antiviral activity against HSV-1 and can be used to develop new and effective anti-HSV-1 agents