Plant Extracts article 96 plant extract 86 nonhuman 60 controlled study 52 unclassified drug 46 Animals 44 chemistry 38 Antiviral Agents 30 drug effect 30 Humans 28 human 26 plant leaf 24 animal 22 antivirus agent 22 priority journal 22 Argentina 20 Vero Cells 20 antiviral activity 20 Cercopithecus aethiops 18 Molecular Structure 18 animal cell 18 human cell 18 Mice 16 Plant Leaves 16 Virus Replication 16 animal experiment 16 isolation and purification 16 medicinal plant 16 metabolism 16