nonhuman article 521 controlled study 370 unclassified drug 296 priority journal 242 Animals 146 Argentina 139 plant extract 138 plant leaf 121 Article 106 plant 102 metabolism 92 genetics 85 animal cell 74 drug isolation 74 chemistry 72 Humans 66 enzyme activity 65 Fungi 64 Plant Leaves 63 human 63 mouse 63 antiviral activity 61 Plant Proteins 60 Plant Extracts 58 plant growth 57 Plants (botany) 56 animal experiment 54 gene expression 53 in vitro study 53