Animals 14 Institute for Cancer Research mouse 14 Mice, Inbred ICR animal 14 mouse 14 Male 11 Mice 11 male 11 controlled study 9 nonhuman 9 Article 8 animal experiment 8 metabolism 8 animal model 7 chemistry 7 unclassified drug 7 isolation and purification 6 Analgesics 5 Disease Models, Animal 5 Female 5 Plant Extracts 5 Plant Leaves 5 analgesic agent 5 disease model 5 female 5 opiate receptor 5 plant extract 5 plant leaf 5 antinociception 4 dose response 4