Antinociceptive activity 5 Mechanisms of antinociception Article 3 animal experiment 3 animal model 3 arginine 3 controlled study 3 glutamic acid 3 hot plate test 3 male 3 methanol 3 mouse 3 n(g) nitroarginine methyl ester 3 naloxone 3 nonhuman 3 opiate receptor 3 plant extract 3 plant leaf 3 unclassified drug 3 vanilloid receptor 1 3 Analgesics 2 Animals 2 Crude methanol extract 2 Fraction 2 Gas Chromatography-Mass Spectrometry 2 Glutamatergic system 2 Institute for Cancer Research mouse 2 Male 2 Melastoma malabathricum 2 Methanol 2