Analysis Medicinal plants 37 Therapeutic use 36 Alkaloids 35 Synthesis 28 Heavy metals 24 Environmental aspects 22 Cancer 21 Water 21 Absorption and adsorption 20 Phytochemicals 19 Research 19 Annonaceae 18 Composition 18 Copper 17 Plants 17 Palm oil 15 Lauraceae 14 Trace elements 14 Antioxidants 13 DNA 13 High performance liquid chromatography 13 Mass spectrometry 13 Materials 13 Apocynaceae 12 Botanical chemistry 12 Measurement 12 Oil palm 12 Pollution 12 Toxicology 12