Pharmacognostic and Phytochemical Investigations of Pseuderanthemum palatiferum (Nees) Radlk. ex Lindau Leaves

Introduction: Fresh leaves of Pseuderanthemum palatiferum (Nees) Radlk. ex Lindau are claimed to cure various diseases and have become a popular medicinal plant among Thai people. Products made from P. palatiferum leaves - including powder decoctions, herbal tea bags and capsules - have been developed and are available in markets in Thailand, but without quality control. Methods: Microscopic characteristics were observed under a light microscope. Physicochemical properties - including loss on drying, total ash, acid-insoluble ash, and water extractive values - were determined. Phytochemical screening for major groups of compounds was performed, and a thin-layer chromatographic (TLC) fingerprint of this plant was developed. Results: The microscopic characteristics showed the arrangement of palisade cells into two layers, and the presence of multicellular trichomes with a warty wall in the upper epidermis. Phytochemical screening revealed that P. palatiferum leaf extract contains flavonoids, phenolic compounds, unsaturated lactone rings, and steroid nuclei. Flavonoids, phenol carboxylic acid and terpenoids were detected in TLC fingerprints of P. palatiferum extract developed using blends of toluene: ethyl acetate: formic acid (5:4.5:0.5) and ethyl acetate: formic acid: water (90:2:2) as solvent systems. Conclusion: The results are useful for the establishment of a monograph on this plant which could be used for quality control of plant materials.