Phytochemical Characterization of the Australian (Aboriginal) Medicinal Plant Dolichandrone heterophylla and Influence of Selected Isolated Compounds on Human Keratinocytes

Abstract

The Miriwoong Aboriginal people of Eastern Kimberley, Western Australia use the leaves and bark of Dolichandrone heterophylla (R. Br.) F. Muell., Bigoniaceae, to treat sores, rashes, grazes, scabies, boils and wounds. Bioassay guided fractionation of an aqueous extract of the leaves and twigs led to the isolation of the known compounds caffeic acid, the phenylethanoids isoacteoside (1) and acteoside (2), and the flavonoids chrysoeriol and luteolin. The structures of these compounds were determined using mass spectrometric and 1D- and 2D-NMR spectroscopic data and verified by comparison with those in the literature. Studies of the effect of isoacteoside (1) and chrysoeriol on HaCaT keratinocytes using the MTT assay revealed that chrysoeriol had growth inhibitory properties towards the cell line in a dose dependent manner (IC50 = 31 μM) whereas 1 was well tolerated up to 50 μM. On the other hand, 1 inhibited the growth of Pseudomonas aeruginosa.