Abstract

Accounts of the medicinal properties of G. aparine found in the literature are critically reviewed. Medicinal properties and constituents of other Galium species are collated in an appendix. The classification, origins, and characteristics of G. aparine, and the etiology and treatment of psoriasis, are also reviewed.
Galium aparine for clinical trial included samples of dried and cut material that required authentication. Plants of four Galium species were grown and differential microscopical features in Galium investigated. The results are supplemented with camera lucida drawings and with photographs. Epicuticular waxes in G. aparine and G. album were photographed for the first time.
The search for potentially antipsoriatic substances in G. aparine led to elemental analysis and the isolation and characterisation of asperuloside. Fast atom bombardment mass spectrometry was used for the first time on a tricyclic iridoid with a γ-lactone ring. Three other glucosidic compounds with asperulosidic reactions were isolated from G. aparine. Analysis showed that anthraquinones, which are reported as absent from the aerial parts of G. aparine, were present in the transition zone. Conversely alkaloids, which are reported as present in the aerial parts, were not detected. The concentration of L-ascorbic acid in G. aparine was determined for the first time using HPLC.
An open clinical trial showed that asperuloside had no antipsoriatic activity and that various extracts of G. aparine had no unequivocal antipsoriatic activity, when formulated in hydrocarbon bases. Reputed antitumour actions of Galium species were not substantiated by results from in vitro cytotoxicity tests carried out with extracts of G. aparine and G. verrucosum L. Asperuloside was not found to be bactericidal or bacteristatic.