Carolus Linnaeus, the ash, worm-wood and other anti-malarial plants.

In 1735 Carolus Linnaeus wrote that quinine was the preferred treatment for malaria but that the bark of the ash (Fraxinus excelsior) and worm-wood (Artemisia absinthium) also had effects on the disease. We here report that lipo- and hydrophilic extracts of the bark of the ash inhibit the in vitro growth of the asexual stages of P. falciparum.

Arthropod repellency, especially tick (Ixodes ricinus), exerted by extract from Artemisia abrotanum and essential oil from flowers of Dianthus caryophyllum.

A toluene extract of southernwood (Artemisia abrotanum) and the essential oil from flowers of carnation (Dianthus caryophyllum ) exerted pronounced a repellent effect both against ticks (nymphs of Ixodes ricinus) and yellow fever mosquitoes (Aedes aegypti). The most potent repellents found were coumarin and thujyl alcohol from A. abrotanum and phenylethanol from D.

Repelling properties of some plant materials on the tick Ixodes ricinus L.

The repellent effects on nymphal stages of Ixodes ricinus L. of some plant materials have been studied in the laboratory. The plant material consisted of an ethanolic extract from Achillea millefolium L.

Efficacy of plant extracts and oils as mosquito repellents.

Some natural products, extract of Achillea millefolium (yarrow), birch/pine tar-, citronella-, clove-, eucalyptus-, geranium-, lavender-, lily of the valley- and peppermint oils have been tested for repellency in the laboratory against Aedes aegypti and in the field predominantly against Aedes communis and A. cinereus. The laboratory tests showed that yarrow extract exhibited a similar repellency as the reference substances N,N-diethyl-m-toluamide and N,N-diethyl-mandelic acid amide.

Ortho hydroxy-substituted molecules might be of importance for the prevention of bloodsucking by mosquitoes.

Achillea millefolium extract contains several compounds, which prevent Aedes aegypti from feeding blood. Some of these compounds might interfere with each other. Caffeic acid, mandelonitrile glucoside, pyrocatechol, salicylic acid, and stachydrine were chosen for tests in paired mixtures.