Comparison of the antiinflammatory effects of Drosera rotundifolia and Drosera madagascariensis in the HET-CAM assay.

The antiinflammatory effects of ethanol and aqueous extracts from Drosera rotundifolia and from Drosera madagascariensis were compared in vivo in the HET-CAM assay. Both extracts from D. rotundifolia and the ethanol extract from D. madagascariensis showed remarkable efficacy at doses of 500 microg/pellet. The inhibition of the inflammation by the extracts was stronger than that by 50 microg hydrocortisone/pellet. In contrast, there was only a very weak effect observed at a dose of 500 microg/pellet of the water extract from D. madagascariensis. The chemical analyses of the extracts showed that the effect cannot be attributed to naphthoquinones, but might be due to flavonoids. Ellagic acid obviously plays an important role in the antiangiogenic effect of the Drosera extracts.