A BIOLOGICAL SCREEN OF SELECTED SPECIES OF THE GENUS EUPHORBIA FOR SKIN IRRITANT EFFECTS

Abstract

Sixty species of the genus Euphorbia were tested for skin inflammation effects, as their crude latex or herb extracts, using the mice ear test. The production of skin inflammation is a general property of the extracts examined, only seven of the species failing to produce redness of mice ears. For the crude extracts producing inflammation of the skin their potency varied from about 0.2 to 45 μg/5 μl of acetone extract. The inflammation produced by the majority of plant extracts reached a maximum effect after 24 hours, but several species demonstrated short term irritant effects reaching a maximum activity 4 hours after application to the skin, their effects thereafter decreasing in an approximately log. linear manner with time. Examples of this type of biological effect were found in the Sections Tithymalus and Euphorbium of the classification of the genus proposed by Pax and Hoffmann. Non-irritant extracts were obtained mainly from the Sections Poinsettia and Anisophyllum.