Abstract

Irritant dermatological investigations of locally occurring Euphorbia prostrata were carried out to discover the irritant principle present in it. For this purpose, successive solvent extraction was carried out by using polar, non polar as well as intermediate polarity solvents for the extraction of active irritant compounds from the whole herb. Irritant potentials of these extracts were evaluated on rabbit’s skin. Biological assay showed that only the chloroform extract was active because it produced irritancy at a certain dose level. Five fractions Ep-1 to Ep-5 were isolated from the active chloroform extract of the plant by column and thin layer chromatography. Irritant dermatological prospective of these fractions were also evaluated on rabbit’s ear skin. Out of the five isolated fractions, Ep-2 and Ep-4 appeared to be the strong irritant fractions, while Ep-1, Ep-3 and Ep-5 proved to be moderately irritant fractions at the same dose level. A possible structure-activity relationship of these active fractions was also discussed based on the ultraviolet (UV) and infrared (IR) spectrum.

Key words: Irritancy, Euphorbiaceae, chromatography.