Topical anti-inflammatory activity of boropinic acid and its natural and semi-synthetic derivatives.

Boropinic acid is a natural isopentenyloxycinnamic acid extracted from the aerial parts of Boronia pinnata Sm. (Rutaceae) with soybean 5-lipoxygenase inhibitory activity. In this paper the topical anti-inflammatory activity of boropinic acid and some of its natural and semi-synthetic derivatives was evaluated using the Croton oil ear test in mice as a model of acute inflammation. Some of the tested compounds (15, 17, 19, 20) revealed an effect comparable (ID(50)=0.18÷0.72μmol/cm(2)) to that of the reference drug indomethacin (ID(50)=0.23μmol/cm(2)), a non-steroidal anti-inflammatory drug.