Antinociceptive properties of ethanolic extract and fractions of Pterodon pubescens Benth. seeds.

We have previously demonstrated that the hydroalcoholic extract from Pterodon pubescens Benth. seeds (sucupira branca, Leguminosae) exhibits anti-arthritic activity and that its oleaginous extract (OEP) and PF1 fraction exhibit acute and topic anti-edematogenic activities. In this work, we studied the antinociceptive activity of OEP and its fractions on the acetic acid-induced abdominal constriction and formalin assays in SW male mice. OEP was obtained by ethanol extraction and its four fractions by sequential liquid-liquid extraction. PF2 GC/MS profile indicated it contains furane diterpenes derivatives of vouacapan and non-vouacapan compounds. The antinociceptive properties were demonstrated to OEP and predominantly to PF1 and PF2 by the writhing test. In the formalin assay, PF1 inhibited both phases and PF2 inhibited mainly the late one. Then, PF1 and PF2 seemed to present antinociceptive effects by different mechanisms, peripheral and/or central inhibitory ones, and showed maximum antinociceptive properties with very low doses, providing a rationale for its popular use in pain disorders.