Evaluation of anti-inflammatory and antinociceptive activities of the Austroplenckia populnea extract in topical formulations

Austroplenckia populnea (Reiss.) Lundell is a Brazilian Cerrado plant that has been widely used in folk medicine and has many therapeutic properties. The aim of this study is to evaluate the anti-inflammatory and antinociceptive properties of a raw hydroalcoholic wood extract of A. populnea in semi-solid formulations administered topically in rats. The extract of A. populnea was administrated topically in male and female Wistar rats using cream and gel (4.0 and 8.0%) in the paw edema test induced by carrageenan and in the formalin test. Creams remained stable, and the gels showed syneresis. In the paw edema test induced by carrageenan, the gels and creams showed a significant effect compared to the control group. Only 4.0% cream showed swelling inhibition at the 3rd hour compared to the Piroxicam gel. Likewise, in the formalin test, the 4.0% cream had an effect similar to the methyl salicylate, showing a significant anti-inflammatory effect. Based in these results, there was antinociceptive effect with 4.0% cream. We conclude that topical preparations with extract of A. populnea may generate new methods for the treatment of local inflammation.   Key words: Analgesia, inflammation, topical administration, formalin test.