Anti-inflammatory effect of crude extract and isolated compounds from Baccharis illinita DC in acute skin inflammation

Ethnopharmacologycal relevance: The tea from the leaves of Baccharis illinita DC (Asteraceae family) is commonly used by the population as anti-inflammatory (including topically), protective gastric and anti-infectious. However, no studies have been done with this species to confirm its topical anti-inflammatory action. Aim: This study evaluated he topical effects of crude extract of leaves (CE) and its active constituents in 12-O-tetradecanoilforbol acetate (TPA)-induced ear oedema. Methodology: CE and compounds effects were tested in commonly used models of TPA-, arachidonic acid (AA)- and capsaicin-ear oedema. Polymorphonuclear (PMN) cell migration was evaluated by mieloperoxidase and analyzed histologically. Results: CE (0.1-1. mg/ear) caused a dose-related inhibition of TPA-induced ear oedema and PMN influx similarly to that produced by topical application of the steroidal anti-inflammatory drug dexamethasone. The active constituents of the AcOEt fraction kaurenoic acid, α-spinasterol, oleanolic acid and baurenol also inhibited TPA-induced ear edema. Histological analysis of the ear of CE-treated animals confirmed the reduction of edema and of PMN infiltration. Both CE and the nosteroidal anti-inflammatory drug indomethacin inhibited the AA-induced ear oedema, but did not change capsaicin-induced oedema. Conclusion: These results indicate that the CE and the active constituents have a topical anti-inflammatory effect and the possible mechanisms for the pharmacological effects are discussed.