Effect of Terpenoids and Flavonoids Isolated from Baccharis conferta Kunth on TPA-Induced Ear Edema in Mice

In this study, we isolated from the aerial parts of Baccharis conferta Kunth (i) a new neoclerodane, denominated "bacchofertone"; (ii) four known terpenes: schensianol A, bacchofertin, kingidiol and oleanolic acid; and (iii) two flavonoids: cirsimaritin and hispidulin. All structures were identified by an exhaustive analysis of nuclear magnetic resonance (NMR) and mass spectroscopy (MS). Extracts from aerial parts were screened for anti-inflammatory activity in the mice ear edema model of 12-O-tetradecanoylforbol-13-acetate mice. Dichloromethane extract (BcD) exhibited 78.5 ± 0.72% inhibition of edema, followed by the BcD2 and BcD3 fractions of 71.4% and 82.9% respectively, at a dose of 1 mg/ear. Kingidiol and cirsimaritin were the most potent compounds identified, with a median effective dose of 0.12 and 0.16 mg/ear, respectively. A histological analysis showed that the topical application of TPA promoted intense cell infiltration, and this inflammatory parameter was reduced with the topical application of isolated compounds.