| Summary: | Infusions and poultices prepared from the aerial parts of <i>Baccharis heterophylla</i> Kunth (Asteraceae) are widely used in Oaxaca (Mexico) for relieving painful and inflammatory complaints. Therefore, the antinociceptive potential of an aqueous extract (31.6–316 mg/kg, p.o.) and essential oil (30–177 µg/paw, i.pl.) of the plant was assessed using the formalin test. Both preparations inhibited the formalin-induced nociception response (100–316 mg/kg and 100–177 µg/paw, respectively) during the test’s second phase. Chemical analysis of the aqueous extract revealed that the major active components were chlorogenic acid (<b>1</b>), 3,4-di-<i>O</i>-(<i>E</i>)-caffeoylquinic acid (<b>2</b>), 3,5-di-<i>O</i>-(<i>E</i>)-caffeoylquinic acid (<b>3</b>), 4,5-di-<i>O</i>-(<i>E</i>)-caffeoylquinic acid (<b>4</b>), 3,5-di-<i>O</i>-(<i>E</i>)-caffeoylquinic acid methyl ester (<b>5</b>), apigenin (<b>6</b>), genkwanin (<b>7</b>), acacetin (<b>8</b>). Compounds <b>1</b>–<b>5</b> and <b>8</b> are new for <i>B. heterophylla</i>. A high-pressure liquid chromatographic method for quantifying chlorogenic acid (<b>1</b>) and di-caffeoylquinic acids <b>2</b>–<b>4</b> in the plant was developed and validated. Analyses of the essential oil and the headspace solid-phase microextraction products, via gas-chromatography-mass spectrometry, revealed that the major volatiles were β-pinene, myrcene, D-limonene, β-caryophyllene, and α-caryophyllene, which have demonstrated antinociceptive properties.
|
|---|