Recent findings in the chemistry of odorants from four Baccharis species and their impact as chemical markers.

Baccharis is a widespread genus belonging to the Asteraceae family that includes almost 400 species exclusively from the Americas. Even when studied in detail, the taxonomic classification among species from this genus is not yet fully defined. Within the framework of our study of the volatile composition of the Baccharis genus, four species (B. trimera, B. milleflora, B. tridentata, and B. uncinella) were collected from the 'Campos de Cima da Serra' highlands of the Brazilian state of Rio Grande do Sul. The aerial parts were dried and extracted by the simultaneous distillation extraction (SDE) procedure. This is the first time that SDE has been applied to obtain and compare the volatile-extract composition in the Baccharis genus. Characterization of the volatile extracts allowed the identification of 180 peaks with many coeluting components; these latter being detailed for the first time for this genus. The multivariate statistical analyses allowed separating the volatile extracts of the four populations of Baccharis into two separate groups. The first one included the B. milleflora, B. trimera, and B. uncinella volatile extracts. The three species showed a high degree of similarity in their volatile composition, which was characterized by the presence of high contents of sesquiterpene compounds, in particular of spathulenol. The second group comprised the extract of B. tridentata, which contained α-pinene, ß-pinene, limonene, and (E)-ß-ocimene in high amounts.

Cytotoxic mechanism of Baccharis milleflora (Less.) DC. essential oil.

The aim of this study was to investigate the cytotoxic activity of the essential oil from cladodes of Bacharis milleflora in relation to Jurkat, Raji and HL-60 cells, as well as exploring the cell mechanisms in order to elucidate how the cytotoxic process occurs. The presence of the following volatile compounds was detected by GC-MS: bicyclogermacrene (12.16%), germacrene D (11.18%), (E)-caryophyllene (9.28%), and α-humulene (8.05%). In general, IC50 values lower than 50µg/mL were obtained for all the tumor cells at 24, 48 and 72h by MTT assay. The decrease in cell DNA content was demonstrated due to the inhibition of the proliferation of Jurkat, Raji and HL-60 cells by B. milleflora essential oil. In particular, Raji cells presented the greatest inhibition of cell proliferation and they were subsequently used to investigate cell death mechanisms. B. milleflora essential oil promoted G0/G1 arrest and also induced cell fragmentation, which was represented by an increase in the sub-G0 population, indicating cell death induced by apoptosis. The selectivity index was 3.97. Necrotic cell death, coupled with low levels of apoptotic cell death, was observed by conventional EB/AO and Hoechst 33342 staining assays, demonstrating that this essential oil acts via both necrotic and apoptotic mechanisms.