This paper provides a comparative account of the essential oil chemical composition and biological activities of five Brazilian species of Baccharis (Asteraceae), namely B. microdonta, B. pauciflosculosa, B. punctulata, B. reticularioides, and B. sphenophylla. The chemical compositions of three species (B. pauciflosculosa, B. reticularioides, and B. sphenophylla) are reported for the first time. Analyses by GC/MS showed notable differences in the essential oil compositions of the five species. α-Pinene was observed in the highest concentration (24.50%) in B. reticularioides. Other major compounds included α-bisabolol (23.63%) in B. punctulata, spathulenol (24.74%) and kongol (22.22%) in B. microdonta, β-pinene (18.33%) and limonene (18.77%) in B. pauciflosculosa, and β-pinene (15.24%), limonene (14.33%), and spathulenol (13.15%) in B. sphenophylla. In vitro analyses for antimalarial, antitrypanosomal, and insecticidal activities were conducted for all of the species. B. microdonta and B. reticularioides showed good antitrypanosomal activities; B. sphenophylla showed insecticidal activities in fumigation bioassay against bed bugs; and B. pauciflosculosa, B. reticularioides, and B. sphenophylla exhibited moderate antimalarial activities. B. microdonta and B. punctulata showed cytotoxicity. The leaves and stems of all five species showed glandular trichomes and ducts as secretory structures. DNA barcoding successfully determined the main DNA sequences of the investigated species and enabled authenticating them.

We report for the first time the presence of cluster crystals of calcium oxalate within the glandular trichomes and oil bodies in the mesophyll for Baccharis species. Moreover, the comparative leaf anatomy and micro‐morphology of six species of Baccharis, namely B. illinita, B. microdonta, B. pauciflosculosa, B. punctulata, B. reticularioides, and B. sphenophylla is investigated by light and scanning electron microscopy. The studied species exhibited differences in their leaf anatomical features such as the morphology of the cuticle, type and occurrence of the stomata, presence or absence of glandular trichomes, shape of the flagelliform trichomes, and the arrangement of the mesophyll tissues. These differences can be helpful in the species identification and classification and could represent informative characters for the reconstruction of the evolution of the genus.

Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (−33 to −41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer.