Anadenanthera colubrina var. cebil (Griseb.) Altschul (Fabaceae family), commonly known as the red angico tree, is a medicinal plant found throughout Brazil’s semi-arid area. In this study, a chemical analysis was performed to investigate the antidiarrheal activity and safety profile of red angico gum (RAG), a biopolymer extracted from the trunk exudate of A. colubrina. Upon FT-IR spectroscopy, RAG showed bands in the regions of 1608 cm⁻¹, 1368 cm⁻¹, and 1029 cm⁻¹, which relate to the vibration of O–H water molecules, deformation vibration of C-O bands, and vibration of the polysaccharide C-O band, respectively, all of which are relevant to glycosidic bonds. The peak molar mass of RAG was 1.89 × 10⁵ g/mol, with the zeta potential indicating electronegativity. RAG demonstrated high yield and solubility with a low degree of impurity. Pre-treatment with RAG reduced the total diarrheal stool and enteropooling. RAG also enhanced Na+/K+-ATPase activity and reduced gastrointestinal transit, and thereby inhibited intestinal smooth muscle contractions. Enzyme-Linked Immunosorbent Assay (ELISA) demonstrated that RAG can interact with GM1 receptors and can also reduce E. coli-induced diarrhea in vivo. Moreover, RAG did not induce any signs of toxicity in mice. These results suggest that RAG is a possible candidate for the treatment of diarrheal diseases.

Patagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. In this sense, Pleurodema thaul is the first amphibian specie to be studied from this large region of South America. Analysis of cDNA-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. The predicted mature peptides were synthesized and all of them showed weak or null antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli with the exception of thaulin-1, a cationic 26-residue linear, amphipathic, Gly- and Leu-rich peptide with moderate antimicrobial activity against E. coli (MIC of 24.7μM). AFM and SPR studies suggested a preferential interaction between these peptides and bacterial membranes. Cytotoxicity assays showed that thaulin peptides had minimal effects at MIC concentrations towards human and animal cells. These are the first peptides described for amphibians of the Pleurodema genus. These findings highlight the potential of the Patagonian region's unexplored biodiversity as a source for new molecule discovery.

Considering the therapeutic potential of Varronia curassavica Jacq. essential oil and the great value in the pharmaceutical market, this study aims to evaluate the influence of plant age on the chemical composition and biological activities of V. curassavica Jacq. essential oil. The plant age is a parameter that can influence the chemical composition of the essential oil, as well as its pharmacological potential. For this purpose, essential oils from aerial parts of V. curassavica produced at different ages (4, 10, 14 and 18 months-age) were used. According to chromatograms obtained by GC-MS, the essential oils were mainly composed of α-pinene, trans-caryophyllene, α-santalene, alloaromadendrene and α-humulene. The chemical composition of V. curassavica essential oils varied qualitatively and quantitatively with the aging of the plants, and the essential oils from plants at 18 month-age appeared to be the most distinct from the others. The tested essential oil samples showed inhibitory activity against Candida albicans (MIC = 1000 µg/mL) but did not show antibacterial activity against the tested bacteria. The cytotoxic activity levels against the murine macrophages varied among the oils extracted from the plants at different ages; the IC₅₀ values of the essential oils increased with age (171.90 µg/mL at 18 month-age). More studies should be carried out to assess whether age also affects the therapeutic effects of essential oils, resulting in the manufacture of plant-derived formulations that balance production costs, toxicity and therapeutic effects.

Solid Lipid Nanoparticles (SLNs) are drug delivery systems with important advantages over conventional nanosystems. Considering previously reported pharmacological and physicochemical properties of Platonia insignis seed butter (BBI), this work aimed at developing, characterizing and performing toxicological and antioxidant studies of SLNs produced from BBI. The GC-MS analysis identified palmitic and oleic acids as the major compounds. Three SLN prototypes were developed through high-shear homogenization followed by ultrasonication. During a 180-day stability evaluation, the formulation SLN/TW-1.5 presented greater stability since pH was around 6.0, as well as a lesser variation of the PdI (Polydispersity Index), particle size and Zeta Potential (ZP), confirmed with Raman Spectroscopy and Atomic Force Microscopy (AFM). The CC₅₀ in macrophages was around 249.4 µg∙mL⁻¹ for BBI, whereas the CC₅₀ value for SLN/TW-1.5 was 45.2 µg∙mL⁻¹. Electron Paramagnetic Resonance (EPR) showed a marked in vitro antioxidant activity for BBI and SLN/TW-1.5. After in vivo SLN/TW-1.5 administration in Zophobas morio larvae, assessment of reduced glutathione (GSH), nitrite (NO₂⁻) and myeloperoxidase (MPO) demonstrated antioxidant activity. Thus, the intrinsic physicochemical properties of BBI allowed the development of an optimized nanoformulation with high stability indexes, besides the great potential for antioxidant applications.

This work is based on research aiming to extract and identify flavonoids from jaborandi (Pilocarpus microphyllus) leaves and investigate their antioxidant and acute antinociceptive capacity. Characterization of the constituents of the ethyl acetate fraction (EtOAcF) obtained from the methanolic extract (ME) was performed by UV-Vis spectrophotometry, infrared spectroscopy, high-performance liquid chromatography (HPLC), mass spectrometry (MS), and cyclic voltammetry, demonstrating the possible majority component of this fraction, the flavone chrysin. Its solubility properties in HPLC are very close to those of the flavonol quercetin, revealing the characteristic presence of this group. An MS spectrum of the fraction revealed a major protonated molecule of m/z 254.9 [M+H]⁺. The EtOAcF fraction showed three oxidation processes at 0.32 V, 0.54 V, and 0.73 V vs. Ag/AgCl. Three reduction processes at the respective potentials: 0.60 V, −0.03 V, and -0.24 V vs. Ag/AgCl, indicating potential antioxidant activity. At DPPH and ABTS antioxidant radical capture assay, The IC₅₀ obtained was 0.5 mg/mL and 0.81 mg/mL, respectively. In vivo test to determine the mechanical nociceptive threshold in the von Frey test, the dose of 100 mg/kg of the EtOAcF was able to cause inhibition of behavioral changes in neuropathy. The results obtained in this study demonstrate the biological potential of an EtOAcF derived from jaborandi leaves.