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Amazonian flora includes several species with the potential to develop pharmaceutical and biotechnological products. The essential oils from Amazonian species possess some biological properties, such as antioxidant, antibacterial, and cytotoxic activities. The essential oil of red sacaca (RSO), Croton cajucara Benth., contains metabolites characterized by antioxidant and anti-inflammatory activities. Nanostructured lipid carriers (NLC) are an advantageous alternative for the effective delivery of drugs because they can solubilize lipophilic actives and reduce their cytotoxicity. This study aimed to optimize the synthesis of RSO-loaded nanostructured lipid carriers (NLC-RSO) using a 23 factorial design and investigate their antioxidant and cytotoxic effects. The red sacaca essential oil (RSO) metabolite profile was characterized using gas chromatography coupled with a mass spectrometer (GC-MS), identifying 33 metabolites, with linalool and 7-hydroxy-calamenene as the major ones, as reported in the literature. The optimized NLC-RSO formulation had a particle size less than 100 nm and a polydispersity index lower than 0.25. After characterizing NLC-RSO using Fourier-transform infrared spectroscopy, powder X-ray diffraction, zeta potential, moisture content, and wettability, in vitro cytotoxicity were performed in A549 and BEAS-2B cell lines using the resazurin metabolism assay. The data indicated a lower IC50 for RSO than for NLC-RSOs in both cell lines. Furthermore, low cytotoxicity of blank nanoparticles (blank NP) and medium chain triglycerides-loaded nanostructured lipid carriers (NLC-MCT) towards both pulmonary cell lines was noted. At a concentration of 50-100 μg/mL, free RSO exhibited higher cytotoxicity than NLC-RSO, demonstrating the protective effect of this lipid carrier in reducing cytotoxicity during metabolite delivery. Similarly, free RSO showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging than NLC-RSO, also indicating this protective effect. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) intracellular reactive oxygen species (ROS) level assay did not show differences between the treatments at higher but non-cytotoxic dosages. Taken together, our results suggest that NLC-RSOs are potential RSO delivery systems for applications related to cancer treatment. [ABSTRACT FROM AUTHOR]

Background: Traditional medicine has inspired the scientific community to discover natural compounds with the ability to inhibit the enzyme acetylcholinesterase (AChE) and with significant antioxidant capacity. These themes are associated with therapeutic processes to decrease the symptoms of Alzheimer's disease (AD). Acetylcholine (Ach) is an important neurotransmitter in the central nervous system responsible for transmitting the nervous impulse and increasing intestinal motility and dilation of sphincters in the gastrointestinal tract. As the species Peumus boldus Molina is widely known and used in folk medicine to treat gastrointestinal discomfort, its constituents could have an affinity for AChE and could be used to treat AD. Materials and Methods: This study evaluated the chemical, inhibitory activity of AChE (using the Elmann method and in silico), antioxidant capacity (DPPH, ABTS, FRAP, and oxidation inhibition of the β-carotene/linoleic acid system), and quantification of total leaf phenols from a commercial sample of P. boldus. Results: The mass spectral analysis allowed identification of the alkaloids isoboldine, boldine, clocaurine, laurotetanine, N-methylurotetanine, reticuline, and N-methylcoclaurine. In the in silico prediction test, the alkaloid N-metillaurotetanine was the best acetylcholinesterase enzyme inhibitor, with energy of -10.1 kcal mol-1. Conclusion: These results are of scientific relevance for the discovery of new drugs to treat dementia associated with Alzheimer's disease and stimulate the continuity of chemical and biological studies (anticholinesterase and antioxidant action) of prepurified fractions and substances isolated from P. boldus leaves. [ABSTRACT FROM AUTHOR]

Poly( o -methoxyaniline) emeraldine-salt form (ES-POMA) was chemically synthesized using hydrochloric acid and subjected to a heat treatment (HT) process for 1 h at 100 °C (TT 100 ) and 200 °C (TT 200 ). The HT process promoted a progressive decrease in crystallinity. The Le Bail method revealed a decomposition from tetrameric to trimeric-folded chains after the HT process. The unheated POMA-ES presented a globular vesicular morphology with varied micrometric sizes. The heat treatment promoted a reduction in these globular structures, increasing the non-crystalline phase. The boundary length (S) and connectivity/Euler feature (χ) parameters were calculated from the SEM images, revealing that ES-POMA presented a wide distribution of heights. The TT 100 and TT 200 presented a narrow boundary distribution, suggesting smoother surfaces with smaller height variations. The UV-VIS analysis revealed that the transition at 343 nm (nonlocal π → π* ) was more intense in the TT 200 due to the electronic delocalization, which resulted from the reduced polymer chain caused by the HT process. In addition to the loss of conjugation, counter ion withdrawal reduced the ion-chain interaction, decreasing the local electron density. This result shows the influence of the chlorine counter ions on the peaks position related to the HOMO → LUMO transition, since the π → polaron transition occurs due to the creation of the energy states due to the presence of counter ions. Finally, the electrical conductivity decreased after the HT process from 1.4 × 10 -4 S.cm -1 to 2.4 × 10 -6 S.cm -1 as result of the polymer deprotonation/degradation. Thus, this paper proposed a systematic evaluation of the POMA molecular structure and crystallite size and shape after heat treatment.