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The present study thus aimed at the development and physicochemical characterization of solid lipid nanoparticles loaded with crude extract of Piper corcovadensisroots (SLN-CEPc) and chitosan-coated solid lipid nanoparticles loaded withcrude extract of P. corcovadensisroots (C-SLN-CEPc), as well as the determination of its antimycobacterial activity against Mycobacterium tuberculosisH37Rv, its cytotoxicity against the Vero cell line and evaluation in the hemolysis assay. Both formulations containing the encapsulated extract showed high encapsulation efficiency, formed by a monodispersed system with small and spherical particles, and there was no aggregation of particles. In the biological assays, SLN-CEPc and C-SLN-CEPc showed promising anti-M. tuberculosisactivity with a minimum inhibitory concentration (MIC) of 12.5 μg/mL, whereas the cytotoxic concentrations obtained at 50% (CC50) in Vero cells were 60.0 and 70.0 μg/mL, respectively. Therefore, nanoencapsulation showed satisfactory results, justifying its usage in the development of new products.

Researchers have concentrated efforts in the search for natural-based reversible inhibitors for cholinesterase enzymes because they may play a key role in the treatment and cure of degenerative diseases like Alzheimer’s Disease. Diverse alkaloids from plants can inhibit the action of acetylcholinesterase enzyme and, among them, berberine is a promising bioactive. Although the mechanism of action of berberine still needs to be fully elucidated, the major concern lies in its poor water solubility and consequent low bioavailability. The solid dispersion technique is a well-known procedure to improve the water affinity of hydrophobic substances, however, the obtention of berberine solid dispersions is yet to be truly investigated. It is also of key importance to elucidate the safety aspects of the berberine-loaded solid dispersions and a range of tests can be applied, such as in vitro cytotoxicity in cell lines and in vivo tests using model organisms. In this work, berberine-loaded solid dispersions were obtained and evaluated as inhibitor of acetylcholinesterase enzyme (AChE). A polypropylene glycol / polyethylene glycol triblock copolymer was used in the solid dispersion formation. In a first step, the influence of berberine on AChE was investigated by docking simulation, showing the active sites in which berberine may anchor to the enzyme. The enzymatic reactions involved in the action of AChE on the acetylcholine were investigated by kinetic modeling. In vitro assays were carried out to confirm the enzymatic kinetics of AChE in the presence of berberine. berberine nanoparticles exerted an improved cytotoxic effect on tumoral cells demonstrating the improvement in water affinity. In vivo assays in Allium cepa were implemented showing that no cytotoxicity or genotoxicity is expected for the berberine solid dispersion. Berberine-loaded solid dispersions may represent a significant step towards safe nanostructures to be used in the treatment of neurodegenerative diseases.

BACKGROUND Developing fast and reliable methods with little sample preparation has become increasingly important for process monitoring and control. Electrochemical methods stand out for their low cost and instrumental simplicity. Furthermore, electrodes with nanoparticles can improve the method's sensitivity and specificity. This study developed carbon paste electrodes modified with nanoparticles of copper and iron. In addition, cyclic voltammetry was performed using a low‐cost potentiostat designed for a Raspberry Pi single‐board computer. As a proof of concept, the constructed electrodes were tested with ferrocyanide and applied to quantify sucrose, and their performance was compared to that of the glassy carbon electrode. RESULTS The nanoparticles were successfully synthesized, as confirmed by morphology and physicochemical characterization. Based on the adjusted R2, the electrode made with the addition of copper oxide nanoparticles has a similar performance to the commercial glassy carbon electrode. All electrodes' root mean square error (RMSE) values were approximately 10−4 mol L−1. The lowest values for the inverse of the analytical sensitivity for sucrose were obtained for the unmodified carbon paste electrode (9.54 × 10−6 mol L−1) and copper oxide nanoparticles electrode (5.30 × 10−6 mol L−1). These electrodes also had the lowest limits of detection (10−5 mol L−1) and, for the limit of quantification, all electrodes had similar values (10−2 mol L−1). CONCLUSION In general, superior performance of carbon paste electrodes was observed concerning the commercial glassy carbon electrodes. Compared to previous studies, the developed electrodes showed good sensitivity and the low cost of the electrochemical system stands out as the main advantage. © 2022 Society of Chemical Industry (SCI).