Exploration of photoprotective and antibiotic activity of wild Polypodiaceae ferns from Costa Rica.

Skin disorders affect millions of people all over the world. There are limited options to treat dermal illnesses such as vitiligo, psoriasis, and atopic dermatitis (eczema). Central American ferns are a potential source of bioactive metabolites against those diseases. Currently, Polypodium leucotomos Poir. is the only one being commercially utilized for this purpose. In this work, we evaluated the concentration of the skin bioactive compounds: quinic and chlorogenic acid, in the extract of 20 wild ferns from Costa Rica. We also evaluated the antimicrobial capabilities of the crude extracts of wild ferns and the sun protection factor (SPF) of the extracts. We found 19 out of 20 have either an important concentration of the compounds mentioned above or antimicrobial properties. Also, most samples result in higher SPF than P. aureum's rhizome. We also have studied the fern acclimatization, at different shading conditions, finding a significant influence of the culturing conditions on metabolite production. After acclimatization. So far, we demonstrate that various ferns included in this study are a potential source of treatments for skin conditions.

Antioxidant and antimicrobial activity of two Costa Rican cultivars of ber (Ziziphus mauritiana): An underexploited crop in the American tropic.

Ber is an antioxidant-rich fruit from Asia and has recently been cultured in Central America. The antioxidant capacity and antimicrobial activity of Z. mauritiana cultured of bers from Guanacaste, Costa Rica, were evaluated. Two farm locations and two cultivars were evaluated. Total polyphenolic compounds (TPC), proanthocyanidin compounds (PAC), and ascorbic acid were spectrophotometrically quantified. Antioxidant activity has been analyzed using the DPPH method. Antimicrobial susceptibility was determined using the Kirby-Bauer disk diffusion method. Ber samples contained 11-44 mg GAE/g TPC. Green fruits and leaves had the highest concentrations. The ascorbic acid concentration in ber fruits was determined between 251 and 466 mg/100 g. Ber vitamin C content is higher than most common fruits. Proanthocyanidin compounds were determined between 1.8 and 9.9 mg 4-MCG/g, and the highest concentration was observed in the leaves. Our samples showed the antioxidant activity of 90-387 µmol TE/g, which was moderate activity. The nutritional quality of ber fruits was related to maturity conditions. The ber fruits, a crop from Asia previously adapted to live in Costa Rica, are rich in vitamin C and TPC, and the concentration of those metabolites was even higher than the concentration reported in bers grown in other countries. The TPC and PACs had an interestingly wide antimicrobial spectrum. Cultivars and farm locations have a significant effect on metabolite production.

Optimization of the Extraction of Antioxidant Compounds from Roselle Hibiscus Calyxes (Hibiscus sabdariffa), as a Source of Nutraceutical Beverages.

Secondary metabolites from Hibiscus sabdariffa have been used to prevent different diseases. Roselle Hibiscus is known for being rich in phenolic bioactive compounds. The extraction conditions are directly related to the chemical composition and then to the overall bioactivity of the extract. In this study, a Box-Behnken experimental design has been used to optimize the antioxidant activity, considering four variables: ethanol:water ratio, temperature, extraction time, and solvent:solid ratio. The experiment comprises 27 experiments and 3 repetitions at the central point. The results are described by surface response analysis and a second-degree polynomial equation. The model explains 87% of the variation in the response. The maximum antioxidant activity is yielded when 1% solids are extracted in 35.5% ethanol at 60 °C for 33 min. Finally, a nutritional functional supplement of 495 µmol Trolox Equivalent (TE) antioxidant capacity was prepared with the optimized extract.

Polycationic Surfaces Promote Whole-Cell Immobilization and Induce Microgranulation of Clostridium saccharoperbutylacetonicum N1-4 for Enhanced Biobutanol Production.

Immobilization is a common strategy used to protect microbial cells to improve the performance of bioprocesses. However, the interaction mechanism between the cells and the immobilization material is generally poorly understood. In this study, we employed natural polysaccharide-based materials as immobilization carriers for clostridial fermentation in an attempt to enhance the production of butanol (a valuable biofuel/biochemical but highly toxic to the host cells) and meanwhile elucidate the interaction mechanisms related to immobilization. The utilization of chitosan powder as the immobilization carrier enhanced butanol productivity by 97% in the fermentation with Clostridium saccharoperbutylacetonicum N1-4 and improved butanol titer by 21% in the fermentation with Clostridium beijerinckii NCIMB 8052. Additionally, analogue derivatives using microcrystalline cellulose (MCC) and cotton cationized on the surface with 3-chloro-2-hydroxypropyltrymethylammonium (CHPTA) and 2-chloro-N,N-diethylaminoethyl chloride (DEAEC) were prepared and used as immobilization carriers for similar fermentation conditions. The CHPTA derivatives showed slightly increased production of butanol and total solvent with C. saccharoperbutylacetonicum. Overall, our results indicated that the interaction between the cell and the carrier material occurs through a double mechanism involving adsorption immobilization and induced aggregation. This work provides insights concerning the effects of the chemical properties of the carrier material (such as the cation density and surface area) on fermentation performance, enabling a better understanding of the interaction between bacterial cells and the cationic materials. The derivatization strategies employed in this study can be applied to most cellulosic materials to modulate the properties and enhance the interaction between the cell and the carrier material for immobilization, thus improving the bioprocess performance.

Transplantation of Human-Fetal-Spinal-Cord-Derived NPCs Primed with a Polyglutamate-Conjugated Rho/Rock Inhibitor in Acute Spinal Cord Injury.

Neural precursor cell (NPC) transplantation represents a promising therapy for treating spinal cord injuries (SCIs); however, despite successful results obtained in preclinical models, the clinical translation of this approach remains challenging due, in part, to the lack of consensus on an optimal cell source for human neuronal cells. Depending on the cell source, additional limitations to NPC-based therapies include high tumorigenic potential, alongside poor graft survival and engraftment into host spinal tissue. We previously demonstrated that NPCs derived from rat fetal spinal cords primed with a polyglutamate (PGA)-conjugated form of the Rho/Rock inhibitor fasudil (PGA-SS-FAS) displayed enhanced neuronal differentiation and graft survival when compared to non-primed NPCs. We now conducted a similar study of human-fetal-spinal-cord-derived NPCs (hfNPCs) from legal gestational interruptions at the late gestational stage, at 19-21.6 weeks. In vitro, expanded hfNPCs retained neural features, multipotency, and self-renewal, which supported the development of a cell banking strategy. Before transplantation, we established a simple procedure to prime hfNPCs by overnight incubation with PGA-SS-FAS (at 50 µM FAS equiv.), which improved neuronal differentiation and overcame neurite-like retraction after lysophosphatidic-acid-induced Rho/Rock activation. The transplantation of primed hfNPCs into immune-deficient mice (NU(NCr)-Foxn1nu) immediately after the eighth thoracic segment compression prompted enhanced migration of grafted cells from the dorsal to the ventral spinal cord, increased preservation of GABAergic inhibitory Lbx1-expressing and glutamatergic excitatory Tlx3-expressing somatosensory interneurons, and elevated the numbers of preserved, c-Fos-expressing, activated neurons surrounding the injury epicenter, all in a low percentage. Overall, the priming procedure using PGA-SS-FAS could represent an alternative methodology to improve the capabilities of the hfNPC lines for a translational approach for acute SCI treatment.

Effect of the bio-inspired modification of low-cost membranes with TiO2:ZnO as microbial fuel cell membranes.

Microbial fuel cells (MFCs) are a novel technique for converting biodegradable materials into electricity. In this study, the efficiency of mixed crystal (TiO2:ZnO) as a membrane modifier of a low-cost, antifouling and self-cleaning cation exchange membrane for MFCs was studied. The modification was prepared using polydopamine (PDA) as the bio-inspired glue, followed by gravity deposition of a mixture of catalyst nanoparticles (TiO2:ZnO 0.03%, 1:1 ratio) as anti-biofouling agents. The effects of the membrane modification were evaluated in terms of power density, open circuit potential, coulombic efficiency, anti-biofouling properties and also color and COD removal efficiency. The results showed that the use of the PDA-modified membrane and a mixture of catalysts facilitated the transfer of cations released during the oxidation process in the anodic compartment of the MFC, which increased the power generation in the MFC by 2.5 times and 5.7 times the current compared to pristine and PDA pristine membranes, decreased the MFC operating cycle time from 5 to 3 days, doubled the lifetime of the membranes and demonstrated higher COD removal efficiency and color removal. Finally, SEM and AFM analysis showed that the modification significantly minimized surface fouling. The modified membranes in this study proved to be a potential alternative to the expensive membranes currently used in MFCs, furthermore, this modification could be an interesting alternative modification for other potential membranes for use in MFCs, due to the fact that the catalyst activation was only performed with visible light (artificial and solar), which could decrease operating costs.

A Hyaluronic Acid Demilune Scaffold and Polypyrrole-Coated Fibers Carrying Embedded Human Neural Precursor Cells and Curcumin for Surface Capping of Spinal Cord Injuries.

Tissue engineering, including cell transplantation and the application of biomaterials and bioactive molecules, represents a promising approach for regeneration following spinal cord injury (SCI). We designed a combinatorial tissue-engineered approach for the minimally invasive treatment of SCI-a hyaluronic acid (HA)-based scaffold containing polypyrrole-coated fibers (PPY) combined with the RAD16-I self-assembling peptide hydrogel (Corning® PuraMatrix™ peptide hydrogel (PM)), human induced neural progenitor cells (iNPCs), and a nanoconjugated form of curcumin (CURC). In vitro cultures demonstrated that PM preserves iNPC viability and the addition of CURC reduces apoptosis and enhances the outgrowth of Nestin-positive neurites from iNPCs, compared to non-embedded iNPCs. The treatment of spinal cord organotypic cultures also demonstrated that CURC enhances cell migration and prompts a neuron-like morphology of embedded iNPCs implanted over the tissue slices. Following sub-acute SCI by traumatic contusion in rats, the implantation of PM-embedded iNPCs and CURC with PPY fibers supported a significant increase in neuro-preservation (as measured by greater ßIII-tubulin staining of neuronal fibers) and decrease in the injured area (as measured by the lack of GFAP staining). This combination therapy also restricted platelet-derived growth factor expression, indicating a reduction in fibrotic pericyte invasion. Overall, these findings support PM-embedded iNPCs with CURC placed within an HA demilune scaffold containing PPY fibers as a minimally invasive combination-based alternative to cell transplantation alone.

Renewable fatty acid ester production in Clostridium.

Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural microbial pathways, leading to improvement in bioproduction efficiency. By leveraging pathways in solventogenic clostridia for co-producing acyl-CoAs, acids and alcohols as precursors, through rational screening for host strains and enzymes, systematic metabolic engineering-including elimination of putative prophages, we develop strains that can produce 20.3 g/L butyl acetate and 1.6 g/L butyl butyrate. Techno-economic analysis results suggest the economic competitiveness of our developed bioprocess. Our principles of selecting the most appropriate host for specific bioproduction and engineering microbial chassis to produce high-value and easy-separable end products may be applicable to other bioprocesses.

Human-Induced Neural and Mesenchymal Stem Cell Therapy Combined with a Curcumin Nanoconjugate as a Spinal Cord Injury Treatment.

We currently lack effective treatments for the devastating loss of neural function associated with spinal cord injury (SCI). In this study, we evaluated a combination therapy comprising human neural stem cells derived from induced pluripotent stem cells (iPSC-NSC), human mesenchymal stem cells (MSC), and a pH-responsive polyacetal-curcumin nanoconjugate (PA-C) that allows the sustained release of curcumin. In vitro analysis demonstrated that PA-C treatment protected iPSC-NSC from oxidative damage in vitro, while MSC co-culture prevented lipopolysaccharide-induced activation of nuclear factor-κB (NF-κB) in iPSC-NSC. Then, we evaluated the combination of PA-C delivery into the intrathecal space in a rat model of contusive SCI with stem cell transplantation. While we failed to observe significant improvements in locomotor function (BBB scale) in treated animals, histological analysis revealed that PA-C-treated or PA-C and iPSC-NSC + MSC-treated animals displayed significantly smaller scars, while PA-C and iPSC-NSC + MSC treatment induced the preservation of ß-III Tubulin-positive axons. iPSC-NSC + MSC transplantation fostered the preservation of motoneurons and myelinated tracts, while PA-C treatment polarized microglia into an anti-inflammatory phenotype. Overall, the combination of stem cell transplantation and PA-C treatment confers higher neuroprotective effects compared to individual treatments.

Identification and Investigation of Autolysin Genes in Clostridium saccharoperbutylacetonicum Strain N1-4 for Enhanced Biobutanol Production.

Biobutanol is a valuable biochemical and one of the most promising biofuels. Clostridium saccharoperbutylacetonicum N1-4 is a hyperbutanol-producing strain. However, its strong autolytic behavior leads to poor cell stability, especially during continuous fermentation, thus limiting the applicability of the strain for long-term and industrial-scale processes. In this study, we aimed to evaluate the role of autolysin genes within the C. saccharoperbutylacetonicum genome related to cell autolysis and further develop more stable strains for enhanced butanol production. First, putative autolysin-encoding genes were identified in the strain based on comparison of amino acid sequence with homologous genes in other strains. Then, by overexpressing all these putative autolysin genes individually and characterizing the corresponding recombinant strains, four key genes were pinpointed to be responsible for significant cell autolysis activities. Further, these key genes were deleted using CRISPR-Cas9. Fermentation characterization demonstrated enhanced performance of the resultant mutants. Results from this study reveal valuable insights concerning the role of autolysins for cell stability and solvent production, and they provide an essential reference for developing robust strains for enhanced biofuel and biochemical production.IMPORTANCE Severe autolytic behavior is a common issue in Clostridium and many other microorganisms. This study revealed the key genes responsible for the cell autolysis within Clostridium saccharoperbutylacetonicum, a prominent platform for biosolvent production from lignocellulosic materials. The knowledge generated in this study provides insights concerning cell autolysis in relevant microbial systems and gives essential references for enhancing strain stability through rational genome engineering.

A General Organocatalytic System for Enantioselective Radical Conjugate Additions to Enals.

Herein, we report a general iminium ion-based catalytic method for the enantioselective conjugate addition of carbon-centered radicals to aliphatic and aromatic enals. The process uses an organic photoredox catalyst, which absorbs blue light to generate radicals from stable precursors, in combination with a chiral amine catalyst, which secures a consistently high level of stereoselectivity. The generality of this catalytic platform is demonstrated by the stereoselective interception of a wide variety of radicals, including non-stabilized primary ones which are generally difficult to engage in asymmetric processes. The system also served to develop organocatalytic cascade reactions that combine an iminium-ion-based radical trap with an enamine-mediated step, affording stereochemically dense chiral products in one-step.

Enhancing the tolerance of Clostridium saccharoperbutylacetonicum to lignocellulosic-biomass-derived inhibitors for efficient biobutanol production by overexpressing efflux pumps genes from Pseudomonas putida.

Furan aldehydes and phenolic compounds generated during biomass pretreatment can inhibit fermentation for biofuel production. Efflux pumps actively transport small molecules out of cells, thus sustaining normal microbial metabolism. Pseudomonas putida has outstanding tolerance to butanol and other small molecules, and we hypothesize that its efflux pump could play essential roles for such robustness. Here, we overexpressed efflux pump genes from P. putida to enhance tolerance of hyper-butanol producing Clostridium saccharoperbutylacetonicum to fermentation inhibitors. Interestingly, overexpression of the whole unit resulted in decreased tolerance, while overexpression of the subunit (srpB) alone exerted significant enhanced robustness of the strain. Compared to the control, the engineered strain had enhanced capability to grow in media containing 17% more furfural or 50% more ferulic acid, and produced ~14 g/L butanol (comparable to fermentation under regular conditions without inhibitors). This study provided valuable reference for boosting microbial robustness towards efficient biofuel production from lignocellulosic materials.

tappAS: a comprehensive computational framework for the analysis of the functional impact of differential splicing.

Recent advances in long-read sequencing solve inaccuracies in alternative transcript identification of full-length transcripts in short-read RNA-Seq data, which encourages the development of methods for isoform-centered functional analysis. Here, we present tappAS, the first framework to enable a comprehensive Functional Iso-Transcriptomics (FIT) analysis, which is effective at revealing the functional impact of context-specific post-transcriptional regulation. tappAS uses isoform-resolved annotation of coding and non-coding functional domains, motifs, and sites, in combination with novel analysis methods to interrogate different aspects of the functional readout of transcript variants and isoform regulation. tappAS software and documentation are available at https://app.tappas.org.

Efecto protector del Desmodium molliculum EAM (manayupa) en ratas con toxicidad hepática inducida por naproxeno / Protective effect of Desmodium molliculum EAM (manayupa) in rats with naproxen-induced liver toxicity

Objetivo. Verificar el efecto protector del extracto acuoso de hojas y tallos de Desmodium molliculum EAM (manayupa), en la toxicidad hepática inducida por el naproxeno en ratas Ratus novergicus variedad Wistar albino, hembras. Materiales y métodos. Estudio experimental. Se utilizaron 36 ratas hembras de 250 ± 10 g, divididas en seis grupos de seis: A (control -); B (control + naproxeno); patrón C (silimarina 100 mg / kg) y 3 experimental (EAM): D 80 mg/kg; E 160 mg/kg y F 240 mg/kg). Los grupos B, C, D, E, F recibieron por vía oral naproxeno 27,38 mg, los primeros cinco días y durante 14 días. El efecto protector hepático se determinó mediante el análisis bioquímico: GOT, GPT, GGT, proteínas totales, albúmina sérica, fosfatasa alcalina y creatinina. Resultados. Se encontró que el grupo B perdió peso (180,65 ± 6,5 g), bilirrubina total (0,76 ± 0,4) bilirrubina directa (1.7 ± 0,8), TGO (160 ± 10,4) y TGP (412 ± 20,4) alto, comparado con el grupo A, C, D, E y F. Conclusiones. El EAM tiene efecto protector sobre la toxicidad hepática inducida por naproxeno en ratas, evidenciado por los parámetros bioquímicos.

Objective. To verify the protective effect of the aqueous extract of leaves and stems of Desmodium molliculum EAM (manayupa), on the hepatic toxicity induced by Naproxen in rats Ratus novergicus albino Wistar variety, females. Materials and methods. 36 female rats of 250 ± 10 g were used, divided into six groups of six: A (Control -), B (Control + Naproxen), Pattern C (Silymarin 100 mg / kg) and 3 Experimental (EAM): D 80 mg / kg, E 160 mg / kg and F 240 mg / kg). Groups B, C, D, E, F orally received Naproxen 27.38 mg, the first five days and for 14 days. The hepatic protective effect was determined by the biochemical analysis: GOT, GPT, GGT, total proteins, serum albumin, alkaline phosphatase, creatinine. Results. group B was found to lose weight (180.65 ± 6.5 g), total bilirubin (0.76 ± 0.4) direct bilirubin (1.7 ± 0.8), TGO (160 ± 10.4) and TGP (412 ± 20.4) high, compared to group A, C, D, E and F. Conclusion. EAM has a protective effect on hepatic toxicity induced by naproxen in rats, evidenced by biochemical parameters.

Photo-Organocatalytic Enantioselective Radical Cascade Reactions of Unactivated Olefins.

Radical cascade processes are invaluable for their ability to rapidly construct complex chiral molecules from simple substrates. However, implementing catalytic asymmetric variants is difficult. Reported herein is a visible-light-mediated organocatalytic strategy that exploits the excited-state reactivity of chiral iminium ions to trigger radical cascade reactions with high enantioselectivity. By combining two sequential radical-based bond-forming events, the method converts unactivated olefins and α,ß-unsaturated aldehydes into chiral adducts in a single step. The implementation of an asymmetric three-component radical cascade further demonstrates the complexity-generating power of this photochemical strategy.

Bacterial Genome Editing with CRISPR-Cas9: Taking Clostridium beijerinckii as an Example.

CRISPR-Cas9 has been explored as a transformative genome engineering tool for many eukaryotic organisms. However, its utilization in bacteria remains limited and ineffective. This chapter, taking Clostridium beijerinckii as an example, describes the use of Streptococcus pyogenes CRISPR-Cas9 system guided by the single chimeric guide RNA (gRNA) for diverse genome-editing purposes, including chromosomal gene deletion, integration, single nucleotide modification, as well as "clean" mutant selection. The general principle is to use CRISPR-Cas9 as an efficient selection tool for the edited mutant (whose CRISPR-Cas9 target site has been disrupted through a homologous recombination event and thus can survive selection) against? the wild type background cells. This protocol is broadly applicable to other microorganisms for genome-editing purposes.

In situ biobutanol recovery from clostridial fermentations: a critical review.

Butanol is a precursor of many industrial chemicals, and a fuel that is more energetic, safer and easier to handle than ethanol. Fermentative biobutanol can be produced using renewable carbon sources such as agro-industrial residues and lignocellulosic biomass. Solventogenic clostridia are known as the most preeminent biobutanol producers. However, until now, solvent production through the fermentative routes is still not economically competitive compared to the petrochemical approaches, because the butanol is toxic to their own producer bacteria, and thus, the production capability is limited by the butanol tolerance of producing cells. In order to relieve butanol toxicity to the cells and improve the butanol production, many recovery strategies (either in situ or downstream of the fermentation) have been attempted by many researchers and varied success has been achieved. In this article, we summarize in situ recovery techniques that have been applied to butanol production through Clostridium fermentation, including liquid-liquid extraction, perstraction, reactive extraction, adsorption, pervaporation, vacuum fermentation, flash fermentation and gas stripping. We offer a prospective and an opinion about the past, present and the future of these techniques, such as the application of advanced membrane technology and use of recent extractants, including polymer solutions and ionic liquids, as well as the application of these techniques to assist the in situ synthesis of butanol derivatives.

Selective construction of quaternary stereocentres in radical cyclisation cascades triggered by electron-transfer reduction of amide-type carbonyls.

Radical-radical cyclisation cascades, triggered by single-electron-transfer to amide-type carbonyls using SmI2-H2O-LiBr, result in the selective construction of quaternary carbon stereocentres. The cascades deliver tricyclic barbiturates with four stereocentres in good yield and with excellent diastereocontrol.

Efecto de barnices fluorados sobre el esmalte erosionado a través de microscopia de fuerza atómica: Estudio in vitro / Efeitos de vernizes fluoretados em esmalte erodido mediante microscopia de força atômica: Estudo in vitro / Effect of fluoride varnishes on eroded enamel by atomic force microscopy: In vitro study

Objetivo: Evaluar el efecto de diferentes barnices fluorados sobre el esmalte erosionado a través de Microscopia de Fuerza Atómica (MFA). Materiales y métodos: Se utilizaron 30 muestras de esmalte de incisivos bovinos sin lesiones de caries defectos estructurales o fracturas, fueron divididas en 3 grupos (N=10): G1 control negativo, G2 Duraphat (Colgate) y G3 Clinpro White Varnish (3M ESPE). El MFA equipado con una punta de no contacto, con parámetros de rugosidad media (Ra) y rugosidad media cuadrática (Rrms), con imágenes de un área de 50x50 micras a una resolución de 256x256 pixeles y 0,5 Hz. Se midió la rugosidad inicial, luego se realizó desafío erosivo con Sprite Zero y remineralización con saliva artificial, después de 4 ciclos de erosión y remineralización se midió la rugosidad del esmalte como protección mecánica y al 1, 2, 3 y 4 días como protección química. Los datos se analizaron estadísticamente con las pruebas de ANOVA, Tukey y T de Student con un nivel de significancia al 5%. Resultados: El test de ANOVA mostró una diferencia en los grupos de barnices de flúor en el 2º, 3º y 4º día en comparación con el grupo control (p <0,05). El test de Tukey mostró una diferencia entre Duraphat y Clinpro en valores de Ra (p = 0,03) y Rrms (p = 0,05) en el 4°día. La T de Student demostró que no hay diferencias para Clinpro en Ra (p = 0,14) y Rrms (p = 0,13) desde los valores iniciales hasta el 4º día. Conclusión: Clinpro White Varnish tiene una mejor acción para reducir la rugosidad superficial en la superficie del esmalte cuando se somete a desafíos ácidos.

Purpose: To evaluate the effect of different fluoride varnishes on eroded enamel through Atomic Force Microscopy (AFM). Materials and Methods: 30 samples of bovine incisor enamel without carious lesions, defective structure or fractures were divided into 3 groups (N = 10): G1: negative control, G2: Duraphat® (Colgate) and G3: Clinpro™ White Varnish (3M ESPE). The AFM was used, equipped with a non-contact tip with parameters such as average roughness (Ra) and the mean square roughness (Rrms) at an area for images of 50 x 50 microns with a resolution of 256 X 256 pixels and 0.5 Hz. First, the initial roughness was measured, then an erosive trail was carried out with Sprite Zero and remineralization with artifi-cial saliva. After 4 cycles of erosion and remineralization, the roughness of enamel as mechanic protection was measured and at 1, 2, 3 and 4 days as chemical protection. Data were analyzed statistically with ANOVA, Tukey and Student T with a significance level of 5%. Results: The ANOVA test showed a difference in the groups of fluoride varnishes on the 2nd, 3rdand 4th day in comparison with the control group (p <0.05). The Tukey test showed a difference between Duraphat® and Clinpro™ in the values of Ra (p = 0.03) and Rrms (p = 0.05) on the 4th day. The Student's T test showed no difference for Clinpro™ in Ra (p = 0.14) and Rrms (0.13) from the initial values until 4th day. Conclusion: Clinpro™ White Varnish shows better results to reduce surface roughness in the enamel when subjected to acidic trails.

Objetivo: Avaliar o efeito de diferentes vernizes fluoretados no esmalte erodido por meio de microscopia de força atômica (MFA). Materiais e Métodos: Foram selecionadas 30 amostras de esmalte de incisivos bovinos sem cárie, defeitos de estrutura ou fraturas, foram divididas em 3 grupos (n = 10): G1: controle negativo, G2: Duraphat (Colgate) e G3: Clinpro White Varnish (3M ESPE). Foi utilizado MFA, equipado com uma ponta de não contato. Determinaram-se parâmetros fotográficos como a rugosidade média (Ra) e rugosidade média quadrática (Rrms) da superfície, com imagens de uma área de 50 x 50 microns com uma resolução de 256 X 256 pixels e 0,5 Hz. Em primeiro lugar procedeu-se realizar a medição da rugosidade inicial, foi realizada o desafio erosivo com Sprite Zero e remineralização com saliva artificial, após 4 ciclos de erosão e remineralização foi medido a rugosidade do esmalte foi medida como proteção mecânica e ao 1, 2, 3 e 4 dias como proteção química. Os dados foram analisados estatisticamente com ANOVA, Tukey T de Student com um nível de significância de 5%. Resultados: O Teste de ANOVA mostrou uma diferença dos grupos de vernizes fluoretados no 2º, 3º e 4º dia em comparação com o grupo controle (p <0,05). O Teste de Tukey mostrou uma diferença entre Duraphat e Clinpro nos valores de Ra (p = 0,03) e Rrms ao 4° dia (p = 0,05). O teste T de Student não mostrou nenhuma diferença para Clinpro em Ra (p = 0,14) e Rrms (0,13) dos valores iniciais até ao dia 4. Conclusão: O Verniz Clinpro White Varnish tem melhor ação na redução da rugosidade da superfície do esmalte quando foi submetido à desafios ácidos.

Efecto gastroprotector y antisecretor de un fitofármaco de hojas de matico (Piper aduncum) / Gastroprotective and antisecretory effect of a phytochemical made from matico leaves (Piper aduncum)

Objetivos. Determinar el efecto gastroprotector y antisecretor del extracto etanólico de las hojas de matico (Piper aduncum) en modelos animales. Materiales y métodos. Para la evaluación del efecto gastroprotector se utilizó 220 ratones de la cepa Balb C57, los cuales fueron aleatorizados en 22 grupos de diez animales, a los cuales se les indujo la formación de úlceras gástricas con indometacina, la gastroprotección se determinó a través de tres aspectos: inflamación, número de bandas hemorrágicas y número de úlceras. Para evaluar el efecto antisecretor se utilizó 64 ratas albinas machos Holtzman, los cuales fueron aleatorizados en ocho grupos de ocho animales, un control y siete grupos de tratamiento con un nivel de dosis de los extractos y dos niveles de dosis en los fitofármacos; la antisecreción se realizó con el ensayo de ligazón pilórica. Resultados. Para la gastroprotección, los extractos de diclorometano, cloroformo, hexano y metanol, lograron una disminución de la inflamación de más del 66% (p<0,05); el extracto etanólico presenta una actividad de 100% para disminuir el número de bandas hemorrágicas (p<0,05); el extracto clorofórmico presenta una actividad antiulcerosa de 75% (p<0,05). Respecto a la antisecreción, el fitofármaco en cápsulas conteniendo el extracto etanólico logró un 72% de reducción del volumen de la secreción gástrica (p<0,01) y un incremento del pH en 104,3% (p<0,01). Conclusiones. En condiciones experimentales los extractos etanólico, sus fracciones y su fitofármaco son gastroprotectores en ratones y antisecretores en ratas.

Objectives. To determine the gastroprotective and antisecretory effect of ethanol extract from matico leaves (Piper aduncum) in animal models. Materials and methods. To evaluate the gastroprotective effect, 220 mice of the Balb C57 strain were used. They were randomized in 22 groups of ten animals each, in which the formation of gastric ulcers was induced with indomethacin. Gastroprotection was determined by evaluating three aspects: inflammation, number of hemorrhagic shocks and number of ulcers. To evaluate the antisecretory effect, 64 white male Holtzman rats were used, which were randomized in eight groups of eight animals, one control and seven groups of treatment with one extract dose level and two phytochemical dose levels. Antisecretion was obtained through the pylorus ligation. Results. Regarding gastroprotection, dichloromethane, chloroform, hexane and methanol extracts decreased inflammation to over 66% (p<0,05). The ethanolic extract shows 100% activity in reducing the number of hemorrhagic bands (p<0,05). The chloroform extract shows antiulcer activity at 75% (p<0,05). In terms of antisecretion, the phytochemical in capsules containing the ethanolic extract achieved 72% reduction of the gastric secretion volume (p<0,01) and 104,3% (p<0,01) PH increase. Conclusions. In experimental conditions, ethanolic extracts, their fractions and phytochemicals have a gastroprotective effect in mice and antisecretory effect in rats.