RESUMEN

An efficient procedure for in vitro propagation of Herreria salsaparrilha Martius was established from single-node explants (fourth and fifth nodes from apex to the base) derived from donor plants maintained under shading-house conditions. After surface sterilization, explants are inoculated in test tubes containing 15 mL of Murashige and Skoog (MS) medium without growth regulators. Cultures are maintained under 35 µmol m-2 s-1 irradiance, a 16/8-h light/dark light regime, at 26 ± 2 °C. The subcultures are carried out under the same conditions, adding 6-benzyladenine 1.0 mg/L and Phytagel® 2.8 g/L. Shoots are elongated and rooted by transferring individual shoots to half-strength MS medium without growth regulators. After 25-30 days, elongated rooted shoots are transferred to plastic pots containing 25-30 mL of sterile distilled water, covered with a transparent plastic bag, and kept under the same growth room conditions for 2 days. Plants are transferred to cups containing autoclaved and washed sand and kept in a shading house (50% light interception) for acclimatization. True-to-type adult plants were successfully recovered under ex vitro conditions.

Asunto(s)

RESUMEN

Este texto faz uma breve revisão histórica da inserção da violência como questão de saúde pública, destacando a importância da Atenção Primária à Saúde e a inovação estratégica com o Programa Nacional de Gênero, Raça, Raça e Valorização da Mulher Trabalhadora no SUS.

This text provides a brief historical review of the inclusion of violence as a public health issue, highlighting the importance of Primary Health Care and strategic innovation with the National Program for Gender, Race, Race and the Appreciation of Working Women in the SUS.

RESUMEN

CXCR1/2 biomolecules play vital roles in cancer cell proliferation, tumor inflammation, and angiogenesis, making them attractive drug targets. In clear cell renal cell carcinoma (RCC) and head and neck squamous cell carcinoma (HNSCC), where CXCR1/2 is overexpressed, inhibition studies are limited. Building upon previous research efforts, we investigated new N,N'-diarylurea analogues as ELR+CXCL-CXCR1/2 inhibitors. Evaluations on RCC and HNSCC cell lines and 3D spheroid cultures identified compound 10 as a lead molecule, exhibiting significant inhibition of invasion, migration, and neo-angiogenesis. It demonstrated strong interference with the signaling pathway, with high selectivity toward kinases. In vivo studies on zebrafish embryos and RCC xenografted mice showed notable anticancer, antimetastatic, and antiangiogenic effects after oral administration and minimal toxicity. Compound 10 emerges as a promising candidate for further preclinical development as an oral anticancer and antiangiogenic drug targeting the ELR+CXCL-CXCR1/2 pathway.

RESUMEN

PURPOSE: To investigate the antibacterial effects of Terminalia catappa Linn (TCL) leaf extracts at different concentrations and the effects of these extracts used as primers on the long-term adhesive properties of two universal adhesives. MATERIALS AND METHODS: After extract preparation, the antimicrobial and antibacterial activities of TCL against Streptococcus mutans (UA 159) were assessed in microdilution assays to provide the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Additionally, to provide quantitative data on the ability of TCL extract to reduce cell viability, colony forming units (CFU) were counted. To examine adhesive properties, 288 human molars were randomly assigned to 32 experimental conditions (n = 9) according to the following variables: (1) treatment agent: negative control (untreated surface), and primers at concentrations of 1xMIC, 5xMIC, and 10xMIC; (2) adhesives: Scotchbond Universal (SBU) and Futurabond Universal (FBU); (3) adhesive strategy: etch-and-rinse (ER) or self-etch (SE); and (4) storage time: 24 h or after 2 years. Primers were applied for 60 s, upon which the teeth were incrementally restored and sectioned into adhesive-dentin bonded sticks. These were tested for microtensile bond strength (µTBS) and nanoleakage (NL) after 24-h and 2-year water storage, as well as in-situ degree of conversion (DC) at 24 h. The chemical profile of the hybrid layer was determined via micro-Raman spectroscopy. Biofilm assay data were analyzed using the Kruskal-Wallis test; the pH of culture media and the chemical profile were analyzed by one-way ANOVA. The adhesive properties (µTBS, NL, DC) were evaluated using a four-way ANOVA and Tukey's test. Significance was set at 5%. RESULTS: Similar values of MIC and MBC were observed (2 mg/ml), showing bactericidal potential. CFU analysis demonstrated that concentrations of 5xMIC and 10xMIC significantly inhibited biofilm formation (p < 0.001). The application of the TCL primer at all concentrations significantly increased the immediate µTBS and DC, and decreased the immediate NL values when compared to the control group (p < 0.05), regardless of the adhesive and adhesive strategies. Despite an increase in the NL values for all groups after 2 years (p > 0.05), in groups where the TCL primer was applied, the µTBS remained constant after 2 years for both adhesives, while a decrease in the µTBS was observed in the control groups (p < 0.05). Usually, 10xMIC showed better results than 1xMIC and 5xMIC (p < 0.05). The application of TCL promoted cross-linking; cross-linking rates increased proportionally to the concentration of TCL (p < 0.05). CONCLUSION: Primers containing TCL promoted bactericidal and bacteriostatic action, as well as cross-linking with dentin, while maintaining the adhesive properties of the adhesive-dentin interface after 2 years of water storage.

Asunto(s)

RESUMEN

BACKGROUND: In clear cell renal cell carcinoma (ccRCC), first-line treatment combines nivolumab (anti-PD-1) and ipilimumab (anti-CTLA4), yielding long-term remissions but with only a 40% success rate. Our study explored the potential of enhancing ccRCC treatment by concurrently using CXCR2 inhibitors alongside immunotherapies. METHODS: We analyzed ELR + CXCL levels and their correlation with patient survival during immunotherapy. RCT001, a unique CXCR2 inhibitor, was examined for its mechanism of action, particularly its effects on human primary macrophages. We tested the synergistic impact of RCT001 in combination with immunotherapies in both mouse models of ccRCC and human ccRCC in the presence of human PBMC. RESUTS: Elevated ELR + CXCL cytokine levels were found to correlate with reduced overall survival during immunotherapy. RCT001, our optimized compound, acted as an inverse agonist, effectively inhibiting angiogenesis and reducing viability of primary ccRCC cells. It redirected M2-like macrophages without affecting M1-like macrophage polarization directed against the tumor. In mouse models, RCT001 enhanced the efficacy of anti-CTLA4 + anti-PD1 by inhibiting tumor-associated M2 macrophages and tumor-associated neutrophils. It also impacted the activation of CD4 T lymphocytes, reducing immune-tolerant lymphocytes while increasing activated natural killer and dendritic cells. Similar effectiveness was observed in human RCC tumors when RCT001 was combined with anti-PD-1 treatment. CONCLUSIONS: RCT001, by inhibiting CXCR2 through its unique mechanism, effectively suppresses ccRCC cell proliferation, angiogenesis, and M2 macrophage polarization. This optimization potentiates the efficacy of immunotherapy and holds promise for significantly improving the survival prospects of metastatic ccRCC patients.

Asunto(s)

RESUMEN

AIMS: To evaluate the effects of testosterone on endothelium-dependent vasodilation and oxidative stress in mesenteric resistance arteries. MAIN METHODS: Spontaneously hypertensive rats (SHR), aged 8 to 10 weeks, were divided into four groups: intact (SHAM), intact treated with testosterone (TTO; 3 mg/kg/day) via subcutaneous route (s.c.), intact treated with testosterone and anastrozole [aromatase enzyme inhibitor (TTO + ANA; 0.1 mg/kg/day, s.c.)] and intact treated with testosterone and finasteride [5 α-reductase enzyme inhibitor (TTO + FIN; 5 mg/kg/day, s.c.)] for four weeks. Concentration-response curves to acetylcholine (ACh, 0.1 nmol/L - 10 µmol/L) were obtained in mesenteric resistance arteries previously contracted with phenylephrine (PE, 3 µmol/L), before and after the use of selective inhibitors. Reactive oxygen species (ROS) levels were assessed in the vessels and the endothelium analyzed by scanning electron microscopy. KEY FINDINGS: TTO group showed a lower participation of nitric oxide (NO), increased oxidative stress, and participation of prostanoids and endothelium-dependent hyperpolarization (EDH), possibly to maintain the vasodilator response. Lower participation of NO and prostanoids, combined to an increased participation of EDH, were observed in the TTO + ANA group, in addition to higher levels of ROS and altered endothelial morphology. The vasodilation to ACh was impaired in TTO + FIN, along increased participation of NO, reduction of prostanoids, and greater EDH-dependent vasodilation. SIGNIFICANCE: Testosterone contributes to endothelial vasodilation by enhancing EDH through an increased participation of epoxyeicosatrienoic acids. While the decrease in NO appears to involve the participation of dihydrotestosterone, 17 ß-estradiol seems to stimulate the action of the NO pathway and prostanoids.

Asunto(s)

RESUMEN

Antimicrobial photodynamic therapy (a-PDT) is a modality that aims to induce microorganisms through visible light, a photosensitizer, and molecular oxygen. This therapy has shown promising results in controlling cariogenic biofilm in vitro and in vivo counterparts. This study investigated bacterial viability and morphological characterization of Streptococcus mutans mature biofilms after combination of erythrosine and a high potency dental curing light. Biofilms were formed on saliva-coated hydroxyapatite disks in batch culture. The samples were performed in triplicates. Fresh medium was replaced daily for five days and treated using 40 µM of E activated by HL 288 J/cm2 and total dose of 226 J at 1200 mW/cm2. Phosphate buffer saline and 0.12% of chlorhexidine were used as negative and positive control, respectively. After treatment, biofilms were assessed for microbial viability and morphological characterization by means of bio-volume and thickness. COMSTAT software was used for image analysis. Data were analyzed using two-way ANOVA followed by Tukey test with significance level 5%. The application of a-PDT and CHX treatments decreased S. mutans bacterial viability. The image analysis showed more red cells on biofilms when compared to other groups, demonstrating photobacterial killing. Erythrosine irradiated with a high potency curing light can potentially act as an antimicrobial tool in the treatment of cariogenic biofilms. The morphology and viability of microorganisms were impacted after treatment. Treatment with photodynamic therapy may be able to reduce the bio-volume and viability of bacteria present in biofilms. CLINICAL RELEVANCE AND RESEARCH HIGHLIGHTS: The use of the a-PDT technique has been applied in dentistry with satisfactory results. Some applications of this technique are in stomatology and endodontics. In the present study, we sought to understand the use of photodynamic therapy in the control of biofilm and the results found are compatible with the objective of microbiological control proposed by this technique, thus raising the alert for future studies in vivo using the combination of a-PDT with erythrosine, since they are easily accessible materials for the dental surgeon and can be applied in clinical practice.

Asunto(s)

RESUMEN

Microglia are specialized brain-resident macrophages that arise from primitive macrophages colonizing the embryonic brain1. Microglia contribute to multiple aspects of brain development, but their precise roles in the early human brain remain poorly understood owing to limited access to relevant tissues2-6. The generation of brain organoids from human induced pluripotent stem cells recapitulates some key features of human embryonic brain development7-10. However, current approaches do not incorporate microglia or address their role in organoid maturation11-21. Here we generated microglia-sufficient brain organoids by coculturing brain organoids with primitive-like macrophages generated from the same human induced pluripotent stem cells (iMac)22. In organoid cocultures, iMac differentiated into cells with microglia-like phenotypes and functions (iMicro) and modulated neuronal progenitor cell (NPC) differentiation, limiting NPC proliferation and promoting axonogenesis. Mechanistically, iMicro contained high levels of PLIN2+ lipid droplets that exported cholesterol and its esters, which were taken up by NPCs in the organoids. We also detected PLIN2+ lipid droplet-loaded microglia in mouse and human embryonic brains. Overall, our approach substantially advances current human brain organoid approaches by incorporating microglial cells, as illustrated by the discovery of a key pathway of lipid-mediated crosstalk between microglia and NPCs that leads to improved neurogenesis.

Asunto(s)

RESUMEN

Cosmetic residues have been found in water resources, especially trace elements of precursors, couplers, and pigments of hair dyes, which are indiscriminately disposed of in the sewage system. These contaminants are persistent, bioactive, and bioaccumulative, and may pose risks to living beings. Thus, the present study assessed the ecotoxicity of two types of effluents generated in beauty salons after the hair dyeing process. The toxicity of effluent derived from capillary washing with water, shampoo, and conditioner (complete effluent-CE) and effluent not associated with these products (dye effluent-DE) was evaluated by tests carried out with the aquatic organisms Artemia salina, Daphnia similis, and Danio rerio. The bioindicators were exposed to pure samples and different dilutions of both effluents. The results showed toxicity in D. similis (CE50 of 3.43% and 0.54% for CE and DE, respectively); A. salina (LC50 8.327% and 3.874% for CE and DE, respectively); and D. rerio (LC50 of 4.25-4.59% and 7.33-8.18% for CE and DE, respectively). Given these results, we can infer that hair dyes, even at low concentrations, have a high toxic potential for aquatic biota, as they induced deleterious effects in all tested bioindicators.

RESUMEN

Kogia sima and Kogia breviceps are apex predators of mesopelagic trophic webs being far from most anthropogenic threats. However, chemical pollutants and naturally synthesized compounds may travel long distances. This study aimed to use kogiid whales as sentinels of mesopelagic trophic webs in the Southwestern Atlantic Ocean. Persistent organic pollutants (POPs), e.g., polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, mirex, hexachlorobenzene (HCB), polybrominated diphenylethers (PBDEs), pentabromoethylbenzene (PBEB) and hexabromobenzene (HBB), and the naturally produced methoxylated BDE (MeO-BDEs) were determined in the blubber of 16 K. sima and 15 K. breviceps. Among the organochlorine compounds, DDTs were the main group found in K. sima and in K. breviceps (1636.6 and 3983.3 ng g-1 lw, respective medians), followed by PCBs (425.9 and 956.1 ng g-1 lw, respectively), mirex (184.1 and 375.6 ng g-1 lw, respectively), and HCB (132.4 and 340.3 ng g-1 lw, respectively). As for the organobromine, the natural MeO-BDEs were predominant (1676.7 and 501.6 ng g-1 lw, respectively), followed by PBDEs (13.6 and 10.3 ng g-1 lw, respectively) and PBEB (2.2 and 2.9 ng g-1 lw, respectively). In general, POPs concentration was higher in K. breviceps than in K. sima. Conversely, MeO-BDEs concentration was higher in K. sima than in K. breviceps. Differences in concentrations in these sympatric odontocetes were attributed to distinct species, sampling sites, and biological parameters and suggest some level of niche segregation. It is noteworthy the long-range reach and bioaccumulation of these synthetic compounds in an unexplored habitat, that present an increasing economic interest.

Asunto(s)

RESUMEN

This study characterizes the osmophores and corolla traits in 18 species of Bignonieae Dumort., a Bignoniaceae tribe occurring in the Cerrado, a neotropical savanna in Brazil. To detect osmophore distribution, whole, newly opened flowers were immersed in Neutral Red Solution. Samples from the corolla tube and lobes were also fixed and analyzed micromorphologically, anatomically, and histochemically. The osmophores showed six markedly different distribution patterns that were not clearly associated with histological features. In most species, osmophores comprised papillose secretory epidermises and a few layers of subepidermal parenchyma. Starch grains, lipid droplets, and terpenes were detected in osmophores. An ornamented cuticle, cuticular folds, glandular and non-glandular trichomes, raised stomata and epicuticular wax granules are common traits in the species studied and may be useful in determining the taxonomy of the group. We found that 94% of the species visited by bees had papillose epidermises while the single hummingbird-pollinated species presented a flattened epidermis. Variations in osmophore pattern among species visited by bees, including variations within the same plant genus, are novel finding. Additionally, the Bignonieae species visited by bees presented a textured corolla surface, which has been reported as facilitating bee attachment and movement towards the floral resource. Future studies with a greater number of Bignonieae species and more detailed pollinator behavioral assays may help in the interpretation of the variations in corolla traits and functional relationships between flowers and pollinators.

Asunto(s)

RESUMEN

The aim of this scoping review was to map the literature related to the "Academia da Saúde" Program, including the objective and rationale of the studies, activities carried out in the program's centers, as well as the actors involved in these actions. The search for evidence was conducted in the MEDLINE, LILACS, Web of Science, Scopus, COCHRANE, and SciELO databases. Additional evidence was investigated in the Catalog of Theses and Dissertations of the Coordination of Improvement of Higher Education Personnel (CAPES-Brazil) and in the Brazilian Digital Library of Theses and Dissertations, in addition to manual searches in the references of the studies/documents. Out of 642 initial records, the information synthesis was composed of 74 studies/documents (n = 54; 73.0% scientific articles, n = 48; 64.9% with cross-sectional design, n = 45; 60.8% quantitative analysis). Nutrition (n = 24; 32.2%) and evaluation of the Program (n = 27; 36.5%) were the main themes analyzed. Regarding the participant/object analyzed in each study, users (n = 39; 52.6%) were the main actors investigated. Future studies should consider investigating the effectiveness of the actions developed in the program centers, especially physical activity and healthy eating practices.

Asunto(s)

RESUMEN

BACKGROUND: Polymethylmethacrylate (PMMA) is the most used material for the manufacturing of eye prostheses. OBJECTIVES: To investigate the cytotoxicity of different cleaning agents for ocular prostheses on human conjunctival cells. MATERIAL AND METHODS: Six groups of specimens were created (saline, soap, 4% chlorhexidine, hydrogen peroxide, 1% triclosan, and citronella oil). Three specimens were made for each disinfectant at each disinfection period (1, 7, 15, 30, 60, and 90 days), totaling 108 specimens. Thus, the specimens were disinfected, with different disinfectants, for different periods of time. After each disinfection process, the specimens were washed with sterile distilled water. A human conjunctival cell line was grown on the acrylic resin specimens and then cytotoxicity tests (MTT and Neutral Red (NR)) were performed. A negative control (untreated cell cultures) and positive control (Tween 20) were created. Two-way analysis of variance (ANOVA) and Bonferroni test were performed (p < 0.05). RESULTS: For the MTT and NR tests, when there was a significant difference between the disinfectant and negative control, the disinfectant generated a significant reduction in cell proliferation most of the time. CONCLUSIONS: All reductions in cell proliferation caused by the disinfectants were clinically acceptable. All disinfectants tested in this study were found to be non-cytotoxic to human conjunctival cells.

Asunto(s)

RESUMEN

The individual and combined association between unhealthy lifestyle behaviors and body weight dissatisfaction in adolescents was investigated. This cross-sectional research used data from 676 students (348 female), aged between 14 and 19 years old (mean of 14.6 years old) from southern Brazil. Unhealthy lifestyle behaviors and body weight dissatisfaction were assessed through a questionnaire. Unhealthy lifestyle behaviors included smoking, excessive alcohol consumption, sedentary lifestyle, and poor diet, and were analyzed as individual factors and as combinations of behaviors. For males, smoking (OR: 2.6; 95% CI: 1.6-4.0) and the combination of smoking/excessive consumption of alcoholic beverages (OR: 2.5; 95% CI: 1.1-5.8) were directly associated with the desire to reduce body weight, whereas the combination of smoking/inadequate diet (OR: 1.3; 95% CI: 1.0-1.6) was associated with the desire to increase body weight. For females, the combinations of inadequate diet/physical inactivity (OR: 1.6; 95% CI: 1.0-2.5) and of smoking/excessive consumption of alcoholic beverages (OR: 1.9; 95% CI: 1.4-2.8) were directly associated with the desire to reduce body weight. The presence of simultaneous unhealthy lifestyle behaviors is associated with bodyweight dissatisfaction in adolescents.

RESUMEN

In DNA, electron excitation allows adjacent pyrimidine bases to dimerize by [2 + 2] cycloaddition, creating chemically stable but lethal and mutagenic cyclobutane pyrimidine dimers (CPDs). The usual cause is ultraviolet radiation. Alternatively, CPDs can be made in the dark (dCPDs) via chemically mediated electron excitation of the skin pigment melanin, after it is oxidized by peroxynitrite formed from the stress-induced radicals superoxide and nitric oxide. We now show that the dark process is not limited to the unusual structural molecule melanin: signaling biomolecules such as indolamine and catecholamine neurotransmitters and hormones can also be chemiexcited to energy levels high enough to form dCPDs. Oxidation of serotonin, dopamine, melatonin, and related biogenic amines by peroxynitrite created triplet-excited species, evidenced by chemiluminescence, energy transfer to a triplet-state reporter, or transfer to O2 resulting in singlet molecular oxygen. For a subset of these signaling molecules, triplet states created by peroxynitrite or peroxidase generated dCPDs at levels comparable to ultraviolet (UV). Neurotransmitter catabolism by monoamine oxidase also generated dCPDs. These results reveal a large class of signaling molecules as electronically excitable by biochemical reactions and thus potential players in deviant mammalian metabolism in the absence of light.

Asunto(s)

RESUMEN

Light is one way to excite an electron in biology. Another is chemiexcitation, birthing a reaction product in an electronically excited state rather than exciting from the ground state. Chemiexcited molecules, as in bioluminescence, can release more energy than ATP. Excited states also allow bond rearrangements forbidden in ground states. Molecules with low-lying unoccupied orbitals, abundant in biology, are particularly susceptible. In mammals, chemiexcitation was discovered to transfer energy from excited melanin, neurotransmitters, or hormones to DNA, creating the lethal and carcinogenic cyclobutane pyrimidine dimer. That process was initiated by nitric oxide and superoxide, radicals triggered by ultraviolet light or inflammation. Several poorly understood chronic diseases share two properties: inflammation generates those radicals across the tissue, and cells that die are those containing melanin or neuromelanin. Chemiexcitation may therefore be a pathogenic event in noise- and drug-induced deafness, Parkinson's disease, and Alzheimer's; it may prevent macular degeneration early in life but turn pathogenic later. Beneficial evolutionary selection for excitable biomolecules may thus have conferred an Achilles heel. This review of recent findings on chemiexcitation in mammalian cells also describes the underlying physics, biochemistry, and potential pathogenesis, with the goal of making this interdisciplinary phenomenon accessible to researchers within each field.

Asunto(s)

RESUMEN

Body weight dissatisfaction has been described as a marker for various health diseases, given its direct association with social, physical, and emotional suffering. We investigated the association between body weight dissatisfaction and health risk behaviors in adolescents. This was a cross-sectional study conducted with 668 adolescents aged 14-19 years in the city of São José, southern Brazil. Body weight satisfaction/dissatisfaction was assessed using a questionnaire validated for the investigated population. Health risk behaviors included smoking, alcohol, illicit drugs, medication, non-prescription anabolic steroids, not using seatbelt, unsafe sexual behavior and not knowing how to deal with day-to-day stress. Among males, 66.1% were dissatisfied with their body weight (32.1% due to thinness and 34.0% due to overweight). Among females, 80.0% were dissatisfied with their body weight (24.5% due to thinness and 55.5% due to overweight). There were no significant differences regarding health risk behaviors according to body weight satisfaction/dissatisfaction and sex. Compared to males who were satisfied with their body weight, those who were dissatisfied due to being overweight were more likely to be using tobacco (OR: 2.9; 95% CI: 2.1-4.2), alcohol (OR: 1.7; 95% CI: 1.5-1.9) and anabolic steroids (OR: 2.7; 95% CI: 1.2-5.7). Compared to females who were satisfied with their body weight, those who were dissatisfied due to thinness were more likely to be consuming alcoholic beverages (OR: 1.6; 95% CI: 1.2-2.0) and less likely to be consuming illicit drugs (OR: 0.5; 95% CI: 0.3-0.8). Interventions aimed at health education regarding the non-adoption of risk behaviors such as alcohol and tobacco use, as well as the non-use of anabolic steroids, and favoring the maintenance of general health, may be important for adolescents with body dissatisfaction. These data suggest that health risk behaviors such as adolescent male use of tobacco, alcohol, and anabolic steroids and the use of alcohol and drugs by female adolescents can be related to body weight dissatisfaction.

Asunto(s)

RESUMEN

The role of androgens in vascular reactivity is controversial, particularly regarding their age-related actions. The objective of this study was to conduct a temporal evaluation of the vascular reactivity of resistance arteries of young male rats, as well as to understand how male sex hormones can influence the vascular function of these animals. Endothelium-mediated relaxation was characterized in third-order mesenteric arteries of 10-, 12-, 16-, and 18w (week-old) male rats. Concentration-response curves to acetylcholine (ACh, 0.1 nmol/L-10 µmol/L) were constructed in arteries previously contracted with phenylephrine (PE, 3 µmol/L), before and after the use of nitric oxide synthase or cyclooxygenase inhibitors. PE concentration-response curves (1 nmol/L-100 µmol/L) were also built. The levels of vascular nitric oxide, superoxide anion, and hydrogen peroxide were assessed and histomorphometry analysis was performed. The 18w group had impaired endothelium-dependent relaxation. All groups showed prostanoid-independent and nitric oxide-dependent vasodilatory response, although this dependence seems to be smaller in the 18w group. The 18w group had the lowest nitric oxide and hydrogen peroxide production, in addition to the highest superoxide anion levels. Besides functional impairment, 18w animals showed morphological differences in third-order mesenteric arteries compared with the other groups. Our data show that time-dependent exposure to male sex hormones appears to play an important role in the development of vascular changes that can lead to impaired vascular reactivity in mesenteric arteries, which could be related to the onset of age-related cardiovascular changes in males.

Asunto(s)

RESUMEN

Betaxanthins are natural products with high antioxidant and anti-inflammatory properties. Here, we describe the semisynthesis of twenty-one betaxanthins derived from proteinogenic amino acids, including the elusive betaxanthin of l-cysteine and two betaxanthins derived from l-lysine, and rationalize their antioxidant properties in mechanistic terms. The antioxidant capacity and redox potential of these betaxanthins were compared to those of model betaxanthins derived from dopamine, l-DOPA (L-3,4-dihydroxyphenylalanine), and pyrrolidine and structure-property relationships were established by using matched molecular pair analysis and a model developed using a genetic algorithm. Either a phenol or indole moiety enhance the antioxidant capacity of betaxanthins, which is overall much higher than that of their amino acid precursors and standard antioxidants, except for the cysteine-betaxanthin. The one-electron oxidation of amino acid betaxanthins produces radicals stabilized in multiple centers, as demonstrated by quantum chemical calculations.

RESUMEN

The typically low thermodynamic and kinetic stability of enzymes is a bottleneck for their application in industrial synthesis. Baeyer-Villiger monooxygenases, which oxidize ketones to lactones using aerial oxygen, among other activities, suffer particularly from these instabilities. Previous efforts in protein engineering have increased thermodynamic stability but at the price of decreased activity. Here, we solved this trade-off by introducing mutations in a cyclohexanone monooxygenase from Acinetobacter sp., guided by a combination of rational and structure-guided consensus approaches. We developed variants with improved activity (1.5- to 2.5-fold) and increased thermodynamic (+5 °C T m) and kinetic stability (8-fold). Our analysis revealed a crucial position in the cofactor binding domain, responsible for an 11-fold increase in affinity to the flavin cofactor, and explained using MD simulations. This gain in affinity was compatible with other mutations. While our study focused on a particular model enzyme, previous studies indicate that these findings are plausibly applicable to other BVMOs, and possibly to other flavin-dependent monooxygenases. These new design principles can inform the development of industrially robust, flavin-dependent biocatalysts for various oxidations.