Effectiveness of the repurposed drug isotretinoin in an experimental murine model of Chagas disease.

Benznidazole and nifurtimox are the drugs currently used for the treatment of Chagas disease, however its side effects may affect patient adherence. In the search for new alternative therapies, we previously identified isotretinoin (ISO), an FDA-approved drug widely used for the treatment of severe acne through a drug repurposing strategy. ISO shows a strong activity against Trypanosoma cruzi parasites in the nanomolar range, and its mechanism of action is through the inhibition of T. cruzi polyamine and amino acid transporters from the Amino Acid/Auxin Permeases (AAAP) family. In this work, a murine model of chronic Chagas disease (C57BL/6 J mice), intraperitoneally infected with T. cruzi Nicaragua isolate (DTU TcI), were treated with different oral administrations of ISO: daily doses of 5 mg/kg/day for 30 days and weekly doses of 10 mg/kg during 13 weeks. The efficacy of the treatments was evaluated by monitoring blood parasitemia by qPCR, anti-T. cruzi antibodies by ELISA, and cardiac abnormalities by electrocardiography. No parasites were detected in blood after any of the ISO treatments. The electrocardiographic study of the untreated chronic mice showed a significant decrease in heart rate, while in the treated mice this negative chronotropic effect was not observed. Atrioventricular nodal conduction time in untreated mice was significantly longer than in treated animals. Mice treated even with ISO 10 mg/kg dose every 7 days, showed a significant reduction in anti-T. cruzi IgG levels. In conclusion, the intermittent administration of ISO 10 mg/kg would improve myocardial compromise during the chronic stage.

2'-Hydroxychalcones as an alternative treatment for trichomoniasis in association with metronidazole.

The treatment for trichomoniasis, based on 5'-nitroimidazol agents, has been presenting failures related to allergic reactions, side effects, and the emergence of resistant isolates. There are no alternative drugs approved for the treatment of these cases; thus, the search for new active molecules is necessary. In this scenario, chalcones have been extensively studied for their promising biological activities. Here, we presented the synthesis of three hydroxychalcones (3a, b, and c), in vitro and in silico analyses against Trichomonas vaginalis. The in vitro biological evaluation showed that hydroxychalcone 3c presented anti-T. vaginalis activity, with complete death in 12 h of incubation at minimum inhibitory concentration (MIC) of 100 µM. 3c showed a dose-dependent cytotoxicity against mammalian VERO cell line, but the association of 3c at 12.5 µM and metronidazole (MTZ) at 40 µM showed 95.31% activity against T. vaginalis trophozoites after 24 h of exposure and did not affect the VERO cell growth, appearing to be a good alternative. In silico analysis by molecular docking showed that 3c could inhibit the activity of TvMGL (methionine gamma-lyase), TvLDH (lactate dehydrogenase), and TvPNP (purine nucleoside phosphorylase) affecting the T. vaginalis survival and also suggesting a different mechanism of action from MTZ. Therefore, these results propose that hydroxychalcones are promising anti-T. vaginalis agents and must be considered for further investigations regarding trichomoniasis treatment.

Evaluation of phytotherapy alternatives for controlling Rhipicephalus (Boophilus) microplus in vitro.

The objective of this study was to identify the main chemical components of the essential oil of Cuminum cyminum L. (cumin) and of the fixed oils of Bertholletia excelsa (Brazil nut) and of Helianthus annuus (sunflower seed). As well as testing the three oils and three different commercial synthetic acaricides against engorged females of Rhipicephalus (Boophilus) microplus in order to explore their acaricidal efficacy. Six different concentrations of the oils (200, 100, 50, 25, 12.5 and 6.25 mg/mL) and the active principles were evaluated with the Adult Immersion Test (AIT). The two main chemicals components of C. cyminum L. were the cuminaldehyde and the γ-terpinene. In both B. excelsa and H. annuus were the linoleic and oleic acid. C. cyminum L. showed high acaricidal activity (100%) over the engorged females and on their reproductive characteristat from the concentration of 100 mg/mL. B. excelsa and H. annuus had low acaricidal activity (39.39% and 58.75% in the concentration of 200 mg/mL respectively). The amidine and the pyrethroid (35.12% and 1.50% respectively). It can be concluded that the oil of C. cyminum L. may be a phytoterapic alternative for the cattle's tick control.

Evaluation of phytotherapy alternatives for controlling Rhipicephalus (Boophilus) microplus in vitro / Avaliação de alternativas fitoterápicas no controle in vitro de Rhipicephalus (Boophilus) microplus

Abstract The objective of this study was to identify the main chemical components of the essential oil of Cuminum cyminum L. (cumin) and of the fixed oils of Bertholletia excelsa (Brazil nut) and of Helianthus annuus (sunflower seed). As well as testing the three oils and three different commercial synthetic acaricides against engorged females of Rhipicephalus (Boophilus) microplus in order to explore their acaricidal efficacy. Six different concentrations of the oils (200, 100, 50, 25, 12.5 and 6.25 mg/mL) and the active principles were evaluated with the Adult Immersion Test (AIT). The two main chemicals components of C. cyminum L. were the cuminaldehyde and the γ-terpinene. In both B. excelsa and H. annuus were the linoleic and oleic acid. C. cyminum L. showed high acaricidal activity (100%) over the engorged females and on their reproductive characteristat from the concentration of 100 mg/mL. B. excelsa and H. annuus had low acaricidal activity (39.39% and 58.75% in the concentration of 200 mg/mL respectively). The amidine and the pyrethroid (35.12% and 1.50% respectively). It can be concluded that the oil of C. cyminum L. may be a phytoterapic alternative for the cattle's tick control.

Resumo O objetivo do presente estudo foi identificar os componentes químicos majoritários do óleo essencial de Cuminum cyminum L. (comino) e dos óleos fixos de Bertholletia excelsa (castanha do Brasil) e de Helianthus annuus (semente de girassol). Assim como testar os três óleos e três diferentes acaricidas comerciais sintéticos contra fêmeas ingurgitadas de Rhipicephalus (Boophilus) microplus, para explorar sua eficácia acaricida. Seis concentrações dos óleos (200, 100, 50, 25, 12,5 and 6,25 mg/mL) e os princípios ativos foram avaliados por meio do Teste de Imersão de Adultas (AIT). Os dois componentes químicos majoritários de C. cyminum L. foram o cuminaldeído e o y-terpineno. Nos óleos de B. excelsa e H. annuus os componentes majoritários foram o ácido n linoleico e oleico, respectivamente. C. cyminum L. mostrou alta atividade acaricida (100%) sobre as fêmeas ingurgitadas e suas caraterísticas reprodutivas, a partir da concentração 100 mg/mL., tornando-se uma fonte alternativa para controlar o carrapato do gado. No entanto sao necessários estudos adicionais, a serem conduzidos in vivo. B. excelsa e H. annuus tiveram baixa atividade acaricida (39,39% e 58,75% na concentração de 200 mg/mL respectivamente), não obstante apresentaram maior efeito que a amidina e o piretroide (35,12% e 1,50% respetivamente). Pode-se concluir que o óleo de C. cyminum pode ser uma alternativa fitoterápica para o controle do carrapato do gado.

Trypanocidal Effect of Isotretinoin through the Inhibition of Polyamine and Amino Acid Transporters in Trypanosoma cruzi.

Polyamines are essential compounds to all living organisms and in the specific case of Trypanosoma cruzi, the causative agent of Chagas disease, they are exclusively obtained through transport processes since this parasite is auxotrophic for polyamines. Previous works reported that retinol acetate inhibits Leishmania growth and decreases its intracellular polyamine concentration. The present work describes a combined strategy of drug repositioning by virtual screening followed by in vitro assays to find drugs able to inhibit TcPAT12, the only polyamine transporter described in T. cruzi. After a screening of 3000 FDA-approved drugs, 7 retinoids with medical use were retrieved and used for molecular docking assays with TcPAT12. From the docked molecules, isotretinoin, a well-known drug used for acne treatment, showed the best interaction score with TcPAT12 and was selected for further in vitro studies. Isotretinoin inhibited the polyamine transport, as well as other amino acid transporters from the same protein family (TcAAAP), with calculated IC50 values in the range of 4.6-10.3 µM. It also showed a strong inhibition of trypomastigote burst from infected cells, with calculated IC50 of 130 nM (SI = 920) being significantly less effective on the epimastigote stage (IC50 = 30.6 µM). The effect of isotretinoin on the parasites plasma membrane permeability and on mammalian cell viability was tested, and no change was observed. Autophagosomes and apoptotic bodies were detected as part of the mechanisms of isotretinoin-induced death indicating that the inhibition of transporters by isotretinoin causes nutrient starvation that triggers autophagic and apoptotic processes. In conclusion, isotretinoin is a promising trypanocidal drug since it is a multi-target inhibitor of essential metabolites transporters, in addition to being an FDA-approved drug largely used in humans, which could reduce significantly the requirements for its possible application in the treatment of Chagas disease.

Effect of Free and Nanoencapsulated Copaiba Oil on Monocrotaline-induced Pulmonary Arterial Hypertension.

Copaiba oil comes from an Amazonian tree and has been used as an alternative medicine in Brazil. However, it has not been investigated yet in the treatment of cardiovascular diseases. This study was designed to test whether copaiba oil or nanocapsules containing this oil could modulate monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male Wistar rats (170 ± 20 g) received oil or nanocapsules containing this oil (400 mg/kg) by gavage daily for 1 week. At the end of this period, a single injection of MCT (60 mg/kg i.p.) was administered and measurements were performed after 3 weeks. The animals were divided into 6 groups: control, copaiba oil, nanocapsules with copaiba oil, MCT, oil + MCT, and nanocapsules + MCT. Afterward, echocardiographic assessments were performed, and rats were killed to collect hearts for morphometry and oxidative stress. MCT promoted a significant increase in pulmonary vascular resistance, right ventricle (RV) hypertrophy, and RV oxidative stress. Both oil and copaiba nanocapsules significantly reduced RV hypertrophy and oxidative stress. Pulmonary vascular resistance was reduced by copaiba oil in natura but not by nanocapsules. In conclusion, copaiba oil seems to offer protection against MCT-induced PAH. Our preliminary results suggest that copaiba oil may be an important adjuvant treatment for PAH.

The antibiofilm effect of blueberry fruit cultivars against Staphylococcus epidermidis and Pseudomonas aeruginosa.

The antibiofilm and antibacterial properties against Pseudomonas aeruginosa and Staphylococcus epidermidis and chemical characterization of six hydroethanolic blueberry extracts (blueberry rabbiteye-Vaccinium virgatum) from different cultivars and means of propagation were investigated. The total flavonoid, anthocyanin, and phenolic contents were determined by specific and well-established methods. Among the cultivars, Briteblue showed the lowest content of all metabolites analyzed, while Bluegem showed the highest concentrations of these compounds. All the micropropagated cultivars presented the highest amounts of chlorogenic acid. The blueberry fruit extracts showed strong activity against S. epidermidis biofilm (up to 84% inhibition) without inhibiting bacterial growth. Likewise, Bluegem micropropagated extract, which had the highest anthocyanin, flavonoids, and phenolic compound content, demonstrated the highest S. epidermidis biofilm inhibitory effect. Finally, a linear correlation between the total phenolic content and the percentage of biofilm inhibition was observed.

Eugenol derivatives as potential anti-oxidants: is phenolic hydroxyl necessary to obtain an effect?

OBJECTIVES: Eugenol, obtained from clove oil (Eugenia caryophyllata), possess several biological activities. It is anti-inflammatory, analgesic, anaesthesic, antipyretic, antiplatelet, anti-anaphylactic, anticonvulsant, anti-oxidant, antibacterial, antidepressant, antifungal and antiviral. The anti-oxidant activity of eugenol have already been proven. From this perspective testing, a series of planned structural derivatives of eugenol were screened to perform structural optimization and consequent increase of the potency of these biological activities. METHODS: In an attempt to increase structural variability, 16 compounds were synthesized by acylation and alkylation of the phenolic hydroxyl group. Anti-oxidant activity capacity was based on the capture of DPPH radical (2,2-diphenyl-1-picryl-hydrazyl), ABTS radical 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), measure of TBARS (thiobarbituric acid-reactive species), total sulfhydryl and carbonyl content (eugenol derivatives final concentrations range from 50 to 200 µm). KEY FINDINGS: Four derivatives presented an efficient concentration to decrease 50% of the DPPH radical (EC50 ) < 100 µm, which has a good potential as a free-radical scavenger. Three of these compounds also showed reduction of ABTS radical. Eugenol derivatives presenting alkyl or aryl (alkylic or arylic) groups substituting hydroxyl 1 of eugenol were effective in reducing lipid peroxidation, protein oxidative damage by carbonyl formation and increase total thiol content in cerebral cortex homogenates. In liver, the eugenol derivatives evaluated had no effect. CONCLUSIONS: Our results suggest that these molecules are promising anti-oxidants agents.

MRSA infections: from classical treatment to suicide drugs.

Infections caused by the methicillin-resistant Staphylococcus aureus (MRSA) are today a major burden in nosocomial disease control. The global trend shows an alarming increase of MRSA infections as well as multi-drug resistance (MDR). The problem is exacerbated by the fact that infections with community-associated (CA) MRSA strains showing increased virulence and fitness add to infections with multi-drug resistant hospital-associated (HA) MRSA. The toxicity of pathogens and limited effectiveness of available treatment have led to high mortality rates and vast expenses caused by prolonged hospitalization and usage of additional antibiotics. Recently approved drugs still have classical targets and upcoming resistance can be expected. In a new approach by targeting co-factor syntheses of bacteria, the drug target and the affected pathways are uncoupled. This novel strategy is based on the thought of a classical pro-drug which has to be metabolized before becoming toxic for the bacterium as a dysfunctional co-factor, named suicide drug. Ideally these metabolizing pathways are solely present in the bacterium and absent in the human host, such as vitamin biosyntheses. This mini-review discusses current ways of MRSA infection treatment using new approaches including suicide drugs targeting co-factor biosyntheses.

Tratamento endodôntico de incisivo inferior fusionado

Introdução: a fusão dentária é caracterizada pela união entre dois germes dentários durante o estágio de desenvolvimento,em consequência de aberração da camada germinativa do ectoderma e do mesoderma. Objetivo:o objetivo desse artigo foi descrever o tratamento endodôntico de incisivo inferior fusionado com dente extranumerário.Métodos: o paciente procurou atendimento com dor espontânea e severa no dente 41. O elemento dentário apresentou coroa atípica com aspecto de dente fusionado e, radiograficamente, observou-se a presença de raiz única e dois canais. Foi determinada a necessidade de tratamento endodôntico, realizado por instrumentos de níquel-titânio. A cada troca de instrumento foi efetuada a irrigação com solução de hipoclorito de sódio a 2,5%e, após o preparo do canal radicular, inundação com EDTA 17% por 5 minutos, com posterior irrigação final com a solução irrigante. A obturação foi realizada por meio da técnica de condensação lateral ativa da guta-percha, associada ao cimento obturador, complementada por termo condensação.Foi realizada a tomografia computadorizada para verificação da qualidade da obturação e a arquitetura da anatomia interna. A paciente retornou para controle clínico e radiográfico de um ano, com o dente evidenciando sinais de normalidade. Conclusão: o cirurgião-dentista deve desenvolver competência no diagnóstico e tratamento adequado das anomalias dentárias, promovendo condições de melhora à saúde bucal dos pacientes

Ultrasound irradiation promoted efficient solvent-free lipase-catalyzed production of mono- and diacylglycerols from olive oil.

This work reports the enzymatic production of mono- and diacylglycerols under the influence of ultrasound irradiation, in a solvent-free system, with and without the presence of surfactants at a constant temperature of 65°C, glycerol to oil molar ratio of 2:1 and a commercial immobilized lipase (Novozym 435) as catalyst. For this purpose, two operation modes were adopted: the use of a sonotrode (ultrasonic probe), without agitation, varying reaction time, irradiation amplitude (25-45% of the total power) and type of surfactant, and a mechanically stirred reactor (600 rpm) under ultrasound irradiation in a water bath, testing different surfactants. Results show that very satisfactory MAG and DAG yields, above 50 wt.%, can be obtained without the use of surfactant, at mild irradiation power supply (∼130 W), with no important enzyme activity losses verified, in a relatively short reaction time (2h), and low enzyme content (7.5 wt.%). Also, reaction kinetic results show that contents of MAG+DAG as high as ∼65 wt.% can be achieved at longer times (6h), indicating a promising route for producing MAG and DAG using ultrasound irradiation.