Nanoemulsion Improves Babassu Palm Oil (Orbignya phalerata) Antioxidant Properties

HIGHLIGHTS Production of lipid nanoemulsions (<100 nm) of industrial interest with low energy demand. The antioxidant properties of babassu oil have been improved and the nanoemulsions are not cytotoxic. Babassu oil is a food and medicinal product. The nanoemulsion is strategic for the developed of new antioxidants phytotherapeutics.

Abstract Background: Babassu oil is an extract from a Brazilian native coconut (Orbignya phalerata Martius) and is used both as a food and a medicinal product. Methods: we produced two babassu oil nanoemulsions and evaluated them regarding their nanoscopic stability, antioxidant activity and cytotoxicity.The nanoemulsions were characterized by Dynamic Light Scattering, and their stability was investigated for 120 days. The antioxidant activity was assessed by Spectroscopy Electron Paramagnetic Resonance, and the cytotoxicity was assessed by a colorimetric method (MTT) with the NIH/3T3 cell lineage. Results: the results showed nanoemulsions with average hydrodynamic diameter lower than 100 nm (p(0.001).and a polydispersity index of less than 0.3 (p(0.001), indicating monodisperse systems and good stability at room temperature. The exposure of nanoemulsions at varying pH revealed that the isoelectric point was at 3.0, and the images obtained by Transmission Electron Microscopy showed spherical droplets with a size 27 nm. The antioxidant activity showed that the babassu nanoemulsions exposed to free radicals had a better response when compared to the oil free samples. The cell viability assays showed low toxicity of the formulation with viability over 92% (p(0.05). Conclusion: babassu oil nanoformulations showed low polydispersity and kinetic stability with effective antioxidant action. Therefore, they can be promising for application in the food industry or as antioxidant phytotherapeutics.

Panorama mundial de estudos com a hidroxicloroquina para o tratamento da COVID-19 / Global perspective of studies with hydroxychloroquine for the treatment of COVID-19

Objetivo: analisar os recentes estudos com a hidroxicloroquina no tratamento da COVID-19. Métodos: comunicação breve relatando os principais resultados com o uso da hidroxicloroquina em ensaios clínicos e o panorama mundial desses estudos. Resultados: a maioria dos ensaios clínicos no mundo é com a hidroxicloroquina, e os resultados com o seu uso são variados. Conclusão: é urgente avaliar melhor a eficácia da hidroxicloroquina no possível tratamento da COVID-19 em pacientes não severos.

Objective: analyze the most recent studies with hydroxychloroquine in the treatment of COVID-19. Methods: brief communication reporting the main results with the use of hydroxychloroquine in clinical trials and the global panorama of these studies. Results: the majority of clinical trials in the world are with hydroxychloroquine, and the results with its use are varied. Conclusion: it is urgent to better evaluate the efficacy of hydroxychloroquine in the possible treatment of COVID-19 in non-severe patients.

Metformin (dimethyl-biguanide) induced DNA damage in mammalian cells

Metformin (dimethyl-biguanide) is an insulin-sensitizing agent that lowers fasting plasma-insulin concentration, wherefore it's wide use for patients with a variety of insulin-resistant and prediabetic states, including impaired glucose tolerance. During pregnancy it is a further resource for reducing first-trimester pregnancy loss in women with the polycystic ovary syndrome. We tested metformin genotoxicity in cells of Chinese hamster ovary, CHO-K1 (chromosome aberrations; comet assays) and in mice (micronucleus assays). Concentrations of 114.4 µg/mL and 572 µg/mL were used in in vitro tests, and 95.4 mg/kg, 190.8 mg/kg and 333.9 mg/kg in assaying. Although the in vitro tests revealed no chromosome aberrations in metaphase cells, DNA damage was detected by comet assaying after 24 h of incubation at both concentrations. The frequency of DNA damage was higher at concentrations of 114.4 µg/mL. Furthermore, although mortality was not observed in in vitro tests, the highest dose of metformin suppressed bone marrow cells. However, no statistically significant differences were noted in micronuclei frequencies between treatments. In vitro results indicate that chronic metformin exposure may be potentially genotoxic. Thus, pregnant woman undergoing treatment with metformin should be properly evaluated beforehand, as regards vulnerability to DNA damage.

Câncer bucal e a terapia fotodinâmica como modalidade terapêutica / Oral cancer and photodynamic therapy as a treatment

O câncer de boca é um dos tipos mais prevalentes dentro da população. Dados epidemiológicos indicam que sejam diagnosticados 10 mil novos casos de câncer de boca por ano. Atualmente, seu tratamento é feito através de cirurgia, radioterapia, quimioterapia ou uma associação destas três modalidades terapêuticas. Por promoverem graves efeitos adversos aos pacientes, constantes esforços são tomados no intuito de desenvolver novos protocolos terapêuticos que possam substituir ou auxiliar os tratamentos convencionais disponíveis atualmente. A terapia fotodinâmica, uma técnica que combina a utilização de fármacos fotossensíveis e irradiação com luz, tem demonstrado ser uma alternativa com sucesso clinicamente demonstrado para o tratamento de tumores superficiais, como os tumores de boca, com efeitos colaterais mínimos. O presente artigo descreve o cenário atual do câncer de boca e suas opções de tratamento, e apresenta a terapia fotodinâmica como uma opção viável de tratamento para este tipo de câncer.

Oral cancer is one of the most prevalent types of cancer. Actually, surgery, chemotherapy, radiotherapy or a combination of these three methods are common treatments for oral cancer. Although these protocols have demonstrated some effectiveness in oral cancer therapy, they can promote a series of side effects for patients during treatment. Alternatively for these traditional treatments, photodynamic therapy has been used clinically for oral cancer and precancerous lesions treatment. This paper presents the photodynamic therapy as an option treatment for oral cancer.

Efeito da terapia fotodinâmica mediada pelo azul de metileno sobre bactérias cariogênicas / Effect of photodynamic therapy mediated by methylene blue in cariogenic bacteria

Objetivos: O objetivo do presente estudo foi avaliar a infl uência das alterações na concentração defotossensibilizador e fl uência de energia de irradiação de laser vermelho (660 nm) na viabilidade de culturasbacterianas derivadas de dentina cariada humana após a aplicação da terapia fotodinâmica (TFD)mediada pelo azul de metileno (AM). Material e método: Utilizaram-se culturas bacterianas derivadasde amostras de dentina cariada de pacientes e uma linhagem de Escherichia coli. Utilizaram-se formulaçõesde azul de metileno nas concentrações de 25 e 50 μg/mL para a aplicação da TFD. Foi utilizada fonte delaser vermelho (660 nm) na potência de 40 mW com três fl uências diferentes (6,8; 20,55 e 61,65 J/cm²).Resultados: O tratamento com AM nas duas concentrações testadas (25 e 50 μg/mL) não apresentouatividade antimicrobiana em todas as culturas bacterianas testadas. Para as culturas bacterianas derivadasde dentina cariada, a fl uência de energia de 6,8 J/cm² não promoveu efeito fotodinâmico quando combinadacom AM; as energias de 20,55 e 61,65 J/cm² foram efetivas na redução da carga microbiana, sendoa fl uência de 61,65 J/cm² a mais indicada para a aplicação da TFD antimicrobiana. As culturas de E. coliforam suscetíveis à atividade antibacteriana da TFD nas três fl uências de energia testadas. Conclusão:Os resultados demonstram que a TFD mediada pelo AM nas duas concentrações testadas (25 e 50 μg/mL)e combinada com a irradiação de laser nas fl uências de 20,55 e 61,65 J/cm², promoveu uma diminuiçãosignifi cativa da carga bacteriana das culturas derivadas de amostras de dentina cariada testadas.

Objectives: The aim of this study was to evaluate the effi cacy of antimicrobial photodynamic therapy (PDT)mediated by methylene blue (MB) in two concentrations (25 e 50 μg/mL) and different red laser (660 nm) energyirradiation on bacterial suspensions derived from infected carious dentine samples. Material and method:Bacterial suspensions derived from infected dentine samples and Escherichia coli cell suspensions were used inthis study. MB in two concentrations (25 e 50 μg/mL) alone or in combination with red laser (660 nm) irradiationin different energies (6,8; 20,55 e 61,65 J/cm²) were used to apply PDT in the bacterial suspensions. Results:MB alone had no signifi cant antibacterial effect against the tested bacterial suspensions. In bacterial suspensionsderived from infected carious dentine, MB combined with 6,8 J/cm² laser irradiation did not show the antibacterialeffect of PDT. Laser irradiation with 20,55 e 61,65 J/cm² combined with MB treatment, produced a signifi cantantibacterial effect, but 61,65 J/cm² was the most effective tested laser energy. Bacterial suspensions of E. coli weredecreased their bacterial load in all tested laser energies. Conclusion: The results presented in this study suggestthat PDT mediated by MB in both tested concentrations (25 e 50 μg/mL) could be used in effectively antibacterialclinical protocols in dentistry.

Cytotoxicity and genotoxicity of endodontic irrigants on human cells / Citotoxicidade e genotoxicidade de irrigantes endodônticos em células humanas

OBJECTIVE: Endodontic irrigants solutions with antibacterial activity have been used in treatment of teeth with infected root canals; however, these solutions can irritate periapical tissues. The aim of this study was to evaluate the cytotoxity and genotoxicity of different endodontic irrigants solutions – sodium hypochlorite (1% and 2%), calcium hydroxide (0.2%), and HCT20 in human KB cells. MATERIAL AND METHOD: Cells were incubated with solutions for 2 and 24 hours. The cell viability was assessed after the trypan blue exclusion and the frequency of cell death mechanism (apoptotic or necrotic) was determined by acridine orange/ethidium bromide fluorescent dyeing test. The genotoxicity effects were assessed by the micronucleus assays. RESULTS AND DISCUSSION: The results showed that Ca(OH)2 alone or in combination with tergentol (HCT20), and NaOCl induced cytotoxicity in KB causing death cells by apoptosis. The micronuclei test showed that KB treated with NaOCl (1%) present an increase in the frequency of micronucleus compared to the control group.

OBJETIVO: Soluções irrigadoras com atividade antibacteriana têm sido usadas no tratamento de dentes com canais radiculares infectados; entretanto, essas soluções podem irritar os tecidos periapicais. O objetivo deste estudo foi avaliar a citotoxicidade e genotoxicidade de diferentes soluções irrigadoras – hipoclorito de sódio (1% e 2%), hidróxidode cálcio (0,2 %) e HCT em células humanas KB. MATERIAL E MÉTODO: As células foram incubadas em soluções por 2 e 24 horas. A viabilidade celular foi determinada após exclusão do tripan blue e a frequência de mecanismo de morte celular (apoptótica ou necrótica) foi determinada pelo teste acridine Orange/ethidium bromide fluorescen dyeing. Os efeitos de genotoxicidade foram determinados pelo ensaio de micronúcleos. RESULTADOS E DISCUSSÃO: Os resultados demonstraram que o Ca(OH2), isoladamente ou em combinação com Tergentol™ (HCT20) e NaOCl, induziram citotoxicidade em KB, causando morte celular por apoptose. O teste de micronúcleos demonstrou que KB tratado codm NaOCl (1%) apresentou aumento na frequência de microdnúcleos quando comparadocom o grupo controle.