Efeito Cardioprotetor da Suplementação Materna com Resveratrol sobre a Toxicidade Induzida por Doxorrubicina em Cardiomiócitos de Neonatos / Cardioprotective Effect of Maternal Supplementation with Resveratrol on Toxicity Induced by Doxorubicin in Offspring Cardiomyocytes

Resumo Fundamento A doxorrubicina (DOX) é frequentemente usada para tratar muitos tipos de cânceres, apesar da cardiotoxicidade dose-dependente. Como alternativa, o resveratrol é um polifenol que tem demonstrado efeitos cardioprotetores em vários modelos de disfunção cardíaca. Objetivo Este estudo investigou se o tratamento com resveratrol em ratas gestantes protege contra toxicidade induzida por doxorrubicina em cardiomiócitos da ninhada. Métodos Ratas Wistar (n-8) receberam sresveratrol como suplemento alimentar durante a gestação. No nascimento da ninhada, os corações (9-11) foram usados para se obter a cultura primária de cardiomiócitos. A cardiotoxicidade induzida por DOX e os efeitos da suplementação com resveratrol foram avaliados por marcadores de stress oxidativo, tais como oxidação da diclorofluoresceína diacetato, diminuição da atividade de enzimas antioxidantes, e oxidação do teor total de grupos sulfidrila, além da avaliação da viabilidade celular, geração de danos ao DNA, bem como a resposta de reparo aos danos ao DNA. Um valor de p <0,05 foi considerado estatisticamente significativo. Resultados Os cardiomiócitos de neonatos de ratas que receberam suplemento resveratrol apresentaram um aumento (p <0,01) na viabilidade das células, e diminuição (p <0,0001) de células apoptóticas/necróticas após o tratamento com DOX, o que está correlacionado às atividades de enzimas antioxidantes e produção de diclorofluoresceína. Além disso, o resveratrol protegeu os cardiomiócitos de danos ao DNA induzidos por DOX, apresentando uma diminuição (p <0,05) nas quebras de DNA induzidas por stress oxidativo, avaliadas pela atividade de enzimas reparadoras do DNA endonuclease III e formamidopirimidina glicosilase. A suplementação com resveratrol aumentou (p <0,05) a expressão da proteína reparadora Sirt6 nos cardiomiócitos dos filhotes. Conclusão Essa pesquisa indica que a suplementação com resveratrol durante o período gestacional tem um efeito cardioprotetor no coração da ninhada contra a toxicidade induzida por DOX, o que pode se dever a sua função antioxidante, e o aumento na resposta de danos ao DNA.

Abstract Background Doxorubicin (DOX) is frequently used to treat many types of cancers, despite its dose-dependent cardiotoxicity. Alternatively, resveratrol is a polyphenol that has shown useful cardioprotective effects in many heart dysfunction models. Objective This study investigated whether resveratrol treatment in pregnant rats protects against doxorubicin-induced toxicity in offspring cardiomyocytes. Methods Wistar rats (n=8) were supplemented with dietary resveratrol during pregnancy. Upon the offspring's birth, hearts (9-11) were used to obtain the primary culture of cardiomyocytes. DOX-induced cardiotoxicity and the effects of resveratrol supplementation were evaluated by oxidative stress markers, such as dichlorofluorescein diacetate oxidation, decrease in the activity of antioxidant enzymes, and oxidation of total sulfhydryl content, in addition to cell viability evaluation, DNA damage generation, and DNA damage repair response. A value of p<0.05 was considered statistically significant. Results Neonatal cardiomyocytes from resveratrol supplemented rats exhibiting an increase (p<0.01) in cell viability and lower (p<0.0001) apoptotic/necrotic cells after DOX treatment, which correlates with the activities of antioxidant enzymes and dichlorofluorescein production. Moreover, resveratrol protected cardiomyocytes from DOX-induced DNA damage, showing a decrease (p<0.05) in DNA breaks induced by oxidative stress, evaluated by the activity of DNA-repair enzymes endonuclease III and formamidopyrimidine glycosylase. Supplementation with resveratrol increased (p<0.05) the expression of the repair protein Sirt6 in the cardiomyocytes of the pups. Conclusion This research indicates that supplementation with resveratrol during the gestational period has a notable cardioprotective effect on the offspring's heart against DOX-induced toxicity, which may well be due to its antioxidant function, and the increase in the DNA damage repair response.

Protective effect of N-acetyl-L-cysteine and rosuvastatin against oxidative stress in fibroblasts from asymptomatic patients with X-ALD: a preliminary study

Introduction: Several studies in the literature have evaluated the role of oxidative stress and adjuvant therapies for X-linked adrenoleukodystrophy (X-ALD). Here, we investigated whether n-acetyl-L-cysteine (NAC) and rosuvastatin (RSV) could influence the generation of reactive species, redox status and nitrative stress in fibroblasts from asymptomatic patients with X-ALD. Methods: Skin biopsy samples were cultured and treated for 2 hours (37 °C) with NAC and RSV. Results: X-ALD fibroblasts generated high levels of reactive oxygen species. These levels were significantly lower in fibroblasts treated with NAC and RSV relative to untreated samples. The X-ALD fibroblasts from asymptomatic patients also had higher catalase activity, and only NAC was able to increase enzyme activity in the samples. Conclusions: Our results indicated that NAC and RSV were able to improve oxidative stress parameters in fibroblasts from asymptomatic patients with X-ALD, showing that adjuvant antioxidant therapy may be a promising treatment strategy for asymptomatic patients with this disease. (AU)

DNA damage in homocystinuria: 8-oxo-, 8-dihydro-2'-deoxyguanosine levels in cystathionine-ß-synthase deficient patients and the in vitro protective effect of N-acetyl­L­cysteine

Introduction: Homocysteine (Hcy) tissue accumulation occurs in a metabolic disease characterized biochemically by cystathionine ß-synthase (CBS) deficiency and clinically by mental retardation, vascular problems, and skeletal abnormalities. Previous studies indicate the occurrence of DNA damage secondary to hyperhomocysteinemia and it was observed that DNA damage occurs in leukocytes from CBS-deficient patients. This study aimed to investigate whether an oxidative mechanism could be involved in DNA damage previously found and investigated the in vitro effect of N-acety-L-cysteine (NAC) on DNA damage caused by high Hcy levels. Methods: We evaluated a biomarker of oxidative DNA damage in the urine of CBS­deficient patients, as well as the in vitro effect of NAC on DNA damage caused by high levels of Hcy. Moreover, a biomarker of lipid oxidative damage was also measured in urine of CBS deficient patients. Results: There was an increase in parameters of DNA (8-oxo-7,8-dihydro-2'- deoxyguanosine) and lipid (15-F2t-isoprostanes levels) oxidative damage in CBS-deficient patients when compared to controls. In addition, a significant positive correlation was found between 15-F2t-isoprostanes levels and total Hcy concentrations. Besides, an in vitro protective effect of NAC at concentrations of 1 and 5 mM was observed on DNA damage caused by Hcy 50 µM and 200 µM. Additionally, we showed a decrease in sulfhydryl content in plasma from CBS-deficient patients when compared to controls. Discussion: These results demonstrated that DNA damage occurs by an oxidative mechanism in CBS deficiency together with lipid oxidative damage, highlighting the NAC beneficial action upon DNA oxidative process, contributing with a new treatment perspective of the patients affected by classic homocystinuria.

Chemical constituents and evaluation of cytotoxic and antifungal activity of Lantana camara essential oils

The essential oil (EO) of aerial parts of Lantana camara L., Verbenaceae, from Simões, Piaui, Northeast of Brazil, were obtained by hydrodistillation and analyzed by GC-FID and GC-MS techniques. In total, 68 compounds were identified. The most representative compounds of the oil were mono and sesquiterpenes. The main compounds found in the oil of the leaves in different months were β-caryophyllene (10.5%, in June of 2009), sabinene (7.98%, in September of 2008), limonene (7.68%, in September of 2008), spathulenol (11.64%, in September of 2008). The oil from stems of L. camara was characterized by a largest amount of sesquiterpenoids, with spatulenol (15.9%) and caryophyllene oxide (17.1% in June of 2009), as main components. β-Gurjunene (32.7%, in September of 2008) was the most prominent compound in the stems oils, which was absent or at very low relative abundance in leaves. L. camara essential oils from leaves were cytotoxic to V79 mammalian cells and also to Artemia salina, showing 50% lethal concentration (LC50) values from 0.23 µg/mL. The in vitro data obtained in this study suggested that EO may also be effective treating yeast infection in patients infected with fluconazole and terbinafine resistant isolates, but its toxicity must be monitored carefully.

Influência dos processos de secagem sobre o teor de flavonoides e na atividade antioxidante dos extratos de Baccharis articulata (Lam.) Pers., Asteraceae / The Influence of drying processes on flavonoid level and the antioxidant activity of Baccharis articulata (Lam.) extracts

O objetivo deste trabalho foi verificar o teor de quercetina obtido dos extratos de partes aéreas de Baccharis articulata (Lam.) Pers., Asteraceae, submetidas a diferentes técnicas de secagem, bem como a avaliação de sua atividade antioxidante in vitro. Foi verificada maior concentração deste flavonoide nas amostras secas em estufa, porém não houve diferença significativa na atividade farmacológica das amostras analisadas.

The objective of this work was to verify the influence of different drying processes on the levels of quercetin of the aerial parts of Baccharis articulata (Lam.) Pers., Asteraceae, as well as the evaluation of the in vitro antioxidant activity of these extracts. We demonstrated that the highest concentration of this flavonoid was detected in oven-dried samples, although there no significant difference in their pharmacological activity of all analyzed samples could be shown.