O açaí (Euterpe oleracea) é um fruto proveniente do açaizeiro, uma palmeira nativa da Amazônia Brasileira, considerado uma “superfruta” devido ao seu alto valor nutricional, com destaque para as antocianinas, associadas a efeitos benéficos à saúde. Uma vez que genótipos de frutos desenvolvidos por programas de melhoramento têm sido avaliados a fim de identificar frutos com composição fitoquímica melhorada e potencial antioxidante, o objetivo deste trabalho foi investigar o efeito do melhoramento genético na composição química, perfil de compostos bioativos e atividade antioxidante de seis genótipos de açaí (E. oleracea). Análises de composição química, perfil de antocianinas e carotenoides e de atividade antioxidante em diversos sistemas in vitro (método ABTS, oxidação da glutationa, teste da desoxirribose e células SH-SY5Y) foram realizadas em 6 genótipos e 1 amostra comercial utilizada como padrão. Com relação a composição química, de maneira geral, os genótipos apresentaram elevados teores de lipídeos (36,30 – 47,44%), fibras totais (11,31 – 15,88%), proteínas (7,78-9,50%) e cinzas (3,49 – 4,44%). Adicionalmente, as antocianinas cianidina 3-glicosídeo (12-43%) e cianidina 3-rutinosídeo (57-88%) foram identificadas nos genótipos avaliados e o genótipo L22P13 apresentou um incremento de 85% no teor de antocianinas totais. Com relação ao perfil de carotenoides, luteína, zeaxantina, α-caroteno e β-caroteno foram os principais carotenoides identificados nos genótipos avaliados, sendo que os genótipos BRS-PAMISTA e L22P13 apresentaram os teores mais elevados de carotenoides totais (125,39μg/g e 118μg/g). Com relação a atividade antioxidante, todos os genótipos reduziram a geração do radical ABTS em maior ou menor grau, embora diferenças significativas entre os genótipos e a amostra comercial não tenham sido observadas (IC50 = 73,98 – 175,7 vs. 121,7 μg/g). Entretanto, houve associação moderada e inversa entre a geração do radical ABTS e níveis de antocianinas e carotenoides. Ausência de diferenças significativas entre os extratos hidroetanólicos dos genótipos e a amostra comercial também foi observada no ensaio da desoxirribose (IC50 = 361,5 – 497,7 vs. 520,1 μg/g). Em cultura de células SH-SY5Y, os extratos hidroetanólicos na concentração de 50 μg/mL apresentaram um efeito protetor contra as espécies reativas geradas pelo H2O2 (ensaio DCFH-DA) e esse resultado foi associado ao teor de antocianinas dos extratos. Os resultados apontam genótipos promissores, com elevados teores de antocianinas e carotenoides, com potencial atividade antioxidante in vitro e um possível efeito protetor de células frente as espécies reativas. / The açaí (Euterpe oleracea) is a fruit of the açaizeiro, a native palm of the Brazilian Amazon, considered a "superfruit" due to its high nutritional value, especially anthocyanins, associated with beneficial health effects. Since fruit genotypes developed by breeding programs have been evaluated to identify fruits with improved phytochemical composition and antioxidant potential, the aim of this study was to investigate the effect of genetic improvement in the chemical composition, bioactive compounds profile and antioxidant activity of six açaí (E. oleracea) genotypes. The analysis of chemical composition, anthocyanins and carotenoids profile and antioxidant activity in various in vitro systems (ABTS method, glutathione oxidation, deoxyribose test and SH-SY5Y cells) were performed in six genotypes of açaí and one commercial sample that was used as standard. Regarding the chemical composition, in general, the genotypes showed high levels of lipids (36.30 – 47.44%), total fiber (11.31 – 15.88%), protein (7.78-9.50%) and ashes (3.49 – 4.44%). In addition, the anthocyanins cyanidin 3-glucoside (12-43%) and cyanidin 3-rutinoside (57-88%) were identified in evaluated genotypes and L22P13 genotype showed an increase of 85% in total anthocyanin content. Regarding the carotenoid profile, lutein, zeaxanthin, α-carotene and β-carotene were the main carotenoid identified in genotypes, being that BRS-PAMISTA and L22P13 genotypes showed the highest levels of total carotenoids (125.39 μg/g and 118 μg/g). Regarding the antioxidant activity, all genotypes reduced ABTS radical generation in greater or lesser extension, although there were no significant differences between hydroethanolic extracts of different genotypes and the commercial sample (IC50 = 73.98 - 175.7 vs. 121.7 μg/g). However, an inverse and moderate association between radical ABTS generation and anthocyanins and carotenoids content was observed. Absence of significant differences between hydroethanolic extracts of evaluated genotypes and the commercial sample was observed also in the deoxyribose assay (IC50 = 361.5 to 497.7 vs. 520.1 μg/g). In culture of SH-SY5Y cells, hydroethanolic extracts at concentration of 50 μg/mL had a protective effect against the reactive species generated by H2O2 (DCFH-DA assay) and this result was associated with the anthocyanins content of the extracts. The results showed promising genotypes with high levels of anthocyanins and carotenoids with antioxidant potential in vitro and a possible protective effect of cells against reactive species.

Orientador: Daniel Carneiro Carrettiero / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biossistemas, 2012

Orientador: Daniel Carneiro Carrettiero. / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biossistemas, 2012.

<p>Neuroblastoma is a malignant childhood cancer, originating from sympathetic neuroblasts of the peripheral nervous system. Neuroblastoma is a heterogenous group of tumours, while some are highly malignant others can spontaneosly mature into a more benign form or regress. Less than half of the patients survive and this statistics has improved only modestly over the past 20 years. </p><p>SH-SY5Y is a human neuroblastoma cell line established from a highly malignant tumour. The cells have retained a capacity to differentiate <i>in vitro</i> in response to low concentrations of the phorbolester 12-O-tetradecanoylphorbol-13-acetate (TPA) in the presence of serum or defined growth factors. Differentiated cells are characterised by neurite formation and upregulation of neuronal marker genes. SH-SY5Y are unresponsive to nerve growth factor (NGF), but when transfected to express the NGF-receptor TrkA, they differentiate in response to NGF. Protein kinase C (PKC) is pivotal for the differentiation response to take place.</p><p>We have investigated the role of signaling through the Ras-MAPK pathway in differentiating SH-SY5Y, with respect to neurite formation, expression of neuronal marker genes and growth control. Our results show that differentiation-promoting treatment induced a sustained activation and nuclear accumulation of the MAPK ERK in SH-SY5Y. The nuclear accumulation of ERK was PKC-dependent. However, nuclear accumulation of ERK was not sufficient for a differentiation response to take place in these cells, but ERK activity was needed for the characteristic upregulation of <i>NPY</i> and <i>GAP-43</i> induced by TPA. ERK activity did not induce neurite formation, neither was it necessary for TPA-induced neurite formation. Instead, stimulation of a pathway distinct from MEK/ERK, but downstream of Ras, was needed for morphological differentiation. We could also show that differentiated cells still entered S-phase and that there was no correlation between expression of the CKI p21_cip1 (an ERK target), BrdU-incorporation or neurite formation. </p>

Neuroblastoma is a malignant childhood cancer, originating from sympathetic neuroblasts of the peripheral nervous system. Neuroblastoma is a heterogenous group of tumours, while some are highly malignant others can spontaneosly mature into a more benign form or regress. Less than half of the patients survive and this statistics has improved only modestly over the past 20 years. SH-SY5Y is a human neuroblastoma cell line established from a highly malignant tumour. The cells have retained a capacity to differentiate in vitro in response to low concentrations of the phorbolester 12-O-tetradecanoylphorbol-13-acetate (TPA) in the presence of serum or defined growth factors. Differentiated cells are characterised by neurite formation and upregulation of neuronal marker genes. SH-SY5Y are unresponsive to nerve growth factor (NGF), but when transfected to express the NGF-receptor TrkA, they differentiate in response to NGF. Protein kinase C (PKC) is pivotal for the differentiation response to take place. We have investigated the role of signaling through the Ras-MAPK pathway in differentiating SH-SY5Y, with respect to neurite formation, expression of neuronal marker genes and growth control. Our results show that differentiation-promoting treatment induced a sustained activation and nuclear accumulation of the MAPK ERK in SH-SY5Y. The nuclear accumulation of ERK was PKC-dependent. However, nuclear accumulation of ERK was not sufficient for a differentiation response to take place in these cells, but ERK activity was needed for the characteristic upregulation of NPY and GAP-43 induced by TPA. ERK activity did not induce neurite formation, neither was it necessary for TPA-induced neurite formation. Instead, stimulation of a pathway distinct from MEK/ERK, but downstream of Ras, was needed for morphological differentiation. We could also show that differentiated cells still entered S-phase and that there was no correlation between expression of the CKI p21cip1 (an ERK target), BrdU-incorporation or neurite formation.

名古屋大学博士学位論文 学位の種類:博士（医療技術学） (課程) 学位授与年月日　平成22年3月25日

O açaí (Euterpe oleracea) é um fruto proveniente do açaizeiro, uma palmeira nativa da Amazônia Brasileira, considerado uma “superfruta” devido ao seu alto valor nutricional, com destaque para as antocianinas, associadas a efeitos benéficos à saúde. Uma vez que genótipos de frutos desenvolvidos por programas de melhoramento têm sido avaliados a fim de identificar frutos com composição fitoquímica melhorada e potencial antioxidante, o objetivo deste trabalho foi investigar o efeito do melhoramento genético na composição química, perfil de compostos bioativos e atividade antioxidante de seis genótipos de açaí (E. oleracea). Análises de composição química, perfil de antocianinas e carotenoides e de atividade antioxidante em diversos sistemas in vitro (método ABTS, oxidação da glutationa, teste da desoxirribose e células SH-SY5Y) foram realizadas em 6 genótipos e 1 amostra comercial utilizada como padrão. Com relação a composição química, de maneira geral, os genótipos apresentaram elevados teores de lipídeos (36,30 – 47,44%), fibras totais (11,31 – 15,88%), proteínas (7,78-9,50%) e cinzas (3,49 – 4,44%). Adicionalmente, as antocianinas cianidina 3-glicosídeo (12-43%) e cianidina 3-rutinosídeo (57-88%) foram identificadas nos genótipos avaliados e o genótipo L22P13 apresentou um incremento de 85% no teor de antocianinas totais. Com relação ao perfil de carotenoides, luteína, zeaxantina, α-caroteno e β-caroteno foram os principais carotenoides identificados nos genótipos avaliados, sendo que os genótipos BRS-PAMISTA e L22P13 apresentaram os teores mais elevados de carotenoides totais (125,39μg/g e 118μg/g). Com relação a atividade antioxidante, todos os genótipos reduziram a geração do radical ABTS em maior ou menor grau, embora diferenças significativas entre os genótipos e a amostra comercial não tenham sido observadas (IC50 = 73,98 – 175,7 vs. 121,7 μg/g). Entretanto, houve associação moderada e inversa entre a geração do radical ABTS e níveis de antocianinas e carotenoides. Ausência de diferenças significativas entre os extratos hidroetanólicos dos genótipos e a amostra comercial também foi observada no ensaio da desoxirribose (IC50 = 361,5 – 497,7 vs. 520,1 μg/g). Em cultura de células SH-SY5Y, os extratos hidroetanólicos na concentração de 50 μg/mL apresentaram um efeito protetor contra as espécies reativas geradas pelo H2O2 (ensaio DCFH-DA) e esse resultado foi associado ao teor de antocianinas dos extratos. Os resultados apontam genótipos promissores, com elevados teores de antocianinas e carotenoides, com potencial atividade antioxidante in vitro e um possível efeito protetor de células frente as espécies reativas. / The açaí (Euterpe oleracea) is a fruit of the açaizeiro, a native palm of the Brazilian Amazon, considered a "superfruit" due to its high nutritional value, especially anthocyanins, associated with beneficial health effects. Since fruit genotypes developed by breeding programs have been evaluated to identify fruits with improved phytochemical composition and antioxidant potential, the aim of this study was to investigate the effect of genetic improvement in the chemical composition, bioactive compounds profile and antioxidant activity of six açaí (E. oleracea) genotypes. The analysis of chemical composition, anthocyanins and carotenoids profile and antioxidant activity in various in vitro systems (ABTS method, glutathione oxidation, deoxyribose test and SH-SY5Y cells) were performed in six genotypes of açaí and one commercial sample that was used as standard. Regarding the chemical composition, in general, the genotypes showed high levels of lipids (36.30 – 47.44%), total fiber (11.31 – 15.88%), protein (7.78-9.50%) and ashes (3.49 – 4.44%). In addition, the anthocyanins cyanidin 3-glucoside (12-43%) and cyanidin 3-rutinoside (57-88%) were identified in evaluated genotypes and L22P13 genotype showed an increase of 85% in total anthocyanin content. Regarding the carotenoid profile, lutein, zeaxanthin, α-carotene and β-carotene were the main carotenoid identified in genotypes, being that BRS-PAMISTA and L22P13 genotypes showed the highest levels of total carotenoids (125.39 μg/g and 118 μg/g). Regarding the antioxidant activity, all genotypes reduced ABTS radical generation in greater or lesser extension, although there were no significant differences between hydroethanolic extracts of different genotypes and the commercial sample (IC50 = 73.98 - 175.7 vs. 121.7 μg/g). However, an inverse and moderate association between radical ABTS generation and anthocyanins and carotenoids content was observed. Absence of significant differences between hydroethanolic extracts of evaluated genotypes and the commercial sample was observed also in the deoxyribose assay (IC50 = 361.5 to 497.7 vs. 520.1 μg/g). In culture of SH-SY5Y cells, hydroethanolic extracts at concentration of 50 μg/mL had a protective effect against the reactive species generated by H2O2 (DCFH-DA assay) and this result was associated with the anthocyanins content of the extracts. The results showed promising genotypes with high levels of anthocyanins and carotenoids with antioxidant potential in vitro and a possible protective effect of cells against reactive species.

Espécies reativas de oxigênio (ERO) são produzidas através da respiração aeróbica e durante processos inflamatórios. Além disso, agressões externas como radiações, poluição, estresse, alcoolismo e tabagismo aumentam a sua produção. Altos níveis de ERO podem ocasionar dano oxidativo à lipídios, proteínas e DNA, comprometendo a função normal da célula, podendo estar envolvidos na patogênese e agravamento de diversas doenças. Há evidências que sugerem que antioxidantes naturais presentes em alimentos conferem benefícios adicionais à saúde, atuando como anticarcinogênicos, antiinflamatórios ou agentes antimutagênicos. O orégano (Oreganum sp) é uma especiaria mediterrânea usada como condimento na alimentação e pela medicina popular para diversos tipos de moléstias. O óleo possui forte ação antimicrobiana, devido ao elevado conteúdo de monoterpenos, sendo os principais o carvacrol, o timol e o para-cimeno. O carvacrol (5-isopropil-2metilfenol) é um fenol monoterpênico, com sabor picante e odor característico e tem sido amplamente usado na indústria de alimentos como aditivo seguro para aumentar a vida útil dos alimentos, como aromatizante em produtos assados, doces, bebidas e gomas de mascar, e/ou agente antimicrobiano com atividades contra bactérias, fungos e leveduras. Estudos têm relatado efeito antidepressivo e ansiolítico do carvacrol em camundongos, assim como proteção contra a radiação UVB diminuindo a peroxidação lipídica, estresse oxidativo e danos no DNA em células linfocitárias humanas e atividade antioxidante em diferentes sistemas de lipídios. Nós avaliamos a viabilidade celular e parâmetros de citotoxicidade do carvacrol em células de neuroblastoma humano SH-SY5Y. Este parece modificar levemente a morfologia das células, sem modificar significativamente a biomassa celular, parecendo ser tóxico na concentração de 100 μg/mL. Nas demais concentrações (1 a 50 μg/mL) não houve citotoxicidade. No ensaio de DCFH-DA o carvacrol reduziu a produção de ERO intracelular e diminui significativamente a produção de radicais peroxil no ensaio TRAP. Esses dados reforçam a ideia do carvacrol ser um potencial antioxidante, sendo necessários mais estudos para avaliar o mecanismo de ação deste composto. / Reactive oxygen species (ROS) are produced through aerobic respiration and during inflammation. Besides, external aggressions such as radiation, pollution, stress, alcoholism and smoking increase their production. Elevated levels of ROS can cause oxidative damage to lipids, proteins and DNA, compromising the normal cell function, and may be involved in the pathogenesis and progression of several diseases. There is suggesting that natural antioxidants found in foods provide additional health benefits, acting as anticarcinogenic, anti-inflammatory agents or antimutagenic. Oregano (Oreganum sp) is a Mediterranean spice used in food as a condiment and in popular medicine to treat several types of diseases. The essential oil has strong antimicrobial activity, due to the high content of monoterpenes, the main ones being carvacrol, thymol and para-cymene. Carvacrol (5-isopropyl-2metilfenol) is a phenol monoterpene with spicy taste and odor and has been widely used in food industry as additive to preserve foods, as flavoring agent in baked goods, candy, drinks and chewing gums, and/or antimicrobial agent with activity against bacteria, fungi and yeasts. Studies have reported antidepressant and anxiolytic effects of carvacrol in mice, as well as protection against UVB radiation, decreased lipid peroxidation, oxidative stress and DNA damage in human lymphocyte cells, and antioxidant activity in different lipid systems. We evaluated cell viability and cytotoxicity parameters of carvacrol in human neuroblastoma cells SH-SY5Y. Carvacrol induced morphology changes in cells without significant modification of the cellular biomass content and it was toxic at the concentration of 100 μg/mL. In other concentrations (1-50 μg/mL) it showed no cytotoxicity. In DCFH-DA assay carvacrol reduced the intracellular ROS production and significantly decreased the production of peroxyl radicals in the TRAP assay. These data reinforce the idea of carvacrol as a potential antioxidant and more research is needed to evaluate the mechanism of action of this compound.

Orientador: Prof. Dr. Daniel Carneiro Carrettiero / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2015. / Doenca de Alzheimer (DA) e uma doenca neurodegenerativa progressiva provocada por perda de sinapses e neuronios, caracterizado por disfuncao da memoria e comprometimento cognitivo global. O anormalmente hiperfosforilada, insoluvel, a proteina tau filamentosa mostrou-se ser o componente principal de emaranhados neurofibrilares, uma caracteristica patologica da DA. Neuroinflamacao e o indutor secundario resposta patologica a deposicao de A e morte celular neuronal associada com DA. Pesquisas documentaram o envolvimento de receptores Toll-like (TLRs) na neuroinflamacao, contribuindo para a patogenese da DA. Todos os TLR ativam as vias inflamatorias conservadas, ativando adicionalmente o Fator Nuclear-kB (NF-kB), resultando na libertacao e a producao de citocinas pro-inflamatorias. Entre a familia TLR, varios estudos indicaram o envolvimento de TLR3 e TLR4 contribuindo para neuroinflamacao. Alem disso, um corpo de dados indica o envolvimento de BAG2 na degradacao da tau fosforilada. Neste contexto, foi investigado o papel de TLR3 e TLR4 na modulacao da BAG2 promovida a degradacao de p-Tau em celulas SH-SY5Y. Neste estudo utilizamos LPS e pIpC para ativar TLR4 e TLR3 respectivamente. Linha de celulas SH-SY5Y foi usadae estabelecendo que o Tau induza a formacao de microtubulos sem limites que esta de acordo com a sua funcao como uma proteina associada amicro tubulos em DA. E tambem, utilizaram-se as celulas SH-SY5Y indiferenciadas uma vez que a expressao de BAG2 e inferior e indiferenciada, em comparacao com celulas diferenciadas. Neste estudo, a ativacao de TLR3 com diferentes concentracoes dem pIpC (1, 10, 50 e 100¿Êg/ml) resultou na regulacao negativa significativa de p-Tau em BAG2 expressao excessiva. Por outro lado, a ativacao de TLR4 com diferentes concentracoes de LPS (10, 50 e 100¿Êg/ml) resultaram em diminuicao dependente da dose na BAG2 expressao excessiva. Alem disso, usou-se JSH-23 para a inibicao de NF-kB. JSH-23 a uma concentracao de 25¿ÊM mostraram regulacao negativa significativa em p-Tau independente do BAG2 expressao excessiva e/ou a estimulacao de TLR3 e TLR4. Inibicao de NF-kB com JSH-23 25¿ÊM resultou na supra regulacao de transcricao significativa BAG2 endogena resultando na degradacao de ptau. Em contraste, a inibicao do NF-kB resultou na supra regulacao de HMW p-tau. BAG2 exogeno sobre a estimulacao TLR4 resultou nodecrescimo da regulacao de HMW p-tau. No entanto JSH-23 endogena induzida BAG2 falhou para regular negativamente HMW p-tau. A ativacao de TLR3/TLR4 nao mostrou toxicidade celular, nem a fosforilacao tau nas celulas SHSY5Y. Alem disso, a estimulacao por LPS na presenca/ausencia de sobre expressao BAG2 nao participa na proliferacao celular. No geral, os resultados demonstram a modulacao BAG2 em TLR4 e TLR3 estimulacao e inibicao de NF-kB degradacao em p-Tau e ou HMW p-Tau em DA. / Alzheimer¿s disease (AD) is a neurodegenerative disorder caused by progressive loss of synapses and neurons, characterized by memory dysfunction and global cognitive impairment. The abnormally hyperphosphorylated, insoluble, filamentous tau protein was shown to be the main component of NFTs, a pathological hallmark of AD. Neuroinflammation is the pathological secondary inducer response to deposition of A and neuronal cell death associated with AD. Considerable research has documented the involvement of Toll-like receptors (TLRs) in neuroinflammation, contributing to the pathogenesis of AD. All TLRs activate conserved inflammatory pathways, further activating nuclear factor-kB (NF-kB) resulting in the release and production of pro-inflammatory cytokines. Among the TLRs family, several studies have indicated the involvement of TLR3 and TLR4 contributing to neuroinflammation. Furthermore, a body of data indicates the involvement of BAG2 in phosphorylated Tau degradation. In this context we investigated the role of TLR3 and TLR4 in modulation of BAG2 promoted p-Tau degradation in SH-SY5Y cells. In this study we used LPS and pIpC to activate TLR4 and TLR3 respectively. SH-SY5Y cell line was used since it is established that the Tau induces the formation of microtubule bundles which is in accord with its function as a microtubule-associated protein in AD. And also, we used undifferentiated SH-SY5Y cells since the expression of BAG2 is lower in undifferentiated as compared to differentiated cell. In this study, activation of TLR3 with different concentration of pIpC (1, 10, 50 and 100ìg/mL) resulted in significant downregulation of p-Tau on BAG2 overexpression. On the other hand, activation of TLR4 with different concentration of LPS (10, 50 and 100ìg/mL) resulted in dose dependent decrease on BAG2 overexpression. . Further we used JSH-23 for NF-kB inhibition. JSH-23 at a concentration of 25ìM showed significant downregulation in p-Tau independent of BAG2 overexpression and/or on TLR4 and TLR3 stimulation. NF-kB inhibition with JSH-23 25ìM resulted in significant upregulation of endogenous BAG2 transcript resulting in p-Tau degradation. In contrast, NF-kB inhibition resulted in upregulation of HMW p-Tau. Exogenous BAG2 on TLR4 stimulation resulted in downregulation of HMW p-Tau. However JSH-23 induced endogenous BAG2 failed to downregulate HMW p-Tau. Activation of TLR3/TLR4 neither showed cell toxicity nor Tau phosphorylation in SH-SY5Y cells. Further LPS stimulation in presence/absence of BAG2 overexpression does not participate in cell proliferation. Overall, our findings demonstrate BAG2 modulation on TLR4 and TLR3 stimulation, and NF-kB inhibition in p-Tau and/or HMW p-Tau degradation in AD.

Espécies reativas de oxigênio (ERO) são produzidas através da respiração aeróbica e durante processos inflamatórios. Além disso, agressões externas como radiações, poluição, estresse, alcoolismo e tabagismo aumentam a sua produção. Altos níveis de ERO podem ocasionar dano oxidativo à lipídios, proteínas e DNA, comprometendo a função normal da célula, podendo estar envolvidos na patogênese e agravamento de diversas doenças. Há evidências que sugerem que antioxidantes naturais presentes em alimentos conferem benefícios adicionais à saúde, atuando como anticarcinogênicos, antiinflamatórios ou agentes antimutagênicos. O orégano (Oreganum sp) é uma especiaria mediterrânea usada como condimento na alimentação e pela medicina popular para diversos tipos de moléstias. O óleo possui forte ação antimicrobiana, devido ao elevado conteúdo de monoterpenos, sendo os principais o carvacrol, o timol e o para-cimeno. O carvacrol (5-isopropil-2metilfenol) é um fenol monoterpênico, com sabor picante e odor característico e tem sido amplamente usado na indústria de alimentos como aditivo seguro para aumentar a vida útil dos alimentos, como aromatizante em produtos assados, doces, bebidas e gomas de mascar, e/ou agente antimicrobiano com atividades contra bactérias, fungos e leveduras. Estudos têm relatado efeito antidepressivo e ansiolítico do carvacrol em camundongos, assim como proteção contra a radiação UVB diminuindo a peroxidação lipídica, estresse oxidativo e danos no DNA em células linfocitárias humanas e atividade antioxidante em diferentes sistemas de lipídios. Nós avaliamos a viabilidade celular e parâmetros de citotoxicidade do carvacrol em células de neuroblastoma humano SH-SY5Y. Este parece modificar levemente a morfologia das células, sem modificar significativamente a biomassa celular, parecendo ser tóxico na concentração de 100 μg/mL. Nas demais concentrações (1 a 50 μg/mL) não houve citotoxicidade. No ensaio de DCFH-DA o carvacrol reduziu a produção de ERO intracelular e diminui significativamente a produção de radicais peroxil no ensaio TRAP. Esses dados reforçam a ideia do carvacrol ser um potencial antioxidante, sendo necessários mais estudos para avaliar o mecanismo de ação deste composto. / Reactive oxygen species (ROS) are produced through aerobic respiration and during inflammation. Besides, external aggressions such as radiation, pollution, stress, alcoholism and smoking increase their production. Elevated levels of ROS can cause oxidative damage to lipids, proteins and DNA, compromising the normal cell function, and may be involved in the pathogenesis and progression of several diseases. There is suggesting that natural antioxidants found in foods provide additional health benefits, acting as anticarcinogenic, anti-inflammatory agents or antimutagenic. Oregano (Oreganum sp) is a Mediterranean spice used in food as a condiment and in popular medicine to treat several types of diseases. The essential oil has strong antimicrobial activity, due to the high content of monoterpenes, the main ones being carvacrol, thymol and para-cymene. Carvacrol (5-isopropyl-2metilfenol) is a phenol monoterpene with spicy taste and odor and has been widely used in food industry as additive to preserve foods, as flavoring agent in baked goods, candy, drinks and chewing gums, and/or antimicrobial agent with activity against bacteria, fungi and yeasts. Studies have reported antidepressant and anxiolytic effects of carvacrol in mice, as well as protection against UVB radiation, decreased lipid peroxidation, oxidative stress and DNA damage in human lymphocyte cells, and antioxidant activity in different lipid systems. We evaluated cell viability and cytotoxicity parameters of carvacrol in human neuroblastoma cells SH-SY5Y. Carvacrol induced morphology changes in cells without significant modification of the cellular biomass content and it was toxic at the concentration of 100 μg/mL. In other concentrations (1-50 μg/mL) it showed no cytotoxicity. In DCFH-DA assay carvacrol reduced the intracellular ROS production and significantly decreased the production of peroxyl radicals in the TRAP assay. These data reinforce the idea of carvacrol as a potential antioxidant and more research is needed to evaluate the mechanism of action of this compound.