Avaliação da atividade anti-hRSV da quercetina e seus derivados acetilados
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Data
2016-03-16
Autores
Lopes, Bruno Rafael Pereira [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
No mundo, estima-se que exista cerca de 12 milhões de casos graves e 3 milhões de casos muito graves de infecção do trato respiratório inferior em crianças anualmente. Dentre os agentes etiológicos destas infecções, o vírus sincicial respiratório humano (hRSV) é a principal causa de internações infantis em países desenvolvidos, agravando os casos de bronquiolite, pneumonia e infecções pulmonares obstrutivas crônicas em pessoas de todas as idades, principalmente crianças e idosos. Estudos preliminares demonstraram que a Quercetina possui ação virucida sobre hRSV, além de inibir sua replicação. Entretanto, não se tem conhecimento do quão promissora é a atividade antiviral de Quercetina sobre o vírus hRSV ou mesmo se esta atividade poderia ser melhorada através de mudanças químicas em sua estrutura molecular. Assim, o objetivo deste trabalho foi estabelecer o índice de seletividade (IS) para Quercetina e seus derivados acetilados durante a infeção por hRSV através de ensaios in vitro. A análise de viabilidade celular através da adição do sal de MTT determinou os valores de CC50 para Quercetina na presença/ausência do vermelho de fenol (85 e 11,4 µM, respectivamente). Dentre as condições testadas, Quercetina apresentou atividade virucida (16-30% de proteção celular) sem apresentar efeitos no pré ou pós-tratamentos. Os valores de CC50 dos compostos derivados Q1 e Q2 foram 37,1 µM e 53,15 µM, respectivamente. O composto Q1 apresentou atividade anti-hRSV nos protocolos virucida e pós-tratamento (60-90%; 4-8 µM). O composto Q2 não apresentou atividade anti-hRSV relevante em nenhuma das condições testadas. A proteção celular apresentada pela Quercetina não possibilitou o cálculo de IS (CC50/CE50) o que nos sugere que este composto não seja um promissor agente anti-hRSV. Os índices de Seletividade calculados para o composto Q1 nos protocolos virucida e pós-tratamento foi de 9,27. O conjunto de resultados obtidos neste trabalho apresenta menor citotoxicidade e melhor performance anti-hRSV do composto Q1 em relação à Quercetina comercial. Estes dados nos estimulam a dar continuidade aos estudos do composto Q1 com o intuito de melhorarmos sua atividade antiviral e assim propormos um novo composto que seja efetivos na prevenção e/ou tratamento das infecções por hRSV.
Worldwide, is estimated that there are about 12 million serious cases and 3 million severe cases of lower respiratory tract infection in children every year. Among the etiological agents of these infections, respiratory syncytial virus (hRSV) is the leading cause of children's hospitalizations in developed countries, aggravating cases of bronchiolitis, pneumonia and chronic obstructive pulmonary infections in people of all ages, especially children and the elderly. Preliminary studies demonstrated that Quercetin has virucidal action on hRSV, and inhibits replication. However, we do not know how promising is the antiviral activity of Quercetin on the hRSV. The objectives of this work is to understand the action of Quercetin and some of its derivatives acetylated on the steps of the replicative cycle of hRSV, determining the selectivity index for each compound. The development of this project will assist in the search for effective compounds in the prevention and/or treatment of hRSV infections. In the cytotoxicity assays, Quercetin showed CC50 values variable depending on the presence/absence of phenol red (11.4 and 85 μM respectively). Among the concentrations tested Quercetin only showed a slight virucidal activity (16-30% concentration 5-10 μM). The CC50 values were derived compounds 37.1 μM for Q1 and Q2 to 53.15 μM. Compound Q1 showed anti-hRSV activity in virucidal and post-treatment protocol (60-90% at 4-8 μM). The Q2 compound showed no anti-hRSV relevant activity. The presence or absence of phenol red had great influence in determining the CC50 values of Quercetin (11.4 μM and 85 μM with phenol red). In addition, Quercetin showed little (virucidal protocol without phenol) or no anti-hRSV activity. Thus it has not been possible to establish the EC50 of Quercetin and determine its selectivity index (SI). The Q1 compound showed a greater CC50 value (37.1 μM) and relevant anti-hRSV activity in post-treatment and virucidal protocols (SI 9.27). Among the compounds tested, Q2 showed the highest value of CC50 (53.15 μM without phenol) however, had little or no anti-hRSV activity, making it impossible to determine their SI.
Worldwide, is estimated that there are about 12 million serious cases and 3 million severe cases of lower respiratory tract infection in children every year. Among the etiological agents of these infections, respiratory syncytial virus (hRSV) is the leading cause of children's hospitalizations in developed countries, aggravating cases of bronchiolitis, pneumonia and chronic obstructive pulmonary infections in people of all ages, especially children and the elderly. Preliminary studies demonstrated that Quercetin has virucidal action on hRSV, and inhibits replication. However, we do not know how promising is the antiviral activity of Quercetin on the hRSV. The objectives of this work is to understand the action of Quercetin and some of its derivatives acetylated on the steps of the replicative cycle of hRSV, determining the selectivity index for each compound. The development of this project will assist in the search for effective compounds in the prevention and/or treatment of hRSV infections. In the cytotoxicity assays, Quercetin showed CC50 values variable depending on the presence/absence of phenol red (11.4 and 85 μM respectively). Among the concentrations tested Quercetin only showed a slight virucidal activity (16-30% concentration 5-10 μM). The CC50 values were derived compounds 37.1 μM for Q1 and Q2 to 53.15 μM. Compound Q1 showed anti-hRSV activity in virucidal and post-treatment protocol (60-90% at 4-8 μM). The Q2 compound showed no anti-hRSV relevant activity. The presence or absence of phenol red had great influence in determining the CC50 values of Quercetin (11.4 μM and 85 μM with phenol red). In addition, Quercetin showed little (virucidal protocol without phenol) or no anti-hRSV activity. Thus it has not been possible to establish the EC50 of Quercetin and determine its selectivity index (SI). The Q1 compound showed a greater CC50 value (37.1 μM) and relevant anti-hRSV activity in post-treatment and virucidal protocols (SI 9.27). Among the compounds tested, Q2 showed the highest value of CC50 (53.15 μM without phenol) however, had little or no anti-hRSV activity, making it impossible to determine their SI.
Descrição
Palavras-chave
Quercetina, hRSV, Antiviral, Derivados acetilados, Quercetin, Acetylated derived