RESUMO Muitos alimentos interagem com medicamentos e podem causar alterações nos efeitos farmacológicos do agente terapêutico coadministrado. A enzima CYP3A4, que pertence ao complexo enzimático do citocromo P450, é responsável pelo metabolismo da maioria dos medicamentos atualmente no mercado e está envolvida em muitas interações medicamentosas. Assim, a interação dessa enzima com sucos de algumas frutas, como a toranja, pode afetar a farmacocinética de vários medicamentos. No entanto, frutas nativas da região amazônica ainda não foram alvo desse tipo de pesquisa. Determinamos polifenóis e flavonoides totais dos frutos amazônicos de açaí (Euterpe precatoria), buriti (Mauritia flexuosa), camu-camu (Myrciaria dubia), cubiu (Solanum sessiliflorum), cupuaçu (Theobroma grandiflorum), jenipapo (Genipa americana) e taperebá (Spondias mombin) e avaliamos os efeitos de cada suco de fruta sobre a atividade de CYP3A4, utilizando o suco de carambola (Averrhoa carambola) como controle positivo. O suco de açaí apresentou o maior teor de polifenóis totais e flavonóides (102,6 ± 7,2 µg equivalente de ácido gálico (GAE) por mL e 7,2 ± 0,6 µg equivalente de quercetina (QE) por mL, respectivamente). Todos os sucos foram capazes de inibir a atividade de CYP3A4. Não houve atividade residual da enzima metabolizadora de fármacos para os sucos de açaí, buriti, cubiu, camu-camu e taperebá, enquanto para cupuaçu, jenipapo e o controle positivo, a atividade residual foi de 44,3, 54,3 e 20,2%, respectivamente. Estudos adicionais devem identificar o(s) fitocomposto(s) responsável(is) por esta atividade de inibição, para esclarecer os mecanismos envolvidos neste fenômeno.

ABSTRACT Many foods interact with drugs and may cause changes in the pharmacological effects of the co-administered therapeutic agent. The enzyme CYP3A4, which belongs to the cytochrome P450 enzyme complex, is responsible for the metabolism of most drugs currently on the market and is involved in many drug interactions. Hence, the interaction of this enzyme with juices of some fruits, such as grapefruit, can affect the pharmacokinetics of various drugs. However, native fruits from the Amazon region have not yet been the target of this type of research. We determined total polyphenols and flavonoids of the Amazonian fruits açaí (Euterpe precatoria), buriti (Mauritia flexuosa), camu-camu (Myrciaria dubia), cubiu (Solanum sessiliflorum), cupuaçu (Theobroma grandiflorum), jenipapo (Genipa americana), and taperebá (Spondias mombin) and evaluated the effects of each fruit juice on CYP3A4 activity, using the star fruit (Averrhoa carambola) juice as positive control. Açaí juice presented the highest content of total polyphenols and flavonoids (102.6 ± 7.2 µg gallic acid equivalent (GAE) per mL and 7.2 ± 0.6 µg quercetin equivalent (QE) per mL, respectively). All juices were able to inhibit the activity of CYP3A4. There was no residual activity of the drug-metabolizing enzyme for açai, buriti, cubiu, camu-camu, and taperebá juice, while for cupuaçu, jenipapo and the positive control, the residual activity was 44.3, 54.3 and 20.2%, respectively. Additional studies should identify the phytocompound(s) responsible for this inhibition activity, to clarify the mechanisms involved in this phenomenon.

ABSTRACT Background: Aedes aegypti is currently controlled with synthetic larvicides; however, mosquitoes have become highly resistant to these larvicides and difficult to eradicate. Studies have shown that insecticides derived from fungal extracts have various mechanisms of action that reduce the risk of resistance in these mosquitoes. One possible mechanism is uncontrolled production of reactive oxygen species (ROS) in the larvae, which can cause changes at the cellular level. Thus, the crude extract of Xylaria sp. was evaluated to investigate the oxidative effect of this extract in A. aegypti larvae by quantifying the oxidative damage to proteins and lipids. Methods: The larvicidal potential of the crude extract of Xylaria sp. Was evaluated, and the extract was subsequently tested in human lung fibroblasts for cytotoxicity and ROS production. ROS level was quantified in the larvae that were killed following exposure to the extract in the larvicide test. Results: The crude extract of Xylaria sp. Caused cytotoxicity and induced ROS production in human lung fibroblasts and A. aegypti larvae, respectively. In the larvicide trial, the extract showed an LC50 of 264.456 ppm and an LC90 of 364.307 ppm, and was thus considered active. The extract showed greater oxidative damage to lipids and proteins, with LC90 values of 24.7 µmol MDA/L and 14.6278 ×10-3 nmol carbonyl/ mg protein, respectively. Conclusions: Crude extracts of Xylaria sp. induced oxidative stress that may have caused the mortality of A. aegypti larvae.

Resumo Virola venosa, popularmente conhecida como ucuuba-da-mata, ocorre naturalmente na região amazônica e tem potencial para fornecer compostos naturais úteis, como já foi mostrado para outras espécies de Virola. Por isso, o objetivo deste estudo foi determinar a composição química dos extratos do tronco e das folhas de V. venosa e os possíveis potenciais antioxidantes e de inibição contra α-glucosidase de seus compostos. Os extratos polares mostraram-se mais ativos em ambos os testes, portanto, um fracionamento guiado por bioatividade foi realizado para designar os compostos responsáveis pelas atividades registradas. Através da combinação de análise CL-EM/EM e isolamento com identificação por RMN, foram identificados oito compostos fenólicos. Testes com os compostos puros principais das frações mais ativas indicaram o ácido ferúlico como o principal contribuinte das atividades biológicas observadas para os extratos brutos, e, consequentemente, o princípio ativo principal de V. venosa.

ABSTRACT Virola venosa, popularly known in Brazil as ucuuba-da-mata, occurs naturally in the Amazon region and has potential to provide useful natural compounds, as already known for other Virola species. Therefore, the objective of this study was to determine the chemical composition of bark and leaf extracts of V. venosa, and to test the antioxidant capacity and α-glucosidase inhibition potential of their compounds. Polar extracts showed to be more active in both assays, therefore a bioactivity-guided fractionation was performed to identify the compounds that were responsible for the recorded activities. Using a combination of LC-MS/MS analysis and isolation with NMR identification, eight phenolic compounds were identified. Assays with pure compounds of the active fraction revealed that ferulic acid was the main contributor compound to the observed bioactivity in the crude extracts.