Seasonal and pluviometric effects on the phenolic compound composition and antioxidant potential of Licania macrophylla Benth (Chrysobalanaceae), a medicinal plant from the Amazon rainforest

Abstract Licania macrophylla is a medicinal plant from the Amazon. It is mainly used in the form of a decoction and has been reported to contain several phenolic compounds. However, the effect of seasonality on the phenolic composition and antioxidant potential of this plant has not been well studied, especially in the Amazon region, an area affected by the rainy and less-rainy seasons. Therefore, we evaluated the seasonality of these aromatic compounds and the antioxidant potential of the extracts from L. macrophylla stem bark. We also determined the correlation between the extraction methods used and precipitation levels during each period for 1 year. The total flavonoid and phenolic content, DPPH-scavenging potential, percentage of phosphomolybdenum complex reduction, and iron-reducing power were quantified. The levels of phenolic compounds were the highest in June, whereas those of flavonoids were the highest in September and October; however, these differences were not significant. The extracts from April, November, and June showed the best results for DPPH scavenging, phosphomolybdenum reduction, and iron reduction power, respectively. Significant differences in the phenolic content and DPPH-scavenging activity were observed between the more- and less-rainy seasons. The total phenolic content was positively correlated with FRAP and DPPH, whereas flavonoid levels were negatively correlated.

Fatores associados à etiologia e patogenese das doenças autoimunes / Factors associated to the etiology and pathogenesis of autoimmune diseases

Este trabalho teve como objetivo elaborar uma revisão de literatura de cunho reflexivo acerca dos fatores etiológicos e determinantes na patogênese das doenças autoimunes, assim como sobre as estratégias terapêuticas existentes ou em fase de desenvolvimento, sendo realizado para tal propósito um levantamento de literaturas especializadas disponíveis online na base de dados do google e do google acadêmico para a obtenção das informações que compõem este trabalho, seguido de uma análise de inclusão ou exclusão conforme os seguintes critérios: os trabalho para serem inclusos na revisão deveriam tratar sobre o tema pesquisado, possuir texto completo, publicados nos idiomas português, inglês e espanhol, no período de 2001 à 2017. O estudo realizado aponta que são associados ao desenvolvimento de doenças autoimunes fatores como 1) comprometimento dos mecanismos imunomoduladores de proteção contra a autoimunidade, 2) mimetização de antígenos de patógenos com moléculas endógenas, 3) modificações de proteínas endógenas ou da expressão gênica por xenobióticos e 4) mutação de genes imunomoduladores adquirida ou herdada e que apesar dos imunossupressores serem a principal estratégia terapêutica, a imunomodulação e a vacinação são recursos que despertam a atenção de pesquisadores e apresentam potencial promissor para aumentar a qualidade de vida dos portadores de doenças autoimunes.

This work aimed to elaborate a literature review about the etiological and determinant factors in the pathogenesis of autoimmune diseases, as well as on the therapeutic strategies existing or in development phase, being carried out for the development of this work a survey of specialized texts available online in the google and google academic databases to the acquisition of the information that composes this work, followed by an analysis of inclusion or exclusion according to the following criteria: the work to be included in the review should be related with the subject searched, possess the full text, be publicized in the Portuguese, English or Spanish languages, from 2001 to 2017. The study done shows that the development of autoimmune diseases is associated with: 1) impairment of immunomodulatory mechanisms to protect against autoimmunity, 2) mimicking of pathogen's antigens with endogenous molecules of the cells, 3) modifications of endogenous proteins or gene expression by xenobiotics, and 4) acquired or inherited immunomodulatory gene mutation; the study also shows that although the immunosuppressant drugs are the main therapeutic strategy, immunomodulation and vaccination are resources that attract the attention of researchers and present promising potential to increase the quality of life of patients with autoimmune diseases.