RESUMO
Microbiota alterations are observed in pathological conditions, and their regulation is a subject of great interest. Gut microbes are affected by diet, and plant polyphenols may have positive effect on gut microbiota; however, plant-derived extracts may have toxic effects. Guarana (Paullinia cupana Mart.) is a nontraditional medicinal plant applied worldwide. Guarana yields an alkaloid and polyphenol-rich seed with antimicrobial, antioxidant, and anti-inflammatory properties, where caffeine is the major compound. We evaluated the effects of guarana seed powder (GSP) and purified caffeine on gut microbial composition and redox and inflammatory parameters in Wistar rats after 21 days of treatment. Fecal microbiota was analyzed utilizing 16S rDNA sequencing. Antioxidant enzymes activities from liver, kidney, and colon, as well as oxidative damage markers, were evaluated. Total nonenzymatic antioxidant potential was also evaluated. Microbiota was altered by both treatments, GSP and caffeine, without loss of diversity. In the liver, the kidney, and the colon, we observed a decrease in the antioxidant enzymes activities in the GSP group with no increase in the expression of oxidative damage markers, although some enzymes were also regulated by caffeine. Taken together, these results suggested that GSP ameliorates redox parameters but negatively affected gut microbiota, partially via caffeine.
Assuntos
Cafeína/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Teobromina/farmacologia , Teofilina/farmacologia , Animais , Antioxidantes/farmacologia , Cafeína/química , Disbiose/induzido quimicamente , Disbiose/microbiologia , Disbiose/patologia , Masculino , Oxirredução/efeitos dos fármacos , Paullinia/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Ratos , Ratos Wistar , Sementes , Teobromina/química , Teofilina/químicaRESUMO
OBJECTIVE: The main objective of this systematic review is to assess the effects of obesity on telomere length. METHODS: The following databases were searched: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), LILACS, SPORTdiscus, and Web of Science from inception to August 2014. The search was performed using the following combinations of terms: telomere AND "overweight" OR "obesity" OR "adiposity," without language restriction. RESULTS: Sixty-three original studies were included in this systematic review, comprising 119,439 subjects. Thirty-nine studies showed either weak or moderate correlation between obesity and telomere length; however, they showed an important heterogeneity. CONCLUSIONS: There is a tendency toward demonstrating negative correlation between obesity and telomere length. The selected studies showed weak to moderate correlation for the main search, and there was an important heterogeneity. For this reason, the causal relationship of obesity and telomere length remains open. Additional controlled longitudinal studies are needed to investigate this issue.
