Estudos e pesquisas Divulga estudos descritivos e análises de resultados de tabulações especiais de uma ou mais pesquisas, de autoria institucional. A série Estudos e pesquisas está subdividida em: Informação

The antioxidant effects of the hydro-alcoholic guaraná extract (Paullinia cupana var. sorbilis Mart.) on nitric oxide (NO) and other compounds generated from the degradation of sodium nitroprusside (SNP) in an embryonic fibroblast culture (NIH-3T3 cells) were evaluated. The guaraná bioactive compounds were initially determined by high-performance liquid chromatography: caffeine=12.240 mg/g, theobromine=6.733 mg/g and total catechins=4.336 mg/g. Cells were exposed to 10 μM SNP during a 6 h period because the cells exhibited >90% mortality at this concentration. Guaraná was added to the cultures in five concentrations (0.5, 1, 5, 10 and 20 mg/mL). The guaraná antioxidant effect was evaluated by viability assays, biochemical oxidation [lipid peroxidation, catalase and superoxide dismutase (SOD) activity] and genotoxicity (DNA Comet assay) analysis. Additionally, oxidative stress was evaluated by a 2,7-dihydrodichlorofluorescein diacetate fluorescence assay. Guaraná reverted the SNP toxicity mainly at lower concentrations (<5 mg), which decreased cell mortality, lipid peroxidation, DNA damage and cell oxidative stress as well as increased the SOD levels. These results demonstrate that guaraná has an antioxidant effect on NO metabolism in situations with higher cellular NO levels.

BackgroundPrevious experimental investigations have suggested that guaraná (Paullinia cupana Kunth, supplied by EMBRAPA Oriental) consumption is associated with a lower prevalence of cardiovascular metabolic diseases and has positive effects on lipid metabolism, mainly related to low density lipoprotein (LDL) levels. As LDL oxidation is an important initial event in the development of atherosclerosis, we performed in vitro and in vivo studies to observe the potential effects of guaraná on LDL and serum oxidation.MethodsThe in vivo protocol was performed using blood samples from 42 healthy elderly subjects who habitually ingested guaraná (GI) or never ingested guaraná (NG). The formation of conjugated dienes (CDs) was analyzed from serum samples. The in vitro protocols were performed using LDL obtained from 3 healthy, non-fasted, normolipidemic voluntary donors who did not habitually ingest guaraná in their diets. The LDL samples were exposed to 5 different guaraná concentrations (0.05, 0.1, 0.5, 1, and 5 μg/mL).ResultsGI subjects demonstrated lower LDL oxidation than did NG subjects (reduction of 27%, p < 0.0014), independent of other variables. In the GI group the total polyphenols was positively associated with LDL levels. Also, guaraná demonstrated a high antioxidant activity in vitro, mainly at concentrations of 1 and 5 μg/mL, demonstrated by suppression of CDs and TBARS productions, tryptophan destruction and high TRAP activity.ConclusionsGuaraná, similar to other foods rich in caffeine and catechins such as green tea, has some effect on LDL oxidation that could partially explain the protective effects of this food in cardiometabolic diseases.

This study quantifies the bioactive molecules in and determines the in vitro protective effect of ethanolic extracts isolated from the peel and pulp of tucumã (Astrocaryum aculeatum, Mart.), an Amazonian fruit rich in carotenoids. The cytoprotective effect of tucumã was evaluated in lymphocyte cultures exposed to H2O2 using spectrophotometric, fluorimetric, and immunoassay assays. The results confirmed that tucumã pulp extract is rich in β-carotene and quercetin, as previously described in the literature. However, high levels of these compounds were also found in tucumã peel extract. The extracts also contained significant amounts rutin, gallic acid, caffeic acid, and chlorogenic acid. Despite quantitative differences in the concentration of these bioactive molecules, both extracts increased the viability of cells exposed to H2O2 in concentrations ranging from 300 to 900 μg/mL. Caspases 1, 3, and 8 decreased significantly in cells concomitantly exposed to H2O2 and these extracts, indicating that tucumã cryoprotection involves apoptosis modulation.

Neuropsychiatric diseases, such as bipolar disorder (BD) and schizophrenia (SCZ), have a very complex pathophysiology. Several current studies describe an association between psychiatric illness and mitochondrial dysfunction and consequent cellular modifications, including lipid, protein, and DNA damage, caused by cellular oxidative stress. Euterpe oleracea (açaí) is a powerful antioxidant fruit. Açaí is an Amazonian palm fruit primarily found in the lowlands of the Amazonian rainforest, particularly in the floodplains of the Amazon River. Given this proposed association, this study analyzed the potential in vitro neuropharmacological effect of Euterpe oleracea (açaí) extract in the modulation of mitochondrial function and oxidative metabolism. SH-SY5Y cells were treated with rotenone to induce mitochondrial complex I dysfunction and before and after we exposed the cells to açaí extract at 5 μg/mL. Treated and untreated cells were then analyzed by spectrophotometric, fluorescent, immunological, and molecular assays. The results showed that açaí extract can potentially increase protein amount and enzyme activity of mitochondrial complex I, mainly through NDUFS7 and NDUFS8 overexpression. Açaí extract was also able to decrease cell reactive oxygen species levels and lipid peroxidation. We thus suggest açaí as a potential candidate for drug development and a possible alternative BD therapy.