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- Effect of chronic consumption of blackberry extract on high-fat induced obesity in rats and its correlation with metabolic and brain outcomesPublication . Meireles, Manuela; Rodríguez-Alcalá, Luís M; Marques, Cláudia; Norberto, Sónia; Freitas, Joana; Fernandes, Iva; Mateus, Nuno; Gomes, Ana Maria; Faria, Ana; Calhau, ConceiçãoFlavonoids have been presented as potential protectors against metabolic and cognitive dysfunction. However, mechanisms underlying these 'claims' have not been sufficiently explored. To analyse the effect of long-term supplementation with blackberry extract (BE) in the context of a high-fat or a standard diet, Wistar rats were divided into 4 groups (n = 6) fed with a standard or a high-fat diet, with or without BE supplementation at 25 mg per kg body weight per day. A high-fat diet significantly impaired glucose tolerance and increased body weight, caloric ingestion, very-low-density lipoprotein, triglycerides and cholesterol. Furthermore, it was observed that a high-fat diet increased dopamine content in the prefrontal cortex and decreased brain derived neurotrophic factor (BDNF) levels both in the prefrontal cortex and in plasma. BE supplementation only affected some of these aspects. BE slightly improved glucose metabolism and significantly decreased levels of lactate, independent of diet. BE decreased levels of BDNF and also interacted with the dopaminergic system, increasing dopamine turnover in the striatum, and reverting dopamine content induced by a high-fat diet in the prefrontal cortex. This study shows that, despite some particular benefits of anthocyanin supplementation, some long-term effects may not be desirable and further studies are needed to optimize ingestion conditions.
- Effect of in vitro digestion upon the antioxidant capacity of aqueous extracts of Agrimonia eupatoria, Rubus idaeus, Salvia sp. and Satureja montanaPublication . Gião, Maria S.; Gomes, Susana; Madureira, Ana R.; Faria, Ana; Pestana, Diogo; Calhau, Conceição; Pintado, Manuela E.; Azevedo, Isabel; Malcata, F. XavierAn in vitro digestion/Caco-2 cell culture model was used to assess the stability and bioavailability of phenolic compounds in aqueous extracts of four herbal infusions, traditionally used as functional drinks in Portugal. Alterations in antioxidant power were monitored by ABTS +, whereas the profile of phenolic compounds was ascertained by HPLC-DAD. The bioavailability of rutin – an important flavonoid present in such extracts, and thus a representative of those compounds, was assessed across Caco-2 cells via LC– MS/MS. Our results indicate that several antioxidant compounds are not affected by the (simulated) digestive process, whereas others undergo decreases in their activity throughout said process; a few have their antioxidant capacity hampered under stomach-like conditions. It was also found that rutin can be transported across the Caco-2 cell barrier.
- Effects of extracts of selected medicinal plants upon hepatic oxidative stressPublication . Gião, M.S.; Pestana, D.; Faria, A.; Guimarães, J.T.; Pintado, M.E.; Calhau, C.; Azevedo, I.; Malcata, F.X.Aqueous extracts of a few medicinal plants traditionally used in Portugal have been assayed for their effects upon hepatic oxidative stress in mice. Previous in vitro studies had allowed characterization of agrimony, sage, savory, and raspberry in terms of overall antioxidant capacity and phenolic content. In the present study, the antioxidant effect and safety of these four plants were evaluated in vivo. For this purpose, mice ingested extracts in aqueous form (or water, used as the control) for 4 weeks; damage to lipids, proteins, and DNA was evaluated by oxidative cell biomarkers by the end of that period. Levels of hepatic glutathione and activities of enzymes involved in metabolism thereof were also determined. Finally, catalase and superoxide dismutase (SOD) activities were quantified, as these enzymes play a crucial role in antioxidant defense. When compared with the control, both raspberry and savory produced significant lipid protection; however, protein damage was significantly lower only in raspberry-treated animals. On the other hand, DNA damage was prevented only by savory. All plants led to a decrease in catalase activity, whereas all but sage also produced a decrease in SOD activity. With regard to glutathione levels and activities of enzymes involved in its metabolism, the aforementioned extracts exhibited different effects. In general, raspberry appeared to be the most promising extract, followed by savory, sage, and agrimony, sorted by decreasing performance in protection; the latter was even slightly toxic. Hence, the plants tested possess compounds with interesting biological activities that may support eventual inclusion in food or feed as functional additives.
- Endocrine disruptor DDE associated with a high-fat diet enhances the impairment of liver fatty acid composition in ratsPublication . Rodríguez-Alcalá, Luis M.; Sá, Carla; Pimentel, Lígia L.; Pestana, Diogo; Teixeira, Diana; Faria, Ana; Calhau, Conceição; Gomes, Ana M. P.The banned pesticide dichlorodiphenyltrichloroethane (DDT) and its main metabolite, p,p′-dichlorodiphenyldichloroethylene (DDE), are commonly found in the food chain and in all tissues of living organisms. DDE is associated with metabolic diseases acting as an endocrine disruptor and more recently with the obesity pandemic. This study focuses on using fatty acid analysis to relate DDE exposure and metabolic dysfunction: liver and adipose tissue (visceral and subcutaneous) composition from male Wistar rats fed a standard (STD) or high-fat (HF) diet versus the addition of DDE in water. DDE exposure increased liver levels of palmitic, stearic, oleic, trans fatty, and linoleic acids having altered the n6 and n3 pathways leading to high concentrations of arachidonic acid and DHA (C22:6 n3). The results of this study confirm the close relationship between this pesticide metabolite and hepatic lipid dysfunction, underscoring its role as an emerging target for the prevention and therapy of nonalcoholic fatty liver disease (NAFLD).
- Blueberry anthocyanins in health promotion: a metabolic overviewPublication . Norberto, Sónia; Silva, Sara; Meireles, Manuela; Faria, Ana; Pintado, Manuela; Calhau, ConceiçãoDiet has gained scientific community attention due to the crucial role in health maintenance, but also in disease treatment, and essential in disease prevention. Several food and food components, particularly phenolic rich foods, have been investigated as they present themselves as putative functional foods. In the past decades, obesity has reached epidemic proportions and consequently, metabolic syndrome (a set of disorders as impaired glucose tolerance, insulin resistance, abdominal obesity, dyslipidemia and high blood pressure, which increase the risk of cardiovascular disease and diabetes) incidence is increasing worldwide at an alarming rate and this phenolic rich foods, specially berries have been investigated to their potential beneficial effect in this disorders. In the present work the chemistry of blueberries (BB) (fruits of some Vaccinium species) was summarised as well as the knowledge about bioavailability and biokinetic of anthocyanins from blueberries with particular emphasis on its implications in metabolic disorders.