Untitled

Funder

Organizational Unit

Publications

Technological stability of solid lipid nanoparticles loaded with phenolic compounds: drying process and stability along storage

Publication . Campos, Débora A.; Madureira, Ana Raquel; Sarmento, Bruno; Pintado, Maria Manuela; Gomes, Ana Maria

Solid lipid nanoparticles (SLNs) have been widely studied and tested as vehicles for natural compounds. Recently, Witepsol and Carnauba SLNs were shown to be effective systems for the entrapment of rosmarinic acid (RA) and herbal extracts. In the present work, the improvement of stability and bioactivity of these systems was studied. Thus, the freeze-drying of SLNs produced with Witepsol and Carnauba waxes loaded with RA and herbal extracts (sage and savory) were tested. The use of three different cryoprotectants (glucose, mannitol and trehalose) at two different concentrations (5 and 10%, w/v) were evaluated. Furthermore, the prepared SLNs were stored under different conditions (atmosphere, temperature, absence or presence of light) and in different packaging materials, over 365 days. The effect on the SLNs physical stability and bioactivity was assessed. The most suitable cryoprotectant was mannitol at 10% (w/v) for all formulations tested. The solid state of SLNs, with storage at room temperature, in glass flasks, protected from light and under N2 controlled atmosphere were the best storage conditions in which the SLNs bioactivity was maintained during 365 days.

2017Journal article

Restricted access

Effect of chronic consumption of blackberry extract on high-fat induced obesity in rats and its correlation with metabolic and brain outcomes

Publication . Meireles, Manuela; Rodríguez-Alcalá, Luís M; Marques, Cláudia; Norberto, Sónia; Freitas, Joana; Fernandes, Iva; Mateus, Nuno; Gomes, Ana Maria; Faria, Ana; Calhau, Conceição

Flavonoids 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.

2016-01Journal article

Restricted access

Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approaches

Publication . Reis, Flávio; Madureira, Ana Raquel; Nunes, Sara; Campos, Débora; Fernandes, João; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luis M.; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana M.; Pintado, M. E.

Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications.

2016Journal article

Open access