Percorrer por autor "Silva, A.M."
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- Comet assay reveals no genotoxicity risk of cationic solid lipid nanoparticles.Publication . Doktorovova, S.; Silva, A.M.; Gaivão, I.; Souto, E.B.; Teixeira, João Paulo; Martins-Lopes, P.Cationic solid lipid nanoparticles (cSLN) are colloidal carriers for genes or drugs, particularly lipophilic drugs. Several reports exist on their high efficiency, but only a few studies report the effect of cSLNs on living cells. In the present work, internalization, cell viability (alamar blue assay) and genotoxic potential (alkaline comet assay) of three cSLN formulations (A–C) were evaluated in HepG2 and Caco-2 cells. cSLN showed an average hydrodynamic diameter (z-ave) of 141–222 nm, zeta-potential of 55.0–72.5mV and polidispersity indices (PdI) of 0.336–0.421. Dispersion in physiological buffers increased z-ave and PdI. 0.01mgml–1 cSLN unaffected cell viability, but 1.0mgml–1 significantly decreased it, being cSLN-C (Compritol-based) the most toxic and HepG2 the most affected. DNA damage was not significantly increased by 0.1mgml–1 cSLN but damage was observed at 1.0mgml–1 cSLN-C. Thus, no genotoxicity is to be expected at concentrations that do not reduce cell viability.
- Impact of physical exercise training on DNA damage and repair: does gender play a role?Publication . Silva, Ana Inês; Soares, J.P.; Silva, A.M.; Gaivão, I.; Mota, M.P.; Matos, M.Acute physical exercise is associated with an enhanced aerobic metabolism, which can result in an increased formation of reactive oxygen species (ROS). ROS can react with DNA, causing strand breaks and modified bases, namely 8-oxoguanine, one of the most common products of oxidative DNA damage, which is repaired by 8-oxoguanine DNA glycosylase 1 (OGG1). Regular physical exercise is considered as a key component of a healthy lifestyle, and its preventive effect, at least in part, is due to oxidative stress induced adaptation, which has been related with an increase in antioxidant activity and in oxidative damage repair enzymes. Gender-related differences concerning DNA damage and DNA repair have been reported. Therefore, the main purpose of this study was to analyse the effects of 16 weeks of combined physical exercise training on DNA damage and repair, in 26 healthy Caucasian individuals, 14 males and 12 females.
- Infusions and decoctions of dehydrated fruits of Actinidia arguta and Actinidia deliciosa: Bioactivity, radical scavenging activity and effects on cells viabilityPublication . Silva, A.M.; Pinto, D.; Fernandes, I.; Albuquerque, T.G.; Costa, H.S.; Freitas, V.; Rodrigues, F.; Oliveira, M.B.P.P.Actinidia deliciosa and A. arguta fruits (kiwifruit and kiwiberry, respectively) are an excellent source of bioactive compounds. The aim of this paper is to valorize the fruits that are not commercialized (e.g. due to inadequate size or physical damage) in infusions and decoctions. The antioxidant activity, the scavenging activity against reactive species, the phenolic profile and the intestinal effects of infusions and decoctions of dehydrated fruits were evaluated and compared. Decoctions presented the highest antioxidant activity and a good ability to capture HOCl and NO. The phenolic composition of A. arguta present quinic acid, cis-caftaric acid and its derivatives, caffeoyl hexoside, luteolin glucuronide, quercetin derivatives and myristin, while A. deliciosa extracts were characterized by the presence of quinic acid, caffeic acid and its derivatives and caffeoyl hexoside. No adverse effects were observed on Caco-2 and HT29-MTX cells. Kiwiberry decoctions showed to be the best option to keep the fruits benefits.