Browsing by Author "Ferreira, Isabel M. P. V. O."
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- Effect of skimmed milk on intestinal tract: prevention of increased reactive oxygen species and nitric oxide formationPublication . Pinho, Susana C. M.; Faria, Miguel A.; Melo, Armindo; Pinto, Edgar; Almeida, Agostinho; Alves, Rui; Cabrita, Ana R. J.; Fonseca, António J. M.; Ferreira, Isabel M. P. V. O.The capacity of skimmed milk to neutralise increased reactive oxygen species (ROS) and to attenuate nitric oxide (NO) production, as well as to present cytoprotective effect at the intestinal level was assessed after in vitro gastro-intestinal digestion. The impact on ROS modulation was evaluated at a non-cytotoxic concentration of hydrogen peroxide (H2O2) in a co-culture of Caco-2 and HT-29 intestinal cells. In parallel, a cytotoxic concentration of H2O2 was used to study the effect of digested milk against induced cell apoptosis. Concerning induced NO production, it was evaluated using the model lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Results showed that digested milk prevented the increase of basal ROS level in the intestinal epithelium and attenuated NO production by LPS-stimulated macrophage cells. In the H2O2-induced cytotoxicity assay, digested milk had no protection against apoptosis, confirmed by the failure in attenuating activated caspase-3/7.
- Foliar application of sodium nitroprusside boosts solanum lycopersicum l. tolerance to glyphosate by preventing redox disorders and stimulating herbicide detoxification pathwaysPublication . Soares, Cristiano; Rodrigues, Francisca; Sousa, Bruno; Pinto, Edgar; Ferreira, Isabel M. P. V. O.; Pereira, Ruth; Fidalgo, FernandaStrategies to minimize the effects of glyphosate (GLY), the most used herbicide worldwide, on non-target plants need to be developed. In this context, the current study was designed to evaluate the potential of nitric oxide (NO), provided as 200 µM sodium nitroprusside (SNP), to ameliorate GLY (10 mg kg−1 soil) phytotoxicity in tomato plants. Upon herbicide exposure, plant development was majorly inhibited in shoots and roots, followed by a decrease in flowering and fruit set; however, the co-application of NO partially prevented these symptoms, improving plant growth. Concerning redox homeostasis, lipid peroxidation (LP) and reactive oxygen species (ROS) levels rose in response to GLY in shoots of tomato plants, but not in roots. Additionally, GLY induced the overaccumulation of proline and glutathione, and altered ascorbate redox state, but resulted in the inhibition of the antioxidant enzymes. Upon co-treatment with NO, the non-enzymatic antioxidants were not particularly changed, but an upregulation of all antioxidant enzymes was found, which helped to keep ROS and LP under control. Overall, data point towards the benefits of NO against GLY in tomato plants by reducing the oxidative damage and stimulating detoxification pathways, while also preventing GLY-induced impairment of flowering and fruit fresh mass.
- Silicon improves the redox homeostasis to alleviate glyphosate toxicity in tomato plants—are nanomaterials relevant?Publication . Soares, Cristiano; Nadais, Pedro; Sousa, Bruno; Pinto, Edgar; Ferreira, Isabel M. P. V. O.; Pereira, Ruth; Fidalgo, FernandaGiven the widespread use of glyphosate (GLY), this agrochemical is becoming a source of contamination in agricultural soils, affecting non-target plants. Therefore, sustainable strategies to increase crop tolerance to GLY are needed. From this perspective and recalling silicon (Si)’s role in alleviating different abiotic stresses, the main goal of this study was to assess if the foliar application of Si, either as bulk or nano forms, is capable of enhancing Solanum lycopersicum L. tolerance to GLY (10 mg kg−1). After 28 day(s), GLY-treated plants exhibited growth-related disorders in both shoots and roots, accompanied by an overproduction of superoxide anion (O2•−) and malondialdehyde (MDA) in shoots. Although plants solely exposed to GLY have activated non-enzymatic antioxidant mechanisms (proline, ascorbate and glutathione), a generalized inhibition of the antioxidant enzymes was found, suggesting the occurrence of great redox disturbances. In response to Si or nano-SiO2 co-application, most of GLY phytotoxic effects on growth were prevented, accompanied with a better ROS removal, especially by an upregulation of the main antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Overall, results pointed towards the potential of both sources of Si to reduce GLY-induced oxidative stress, without major differences between their efficacy.