3 resultados para ANTIOXIDANT DEFENSES
em Repositório Científico da Universidade de Évora - Portugal
Resumo:
The high antioxidant activity of purslane, Portulaca oleracea L., gives it a high nutritional and functional value. The commercial production of purslane has increased in Portugal, making it necessary to know the effects of inputs, mainly nitrogen, on the antioxidant activity. The main goal of this study was to evaluate the influence of nitrogen application on purslane antioxidant activity. The experiment was carried out with for treatments: 30, 60 and 90 kg/ha of nitrogen. Plants of golden-leaf purslane were grown in Styrofoam-boxes filled with substrate and fertigated two times per week, over four weeks with ammonium nitrate solution (16.9% NO3-N and 16.7 NH4+-N). The increase in the nitrogen level decreased the water-soluble proteins content. However the ascorbate, phenols content as well as antioxidant activity measured by FRAP method was not affected by nitrogen level. Plants shoot antioxidant activity, measured by DPPH method decreased significantly in the treatment with 90 kg N/ha (26.20 g/g gallic acid). On the other hand, plant shoot antioxidant activity mediated by peroxidases was higher in treatment 30 kg N/ha (0.459 µmol min-1/mg prot.). Application of 60 kg N/ha allowed a vigorous plant growth without disturb its antioxidants and conservation properties.
Resumo:
Lavenders have been used in folk medicine as disinfectant, expectorant, analgesic, anti-spasmodic, laxative and stimulant. Some species are endemic of Iberian Peninsula and often found in the Portuguese montado, including Lavandula stoechas subsp. luisieri and Lavandula pedunculata. The investigation of the antioxidant and anti-inflammatory potential of the Portuguese montado flora is very poor and restricted to a few botanical families, and their biological activities are mainly attributed to the essential oils. So, it is crucial to know the properties of Lavandula EOs, contributing for animal health and the valorisation of Portuguese montado flora. The aim of this study was to evaluate chemical composition, antioxidant properties and screening anti-inflammatory potential of EOs and extracts of Lavandula stoechas L. subsps. luisieri Rozeira, Lavandula pedunculata (Mill.) Cav. subsp. pedunculata and Lavandula viridis L’Hér, wild grown in the south of Portugal.
Resumo:
In Alzheimer’s disease, the most common form of dementia, the loss of cholinergic neurons leads to the progressive reduction of acetylcholine in the brain, resulting cognitive impairment. Inhibition of the hydrolysis of acetylcholine by blocking acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) has been considered as a potential target in the treatment of Alzheimer’s disease. Essential oils and extracts of aromatic plants may have an important role in the oxidative stress protection. Traditionally, in Alentejo (Portugal), aromatic herbs Calamintha nepeta, Foeniculum vulgare, Mentha spicata and Thymus mastichina are often used by local population as condiments in food preparations. In this study, essential oils (EOs) and aqueous extracts (decoction waters) of these flavouring herbs were selected in order to evaluate its antioxidant potential and ability to inhibit AChE and BChE activities. Results suggest the potential use of EOs and extracts as nutraceutical or pharmaceutical preparations in the prevention of the oxidative stress and degenerative diseases.