Bioactive properties of wild edible mushrooms

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Phenolics and Antioxidant Activity of Mushroom Leucopaxillus giganteus Mycelium at Different Carbon Sources

Publication . Barros, Lillian; Ferreira, Isabel C.F.R.; Baptista, Paula

This article reports the first approach to the antioxidant potential evaluation of the edible mushroom Leucopaxillus giganteus mycelium obtained in the presence of four different carbon sources: glucose, sucrose, fructose and mannitol. Despite the use of Leucopaxillus mushroom species in chemical industry for extraction of clitocybin antibiotic, the production of its mycelium for pharmacological applications has not been explored. The concentration of antioxidant compounds increased along the growth time as a response to the oxidative stress and therefore free radicals production. The aldohexose glucose proved to be the most appropriate carbon source to increase antioxidant activity, leading to the highest phenols content and lowest EC50 values. Significant negative linear regressions were established between phenols and flavonoids contents, and antioxidant activity, which support that the extracts mechanism of action for the different antioxidant activity assays may be identical, being related with the content in those compounds and their free radical scavenging activity.

2008Journal article

Open access

Actividade antioxidante de Lactarius piperatus em diferentes fases de maturação

Publication . Barros, Lillian; Baptista, Paula; Ferreira, Isabel C.F.R.

Neste trabalha, avaliou-se o efeito do estado de maturação do corpo frutificante de um cogumelo silvestre, Lactarius piperatus, na sua actividade antioxidante e produção de antioxidantes. Realizaram-se vários testes bioquímicos para determinar as propriedades antioxidantes: poder redutor, capacidade bloqueadora de radicais DPPH (2,2-difenil-l-picrilhidrazilo), inibição da hemólise de eritrócios mediada por radicais peroxilo e inibição da peroxidação lipídica pelo método do β–carotenolinoleato. Foram também determinadas as quantidades de fenóis, flavonóides, ácido ascórbico, β-caroteno e licopeno presentes em corpos frutificantes imaturos, maturos e degradados. O estado maturo, mas ainda com esporos imaturos foi aquele em que foram encontrados mais antioxidantes e valores de EC50 mais baixos para a actividade antioxidante.

2007Conference object

Open access

Free radical scavenging activity and bioactive compounds of five Agaricus sp. edible mushrooms

Publication . Barros, Lillian; Baptista, Paula; Correia, Daniela M.; Ferreira, Isabel C.F.R.

Reactive oxygen and free radicals play an important role in cellular injury and the ageing process and also are considered to induce the lipid peroxidation that causes the deterioration of foods. Although organisms have endogenous antioxidant defenses produced during normal cell aerobic respiration against the reactive oxygen species, other antioxidants are taken from the diet, both from natural or synthetic origin.

2007Conference object

Open access

Free-radical scavenging capacity and reducing power of wild edible mushrooms from northeast Portugal: individual cap and stipe activity

Publication . Ferreira, Isabel C.F.R.; Baptista, Paula; Vilas-Boas, Miguel; Barros, Lillian

The antioxidant properties of two wild edible mushroom species from the northeast of Portugal, Lactarius deliciosus (L.) Gray and Tricholoma portentosum (Fr.) Que´l., were evaluated. Methanolic extracts from the entire mushroom, the cap and the stipe, separately, were screened for their reducing power and free radical scavenging capacity by chemical assays. The total phenolic content was determined, in order to assess its effect on the extract’s antioxidant activity. Both two species showed antioxidant potential; but L. deliciosus proved to be more active. The portion of the mushroom used had an influence on the results obtained, with the cap methanolic extracts exhibiting the greatest antioxidant effect.

2007Journal article

Open access

Propriedades antioxidantes de extractos metanólicos de Lactarius deliciosus (L.) Gray

Publication . Ferreira, Isabel C.F.R.; Baptista, Paula; Vilas-Boas, Miguel; Azevedo, Cristina; Silva, Neusa; Barroso, Patrícia; Freire, Joana C.F.

As espec1es reactivas de oxigénio formam-se durante o metabolismo celular normal. mas em altas concentrações podem tornar-se tóxicas. As células dos mamíferos possuem defesas intracelulares como a superóxido dismutase, a catalase ou a glutationa peroxidase, que as protegem de níveis excessivos de radicais livres. A adição de compostos exógenos, nomeadamente vitaminas (A, E, β-caroteno), minerais ( selénio, zinco) e proteínas (transferrina, ceruleoplasmina, albumina) pode constituir uma protecção adicional. Estes antioxidantes naturais capazes de neutralizar radicais livres podem ter um papel central na prevenção de doenças vasculares. algumas formas de cancro e de stress oxidativo responsável por danos no DNA e nas proteínas.

2005Conference object

Open access