Understanding the interactions between P-glycoprotein and microRNAs in the transfer of drug resistance by extracellular vesicles

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Leccinum vulpinum Watling: nutritional, antioxidant and antitumour potential

Publication . Reis, Filipa S.; Sousa, Diana; Barros, Lillian; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena

The global economic value of mushrooms is significant, not only due to their value as food [1] but also their medicinal properties, some of them having particularly been described to have antioxidant and antitumour potential [2,3]. Furthermore, some mushroom extracts have reached clinical trials. Additionally, in Japan, PSK (a polysaccharide conjugate isolated from Trametes versicolor (L.) Lloyd), is prescribed as an adjunct to conventional cancer therapies and surgical treatments of colorectal and gastric cancers [4]. The aim of this work was to study the chemical profile of Leccinum vulpinum Watling, regarding its content in nutrients and non-nutrients. Moreover, to study the in vitro antioxidant and antitumour potential of its phenolic extract. L. vulpinum wild samples were collected in Bragança, in the northeastern region of Portugal. The nutritional value was assessed following standard procedures. The individual profiles in soluble sugars, fatty acids and micronutrients were obtained through chromatographic techniques. The antioxidant potential of the phenolic extract was evaluated through the reducing power, DPPH radical-scavenging activity and lipid peroxidation inhibition assays. To assess the antitumour potential, the extract was screened against a panel of human tumour cell lines (MCF-7, NCI-H460, HCT-15 and AGS). Studies of effect on cell proliferation, cell cycle profile and apoptosis were performed on MCF-7 cells. The effect on DNA damage was evaluated with the Comet assay. L. vulpinum showed a nutritional profile with low fat levels, fructose, mannitol and trehalose as the foremost free sugars, and high percentage of mono- and polyunsaturated fatty acids. The main isoforms of vitamin E detected were the β- and γ-tocopherol. L. vulpinum also revealed the presence of phenolic acids (e.g., gallic, protocatechuic and p-hydroxybenzoic acids) and other organic acids (e.g., citric acid). The phenolic extract presented reducing capacity, radical-scavenging activity and lipid peroxidation inhibition. Regarding the antitumour potential, the extract inhibited the growth of all the tested cell lines. In addition, it decreased cellular proliferation, induced apoptosis and caused DNA damage of MCF-7 cells. The present study highlights the importance of conserving the national mycological resources, as a source of bioactive compounds with antioxidant and antitumour activity.

2016Conference object

Open access

Potencial antitumoral de cogumelos silvestres: um caso de estudo com espécies Leccinum.

Publication . Reis, Filipa S.; Sousa, Diana; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena

Além de constituírem uma excelente opção como alimento devido ao seu valor nutricional, os cogumelos (silvestres e/ou comerciais) têm sido descritos como matrizes naturais com inúmeras propriedades bioativas, incluindo potencial antitumoral [1,2]. No presente trabalho foi estudado um extrato fenólico, obtido da espécie Leccinum vulpinum Watling, que revelou ser rico essencialmente em ácidos hidroxibenzóicos (nomeadamente ácido gálico, ácido protocatéquico e ácido p-hidroxibenzóico). Foi efetuado um screening inicial, testando o referido extrato contra um painel de linhas celulares tumorais humanas (MCF-7: adenocarcinoma de mama; NCI-H460: carcinoma de pulmão; HCT-15: adenocarcinoma colorectal; e AGS: adenocarcinoma gástrico), de forma a verificar o seu efeito no crescimento celular das linhas em estudo. Uma vez que a proliferação celular foi inibida em todas as linhas testadas, e dada a evidência de uma relação inversa entre o consumo de cogumelos e a redução do risco de incidência do cancro da mama [3], foi efetuado um estudo detalhado na linha celular MCF-7. Para tal, foram realizados alguns ensaios funcionais, de modo a verificar os efeitos do extrato na proliferação celular, no perfil de ciclo celular e apoptose. O potencial do extrato como indutor de danos ao nível do ADN foi também avaliado. De uma forma geral, o extrato fenólico da espécie L. vulpinum diminuiu a proliferação celular, sendo que o tratamento celular com uma concentração de extrato correspondente ao GI75 reduziu significativamente a percentagem de células na fase S do ciclo celular. Adicionalmente, o extrato induziu apoptose, sendo que o tratamento celular com uma concentração de extrato correspondente ao GI50 e ao GI75 aumentou a percentagem de células em apoptose para 13,4% e para 27%, respectivamente, enquanto os valores controlo de apoptose foram de 6 - 9%. Os resultados obtidos sugerem também que o extrato em estudo causou danos ao nível do ADN celular, uma vez que proteínas envolvidas na reparação de danos no ADN, nomeadamente PARP, ficaram sobre-expressas nas células tratadas com o extrato. Isto foi confirmado pelo Ensaio Cometa (Alkaline Comet Assay), tendo sido verificado um aumento significativo da percentagem de ADN na “cauda” do Cometa, após tratamento celular com 250 mg/mL de extrato.

2016Conference object

Open access

Leccinum vulpinum Watling induces DNA damage, decreases cell proliferation and induces apoptosis on the human MCF-7 breast cancer cell line

Publication . Reis, Filipa S.; Sousa, Diana; Barros, Lillian; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena

The current work aimed to study the antitumour activity of a phenolic extract of the edible mushroom Leccinum vulpinum Watling, rich essentially in hydroxybenzoic acids. In a first approach, the mushroom extract was tested against cancer cell growth by using four human tumour cell lines. Given the positive results obtained in these initial screening experiments and the evidence of some studies for an inverse relationship between mushroom consumption and breast cancer risk, a detailed study of the bioactivity of the extract was carried out on MCF-7 cells. Once the selected cell line to precede the work was the breast adenocarcinoma cell line, the human breast non-malignant cell line MCF-10A was used as control. Overall, the extract decreased cellular proliferation and induced apoptosis. Furthermore, the results also suggest that the extract causes cellular DNA damage. Data obtained highlight the potential of mushrooms as a source of biologically active compounds, particularly with antitumour activity.

2016Journal article

Open access

Leccinum vulpinum Watling: nutritional, antioxidant and antitumour potential

Publication . Reis, Filomena; Sousa, Diana; Barros, Lillian; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena

The global economic value of mushrooms is significant, not only due to their value as food [1] but also their medicinal properties, some of them having particularly been described to have antioxidant and antitumour potential [2,3]. Furthermore, some mushroom extracts have reached clinical trials. Additionally, in Japan, PSK (a polysaccharide conjugate isolated from Trametes versicolor (L.) Lloyd), is prescribed as an adjunct to conventional cancer therapies and surgical treatments of colorectal and gastric cancers [4]. The aim of this work was to study the chemical profile of Leccinum vulpinum Watling, regarding its content in nutrients and non-nutrients. Moreover, to study the in vitro antioxidant and antitumour potential of its phenolic extract. L. vulpinum wild samples were collected in Bragança, in the northeastern region of Portugal. The nutritional value was assessed following standard procedures. The individual profiles in soluble sugars, fatty acids and micronutrients were obtained through chromatographic techniques. The antioxidant potential of the phenolic extract was evaluated through the reducing power, DPPH radical-scavenging activity and lipid peroxidation inhibition assays. To assess the antitumour potential, the extract was screened against a panel of human tumour cell lines (MCF-7, NCI-H460, HCT-15 and AGS). Studies of effect on cell proliferation, cell cycle profile and apoptosis were performed on MCF-7 cells. The effect on DNA damage was evaluated with the Comet assay. L. vulpinum showed a nutritional profile with low fat levels, fructose, mannitol and trehalose as the foremost free sugars, and high percentage of mono- and polyunsaturated fatty acids. The main isoforms of vitamin E detected were the β- and γ-tocopherol. L. vulpinum also revealed the presence of phenolic acids (e.g., gallic, protocatechuic and p-hydroxybenzoic acids) and other organic acids (e.g., citric acid). The phenolic extract presented reducing capacity, radical-scavenging activity and lipid peroxidation inhibition. Regarding the antitumour potential, the extract inhibited the growth of all the tested cell lines. In addition, it decreased cellular proliferation, induced apoptosis and caused DNA damage of MCF-7 cells. The present study highlights the importance of conserving the national mycological resources, as a source of bioactive compounds with antioxidant and antitumour activity.

2016Conference object

Open access

Leccinum vulpinum antitumor potential: which cell biological functions may be affected?

Publication . Reis, Filipa S.; Sousa, Diana; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.

Besides being an excellent choice as food for their high nutritional value, mushrooms have been identified as products with bioactive properties, including antitumor potential. Herein, a phenolic extract, obtained from the edible mushroom Leccinum vulpinum Watling, which was rich essentially in hydroxybenzoic acids (i.e., gallic acid, protocatechuic acid and p-hydroxybenzoic acid) was analyzed. The extract was tested against a panel of four different human tumor cell lines (MCF-7, NCI-H460, HCT-15 and AGS), to perform an initial screening of its impact on the growth of these cells. Since the proliferation of all the tumor cell lines was inhibited, and given the evidence of an inverse relationship between mushroom’s consumption and breast cancer risk reduction [1], a detailed study was performed on breast adenocarcinoma cells. Some functional assays were carried out, namely cell proliferation, cell cycle profile and apoptosis. The potential of the extract as an inducer of DNA damage was also evaluated. Overall, the extract decreased the cellular proliferation (cells treated with the GI75 concentration of the extract reduced significantly the percentage of cells in the S-phase) and induced apoptosis (cells treated with the GI50 concentration of the extract increased the percentage of cells undergoing apoptosis to 13.4% and cells treated with the GI75 concentration increased that percentage to 27%). The obtained results suggest that the extract also causes cellular DNA damage, since some proteins involved in the repair of DNA damage (PARP), are increased. Through the Comet assay, a significant increase of the percentage of Tail DNA upon treatment with 250 mg/mL of the extract, was also observed.

2016Conference object

Open access