Percorrer por autor "Sousa, Diana"
A mostrar 1 - 10 de 17
Resultados por página
Opções de ordenação
- Achillea millefolium L. hydroethanolic extract inhibits growth of human tumor cell lines by interfering with cell cycle and inducing apoptosisPublication . Pereira, Joana M.; Peixoto, Vanessa; Teixeira, Alexandra Margarida; Sousa, Diana; Barros, Lillian; Ferreira, Isabel C.F.R.; Vasconcelos, M. Helena
- Cell growth inhibitory effect of an aqueous extract of Achillea millefolium in human tumor cell linesPublication . Pereira, Joana M.; Peixoto, Vanessa; Teixeira, Alexandra Margarida; Sousa, Diana; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaPlants used in folk medicine have increased importance in the pharmaceutical field. Achillea millefolium, also known as yarrow, is a traditional plant that can be found in Europe, Asia, North Africa and North America [1, 2]. Yarrow was shown to have antitumour, antimicrobial, antiinflammatory and antioxidant properties [3]. Indeed, several studies indicated that this plant has antioxidant potential due to its chemical composition in phenolic acids and flavones [3]. The aim of this work was to study if an aqueous extract of A. millefolium presents cell growth inhibitory activity in three human tumor cell lines: non-small cell lung cancer (NCI-H460), human colorectal adenocarcinoma (HCT-15) and breast adenocarcinoma (MCF-7). Sulforhodamine B assay was carried out to determine in which cells the extract was more potent. In addition, the effect of the aqueous extract on NCI-H460 cell cycle profile and programmed cell death was analyzed by flow cytometry following incubation with propidium iodide (PI) or Annexin V-FICT/PI staining, respectively. Results showed that A. millefolium extract inhibited the growth of the mentioned cell lines. Moreover, further studies of this extract in NCI-H460 cells indicated that the reduction in cell growth was due to alterations in cell cycle profile and in apoptosis. Future work will also include analysis of protein expression by Western Blot to further unravel the mechanism of action of this extract.
- Cordyceps militaris (L.) link fruiting body reduces NCI-H460 cellular viability through a mechanism involving p53 and p21Publication . Bizarro, Ana; Ferreira, Isabel C.F.R.; Soković, Marina; Van Griensven, Leo J.L.D.; Sousa, Diana; Vasconcelos, M. Helena; Lima, Raquel T.Mushroom extracts are recognized by their numerous potential medicinal properties. Recently, a methanolic extract from Cordyceps militaris (L.) Link (an edible entomopathogenic fungus widely used in traditional Chinese medicine) has been shown to inhibit cell growth of several human tumour cell lines [1,2]. However, its mechanism of action remained unknown. The aim of the present work was to study the antitumour mechanism of action of the methanolic extract of C. militaris, in the NCI-H460 cell line which is representative of non-small cell lung cancer. Results showed that the extract reduced viable cell number (observed with the trypan blue exclusion assay) by: i) decreasing cellular proliferation (analysed with the BrdU incorporation assay), ii) inducing cell cycle arrest at GO/GI phase (analysed by flow cytometry following propidium iodide-PI labelling) and iii) increasing apoptosis (analysed by flow cytometry following Annexin V-FITC and PI labelling). In addition, results also showed that treatment with the extract increased the cellular levels of p53 and p21. Moreover, this study also showed evidences of DNA damage caused by this extract, since an increase in the levels ofp-H2A.X and 53BP1 were observed, together with an increase in the number of 53BP1 foci/cell. In conclusion, this extract reduced NCI-H460 cellular viability, possibly through a mechanism which involves DNA damage and p53.
- Cordyceps militaris (L.) Link fruiting body reduces the growth of a non-small cell lung cancer cell line by increasing cellular levels of p53 and p21Publication . Bizarro, Ana; Ferreira, Isabel C.F.R.; Soković, Marina; Van Griensven, Leo J.L.D.; Sousa, Diana; Vasconcelos, M. Helena; Lima, Raquel T.Cordyceps militaris (L.) Link, an edible entomopathogenic fungus widely used in traditional Chinese medicine, has numerous potential medicinal properties including antitumor activity. The methanolic extract of C. militaris fruiting body was recently shown to have tumor cell growth inhibitory activity in several human tumor cell lines. Nonetheless, the mechanism of action involved is still not known. This work aimed at further studying the effect of the methanolic extract of C. militaris regarding its antitumor mechanism of action, using the non-small cell lung cancer cell line (NCI-H460) as a model. Results showed that treatment with the extract decreased cellular proliferation, induced cell cycle arrest at G0/G1 and increased apoptosis. In addition, the extract increased the levels of p53 and p21. Moreover, an increase in p-H2A.X and 53BP1 levels, together with an increase in the number of 53BP1 foci/cell (all indicative of DNA damage), were also observed after treatment with the extract. This work suggests that this extract affected NCI-H460 cellular viability through a mechanism involving DNA damage and p53 activation. This further supports the potential of this extract as a source of bioactive compounds, which may be used in anticancer strategies.
- Flower extracts of Filipendula ulmaria (L.) Maxim inhibit cell growth of human tumour cell linesPublication . Lima, M. João; Sousa, Diana; Lima, Raquel T.; Carvalho, Ana Maria; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaAccording to the World Health Organization, cancer is the leading cause of death worldwide and its mortality is expected to rise in the next few years. Despite all efforts, the current therapeutic arsenal is not sufficient to reduce these numbers. Therefore, it is imperative to identify new sources of anticancer drugs. Filipendula ulmaria (L.) Maxim is part of the ethnobothanical patrimony of the Iberian Peninsula. For centuries, it has been used as a medicinal species due to its rich antioxidant content, which includes flavonoids and ascorbic acid [l]. Nonetheless, little is known about its antiproliferative activity in cancer cells. Thus, the aims of this project were to: i) investigate if different flower extracts of F. ulmaria have cell growth inhibitory activity in human tumour cell lines and ii) study the mechanism of action of one of the most potent extracts. Four flower extracts obtained by different extraction methods (decoction, infusion, methanol and methanol:water 80:20, v!v) were screened for tumour cell growth inhibitory activity in three human tumour cell lines: NCI-H460 (non-small cell lung cancer), A375-C5 (melanoma) and MCF-7 (breast adenocarcinoma). One of the most potent extracts (obtained by decoction) was further studied in the NCI-H460 cell line (one of the most sensitive), by investigating its effect on viable cell number, programmed cell death, cellular proliferation and cell cycle profile. Results showed that all extracts have growth inhibitory activity in the studied cell lines, in particular the extract obtained by decoction (GI50 of 70.0 ± 8.6, 96.0 ± 12.4 and 63.3 ± 7.6 flg/mL in the NCI-H460, MCF-7 and A373-C5 cells, respectively). Further studies in the NCI-H460 cell line showed that this extract reduced viable cell number. Moreover, treatment with this extract resulted in a strong reduction of cellular proliferation, with a slight increase in the percentage of cells in the G l phase of the cell cycle. No significant alterations in programmed cell death were observed, although results showed a statistically significant increase in the cellular levels of p53 and p2l. Future work will confirm if this extract is non-toxic to human non-tumour cells.
- Flower extracts of Filipendula ulmaria (L.) Maxim inhibit the proliferation of human tumour cell linesPublication . Lima, M. João; Sousa, Diana; Lima, Raquel T.; Carvalho, Ana Maria; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaEthnobotanical surveys document wild plants that have been commonly used worldwide to prepare homemade remedies. Filipendula ulmaria (L.) Maxim (meadowsweet) is good example ofa popular medicinal species that can be found throughout most Europe and Asia.
- Flower extracts of Filipendula ulmaria (L.) Maxim inhibit the proliferation of the NCI-H460 tumour cell linePublication . Lima, M. João; Sousa, Diana; Lima, Raquel T.; Carvalho, Ana Maria; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaFilipendula ulmaria (L.) Maxim (meadowsweet) is a popular medicinal species that can be found throughout most Europe and Asia. The plant is known for its rich antioxidants content, having compounds such as flavonoids and ascorbic acid. Therefore, the aim of this work was to investigate if the flower extracts of F. ulmaria (L.) Maxim have cell growth inhibitory activity in three human tumour cell lines representative of non-small cell lung cancer (NCI-H460), melanoma (A375-C5) and breast adenocarcinoma (MCF-7). One of the most potent extracts was selected to be further studied in the NCI-H460 cells, by investigating its antiproliferative potential, the effect on cell cycle profile and on programmed cell death. The obtained results showed that all the extracts inhibited the growth of the mentioned cell lines, with the one obtained by decoction being the most potent. Its effect on the NCI-H460 cells was due to a reduction in cellular proliferation, but not to alterations in programmed cell death. Interestingly, cellular treatment with the extract caused a statistically significant increase in the cellular levels of p21. Data obtained highlight the potential interest of F. ulmaria as a source of bioactive compounds.
- 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.
- Leccinum vulpinum Watling induces DNA damage, decreases cell proliferation and induces apoptosis on the human MCF-7 breast cancer cell linePublication . Reis, Filipa S.; Sousa, Diana; Barros, Lillian; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaThe 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.
- Leccinum vulpinum Watling: nutritional, antioxidant and antitumour potentialPublication . Reis, Filomena; Sousa, Diana; Barros, Lillian; Martins, Anabela; Morales, Patricia; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaThe 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.