Percorrer por autor "Alves, Ricardo"
A mostrar 1 - 5 de 5
Resultados por página
Opções de ordenação
- Anticancer potential of spores of the soil fungus Pisolithus tinctoriusPublication . Oliveira, Rui S.; Alves, Ricardo; Preto, Marco; Martins, RosárioCancer is one of the major causes of death worldwide being the search for new anticancer drugs essential for the treatment of this disease. The sporocarps of the soil fungus Pisolithus tinctorius contain pisosterol, a triterpene that has been shown to have antitumor activity against some cancer cell lines. Nevertheless, no studies have focused on the anticancer potential of other structures such as spores, and so the anticancer potential of P. tinctorius, remains largely unknown. The main objective of this study was to evaluate the potential of P. tinctorius spores as a source of anticancer compounds.
- Cytotoxicity Induced by Extracts of Pisolithus tinctorius Spores on Human Cancer and Normal Cell Lines—Evaluation of the Anticancer PotentialPublication . Alves, Ricardo; Preto, Marco; Vasconcelos, Vítor; Oliveira, Rui S.; Martins, RosarioFungi have been considered a potential source of natural anticancer drugs. However, studies on these organisms have mainly focused on compounds present in the sporocarp and mycelium. The aim of this study was to assess the anticancer potential of fungal spores using a bioassay-guided fractionation with cancer and normal cell lines. Crude extracts from spores of the basidiomycetous fungus Pisolithus tinctorius were prepared using five solvents/solvent mixtures in order to select the most effective crude extraction procedure. A dichloromethane/methanol (DCM/MeOH) mixture was found to produce the highest extraction yield, and this extract was fractionated into 11 fractions. Crude extracts and fractions were assayed for cytotoxicity in the human osteocarcinoma cell line MG63, the human breast carcinoma cell line T47D, the human colon adenocarcinoma cell line RKO, and the normal human brain capillary endothelial cell line hCMEC/D3. Cytotoxicity was assessed by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) reduction assay. The results showed a reduction in cancer cell viability of approximately 95% with 4 of 11 fractions without a significant reduction in viability of hCMEC/D3 cells. Data demonstrated that spores of P. tinctorius might serve as an interesting source of compounds with potential anticancer properties.
- Cytotoxicity of the soil fungus Pisolithus tinctorius spores against cancer cells – a potential source of anticancer drugsPublication . Alves, Ricardo; Fernandes, João; Preto, Marco; Oliveira, Rui S.; Martins, RosarioCancer is one of the major causes of death worldwide being the search for new anticancer drugs essential for the treatment of this disease. The sporocarps of the soil fungus Pisolithus tinctorius contain pisosterol, a triterpene that has been shown to have antitumor activity against some cancer cell lines. Nevertheless, no studies have focused on the anticancer potential of other structures such as spores, and so the anticancer potential of P. tinctorius, remains largely unknown.
- Cytotoxity induced by extracts of Pisolithustinctorius spores on human cancer and normal cell lines – evaluation of the anticancer potentialPublication . Alves, Ricardo; Preto, Marco; Oliveira, Rui S.; Martins, RosárioCancer is one of the most important causes of death and morbidity worldwide. According to the World Health Organization 8.2 million people have died from cancer in 2012. The treatment of this fast growing disease is regarded as a major challenge in health for the XXI century. Conventional anti-cancer therapy is usually aggressive to the patients due to systemic toxicity caused by lack of specificity of the chemotherapy drugs (Kidd, 2000). This has triggered the interest of the scientific community to search for new and more effective therapies, less aggressive than conventional treatments. Used since antiquity in oriental civilizations, fungi, in particular mushrooms have been shown to limit or reverse tumor growth (Kidd, 2000). Pisolithustinctorius (Basidiomycota) is a soil fungus with world-wide distribution that it known to form ectomycorrhizal symbioses in forest ecosystems (Kope & Fortin, 1990). The sporocarps of this fungus contain Pisosterol, a triterpene that has been shown to have antitumor activity against some cancer cell lines (Montenegro et al., 2004). Nevertheless, no studies have focused on the anticancer potential of other structures such as spores and thus the anticancer potential of P. tinctorius , remains largely unknown.
- Sustainability and Ethics in Integrated Annual Reports – A Preliminary StudyPublication . Alves, Ricardo; Monteiro de Oliveira, Antonio; Borges, AaaPurpose: The importance of sustainability (De Villiers et al, 2022), as well as the way organizations report on issues related to their social performance (Ibáñez-Forés et al, 2023), has been increasing (De Villiers, et al, 2022; 2024; Şahin & Çankaya, 2020). This increase, especially in large European companies (Lock & Seele, 2016; Moneva et al, 2023; Tarquinio et al, 2018), is related to different objectives, among which we can highlight: legal obligation (Camilleri, 2022), the relationship between ethics, sustainability and financial performance (Kim et al, 2023; Thuy et al, 2021), or organizational reputation (Odriozola et al, 2017). Nevertheless, different authors (e.g., Elving, 2013; Greenwood & Van Buren, 2013; García-Sánchez et al., 2020; Zhao et al., 2023) have noted problems of lack of trust on the part of stakeholders with regard to the information disclosed (Nguyen et al., 2023), which they refer to as CSR-Scepticism and Green-Scepticism), and the credibility of this information is necessary for business development (Moggi, 2023). Within the scope of this analysis, behaviors and the reporting of sustainability and ethics are particularly relevant. Aguinis & Glavas (2019) point out that the most common method used to focus on the company and the analysis of its analytical results, but today it focuses on individual analysis (Kim et al., 2023; Marti et al., 2023; Zhao et al., 2023) and it is this reporting process that we propose to analyze. This analysis aims to contribute to the debate and, increasing prominence, of Sustainability and Ethics in the Integrated Annual Reports of large European companies. Methodology: We adopt post-positivism as philosophical ground and a quantitative approach. In data collection, we used systematic and individual documentary observation. The sample collected consists of 250 Integrated Reports from 25 companies over the period from 2013 to 2022 – 10 years. The 25 companies, 5 per country, were selected based on the Market Capitalization – national MarketCap, at the date the data was obtained. We selected 5 countries: Germany, France, Italy, Portugal and the United Kingdom and as a MarketCap proxy the main national indices: DAX 40, CAC 40, FTSE MIB, PSI 20 and FTSE 100 respectively. To compute the multiple regression models, we used STATA/SE 13.1. Results: The growing importance of Sustainability and Ethics references for the period under analysis is statistically significant. There is also statistically significant evidence regarding the Corporate Governance effect, the behavior of different countries, different sectors and their annual evolution. Research limitations: From an empirical point of view, the sample was limited to the 5 largest companies from 5 European countries, which limits the generalization of behavior. As this is a preliminary study, more must be carried out. Originality: This analysis is innovative in providing new insights into Sustainability and Ethics reporting in the Integrated Annual Reports of large European companies.