Cytotoxic effect of Agaricus bisporus and Lactarius rufus β-d-glucans on HepG2 cells

AbstractThe cytotoxic activity of β-d-glucans isolated from Agaricus bisporus and Lactarius rufus fruiting bodies was evaluated on human hepatocellular carcinoma cells (HepG2). NMR and methylation analysis suggest that these β-d-glucans were composed of a linear (1→6)-linked and a branched (1→3), (1→6)-linked backbone, respectively. They both decreased cell viability at concentrations of up to 100μgmL−1, as shown by MTT assay. The amount of LDH released and the analysis of cell morphology corroborated these values and also showed that the β-d-glucan of L. rufus was more cytotoxic to HepG2 cells than that of A. bisporus. The treatment of HepG2 cells with L. rufus and A. bisporus β-d-glucans at a dose of 200μgmL−1 for 24h promoted an increase of cytochrome c release and a decrease of ATP content, suggesting that these polysaccharides could promote cell death by apoptosis. Both β-d-glucans were tested against murine primary hepatocytes at a dose of 200μgmL−1. The results suggest that the L. rufus β-d-glucan was as cytotoxic for hepatocytes as for HepG2 cells, whereas the A. bisporus β-d-glucan, under the same conditions, was cytotoxic only for HepG2 cells, suggesting cell selectivity. These results open new possibilities for use of mushroom β-d-glucans in cancer therapy

Effect of temperature acclimation on the liver antioxidant defence system of the Antarctic nototheniids Notothenia coriiceps and Notothenia rossii

Made available in DSpace on 2019-09-12T16:53:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2014Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Instituto Nacional de Ciência e Tecnologia Antártico de Pesquisas Ambientais (INCT-APA)The aim of this study was to determine whether endemic Antarctic nototheniid fish are able to adjust their liver antioxidant defence system in response to the temperature increase. The activity of the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) enzymes as well as the content of non-enzymatic oxidative stress markers such as reduced glutathione (GSH), lipid peroxidation (LPO) and protein carbonyl (PC) were measured in the liver of two Antarctic fish species, Notothenia rossii and Notothenia coriiceps after 1,3 and 6 days of exposure to temperatures of 0 C and 8 C. The GST activity showed a downregulation in N. rossii after 6 days of exposure to the increased temperature. The activity profiles of GST and GR in N. rossii and of GPx in N. coriiceps also changed as a consequence of heating to 8 C. The GSH content increased by heating to 8 C after 3 days in N. coriiceps and after 6 days in N. rossii. The content of malondialdehyde (MDA), a LPO marker, showed a negative modulation by the heating to 8 C in N. rossii after 3 days of exposure to temperatures. Present results show that heating to 8 C influenced the levels and profiles of the antioxidant enzymes and defences over time in the nototheniid fish N. rossii and N. coriiceps. (C) 2014 Elsevier Inc. All rights reserved.[Machado, Cintia; Zaleski, Tania; Krebsbach, Priscila; Rios, Flavia Sant'Anna; Donatti, Lucelia] Univ Fed Parana, Dept Cell Biol, Adapt Biol Lab, BR-80060000 Curitiba, Parana, Brazil[Rodrigues, Edson] Universidade de Taubaté (Unitau), Basic Biosci Inst, Sao Paulo, Brazil[Carvalho, Cleoni dos Santos] Univ Fed Sao Carlos, Dept Biol, Sorocaba, SP, Brazil[Suter Correia Cadena, Silvia Maria; Gozzi, Gustavo Jabor] Univ Fed Parana, Dept Biochem, Curitiba, Parana, Brazi

Hypoxia protects against the cell death triggered by oxovanadium–galactomannan complexes in HepG2 cells

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Celecoxib prevents tumor growth in an animal model by a COX-2 independent mechanism

Nonsteroidal antiinflammatory drugs (NSAIDs) have been shown to reduce cell growth in several tumors. Among these possible antineoplastic drugs are cyclooxygenase-2 (COX-2)-selective drugs, such as celecoxib, in which antitumoral mechanisms were evaluated in rats bearing Walker-256 (W256) tumor. W256 carcinosarcoma cells were inoculated subcutaneously (10(7) cells/rat) in rats submitted to treatment with celecoxib (25 mg kg(-1)) or vehicle for 14 days. Tumor growth, body-weight gain, and survival data were evaluated. The mechanisms, such as COX-2 expression and activity, oxidative stress, by means of enzymes and lipoperoxidation levels, and apoptosis mediators were also investigated. A reduction in tumor growth and an increased weight gain were observed. Celecoxib provided a higher incidence of survival compared with the control group. Cellular effects are probably COX-2 independent, because neither enzyme expression nor its activity, measured by tumoral PGE(2), showed significant difference between groups. It is probable that this antitumor action is dependent on an apoptotic way, which has been evaluated by the expression of the antiapoptotic protein Bcl-xL, in addition to the cellular changes observed by electronic microscopy. Celecoxib has also a possible involvement with redox homeostasis, because its administration caused significant changes in the activity of oxidative enzymes, such as catalase and superoxide dismutase. These results confirm the antitumor effects of celecoxib in W256 cancer model, contributing to elucidating its antitumoral mechanism and corroborating scientific literature about its effect on other types of cancer.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)[402414/2005-5]UFPRUFP