[Show abstract][Hide abstract] ABSTRACT: Intestinal cancers are correlated with diet. Thus, determining and understanding nutrient-genome interactions is important. The present work assessed the action of the oligoelement selenium on cell proliferation, cytotoxicity, and in situ apoptosis induction and on the expression CASP9, BCL-XL and APC genes in intestinal adenocarcinoma cells (HT29). HT29 cells were cultured and treated with selenium at concentrations of 5, 50 and 500ng/mL with or without the damage-inducing agent doxorubicin. These cells were then evaluated for cytotoxicity (MTT), cell proliferation and in situ apoptosis induction. To evaluate gene expression, only the cells treated with 500ng/mL of selenium were used. RNA was extracted from these cells, and the expressions of CASP9, BCL-XL and APC were analyzed by the RT-PCR method. The GAPDH gene was used as a reference gene. The MTT assay showed that selenium was not cytotoxic at any of the concentrations tested. The cell proliferation assay showed that selenium did not interfere with cell proliferation at the three concentrations tested. In contrast, when the three concentrations were combined with doxorubicin, a significant decrease in the proliferation rate was observed. The apoptosis rate was significantly increased in the selenium (500ng/mL) and doxorubicin group. CASP9 expression was increased and BCL-XL expression decreased in the selenium (500ng/mL) and doxorubicin group. APC was significantly increased in the selenium group alone. These results show that selenium increases apoptosis, especially when it is associated with a damage-inducing agent. Also, selenium has an important role in the expression of the APC gene, which is related to cell cycle regulation.
Full-text · Article · Jul 2011 · Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
[Show abstract][Hide abstract] ABSTRACT: The development of various types of cancer results from the interaction among endogenous, environmental and hormonal factors, where the most notable of these factors is diet. The aim of the present study was to determine the antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities of Agaricus blazei. The test antigenotoxicity (Comet Assay) and anticarcinogenic (Test of Aberrant Crypt Foci) assess changes in DNA and/or intestinal mucosa that correlate to cancer development. Tests of phagocytosis in the spleen and differential count in blood cells allow the inference of modulation of the immune system as well as to propose a way of eliminating cells with DNA damage. Supplementation with the mushroom was carried out under pre-treatment, simultaneous treatment, post-treatment and pre-treatment+continuous conditions. Statistical analysis demonstrated that the mushroom did not have genotoxic activity but showed antigenotoxic activity. Supplementation caused an increase in the number of monocytes and in phagocytic activity, suggesting that supplementation increases a proliferation of monocytes, consequently increasing phagocytic capacity especially in the groups pre-treatment, simultaneous and pre-treatment+continuous. The data suggest that A. blazei could act as a functional food capable of promoting immunomodulation which can account for the destruction of cells with DNA alterations that correlate with the development of cancer, since this mushroom was demonstrated to have a preventive effect against pre-neoplastic colorectal lesions evaluated by the aberrant crypt foci assay. According to these results and the literature, it is believed that supplementation with A. blazei can be an efficient method for the prevention of cancer as well as possibly being an important coadjuvant treatment in chemotherapy.
Full-text · Article · Feb 2011 · Regulatory Toxicology and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Endo-1,4-β-xylanases are extracellular enzymes that make the hydrolysis of substrates β 1,4. Xylan is the main representative among the substrates that are susceptible to hydrolytic attack of xylanases. Xylanases have a wide application in different sectors of the economy. The purpose of this study was to review the published literature on the main methodologies used to study these enzymes, as well as gather some kinetic parameters. The reviewed methodologies are centered mainly in the purification process, since that is an essential step for the optimization of its enzymatic activity and therefore industrial application. The highlights are the techniques that use the saline precipitation and refined methodologies as chromatography and its variations, as well as factorial design studies and enzyme immobilization. These methodologies aim respectively, among other things, optimal conditions for enzyme production and recycling.
[Show abstract][Hide abstract] ABSTRACT: This study aimed to evaluate the quimiopreventive ability of phenylalanine. We used pregnant and non-pregnant female mice divided into the following groups: G1-PBS, (0.1 mL/kg b.w); G2, cyclophosphamide (35 mg/kg p.c.-i.p.); G3 and G4, phenylalanine (150 and 300 mg/kg b.w respectively-v.o.) and G5 and G6, association between the two doses of phenylalanine and cyclophosphamide, respectively. The peripheral blood samples were taken at T0, before the administration of any drug test and / or vehicles, also at T24 and T48 where the collections were made 24 and 48 h after administration of cyclophosphamide, respectively. A general analysis has found that, for the group of non-pregnant female, the antimutagenic evaluation showed reduction percentages of damage of 57.24% and 31.64% for G5 and G6, respectively, at T24, and 29.32% and 24.13% for G5 and G6, respectively, at T48. Antimutagenic pregnant animals in the 24 h quimiopreventive efficiency shown only for the lower dose (G5) and the percentages of reduction were 43.25% in G5 and G6 at 18.47%. At T48 the harm-reduction percentages were 44.67% and 37.76% for G5 and G6, respectively.
Full-text · Article · Jun 2010 · Revista Brasileira de Farmacognosia
[Show abstract][Hide abstract] ABSTRACT: The modifications in the society have as consequence the change in the life style that determine alterations of the alimentary habits causing, amongst other damages to the health, the increase of the incidence of cancer in the population. The functional food introductions in the daily feed- ing can assist in the prevention and treatment of diseases. Amongst used functional foods more the green tea is distinguished. This bibliographical revision presents the benefits of this grass in studies that studies evidence the efficiency in the prevention and the treatment of the cancer, demonstrating its antioxidant and chemmeotherapy activity.