Showing papers by "Lusânia Maria Greggi Antunes published in 2017"

Cocoplum (Chrysobalanus icaco L.) anthocyanins exert anti-inflammatory activity in human colon cancer and non-malignant colon cells

Abstract: Cocoplum (Chrysobalanus icaco L.) (CP) is an anthocyanin-rich fruit found in tropical areas around the globe. CP polyphenols are associated with beneficial effects on health, including reduction of inflammation and oxidative stress. Due to its functional properties, the consumption of this fruit may be beneficial in the promotion of human health and reduce the risk for chronic diseases. The objective of this study was to assess the anti-inflammatory and anti-proliferative activities of anthocyanins extracted from CP (1.0 to 20.0 μg ml−1 gallic acid equivalents [GAE]) in CCD-18Co non-malignant colonic fibroblasts and HT-29 colorectal adenocarcinoma cells. Tumor necrosis factor alpha (TNF-α, 10 ng mL−1) was used to induce inflammation in CCD-18Co cells. CP anthocyanins were identified and quantified using HPLC-ESI-MSn. The chemical analysis of CP extract identified delphinidin, cyanidin, petunidin and peonidin derivatives as major components. Cell proliferation was suppressed in HT-29 cells at 10.0 and 20.0 μg ml−1 GAE and this was accompanied by increased intracellular ROS production as well as decreased TNF-α, IL-1β, IL-6, and NF-κB1 expressions at 20.0 μg ml−1 GAE. Within the same concentration range, there was no cytotoxic effect of CP anthocyanins in CCD-18Co cells and TNF-α-induced intracellular ROS-production was decreased by 17.3%. IL-1β, IL-6 and TNF-α protein expressions were also reduced in TNF-α-treated CCD-18Co cells by CP anthocyanins at 20.0 μg ml−1 GAE. These results suggest that cocoplum anthocyanins possess cancer-cytotoxic and anti-inflammatory activities in both inflamed colon and colon cancer cells.

CR-LAAO, an L-amino acid oxidase from Calloselasma rhodostoma venom, as a potential tool for developing novel immunotherapeutic strategies against cancer.

Abstract: L-amino acid oxidases from snake venoms have been described to possess various biological functions. In this study, we investigated the inflammatory responses induced in vivo and in vitro by CR-LAAO, an L-amino acid oxidase isolated from Calloselasma rhodostoma venom, and its antitumor potential. CR-LAAO induced acute inflammatory responses in vivo, with recruitment of neutrophils and release of IL-6, IL-1β, LTB4 and PGE2. In vitro, IL-6 and IL-1β production by peritoneal macrophages stimulated with CR-LAAO was dependent of the activation of the Toll-like receptors TLR2 and TLR4. In addition, CR-LAAO promoted apoptosis of HL-60 and HepG2 tumor cells mediated by the release of hydrogen peroxide and activation of immune cells, resulting in oxidative stress and production of IL-6 and IL-1β that triggered a series of events, such as activation of caspase 8, 9 and 3, and the expression of the pro-apoptotic gene BAX. We also observed that CR-LAAO modulated the cell cycle of these tumor cells, promoting delay in the G0/G1 and S phases. Taken together, our results suggest that CR-LAAO could serve as a potential tool for the development of novel immunotherapeutic strategies against cancer, since this toxin promoted apoptosis of tumor cells and also activated immune cells against them.

Lead (Pb) exposure induces disturbances in epigenetic status in workers exposed to this metal.

Abstract: Previous studies showed that lead (Pb) exposure may modulate gene expression by changes in the epigenetic status. However, little is known about the impact of Pb exposure and alterations on DNA methylation patterns in humans exposed to this metal. The aim of this study was to assess the consequences of exposure to Pb on DNA global methylation, in order to gain a better understanding of the interactions between Pb exposure and epigenetic effects. The study included 100 male workers employed in automotive battery factories from Parana State, Brazil. Concentrations of Pb in blood (B-Pb) and plasma (P-Pb) were determined by ICP-MS, the percentage (%) of global DNA methylation was determined by quantification of 5-methylcytosine using indirect ELISA, and sociodemographic data collected by questionnaire by trained interviewers. The mean age was 37 ± 10 (18–67 years); 18% of participants were smokers, while 32% reported consumption of alcoholic beverages. The B-Pb and P-Pb levels were 20 ± 11 and 0.56 ± ...

Evaluation of distribution, redox parameters, and genotoxicity in Wistar rats co-exposed to silver and titanium dioxide nanoparticles

Abstract: The increasing production of silver nanoparticles (AgNPs) and titanium dioxide nanoparticles (TiO2NPs) has resulted in their elevated concentrations in the environment. This study was, therefore, aimed at determining the distribution, redox parameters, and genotoxic effects in male Wistar rats that were treated with either AgNP or TiO2NP individually, as well as under a co-exposure scenario. Animals were exposed via oral gavage to either sodium citrate buffer (vehicle), 0.5 mg/kg/day TiO2NP, 0.5 mg/kg/day AgNP or a mixture of TiO2NPs and AgNPs. Exposure lasted 45 days after which rats were sacrificed, and tissue biodistribution of Ag and Ti measured. The blood concentration of glutathione (GSH) and activities of glutathione peroxidase (GPx) and catalase (CAT) were determined while the genotoxicity was analyzed using the comet assay in peripheral blood and liver cells. The tissue concentrations of Ag followed the order; blood > liver > kidneys while for Ti the order was kidneys > liver > blood. The...

Methionine-supplemented diet affects the expression of cardiovascular disease-related genes and increases inflammatory cytokines in mice heart and liver.

Abstract: Some important environmental factors that influence the development of cardiovascular diseases (CVD) include tobacco, excess alcohol, and unhealthy diet. Methionine obtained from the diet participates in the synthesis of DNA, proteins, lipids and affects homocysteine levels, which is associated with the elevated risk for CVD development. Therefore, the aim of this study was to investigate the manner in which dietary methionine might affect cellular mechanisms underlying CVD occurrence. Swiss albino mice were fed either control (0.3% DL-methionine), methionine-supplemented (2% DL-methionine), or a methionine-deprived diet (0% DL-methionine) over a 10-week period. The parameters measured included plasma homocysteine concentrations, oxidative stress by reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, levels of inflammatory cytokines IL-1s, TNF-α, and IL-6, as well as expression of genes associated with CVD. The levels of apolipoprotein A5 (APOA5), a regulator of plasma triglycerides, were measured. The methionine-supplemented diet increased oxidative stress by lowering the GSH/GSSG ratio in heart tissues and decreased expression of the genes Apob, Ctgf, Serpinb2, Spp1, Il1b, and Sell, but elevated expression of Thbs4, Tgfb2, Ccr1, and Vegfa. Methionine-deprived diet reduced expression of Col3a1, Cdh5, Fabp3, Bax, and Hbegf and increased expression of Sell, Ccl5, Itga2, Birc3, Msr1, Bcl2a1a, Il1r2, and Selp. Methionine-deprived diet exerted pro-inflammatory consequences as evidenced by elevated levels of cytokines IL-1s, TNF-α, and IL-6 noted in liver. Methionine-supplemented diet increased hepatic IL-6 and cardiac TNF-α. Both methionine supplementation and deprivation lowered hepatic levels of APOA5. In conclusion, data demonstrated that a methionine-supplemented diet modulated important biological processes associated with high risk of CVD development.