Cátia dos Santos Branco

Resveratrol and ascorbic acid prevent DNA damage induced by cryopreservation in human semen

Cryopreservation of human semen can cause DNA damages, which compromise the fertilization and normal embryo development. The present study showed that the antioxidant resveratrol prevents these damages both in fertile and infertile men. The addition of ascorbic acid before cryopreservation can reduce DNA damages only in infertile men. Although further studies are needed, the present work showed that resveratrol could be considered in human cryopreservation procedures to avoid/minimize DNA damages and preserve sperm integrity.

Genotoxic biomonitoring of tobacco farmers: Biomarkers of exposure, of early biological effects and of susceptibility

Tobacco farming presents several hazards to those who cultivate and harvest the plant. The genotoxic and mutagenic effects in tobacco farmers were investigated. In order to verify the relationship between genetic susceptibility and biomarkers GSTT1, GSTM1, GSTP1, CYP2A6, PON, OGG1, RAD51, XRCC1, and XRCC4 genes polymorphism were evaluated. Oxidative stress markers and trace elements content were determined. Peripheral blood cells samples were collected from 111 agricultural workers during pesticides application and leaf harvest, and 56 non-exposed subjects. Results show that farmers are exposed to mixture of substances with genotoxic and cytotoxic potential. Only GSTM1 null and CYP2A6*9 showed significant associations with cytokinesis-blocked micronuclei assay results. In pesticide application an increase in trace elements content was observed. The results indicated that exposure to pesticides and nicotine can influence antioxidant enzymes activity. Our study drives the attention once more to the need for occupational training on safe work environment for farm workers.

Effects of resveratrol supplementation on cryopreservation medium of human semen

OBJECTIVE To analyze oxidative stress markers and seminal standard parameters after using resveratrol (0.1, 1.0, and 10.0 mM), an important antioxidant, in the cryopreservation of human semen. DESIGN In vitro prospective study. SETTING Institutional study. PATIENT(S) Infertile and fertile men. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Levels of thiobarbituric acid-reactive species (TBARS), superoxide dismutase (SOD), and catalase (CAT) activities and spermatozoa concentration, motility, and morphology. RESULT(S) Increased TBARS levels were observed in the post-thawing semen in both fertile and infertile men. Infertile men had lower CAT and SOD activities in prefreezing and post-thawing samples when compared with fertile men. The addition of resveratrol in all the concentrations assayed was able to prevent post-thawing lipoperoxidation in both fertile and infertile men. However, this effect was not dose dependent. The cryopreservation process was not able to change sperm concentration or morphology. However, a decrease in sperm motility was observed in both the fertile and infertile men. The addition of resveratrol was not able to prevent this effect. CONCLUSION(S) Resveratrol avoids oxidative damages induced by the cryopreservation of human semen, but it is not able to restore the decrease in sperm motility.

Infusion, decoction and hydroalcoholic extracts of leaves from artichoke (Cynara cardunculus L. subsp. cardunculus) are effective scavengers of physiologically relevant ROS and RNS

The globe artichoke (Cynara cardunculus L. subsp. cardunculus) is a perennial plant cultivated in the Mediterranean region and Americas for its edible young flower heads and as an interesting source of bioactive compounds. The present study was undertaken to evaluate scavenging capacity against the most physiologically relevant reactive oxygen species (ROS) and reactive nitrogen species (RNS) of three different extracts from artichoke leaves (infusion, decoction and hydroalcoholic) using different solvents, commonly accepted for human consumption (water and a mixture of ethanol/water). Additionally, the phenolic compounds in each extract were identified and quantified by high performance liquid chromatography coupled to diode array and mass spectrometer detectors (HPLC-DAD-MS/MS). Chlorogenic acid was the major phenolic compound identified in all extracts, followed by 1,3-dicaffeoylquinic acid (cynarin), luteolin-7-rutinoside and the infusion extract presented the highest phenolic content (108mg/g extract, dry basis). In general, the extracts of artichoke leaves presented a remarkable capacity to scavenge ROS and RNS with IC50 values in a low μg/mL range (3.4-43μg/mL). These findings suggest that artichoke could be a potential source of natural antioxidants and has an undeniable nutraceutical value.

Concentration of biologically active compounds extracted from Ilex paraguariensis St. Hil. by nanofiltration.

The aim of this study was to characterise the bioactive compounds in mate (Ilex paraguariensis St. Hil) extract and in concentrated mate extract obtained by nanofiltration (NF). Also, the impact of NF on the antioxidant activity of both mate extracts was evaluated in vitro and using eukaryotic cells of Saccharomyces cerevisiae (yeast assay). The results showed a significant increase in the contents of total phenolics (338%), chlorogenic acid (483%), theobromine (323%), caffeine (251%), chlorophyll (321%), condensed tannins (278%) and saponins (211%) in the concentrated mate extract. The concentrated mate extract showed higher in vitro antioxidant activity than the mate extract. According to the results obtained, it can be stated that the use of nanofiltration membrane is a valid approach for the concentration of biologically active compounds in aqueous extract of mate.

Genetic and oxidative damage of peripheral blood lymphocytes in workers with occupational exposure to coal

Coal is an important fossil fuel used to generate energy. Coal dust is constituted primarily of hydrocarbons and metals. During coal extraction, large quantities of coal dust particles are emitted, contributing to environmental pollution. Coal miners are constantly exposed to coal dust and its derivatives. The goal of this study was to evaluate the potential genotoxic effects of coal and oxidative stress in individuals from Candiota who were exposed to coal as part of their occupation. The comet assay and micronucleus (MN) test were used to assess these effects. This study involved 128 male participants of whom 71 reported work that included exposure to coal (exposed group) and 57 reported working at different jobs (unexposed group). The exposed group had a significantly increased damage index and damage frequency, as assessed using the comet assay, and increased MN and nucleoplasmic bridge frequencies, as assessed using the MN assay, compared with unexposed individuals. Significant and positive correlations between MN frequencies in the lymphocytes and buccal cells of control and exposed individuals were observed. The exposed individuals presented lower average levels of thiobarbituric acid reactive substances (TBARS) and catalase activity (CAT), while the mean superoxide dismutase activity (SOD) levels were higher in this group. The exposed group also had higher hematocrit levels. No correlation between DNA damage and inorganic elements, as identified using PIXE, was found; however, there was a correlation between the damage index and zinc. The evidence that exposure to coal and its derivatives presents a genetic hazard demonstrates the need for protective measures and educational programs for coal miners.

Araucaria Angustifolia: A Potential Nutraceutical with Antioxidant and Antimutagenic Activities

The Araucaria angustifolia (Bertolini, Otto Kuntze) tree belongs to the family Araucariaceae and is known as Brazilian pine. The female strobilus consists of seeds (the edible part of A. angustifolia) and bracts (non-developed seeds). These bracts, which represent approximately 80% of the female strobilus, have no use. It has previously been suggested that the dietary intake of antioxidants could be a useful strategy to reduce the incidence of diseases associated with oxidative stress, such as cancer, atherosclerosis and neurodegenerative disorders. This study aimed to evaluate the phenolic profile and the possible antioxidant, mutagenic and antimutagenic activities of the aqueous extract from bracts of A. angustifolia. The results showed that the extract of A. angustifolia presents important in vitro and in vivo antioxidant activity. Additionally, lower concentrations of the extract were non-mutagenic and avoided DNA damage induced by hydrogen peroxide in yeast cells. Catechin, epicatechin and rutin were the main phenolic compounds found in the extract. These results may provide new perspectives for the development of strategies with natural compounds in the nutraceutical field. In addition, the use of this waste will help maintain the environmental balance.

Telomere measurement in individuals occupationally exposed to pesticide mixtures in tobacco fields

Occupational exposure to pesticides in tobacco fields causes genetic damage in farmers. The aim of this study was to analyze tobacco farmers chronically exposed to low doses of pesticides and nicotine (present in the tobacco leaves) in relation to absolute telomere length (aTL), and explore the influence of lifestyle characteristics, oxidative stress, and inorganic element levels. DNA was isolated from peripheral blood samples from agricultural workers and non‐exposed individuals, and aTL was measured by quantitative real time polymerase chain reaction (qPCR) analysis. Oxidative stress (thiobarbituric acid reactive substances [TBARS], which measures oxidative damage to lipids; and toxic equivalent antioxidant capacity [TEAC], which measures total equivalent antioxidant capacity) was evaluated in serum, and inorganic element content was analyzed in whole blood through particle‐induced X‐ray emission technique. It was found that exposure to pesticides and tobacco smoking had significant effects on aTL. Individuals occupationally exposed to complex mixtures of pesticides in tobacco fields and individuals who smoked had decreased aTL compared with the non‐exposed group. TBARS and TEAC were significantly elevated in the exposed group. There were no significant differences in inorganic elements. There was no evidence of an influence of age, gender, consumption of alcoholic beverages, or intake of fruits and vegetables on aTL within the groups. In addition, years of work in the tobacco field in the exposed group did not influence any of the variables analyzed. Although further studies were needed, these results suggested differences in telomere maintenance in tobacco farmers compared with the control group, indicating that telomere length may be a good biomarker of occupational exposure. Environ. Mol. Mutagen. 57:74–84, 2016.

Antioxidant and Antigenotoxic Activities of the Brazilian Pine Araucaria angustifolia (Bert.) O. Kuntze

Polyphenols are natural products with recognized potential in drug discovery and development. We aimed to evaluate the polyphenolic profile of Araucaria angustifolia bracts, and their ability to scavenge reactive species. The antioxidant and antigenotoxic effects of A. angustifolia polyphenols in MRC5 human lung fibroblast cells were also explored. The total polyphenol extract of A. angustifolia was determined by the Folin–Ciocalteu reagent and the chemical composition was confirmed by HPLC. Reactive oxygen species’ scavenging ability was investigated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and superoxide dismutase- and catalase-like activities. The protective effect of the extract in MRC5 cells was carried out by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method and the determination of oxidative lipids, protein, and DNA (alkaline and enzymatic comet assay) damage. Total phenolic content of the A. angustifolia extract was 1586 ± 14.53 mg gallic acid equivalents/100 g of bracts. Catechin, epicatechin, quercetin, and apigenin were the major polyphenols. The extract was able to scavenge DPPH radicals and exhibited potent superoxide dismutase and catalase-like activities. Moreover, A. angustifolia extract significantly protected MRC5 cells against H2O2-induced mortality and oxidative damage to lipids, proteins, and DNA. Therefore, A. angustifolia has potential as a source of bioactive chemical compounds.

Mitochondria and redox homoeostasis as chemotherapeutic targets of Araucaria angustifolia (Bert.) O. Kuntze in human larynx HEp-2 cancer cells.

Natural products are among one of the most promising fields in finding new molecular targets in cancer therapy. Laryngeal carcinoma is one of the most common cancers affecting the head and neck regions, and is associated with high morbidity rate if left untreated. The aim of this study was to examine the antiproliferative effect of Araucaria angustifolia on laryngeal carcinoma HEp-2 cells. The results showed that A. angustifolia extract (AAE) induced a significant cytotoxicity in HEp-2 cells compared to the non-tumor human epithelial (HEK-293) cells, indicating a selective activity of AAE for the cancer cells. A. angustifolia extract was able to increase oxidative damage to lipids and proteins, and the production of nitric oxide, along with the depletion of enzymatic antioxidant defenses (superoxide dismutase and catalase) in the tumor cell line. Moreover, AAE was able to induce DNA damage, nuclear fragmentation and chromatin condensation. A significant increase in the Apoptosis Inducing Factor (AIF), Bax, poly-(ADP-ribose) polymerase (PARP) and caspase-3 cleavage expression were also found. These effects could be related to the ability of AAE to increase the production of reactive oxygen species through inhibition of the mitochondrial electron transport chain complex I activity and ATP production by the tumor cells. The phytochemical analysis of A. angustifolia, performed using High Resolution Mass Spectrometry (HRMS) in MS and MS/MS mode, showed the presence of dodecanoic and hexadecanoic acids, and phenolic compounds, which may be associated with the chemotherapeutic effect observed in this study.