Vinícius de Paula Venâncio

Genotoxic and mutagenic effects of erythrosine B, a xanthene food dye, on HepG2 cells

Erythrosine (ErB) is a xanthene and an US Food and Drug Administration approved dye used in foods, drugs and cosmetics. Although its utilization is permitted, ErB is described as inhibitor of enzymes and protein-protein interactions and is toxic to pituitary and spermatogenesis processes. However, the genotoxicity and mutagenicity of ErB is inconclusive in the literature. This study aimed to analyze the genotoxicity of this dye using the alkaline comet assay and is the first investigation to evaluate ErB mutagenicity using the cytokinesis block micronucleus cytome (CBMN-Cyt) assay in HepG2 cells. These cells were chosen because they produce phase I and phase II enzymes that can mimic in vivo metabolism. The cells were treated with seven concentrations (0.1-70.0 μg mL(-1)) of ErB, and the results showed genotoxicity at the two highest concentrations and mutagenicity at six concentrations. Furthermore, as micronuclei result from clastogenic and aneugenic processes, while comet assay is often considered more sensitive and detects DNA single strain breaks, we suggest that an aneugenic is responsible for the observed damage. Although ErB is approved for use in the food, cosmetic and pharmaceutical industries, it must be used carefully because it damages the DNA structure.

Overtraining is associated with DNA damage in blood and skeletal muscle cells of Swiss mice

BackgroundThe alkaline version of the single-cell gel (comet) assay is a useful method for quantifying DNA damage. Although some studies on chronic and acute effects of exercise on DNA damage measured by the comet assay have been performed, it is unknown if an aerobic training protocol with intensity, volume, and load clearly defined will improve performance without leading to peripheral blood cell DNA damage. In addition, the effects of overtraining on DNA damage are unknown. Therefore, this study aimed to examine the effects of aerobic training and overtraining on DNA damage in peripheral blood and skeletal muscle cells in Swiss mice. To examine possible changes in these parameters with oxidative stress, we measured reduced glutathione (GSH) levels in total blood, and GSH levels and lipid peroxidation in muscle samples.ResultsPerformance evaluations (i.e., incremental load and exhaustive tests) showed significant intra and inter-group differences. The overtrained (OTR) group showed a significant increase in the percentage of DNA in the tail compared with the control (C) and trained (TR) groups. GSH levels were significantly lower in the OTR group than in the C and TR groups. The OTR group had significantly higher lipid peroxidation levels compared with the C and TR groups.ConclusionsAerobic and anaerobic performance parameters can be improved in training at maximal lactate steady state during 8 weeks without leading to DNA damage in peripheral blood and skeletal muscle cells or to oxidative stress in skeletal muscle cells. However, overtraining induced by downhill running training sessions is associated with DNA damage in peripheral blood and skeletal muscle cells, and with oxidative stress in skeletal muscle cells and total blood.

Clinical and Vitamin Response to a Short-Term Multi-Micronutrient Intervention in Brazilian Children and Teens: From Population Data to Interindividual Responses

Scope Micronutrients are in small amounts in foods, act in concert, and require variable amounts of time to see changes in health and risk for disease. These first principles are incorporated into an intervention study designed to develop new experimental strategies for setting target recommendations for food bioactives for populations and individuals. Methods and results A 6‐week multivitamin/mineral intervention is conducted in 9–13 year olds. Participants (136) are (i) their own control (n‐of‐1); (ii) monitored for compliance; (iii) measured for 36 circulating vitamin forms, 30 clinical, anthropometric, and food intake parameters at baseline, post intervention, and following a 6‐week washout; and (iv) had their ancestry accounted for as modifier of vitamin baseline or response. The same intervention is repeated the following year (135 participants). Most vitamins respond positively and many clinical parameters change in directions consistent with improved metabolic health to the intervention. Baseline levels of any metabolite predict its own response to the intervention. Elastic net penalized regression models are identified, and significantly predict response to intervention on the basis of multiple vitamin/clinical baseline measures. Conclusions The study design, computational methods, and results are a step toward developing recommendations for optimizing vitamin levels and health parameters for individuals.

Differential genotoxicity and cytotoxicity of phomoxanthone A isolated from the fungus Phomopsis longicolla in HL60 cells and peripheral blood lymphocytes

Phomoxanthone A (PhoA) is a compound isolated from the endophytic fungus Phomopsis longicolla, associated with marine algae Bostrychia radicans. Although this metabolite was previously described regarding its high biological potential, there are no reports concerning the effects of this compound on DNA integrity. This study aimed to evaluate, in lymphocytes and promyelocytic leukemia HL60 cells, the cytotoxicity of this compound through MTT and neutral red (NR) assays, as well as its genotoxicity and mutagenicity by alkaline comet assay and cytokinesis-block micronucleus cytome assay (CBMN-Cyt), respectively. Cells were treated with PhoA concentrations ranging from 0.01 to 100.0μg/mL, and the results show that this molecule did not exhibit cytotoxicity, genotoxicity or mutagenicity in lymphocytes at any tested concentration. Furthermore, PhoA was highly cytotoxic, genotoxic and mutagenic to HL60 cells, establishing a differential response of this natural product in normal and cancer cells. PhoA was highly selective towards HL60 compared to lymphocytes, causing no damage in the latter cell line, suggesting that this compound could be a promising compound in antitumoral drug development.

Maternal vitamin B6 deficient or supplemented diets on expression of genes related to GABAergic, serotonergic, or glutamatergic pathways in hippocampus of rat dams and their offspring

SCOPE Vitamin B6 plays crucial roles on brain development and its maternal deficiency impacts the gamma-aminobutyric acid (GABA)ergic, serotonergic, glutamatergic, and dopaminergic systems in offspring. However, the molecular mechanisms underlying these neurological changes are not well understood. Thus, we aimed at evaluating which components of those neurotransmitter metabolism and signaling pathways can be modulated by maternal vitamin B6 -deficient or B6 -supplementated diets in the hippocampus of rat dams and their offspring. METHODS AND RESULTS Female Wistar rats were fed three different diets: control (6 mg vitamin B6 /kg), supplemented (30 mg vitamin B6 /kg) or deficient diet (0 mg vitamin B6 /kg), from 4 weeks before pregnancy through lactation. Newborn pups (10 days old) from rat dams fed vitamin B6 -deficient diet presented hyperhomocysteinemia and had a significant increase in mRNA levels of glutamate decarboxylase 1 (Gad1), fibroblast growth factor 2 (Fgf2), and glutamate-ammonia ligase (Glul), while glutaminase (Gls) and tryptophan hydroxylase 1 (Tph1) mRNAs were downregulated. Vitamin B6 supplementation or deficiency did not change hippocampal global DNA methylation. CONCLUSION A maternal vitamin B6 -deficient diet affects the expression of genes related to GABA, glutamate, and serotonin metabolisms in offspring by regulating Gad1, Glul, Gls, and Tph1 mRNA expression.

Effects of maternal vitamin B6 deficiency and over-supplementation on DNA damage and oxidative stress in rat dams and their offspring

Vitamin B6 is a cofactor for more than 140 essential enzymes and plays an important role in maternal health and fetal development. The goal of this study was to investigate the effects of maternal vitamin B6 on DNA damage and oxidative stress status in rat dams and their offspring. Female Wistar rats were randomly assigned to three dietary groups fed a standard diet (control diet), a diet supplemented with 30 mg/kg of vitamin B6, or a deficient diet (0 mg/kg of vitamin B6) for 10 weeks before and during mating, pregnancy and lactation. The dams were euthanized at weaning, and their male pups were euthanized either 10 days or 100 days after birth. We found that maternal vitamin B6 deficiency increased the micronucleus frequency in peripheral blood and bone marrow cells and also increased the concentration of hepatic TBARS (thiobarbituric acid reactive substances) in newborn pups (10 days old). In conclusion, maternal 5- to 6-fold over-supplementation of vitamin B6 had no adverse effects, however its deficiency may induce chromosomal damage and hepatic lipid peroxidation in the offspring.