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Oxidative/nitrosative damage takes part in chronic disease development, which generates an urgent need for intervention and better therapies to manage them. The scientific community has demanded easy-to-run, cheap, and reliable methods for cellular antioxidant activity assays. This work standardised and validated an erythrocyte cellular antioxidant activity and membrane protection/injury (HERYCA-P) protocol to study food-derive extracts. The method measures intracellular reactive oxygen species (ROS) generation, lipoperoxidation, and haemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. Quercetin decreased ROS generation by 50.4% and haemolysis by 2.2%, while ascorbic acid inhibited lipid peroxidation by 40.1%. Total phenolic contents of teas were correlated with decreased ROS generation (r = -0.924), lipoperoxidation (r = -0.951), and haemolysis (r = -0.869). The erythrocyte ROS generation and lipoperoxidation were also associated with CUPRAC (r = -0.925; r = -0.951) and hydroxyl radical scavenging activity (r = -0.936; r = -0.949). The precision rates of antioxidant standards and tea samples were below 15%. HERYCA-P is feasible as a complementary antioxidant assay for food matrices.

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This study investigated the effect of a 50% reduction in sodium nitrite and the addition of nisin (200 mg/kg) and different concentrations (0, 0.5%, 0.75%, and 1%) of jabuticaba peel extract (JPE) on the main attributes affected by this chemical additive in Bologna-type sausages. The modified treatments showed approximately 50% lower residual nitrite than the control throughout the storage (60 days at 4 °C). The proposed reformulation did not affect the color (L*, a*, and b*), and the ΔE values (< 2) demonstrated high color stability during storage. Physicochemical (TBARS and volatile compounds) and sensory analyses performed to evaluate oxidative stability indicated that JPE exhibited antioxidant activity comparable to sodium nitrite. The microbiological quality of the reformulated products was similar to the control, but further studies should be conducted to assess the effect of this reformulation strategy on the growth of pathogenic microorganisms impacted by nitrite.

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This study aimed to improve the color and oxidative stabilities of dark Nellore bull steaks with greater-than-normal ultimate pH (pHu) by the injection (8% raw wet weight basis) of a solution with L-lactate (2.5%), phosphate (0.3%) and rosemary extract (0.06%), with further packaging in high oxygen atmosphere (HiOx MAP). Longissimus lumborum muscles from pasture-fed Nellore bulls were divided into three pHu ranges: normal (<5.80), intermediate (5.81-6.19), and high (≥6.2). Muscles were then halved, with sections were randomly assigned to non-enhanced (C, n = 6/pHu range) or injected (E, n = 6/pHu range) groups, at 72 h postmortem. Each section was cut into 2 cm-slices, which were HiOx-packed and then stored for 5 days (dark) and displayed for 9 days (fluorescent lighting) at 2 °C. Higher pHu steaks exhibited greater a*, b*, h*, C* and surface oxymyoglobin and lower surface deoxymyoglobin and oxygen consumption compared to those of normal pHu between days 0 and 5 (p < 0.05). Over the time, normal-pHu muscles showed oxidative protection (lower TBARS and greater metmyoglobin reducing ability values, p < 0.05) in enhanced-steaks. Therefore, enhancement and HiOx MAP seem to produce greater-than-normal pHu Nellore bull steaks with a preferable color and quality, even after display time.

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Reactive oxygen species (ROS) are intimately linked to bioenergetics and redox biology, contributing to cellular functioning and physiological signaling, but also acting as toxic agents during oxidative stress. Hence, the balance between pro-oxidant reactions and the activity of antioxidant defenses sustains a basal oxidative status, controls the increase of redox signaling, and mediates potential pathological events during oxidative stress. Maternal experience, especially during nursing, requires high energetic demands and expenditure to ensure the well-being of the offspring. The mother must adapt from satisfying her own needs to additionally fulfilling those of her descendants. Oxidative stress has been proposed as one of the reproductive trade-off hallmarks. However, the oxidative shielding hypothesis has also been proposed in the context of reproduction. The reproductive experience induces a wide range of well-documented changes in the female brain, which potentially lead to protection against the enhanced oxidative activity. To date, the metabolic and cellular mechanisms that underlie lactation-induced neuroprotection against oxidants are unknown. The neuroendocrine changes in the brain of the lactating dam promote diminished propensity to excitotoxic brain injury and stress, as well as enhanced neuroprotection and plasticity. In addition to review studies on the oxidant balance due to motherhood, we included new data from our laboratory, addressing the importance of measuring pro-oxidant reactions in separated brain regions. The hippocampus of lactating rats exhibits lower levels of pro-oxidant reactions than that of virgin rats, supporting the oxidative shielding hypothesis in lactation.

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Background: Sepsis is a severe global health problem, with high morbidity and mortality. In sepsis, one of the main affected organs is the liver. Hepatic alterations characterize a negative prognostic. Omega-3 fatty acids (ω3), eicosapentaenoic acid, and docosahexaenoic acid, are part of the main families of polyunsaturated fatty acids. ω3 has been used in studies as sepsis treatment and as a treatment for non-alcoholic liver disease. Aim: We aimed to evaluate the effects of treatment with fish oil (FO) rich in ω3 on liver changes and damage resulting from experimental sepsis. Methodology: A model of severe sepsis in Wistar rats was used. Oxidative stress in the liver tissue was evaluated by means of tests of thiobarbituric acid reactive substances, 2,7-dihydrodichlorofluorescein diacetate , catalase, and glutathione peroxidase, in the serum TBARS, DCF, thiols and, to assess liver dysfunction, alanine aminotransferase and aspartate aminotransferase. Hepatic tissue damage was evaluated using H&E histology. Results: In assessments of oxidative stress in liver tissue, a protective effect was observed in the tests of TBARS, DCF, CAT, and GPx, when compared the sepsis versus sepsis+ω3 groups. Regarding the oxidative stress in serum, a protective effect of treatment with ω3 was observed in the TBARS, DCF, and thiols assays, in the comparison between the sepsis and sepsis+ω3 groups. ω3 had also a beneficial effect on biochemical parameters in serum in the analysis of ALT, creatinine, urea, and lactate, observed in the comparison between the sepsis and sepsis+ω3 groups. Conclusion: The results suggest ω3 as a liver protector during sepsis with an antioxidant effect, alleviating injuries and dysfunctions.

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Trichomoniasis is a great public health burden worldwide and the increase in treatment failures has led to a need for finding alternative molecules to treat this disease. In this study, we present in vitro and in silico analyses of two 2,8-bis(trifluoromethyl) quinolines (QDA-1 and QDA-2) against Trichomonas vaginalis. For in vitro trichomonacidal activity, up to seven different concentrations of these drugs were tested. Molecular docking, biochemical, and cytotoxicity analyses were performed to evaluate the selectivity profile. QDA-1 displayed a significant effect, completely reducing trophozoites viability at 160 µM, with an IC50 of 113.8 µM, while QDA-2 at the highest concentration reduced viability by 76.9%. QDA-1 completely inhibited T. vaginalis growth and increased reactive oxygen species production and lipid peroxidation after 24 h of treatment, but nitric oxide accumulation was not observed. In addition, molecular docking studies showed that QDA-1 has a favorable binding mode in the active site of the T. vaginalis enzymes purine nucleoside phosphorylase, lactate dehydrogenase, triosephosphate isomerase, and thioredoxin reductase. Moreover, QDA-1 presented a level of cytotoxicity by reducing 36.7% of Vero cells' viability at 200 µM with a CC50 of 247.4 µM and a modest selectivity index. In summary, the results revealed that QDA-1 had a significant anti-T. vaginalis activity. Although QDA-1 had detectable cytotoxicity, the concentration needed to eliminate T. vaginalis trophozoites is lower than the CC50 encouraging further studies of this compound as a trichomonacidal agent.

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This study examined the leaves of Baccharis macrantha to obtain extracts of Baccharis macrantha (EBM) and to determine the total flavonoid content (TFC) and the total polyphenol content (TPC). The main objective of this work was to quantify TPC and TFC of extracts of B. macrantha from Ecuador and evaluate its antioxidant and anti-inflammatory activities and inhibition of lipid peroxidation. The extraction method was optimized with solvents, ethanol, and methanol, at temperatures of 30-60 °C and extraction times of 5-20 min. The optimal TFC extraction conditions were at EtOH25% at 50 °C for 10 min. The optimal TPC extraction conditions were at EtOH50% at 50 °C for 10 min. EBM was characterized by TLC and HPLC with three standards: gallic acid, catechin, and quercetin. EBM-EtOH25% and EBM-EtOH50% obtained at 50 °C for 10 min were used to identify quercetin and evaluate biologicals activities. Quercetin was detected in EBM (EtOH25% and EtOH50%). EBM anti-inflammatory activity was evaluated with the red blood cell stabilization (RBC) method. The RBC model showed values of 49.72% of protection lysis RBC to EBM-EtOH25% and 50.71% of protection lysis RBC to EBM-EtOH50%. The EBM in vitro inhibition of lipid peroxidation showed a protection of 77.00% (EtOH25%) and 73.11% (EtOH50%) when the TBARs method was used. EBM-EtOH25% and EtOH50% showed high antioxidant activity. EBM-EtOH25% presented values of ABTS (1172 µmol TE/g EBM), DPPH (836 µmol TE/g, EBM), and FRAP (85.70 µmol TE/g, EBM).

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(1) The evidence points to an increase in oxygen reactive species as one of the possible causes of fibromyalgia (FM). In addition, it is plausible that an imbalance in redox markers can be associated with pain amplification and dynapenia in FM patients. The aim of our study was to investigate possible factors associated with muscle pain and lean body mass in FM patients. (2) Methods: This was a quantitative, exploratory and cross-sectional study of 47 patients with FM (53.45 + 7.32 years). We evaluated self-perceptions of muscle pain, lean body mass, body composition, quality of life, sleep quality, depression index, muscle performance and oxidative stress biomarkers. (3) Results: We observed that lower blood levels of antioxidants and poor quality of life explained 21% of the greater muscle pain. In addition, high blood levels of oxidative stress, worse muscle performance and poor quality of life explained 27% of the lower lean mass in patients with FM. (4) Conclusions: Larger amounts of lipid peroxidation and reductions in antioxidant levels, in addition to lower muscle performance and poor life quality, are possible independent contributors to greater muscle pain and lower lean body mass in FM patients.

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Preeclampsia (PE) is a pregnancy-specific syndrome with multisystem involvement which leads to fetal, neonatal, and maternal morbidity and mortality. A model of salt-loaded pregnant rats has been previously studied, sharing several pathological characteristics of preeclamptic women. In this study, it was compared the effects of the treatment with an oral magnesium salt, magnesium gluconate (Mg-gluconate), on the osmotic fragility of red blood cells, lipid peroxidation, and PMCA activity of placental homogenates and red blood cell ghosts in salt-loaded pregnant rats. Mg-gluconate has a higher antioxidant capacity than MgSO4 due to the presence of several hydroxyl groups in the two anions of this salt. Salt-loaded pregnant rats received 1.8% NaCl solution ad libitum as a beverage during the last week of pregnancy. On day 22nd of pregnancy, the rats were euthanized and red blood cells and placenta were obtained. Salt-loaded pregnant rats showed an increased level of lipid peroxidation and a lowered PMCA activity in placental and red blood cell ghosts, as well as an increased osmotic fragility of their red blood cells. The treatment of the salt-loaded pregnant rats with Mg-gluconate avoids the rise in the level of lipid peroxidation and the concomitant lowering of the PMCA activity of their red blood cell membranes, reaching values similar to those from control pregnant rats. Also, this treatment prevents the increase of the osmotic fragility of their red blood cells, keeping values similar to those from control pregnant rats. Mg-gluconate seems to be an important candidate for the replacement of the MgSO4 treatment of preeclamptic women.

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The aim of this study was to evaluate the follicular development, morphological integrity, and oxidative stress of preantral ovarian follicles from Bos taurus indicus females grown in vitro with ascorbic acid. Ovaries (n = 20) from Bos taurus indicus females were collected, fragmented, and were cultured in vitro for 6 or 12 days in minimum essential medium (MEM), or MEM supplemented with 50 or 100 ng/ml ascorbic acid, with an extracellular matrix of agarose gel, in an incubator at 38.5°C; every 2 days, 100% of the culture medium was replaced. The data were analyzed using the chi-squared test and/or Fisher's exact test. In the event of a significant effect, the proportions were compared using a 2 × 2 proportion test. The oxidative stress analysis data were submitted to analysis of variance followed by the Bonferroni test. Values were considered significant when P ≤ 0.05. The addition of 100 ng/ml of ascorbic acid to the in vitro culture medium of preantral ovarian follicles from bovine females promoted follicular development, was efficient in maintaining morphological integrity, as well as the stability of reactive oxygen species, after 6 days of in vitro culture.

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