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The objectives of this study were (1) to evaluate the capacity of human plasma that had been obtained from healthy adult volunteers before and after they ingested vitamin E or C to inhibit induced lipoperoxidation in vitro (antioxidant capacity of plasma [ACP]), and (2) to compare the efficiency of these vitamins with that of a commercial mixture of antioxidant vitamins, cofactors, and minerals (MAOx). Seventy-nine healthy individuals between 19 and 23 y of age were randomly assigned to 1 of 4 groups. Each received a daily dose of antioxidants for 7 d: vitamin C (n=18; 500 mg), vitamin E (n=21; 400 IU), vitamins C and E (n=19), or MAOx (n=21; 1.2 g). ACP and plasma malondialdehyde were measured at 4 and 24 h and 7 d. ACP increased significantly (P<.05) in all 4 groups within 4 h of antioxidant intake, and this effect was sustained throughout supplementation. Plasma ACP increased significantly over basal values in the group taking MAOx; relative increases were 42%, 44%, and 55% at 4 h, 24 h, and 7 d, respectively (P<.001). Smaller increases in plasma ACP were observed in the vitamin C group (25%, 32%, and 36%) and, specifically, in the vitamin E group (17%, 24%, and 28%) (P<.05). The mixture of vitamins and minerals was comparatively more efficient than vitamin C or E alone, presumably because MAOx contains various antioxidant compounds with different redox potentials, leading to the possible development of chain reactions. [ABSTRACT FROM AUTHOR]

Epaltes mexicana is a plant widely used in traditional medicine and as a food in Mexico; however, its phytochemical and pharmacological studies are limited. This study aimed to identify the active secondary metabolites of Epaltes mexicana and determine its cytotoxic activity on cancer cell lines. Three organic extracts were obtained by maceration using n-hexane, dichloromethane, and methanol. The n-hexane extract was fractioned by simple column chromatography. Eight terpenes were annotated in collection 6 (C6) by LC-QTOF-MS using a gradient elution and Electrospray Ionization (ESI) in positive ion mode: 1) Gibberellin A15, 2) farfugin A, 3) dehydromyodesmone, 4) eremopetasitenin A1, 5) hydroxyisonobilin, 6) anhydrocinnzeylanine, 7) nigakilactone H and 8) taxodione. On the other hand, C6 showed a concentration-dependent cytotoxic effect on cancer cell lines MCF-7 (E max  = 74.69 ± 6.19 % and IC 50  = 6.31 μg/mL), MDA-MB-231 (E max  = 79.28 ± 12.12 % and IC 50  = 124.21 μg/mL), and SiHa (E max  = 82.96 ± 6.02 % and IC 50  = 124.31 μg/mL). The C6 did not show a cytotoxic effect against DU-145 and non-cancerous cells from the mammary glands MCF-10A. These results indicate cytotoxic specificity on cancer cell lines and support the hypothesis that terpenes identified in E. mexicana must be investigated and developed for non-clinical and clinical trials as potential anti-cancer drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

For this study, procyanidins generated through the autoxidation of (-)-epicatechin (Flavan-3-ol) under mildly acidic conditions (pH = 6.0) were characterized with ultra high-performance liquid chromatography (UHPLC) coupled with tandem mass spectrometry (MS/MS). Two procyanidins (types A and B) and a mix of oligomers were generated through the autoxidation of (-)-epicatechin. The antiproliferative activity of this mixture of procyanidins on MDA-MB-231, MDA-MB-436, and MCF-7 breast cancer cells was evaluated. The results indicate that the procyanidin mixture inhibited the proliferation of breast cancer cells, where the activity of the procyanidin mixture was stronger than that of (-)-epicatechin. Moreover, the mechanism underlying the antiproliferative activity of procyanidins was investigated. The resulting data demonstrate that the procyanidins induced apoptotic cell death in a manner selective to cancerous cells. In particular, they caused the activation of intrinsic and extrinsic apoptotic pathways in the breast cancer cells. The findings obtained in this study demonstrate that the generation of procyanidins in vitro by the autoxidation of (-)-epicatechin has potential for the development of anti-breast cancer agents.

Background: The arrival of large quantities of Sargassum in the Mexican Caribbean Sea has generated major environmental, health and economic problems. Although Sargassum has been used in the generation of some commercial products, few studies have described its possible applications as a source of compounds with anticancer activity., Objective: This study aimed to evaluate the antiproliferative effects of different Sargassum extracts on various cancer cell lines. Furthermore, LC/QTOF-MS was used to identify the compounds related to the antiproliferative effect., Methods: First, determination of the seaweed was performed, and dichloromethane, chloroform and methanol extracts were obtained. The extracts were evaluated for their antiproliferative effects by MTT in breast (MDAMB- 231 and MCF-7), prostate (DU-145), lung (A549) and cervical (SiHa) cancer cell lines. Finally, LC/QTOFMS identified the compounds related to the antiproliferative effect., Results: The authentication showed Sargassum fluitans as the predominant species. The extracts of dichloromethane and chloroform showed an antiproliferative effect. Interestingly, the fractionation of the chloroform extract showed two fractions (FC1 and FC2) with antiproliferative activity in MDA-MB-231, SiHa and A549 cancer cell lines. On the other hand, three fractions of dichloromethane extract (FD1, FD4 and FD5) also showed antiproliferative effects in the MDA-MB-231, MCF-7, SiHa and DU-145 cancer cell lines. Furthermore, LC/QTOF-MS revealed the presence of eight major compounds in FC2. Three compounds with evidence of anticancer activity were identified (D-linalool-3-glucoside, (3R,4S,6E,10Z)-3,4,7,11-tetramethyl-6,10-tridecadienal and alpha-tocotrienol)., Conclusion: These findings showed that Sargassum fluitans extracts are a possible source of therapeutic agents against cancer and could act as scaffolds for new drug discovery., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background/objectives: Cocoa consumption is associated with health benefits due to its high content of polyphenols. However, the effects of short-term cocoa consumption remain unclear. We aimed to determine the effects generated by cocoa consumption (for 7 days) in young adults in normoweight and class II obesity., Subjects/methods: Before-and-after study was carried out in normoweight (NW) (n = 15) and class II obesity (CIIO) (n = 15) young adults. The NW and CIIO participants consumed 25 and 39 g of cocoa, respectively, per day for 7 days. The effect of cocoa consumption was evaluated on the lipid profile, insulin resistance (IR), and inflammation. Oxidative damage was also examined by assessing the biomarkers of oxidative damage in plasma. In addition, recombinant human insulin was incubated with blood obtained from the participants, and the molecular damage to the hormone was analyzed., Results: Cocoa consumption resulted in decreased low-density lipoprotein-cholesterol in both groups ( P = 0.04), while the total cholesterol, high-density lipoprotein cholesterol, and triglycerides were maintained at the recommended levels. Initially, IR was detected in the CIIO group (homeostasis model assessment [HOMA] = 4.78 ± 0.4), which is associated with molecular damage to insulin. Interestingly, intervention with cocoa resulted in improved IR (HOMA = 3.14 ± 0.31) ( P = 0.0018) as well as molecular damage to insulin. Finally, cocoa consumption significant decreased the arginase activity ( P = 0.0249) in the CIIO group; this is a critical enzymatic activity in the inflammatory process associated with obesity., Conclusions: The short-term consumption of cocoa improves the lipid profile, exerts anti-inflammatory effects, and protects against oxidative damage. Results of this study indicate that cocoa consumption can potentially improve IR and restore a healthy redox status., Competing Interests: Conflict of Interest: The authors declare no potential conflicts of interests., (©2023 The Korean Nutrition Society and the Korean Society of Community Nutrition.)

The mechanism is unclear for the reported protective effect of hyperbaric oxygen preconditioning against oxidative stress in tissues, and the distinct effects of hyperbaric oxygen applied after stress. The trained mice were divided into three groups: the control, hyperbaric oxygenation preconditioning, and hyperbaric oxygenation applied after mild (fasting) or hard (prolonged exercise) stress. After preconditioning, we observed a decrease in basal levels of nitric oxide, tetrahydrobiopterin, and catalase despite the drastic increase in inducible and endothelial nitric oxide synthases. Moreover, the basal levels of glutathione, related enzymes, and nitrosative stress only increased in the preconditioning group. The control and preconditioning groups showed a similar mild stress response of the endothelial and neuronal nitric oxide synthases. At the same time, the activity of all nitric oxide synthase, glutathione (GSH) in muscle, declined in the experimental groups but increased in control during hard stress. The results suggested that hyperbaric oxygen preconditioning provoked uncoupling of nitric oxide synthases and the elevated levels of GSH in muscle during this study, while hyperbaric oxygen applied after stress showed a lower level of GSH but higher recovery post-exercise levels in the majority of antioxidant enzymes. We discuss the possible mechanisms of the redox response and the role of the nitric oxide in this process.

Breast cancer (BC) is the most frequently diagnosed cancer and is the second-most common cause of death in women worldwide. Because of this, the search for new drugs and targeted therapy to treat BC is an urgent and global need. Histone deacetylase 6 (HDAC6) is a promising anti-BC drug target associated with its development and progression. In the present work, the design and synthesis of a new family of dihydropyrazole-carbohydrazide derivatives (DPCH) derivatives focused on HDAC6 inhibitory activity is presented. Computational chemistry approaches were employed to rationalize the design and evaluate their physicochemical and toxic-biological properties. The new family of nine DPCH was synthesized and characterized. Compounds exhibited optimal physicochemical and toxicobiological properties for potential application as drugs to be used in humans. The in silico studies showed that compounds with -Br, -Cl, and -OH substituents had good affinity with the catalytic domain 2 of HDAC6 like the reference compounds. Nine DPCH derivatives were assayed on MCF-7 and MDA-MB-231 BC cell lines, showing antiproliferative activity with IC 50 at μM range. Compound 2b showed, in vitro, an IC 50 value of 12 ± 3 µM on human HDAC6. The antioxidant activity of DPCH derivatives showed that all the compounds exhibit antioxidant activity similar to that of ascorbic acid. In conclusion, the DPCH derivatives are promising drugs with therapeutic potential for the epigenetic treatment of BC, with low cytotoxicity towards healthy cells and important antioxidant activity.

Background and Objectives: The excess of body fat and muscle mass loss in adulthood results in sarcopenic obesity, which is associated with disability and poor physical condition. A relationship among obesity, sarcopenia and oxidative stress also has been established. These aspects limit a good muscle function which is crucial in the independence of older women with and without sarcopenic obesity. This study had as objective to design a moderate intensity exercise program for older women with sarcopenic obesity, and to examine its effects on oxidative damage and physical function. We hypothesized that the exercise program will reduce oxidative damage and to improve the physical function of older women with sarcopenic obesity., Methods: Thirty healthy women (68 ± 5.05 years old) and 30 women with sarcopenic obesity (68.06 ± 5.75 years old) from the Integral Development of the Family rest home participated in the evaluation. The participants underwent evaluations of body composition, physical fitness (timed up-and-go [TUG] test, reaction time, gait speed, flexibility and muscle strength) and oxidative stress (oxidative damage to lipid and protein as well as evaluation of the antioxidant system) before and after of moderate intensity exercise program. The program consisted of warm-up, flexibility; aerobic exercises of moderate intensity (VO 2 max and HR max between 60% and 70%); isotonic exercises of low intensity with progressive weight (250 g of initial weight, with increase every two weeks until reaching 750 g of final weight) and global stretching at the end of each section. The program was monitored on a personal basis and undertaken three times a week over three months., Results: In both groups, the program induced a five-fold increase in muscle strength, an increase in flexibility and improvement of fragility parameters (TUG and gait speed) (P ≤ 0.001, respectively). Furthermore, this exercise program decreased oxidative damage and increased antioxidant defense (P ≤ 0.001) to a greater extent in the sarcopenic group., Conclusion: It was concluded that moderate intensity exercise is an effective approach to promote changes in body composition, physical fitness and to reduce oxidative damage in older women with and without sarcopenic obesity. These findings might have important implications for the prevention or treatment of sarcopenic obesity in older people., (Copyright © 2021 Elsevier Inc. All rights reserved.)

(-)-Epicatechin is a phenolic compound with antioxidant activity that is present in natural food and drinks, such as cocoa and red wine. Evidence suggests that (-)-epicatechin exhibits anticancer activity; however, its mechanism of action is poorly understood. Here, we investigated the anticancer effects of (-)-epicatechin and its mechanism of action in breast cancer cells. We assessed the anticancer activity by cell proliferation assays, apoptosis by DNA fragmentation and flow cytometry. The expression of proteins associated with apoptosis was analyzed by the human apoptosis array. MitoSOX TM Red and biomarkers of oxidative damage were used to measure the effect of (-)-epicatechin on mitochondrial reactive oxygen species (ROS) and cellular damage, respectively. (-)-Epicatechin treatment caused a decreasing in the viability of MDA-MB-231 and MCF-7 cells. This cell death was associated with DNA fragmentation and an apoptotic proteomic profile. Further, (-)-epicatechin in MDA-MB-231 cells upregulated death receptor (DR4/DR5), increased the ROS production, and modulated pro-apoptotic proteins. In MCF-7 cells, (-)-epicatechin did not involve death receptor; however, an increase in ROS and the upregulation of pro-apoptotic proteins (Bad and Bax) were observed. These changes were associated with the apoptosis activation through the intrinsic pathway. In conclusion, this study shows that (-)-epicatechin has anticancer activity in breast cancer cells and provides novel insight into the molecular mechanism of (-)-epicatechin to induce apoptosis., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Background: Hepatic encephalopathy (HE) in patients with chronic liver disease (CLD) is one of the main causes of reentry to the emergency department. Oxidative stress (OxS) regulated by ammonia leads to cerebral edema and astrocytes senescence in animal models, but seems to be different in humans., Objective: To analyze if OxS and ammonia in plasma are related to each other in the different grades of HE-CLD and to compare them with healthy volunteers (HV)., Methods: In a cross-sectional study, we included 60 subjects in 2 groups: (a) 30 HV and (b) 30 HE patients. Plasma levels of oxidation lipids/proteins, ammonia, and West-Haven score were evaluated. Student t test, Spearman's correlation, and ANOVA with Dunn's post hoc test were performed., Results: Ammonia in HV and HE patients was 39-49 vs. 95-345 μmol/L, respectively (p < 0.0001). Malondialdehyde (MDA) in HV was 6.58 ± 3.11 compared to 16.69 ± 6.19 μmol/L in HE (p < 0.0001). Protein oxidation by osazone (carbonyls), formazan, and dityrosines was higher in HE than in HV (p < 0.0001). Ammonia level was directly associated to HE severity, but without correlation with lipid MDA or protein OxS formazan, carbonyls, and dityrosines. Lipid peroxidation showed higher levels at degree 2 and protein oxidation at degree 3 of HE., Conclusions: We confirm that OxS accompanies hyperammonemia in HE; however they contribute in different proportions to their natural progression. Early reduction of OxS in HE could contribute to minimize the neurotoxicity into CLD., (© 2019 S. Karger AG, Basel.)

Natural compounds such as (-)-epicatechin show a variety of biological properties including anticancer activity. Nonetheless, (-)-epicatechin's therapeutic application is limited due to its low water solubility and sensitivity to oxygen and light. Additionally, previous studies have reported that the encapsulation of flavonoids in nanoparticles might generate stable deliverable forms, which improves the availability and solubility of the bioactive compounds. The aims of this study were to generate (-)-epicatechin-loaded lecithin-chitosan nanoparticles (EC-LCT-NPs) by molecular self-assembly and to assess their cytotoxic potential against breast cancer cells. Various parameters were measured to characterize the EC-LCT-NPs including size, polydispersity index (PdI), zeta potential, morphology and entrapment efficiency. The results showed that the mean particle size of the EC-CLT-NPs was 159 ± 2.23 nm (PdI, 0.189), and the loading and entrapment efficiencies of (-)-epicatechin were 3.42 ± 0.85% and 56.1 ± 3.9%, respectively. The cytotoxic effect of the EC-CLT-NPs was greater than that of free (-)-epicatechin on breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-436 and SK-Br3). Indeed, EC-LCT-NPs showed an IC 50 that was four-fold lower (85 μM) than free (-)-epicatechin (350 μM) and showed selectivity to cancerous cells. This study demonstrated that encapsulating (-)-epicatechin into lecithin-chitosan nanoparticles opens new options for breast cancer treatment., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Hyperammonemia results from hepatic inability to remove nitrogenous products generated by protein metabolism of intestinal microbiota, which leads to hepatic encephalopathy (HE) in chronic liver disease (CLD). In ammonium neurotoxicity, oxidative stress (OxS) plays a pathogenic role. Our objective was to evaluate if intestinal mannitol is as effective and safe as conventional treatment for diminishing hyperammonemia, OxS, and HE in patients with CLD., Material and Methods: We included 30 patients with HE classified by "Haven Criteria for Hepatic Encephalopathy". They were randomized into two groups: 1) Mannitol Group (MG) with mannitol 20% administered into the intestine by an enema, 2) conventional group (CG) with lactulose 40 g enema both substances were diluted in 800 mL of double distilled solution every 6 h; all patients received neomycin. We evaluated ammonia concentration, plasma oxidative stress, HE severity, intestinal discomfort and adverse effects., Results: Hyperammonemia (171 ± 104 vs 79 ± 49 μmol ammonia/L, p < 0.01), and oxidative stress (MDA 29 vs 27%, formazan 15 vs 11%, carbonyls 16 vs 9% and dityrosines 10 vs 5%) were reduced in MG and CG respectively. The HE severity decreased by two degrees compared to baseline values in both groups. Intestinal discomfort and electrolyte plasma alterations were less frequent (p < 0.05) in MG than CG., Conclusions: Intestinal mannitol is as effective and safe as conventional treatment for reducing hyperammonemia, oxidative stress, and hepatic encephalopathy of CLD patients in the emergency room. Likewise, mannitol is better tolerated than conventional treatment., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: This study sought to determine whether the angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism, obesity and oxidative damage are risk factors for the development of preeclampsia in Mexican women., Study Design: A total of 66 women with preeclampsia (PE) and 37 women with normal pregnancies (NP) were included in the study. DNA was extracted from whole blood, and the ACE I/D polymorphism was evaluated by polymerase chain reaction. ACE activity and oxidative damage were assessed in plasma. The intergroup comparisons were analyzed by an analysis of variance (ANOVA) with post hoc tests. Hardy-Weinberg equilibrium (HWE) was tested by x 2 analysis, odds ratios (OR) were calculated as a measure of the degree of relative risk of preeclampsia, and for correlations, we used Spearman's correlation coefficient., Results: The frequency of the DD genotype was higher in PE (34.84%) than NP (10.82%). The OR of the DD genotype and D allele were associated with a 4.4-fold (CI=95% 2.24-14) and 3-fold (CI=95% 1.69-5.62) increased risk of developing PE, respectively. Major ACE activity in the DD genotype and obesity were features of the PE group; oxidative damage to proteins and a reduction in the activity of the antioxidant system showed a correlation with BMI (p<0.01)., Conclusion: Our results suggest that ACE I/D polymorphism, high ACE activity, body mass index and oxidative damage may play key roles in the pathogenesis of PE in the Mexican population. Furthermore, these findings could be used as predictive factors of PE., (Copyright © 2017 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.)

Background: Several studies have demonstrated the protective effects of cocoa consumption, due to its anti-inflammatory and antioxidant properties. Acute exercise induces oxidative stress and causes muscular damage during training. This study was designed to examine the effect of cocoa consumption on the markers of muscle damage, oxidative stress and physical fitness in professional soccer players., Methods: Fifteen players (15-18 years old) were included in the study. Biochemical parameters, markers of muscle damage and oxidative stress, and physical performance were evaluated before and after cocoa consumption. Biochemical parameters determined the healthy metabolic status of the study group; biomarkers of muscle and oxidative damage were measured in blood to establish muscle and redox status., Results: However, high levels of biomarkers of muscle damage were detected. Interestingly, cocoa consumption decreased the muscle damage biomarkers of CK and LDH by 39.4% and 23.03%, respectively. The redox status was modified by a decrease in oxidative damage (carbonyl groups, 26.31%; thiol groups, 27.52%; MDA, 32.42%) and an increase in total antioxidant capacity (15.98%) and GSH-Px activity (26.37%). In addition, we observed an increase in physical performance by 4% in the Cooper Test., Conclusions: Our findings suggest that a short period of cocoa consumption could be useful in maintaining a good physical fitness, due to the favourable effects on muscle and redox status in athletes during exhaustive exercise.

Aim of the Study: In breast cancer, oestrogen receptor (ER), progesterone receptor (PgR), and HER2 (HER2/Neu) expression status are used to classify neoplasms into subtypes: Luminal A, Luminal B, HER2/Neu type, and Basallike. The aim of the present study was to establish the molecular subtypes of breast cancers and their association with tumour characteristics and reproductive factors in Mexican women., Material and Methods: A total of 1326 biopsies of breast tumour tissues were analysed for ER, PR, and HER2/Neu by immunohistochemistry (IHC). Information regarding age, tumour characteristics, and node involvement profiles were collected., Results: IHC established that the most common subtype of breast cancer was Luminal A (64.93%), followed by Basal-Like (13.88%), Luminal B (12.52%), and HER2/Neu (8.67%). T2-size tumours (> 2 cm but < 5 cm) were present in 47.59% of all patients. Univariate analysis showed that lymph node positivity (p = 0.009), stage (p = 0.013), and placement of the tumour (p = 0.001) were factors associated with breast cancer subtype., Conclusions: Our data show that IHC is useful for distinguishing different subtypes of breast cancer and that Luminal A is the most common breast cancer subtype in the Mexican population. All subtypes were associated with unfavourable clinicopathological features, suggesting that late diagnosis is an important contributor to high mortality rates in the Mexican population.

We investigated whether oxidative damage and insulin polymerization at a systemic level are associated with the insulin resistance (IR) observed in obese subjects. We evaluated 3 groups (n=16/each) divided according to body mass index (BMI): Normal weight (NW) with a BMI of 18.5-24.9, obese 1 (O1) 30-34.9, and obese 3 (O3)>40 kg/m(2). IR and oxidative damage status of the groups were established by HOMA value and the analysis of biomarkers of oxidative stress in plasma. Insulin polymers in systemic circulation were detected using an antibody specific coupled to magnetic beads, which were incubated in plasma from the study groups. Analysis of magnetic beads by electrophoresis on polyacrylamide gel and silver stain assessed the presence of insulin polymers. The inhibition of polymers formation was studied by the presence of (-)-epicatechin. We demonstrated that O1 and O3 subjects with IR showed higher oxidative damage to their plasma lipids and proteins than NW subjects. This oxidative damage was associated with the presence of insulin polymers in the plasma of the O1 and O3 subjects. This polymer showed a high concentration of carbonyl groups by Western blot, suggesting the participation of oxidative damage in the generation of the polymer. The antioxidant (-)-epicatechin decreased the formation of the insulin polymer, indicating that the prevention of oxidative damage can inhibit insulin polymerization. Our study revealed an association between the presence of carbonyl stress, IR, and insulin polymer formation in obese subjects. This study also demonstrates that the antioxidant (-)-epicatechin inhibits insulin polymerization., (© Georg Thieme Verlag KG Stuttgart · New York.)

To compare oxidative stress (OS) biomarkers and antioxidant capacity of plasma (ACP) between dcSSc (diffuse cutaneous systemic sclerosis) and healthy Mexicans and their possible relationship with autoantibodies, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and uric acid (UA). We included 28 dcSSc and 28 healthy individuals. Patients were grouped in early and late dcSSc and were excluded if they had infections, neoplasias, comorbidity, or antioxidant treatment. Lipoperoxidation products (malondialdehyde), protein oxidation products (carbonyls, dityrosines), ACP, CRP, ESR, and UA were investigated. Age was 47.5 ± 10 in dcSSc versus 48 ± 7 years in controls. In dcSSc, OS was higher and ACP was decreased versus controls (p < 0.001). OS was similar in early and late dcSSc. Anti-Scl-70 (anti-topoisomerase I) was associated with a higher OS (p < 0.05). Eight dcSSc patients had hyperuricemia (28.5 %). A significant correlation between UA and malondialdehyde, dityrosines and carbonyls levels (r = 0.52, r = 0.78 and r = 0.69, p < 0.01) respectively, was found in dcSSc group. A high level of ESR was present in 71 % and CRP in 40 % of dcSSc patients. Mexican dcSSc patients had elevated lipid/protein OS with respect to healthy controls. These OS biomarkers have direct correlation with UA levels. ESR and CRP were elevated in a great number of dcSSc patients. These biochemical markers suggest that dcSSc patients have a continuous stimulus for endothelial dysfunction and accelerated atherogenesis.

Pregnancy is a state of vasodilation mediated by nitric oxide (NO). This vasodilation is impaired in women with preeclampsia, and an alteration in the L-arginine-NO pathway may be a causal factor. The production of NO and arginase activity were investigated in plasma and human umbilical vein endothelial cells (HUVECs) from women with preeclampsia, which were associated with arginase II, eNOS, caveolin, angiotensin 1 and 2 receptor expression (AT1R and AT2R, respectively). The effect of (-)-epicatechin on arginase activity and production of anion superoxide in HUVEC also were investigated. Healthy volunteer non-pregnant (HV), normal pregnant (NP) and preeclamptic (PE) women were recruited for this study. Higher values of nitrite/nitrate (NO(2)/NO(3)) were detected in the plasma from PE women as opposed to HV and NP. Lower arginase activity in PE versus HV or NP women was observed. HUVECs from PE women showed lower values of NO(2)/NO(3), higher activity of arginase and higher expression of AT(1)R and AT(2)R than HUVECS from NP women. Interestingly, arginase activity was associated with AT(2)R stimulation; indeed this activity and the high NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activity in HUVECs from PE women can uncouple the production or inactivation of NO. However, we demonstrated that (-)-epicatechin could lead to a decrease in the activity of both enzymes.

Background: Obesity and the metabolic syndrome affect a considerable segment of the population worldwide, including health professionals. In fact, several studies have reported that physicians tend to have more cardiovascular risk factors than their patients. The present cross-sectional study assessed whether the Health Sciences students had a healthier lifestyle, thus could have a more preventive attitude towards chronic diseases than the general population., Materials and Methods: Students of the medical-biological areas were surveyed by answering a questionnaire about familiar cardiovascular risk factors, personal smoking, alcohol drinking, dietary and exercise habits. Blood pressure was also measured, along with weight, height, and abdominal circumference., Results: 23.4% of the participants were overweight and 10% obese. Parental obesity was the most frequent risk factor, followed by social drinking and smoking. We found high consumption of animal derived foods, breakfast- like cereals, pastries, white bread and sweetened beverages; while low intake of fruit and vegetables were reported. More than half the sample reported to practice very little or no exercise at all., Discussion and Conclusions: We found similar or even higher rates of risk factors than the average population, that may eventually lead to the development of chronic cardiometabolic diseases. Thus we can infer that biomedical education is inefficient in inducing healthy lifestyles among biomedical students, which could have impact in their future practice as they will most probable become obese health-professionals, thus fail to effectively treat their own patients., (Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.)

Background: Studies show that diet and exercise are important in the treatment of obesity. The aim of this study was to determine whether additional regular moderate aerobic exercise during a treatment with hypocaloric diet has a beneficial effect on oxidative stress and molecular damage in the obese patient., Methods: Oxidative stress of 16 normal-weight (NW) and 32 obese 1 (O1) subjects (BMI 30-34.9 kg/m(2)) were established by biomarkers of oxidative stress in plasma. Recombinant human insulin was incubated with blood from NW or O1 subjects, and the molecular damage to the hormone was analyzed. Two groups of treatment, hypocaloric diet (HD) and hypocaloric diet plus regular moderate aerobic exercise (HDMAE), were formed, and their effects in obese subjects were analyzed., Results: The data showed the presence of oxidative stress in O1 subjects. Molecular damage and polymerization of insulin was observed more frequently in the blood from O1 subjects. The treatment of O1 subjects with HD decreased the anthropometric parameters as well as oxidative stress and molecular damage, which was more effectively prevented by the treatment with HDMAE., Conclusion: HD and HDMAE treatments decreased anthropometric parameters, oxidative stress, and molecular damage in O1 subjects., (Copyright © 2012 S. Karger GmbH, Freiburg.)

Obesity and its associated disorders constitute a growing epidemic across the world. Numerous studies have demonstrated the presence of systemic oxidative stress in patients with obesity. In this study, we show the effects of oxidative stress present in the blood from obese patients on recombinant human insulin. Insulin was incubated with whole blood (WB) from overweight subjects (OW), obese 1 patients (O1), or normal weight volunteers (NW) (n=16 for each group). Whole blood from OW and O1, unlike WB from NW, increased the carbonyl content of insulin; however, only whole blood from O1 patients increased the amount of formazan present in the hormone. Interestingly, the incubation of insulin with WB from O1 provoked a decrease in the hypoglycemic activity of the hormone (18%), an effect due to insulin polymerization. In addition, we showed that the formation of the insulin polymer generated the formation of new epitopes and the development of a new immunogenicity. These observations show that oxidative stress present in the WB of O1 patients can result in abolition of the biological activity of insulin and contribute to the development of an immune response to the hormone., (© Georg Thieme Verlag KG Stuttgart · New York.)

Oxidative stress damage to biomolecules has been implicated in several diseases including diabetes mellitus. In the present study, we investigated the effect of oxidative stress in whole blood (WB) from diabetic patients (n = 60) on recombinant human insulin. Insulin was incubated with WB obtained from diabetic patients (DP) who had hyperglycemia (>300 mg/dL) or from 41 healthy volunteers (HV). Whole blood of DP, unlike WB of HV, induced higher values of formazan (142%), dityrosines (279%), and carbonyls (58%) in the insulin residues. Interestingly, the insulin modified by WB of DP showed less hypoglycemic activity in rat (30%) in comparison with insulin incubated with WB of HV. The incubation of insulin in WB from DP induces chemical changes in insulin and a decrease in its biological activity, events that might be associated with the high levels of oxidative stress markers found in the plasma of these patients.

Oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). To investigate the correlation between the progression of COPD and plasma biomarkers of chronic inflammation and oxidative injury, blood samples were obtained from healthy volunteers (HV, n = 14) and stabilized COPD patients. The patients were divided into three groups according to their GOLD stage (II, n = 34; III, n = 18; IV, n = 20). C-reactive protein (CRP), protein carbonyls (PC), malondialdehyde (MDA), susceptible lipoperoxidation of plasma substrates (SLPS), and myeloperoxidase activity (MPO) were measured. The plasma concentration of SLPS was measured as the amount of MDA generated by a metal ion-catalyzed reaction in vitro. PC, SLPS, and CPR were increased significantly (p < 0.001) in COPD patients when compared to HV. MDA concentrations and MPO activities were not significantly different from those of the HV group. In conclusion, increased oxidation of lipids and proteins resulting in a progressive increase in the amount of total plasma carbonyls and oxidative stress the presence of oxidative stress during COPD progression, concomitant with an increased oxidation of lipids and proteins resulting in a progressive and significant increase in the amount of total carbonyls formed from lipid-derived aldehydes and direct amino acid side chain oxidation in plasma, may serve as a biomarker and independent monitor of COPD progression and oxidative stress injury.

Lipid peroxidation induced by reactive oxygen species might modify circulating biomolecules because of the formation of alpha,beta-unsaturated or dicarbonylic aldehydes. In order to investigate the interaction between a lipoperoxidation product, acrolein, and a circulating protein, insulin, the acrolein-insulin adduct was obtained. To characterize the adduct, gel filtration chromatography, sodium dodecylsulfate-polyacrylamide gel electrophoresis and carbonyl determination were performed. Induction of hypoglycemia in the rat and stimulation of glucose uptake by 3T3 adipocytes were used to evaluate the biological efficiency of the adduct compared with that of native insulin (Mackness, B., Quarck, R., Verte, W., Mackness, M., and Holvoet, P. (2006) Arterioscler., Thromb. Vasc. Biol. 26, 1545-1550). Formation of the acrolein-insulin complex in vitro increased the carbonyl group concentration from 2.5 to 22.5 nmol/mg of protein, and it formed without intermolecular aggregates (Halliwell, B., and Whiteman, M. (2004) Br. J. Pharmacol. 142, 231-255. The hypoglycaemic effect 18 min after administration to the rat is decreased by 25% (Robertson, R. P. (2004) J. Biol. Chem. 279, 42351-42354. An adduct concentration of 94 nM, compared to 10 nM for native insulin, was required to obtain the A 50% (concentration needed to obtain 50% of maximum transport of glucose uptake by 3T3 adipocytes). In conclusion, formation of the acrolein-insulin adduct modifies the structure of insulin and decreases its hypoglycemic effect in rat and glucose uptake by 3T3 adipocytes. These results help explain how a toxic aldehyde prone to be produced in vivo can structurally modify insulin and change its biological action.

In myocardial infarctions with ST-segment elevation, ischemia followed by reperfusion (IR) leads to arrhythmia, myocardial stunning and endothelial dysfunction injury by reactive oxygen species (ROS). To determine the impact of ROS, we examined the effect of antioxidant vitamins on biochemical changes and arrhythmias induced by reperfusion before and after therapeutic thrombolysis (Actilyse). As compared with those receiving placebo, in individuals who received antioxidants, there was a significant decrease in premature ventricular beats (100% vs 38%), atrial fibrillation (44% vs 6%), ventricular tachycardia (31% vs 0%), first-degree atrial-ventricular block (44% vs 6%), plasma malondialdehyde at the first hour after initiation of thrombolysis (1.07 +/- 0.10 vs 0.53 +/- 0.10 nmols plasma malondialdehyde/mg protein) and circulating neutrophils after 24 hr after reperfusion. The antioxidant capacity of plasma was increased from 1.89 +/- 0.15 to 3.00 +/- 0.31 units/mg protein and paraoxonase-1 rose from 0.77 +/- 0.08 to 1.27 +/- 0.11 nmol/min/mg protein. These findings suggest that antioxidants might be useful as adjuvants in controlling reperfusion induced arrhythmias following therapeutic alteplase thrombolysis.

The formation of dityrosine of human insulin oxidized by metal-catalyzed oxidation system (H2O2/Cu) was estimated by fluorescent methods. The oxidation of tyrosine and phenylalanine residues present on the insulin molecule was evident after 2 minutes of in vitro oxidation due to the formation of protein-bound dityrosine. The success of oxidative protein modification was followed until available aromatic residues were consumed (60 minutes), measured by their emission at 405 nm. The structural and chemical changes on insulin molecule are related to the loss of biological activity as assessed by measuring the increase of U-14C-glucose utilization by human adipose tissue in a radiorespirometry system. The oxidation of glucose (14CO2 production) of the adipose cells was increased 35 % (301 +/- 119 to 407 +/- 182 cpm/mg in dry weight. P < 0.05) in presence of 0.1 IU and 69 % (301 +/- 119 to 510 +/- 266 cpm/dry weight. P < 0.05) for 1.0 IU of insulin. The recombinant human insulin oxidized for 5 minutes only increased the glucose oxidation by 25 %. In conclusion, these observations show that dityrosine formation and other oxidative chemical changes of insulin due to its in vitro oxidation decrease and can abolish its biological activity.

Oxidative stress occurs when the production of reactive oxygen species (ROS) exceeds the endogenous antioxidant defense. Peroxidations induced by ROS are the key of chemical and structural modifications of biomolecules including circulating proteins. To elucidate the effect of ROS on circulating proteins and considering the presence of oxidative stress in Diabetes Mellitus, the effects of ROS, in vitro, on human insulin were studied. We utilized the Fenton reaction for free hydroxyl radical (HO*) generation in presence of human recombinant insulin measuring chemical changes on its molecular structure. The induced changes in insulin were: a) significant increase on absorbance (280 nm) due to phenylalanine hydroxylation (0.023 +/- 0.007 to 0.13 +/- 0.07). b) Peroxidation products formed on amino acids side branches (peroxyl and alcohoxyl group); measured as increased capacity of reduce nitroblue of tetrazolium (NBT) to formazan (0.007 +/- 0.007 to 0.06 +/- 0.02). c) Increased concentration of free carbonyl groups (8.8 +/- 8.7 to 45.6 +/- 20.2 pmoles dinitrophenylhidrazones/nmol insulin) with lost of secondary structure, and d) Modification of epithopes decreasing the insulin antigen-antibody reactivity measured as a decrease in insulin concentration by RIA. In conclusion, the radical hydroxyl in vitro is able to induce molecular modifications on insulin.

Regulation of catalase (CAT) expression, a major antioxidant enzyme that detoxifies H2O2, is very complex. Garlic is effective to prevent or ameliorate oxidative stress probably through its intrinsic antioxidant properties and/or to its ability to modify antioxidant enzyme expression. In this paper we studied the effect of a 2% garlic diet on the renal and hepatic CAT expression (mRNA levels, and enzyme activity, content, synthesis, and degradation). The study was made 2 weeks after feeding rats with a 2% garlic diet. CAT activity and content were measured by a spectrophotometric method and Western blot, respectively. CAT mRNA levels and CAT synthesis (k(s)) and degradation (kD) in vivo were measured by Northern blot and kinetic of reappearance of CAT activity after aminotriazole injection, respectively. Garlic-treatment decreased CAT activity and content, and CAT mRNA levels were unchanged in both tissues. k(s) decreased and kD remained unchanged in kidney and liver. The decrease in k(s) without changes in kD and CAT mRNA levels could explain the low CAT expression in garlic-fed rats. In vivo H2O2 generation in kidney and liver was markedly decreased in garlic-fed rats which could be due to a direct antioxidant effect of garlic. This may be the initial event in the garlic-fed rats that leads to the decreased CAT expression. Our data strongly suggest that the diminished renal and hepatic CAT expression in garlic-fed rats is mediated by post-transcriptional changes (mainly low translational efficiency) which could be an adaptation to the low H2O2.

Reactive oxygen species are involved in gentamicin (GM) nephrotoxicity, and garlic is effective in preventing or ameliorating oxidative stress. Therefore, the effect of garlic on GM nephrotoxicity was investigated in this work. Four groups of rats were studied: (i) fed normal diet (CT), (ii) treated with GM (GM), (iii) fed 2% garlic diet (GA), and (iv) treated with GM and 2% garlic diet (GM + GA). Rats were placed in metabolic cages and GM nephrotoxicity was induced by injections of GM (75 mg/kg every 12 h) for 6 d. Lipoperoxidation and enzyme determinations were made in renal cortex on day 7. GM nephrotoxicity was made evident on day 7 by (i) tubular histological damage, (ii) enhanced BUN and urinary excretion of N-acetyl-beta-D-glucosaminidase, and (iii) decreased creatinine clearance. These alterations were prevented or ameliorated in GM + GA group. The rise in lipoperoxidation and the decrease in Mn-SOD and glutathione peroxidase (GPx) activities observed in the GM group, were prevented in the GM + GA group. Cu, Zn-SOD activity and Mn-SOD and Cu,Zn-SOD content did not change. CAT activity and content decreased in the GM, GA, and GM + GA groups. CAT mRNA levels decreased in the GM group. The protective effect of garlic is associated with the prevention of the decrease of Mn-SOD and GPx activities and with the rise of lipoperoxidation in renal cortex.

Nephrotic syndrome (NS) is characterized by proteinuria, oxidative stress and endogenous hyperlipidemia. Hyperlipidemia and oxidative stress may be involved in coronary heart disease and the progression of renal damage in these patients. Garlic has been suggested to be beneficial in various disease states. Some of the beneficial effects of garlic may be secondary to its hypolipidemic and antioxidant properties. Therefore, the effect of a 2% garlic diet on acute and chronic experimental NS induced by puromycin aminonucleoside (PAN) was studied in this work. Acute NS was induced by a single injection of PAN to rats which were sacrificed 10 days later. Chronic NS was induced by repeated injections of PAN to rats which were sacrificed 84 days after the first injection. Garlic treatment was unable to modify proteinuria in either acute or chronic NS, and hypercholesterolemia and hypertriglyceridemia in acute NS. However, garlic treatment diminished significantly total-cholesterol, LDL-cholesterol and triglycerides, but not HDL-cholesterol in chronic NS. Garlic induced no change in the percentage of sclerotic glomeruli in chronic NS and a significative decrease on the percentage of sclerotic area of these glomeruli (33 +/- 3% in NS+Garlic group vs. 47 +/- 4% in NS group, p = 0.0126). The enhanced in vivo renal H2O2 production and the diminished renal Cu, Zn-SOD and catalase activities in acute NS, and the decreased renal catalase activity in chronic NS were not prevented by garlic treatment. These data indicate that garlic treatment ameliorates hyperlipidemia and renal damage in chronic NS which is unrelated to proteinuria or antioxidant enzymes.