DELETERIOUS EFFECT OF HIGH CARNOSINE CONCENTRATIONS IN EXTENDERS DURING SPERM CRYOPRESERVATION IN DOGS / EFECTO DELETÉREO DE ALTAS CONCENTRACIONES DE CARNOSINA EN DILUYENTES DURANTE LA CRIOPRESERVACIÓN ESPERMÁTICA EN PERROS

Cryopreservation is a key process among the canine reproductive biotechnologies. However, during sperm cryopreservation an excessive reactive oxygen species (ROS) generation occurs, leading to decrease in sperm quality. Therefore, several antioxidants were tested during sperm cryopreservation to prevent such effects, however the carnosine it has not used. Carnosine is a protein present in the seminal plasma, and unlike other antioxidants has the ability to remove products of lipid peroxidation (malondialdehyde), which are as harmful as ROS. Thus, the aim of this study was to evaluate the effects of different carnosine concentrations, during sperm cryopreservation in dogs. For this purpose, six dogs in reproductive age were used, and after sperm collection the samples were cryopreserved in Control (tris-citrate egg yolk extender), Carnosine 1mM, 50mM and 100mM groups. After thawing samples were analyzed by computer-assisted analysis of sperm motility, plasma membrane (eosin/nigrosin), acrosome integrity (fast green/rose Bengal), mitochondrial activity, DNA integrity and sperm resistance to oxidative stress (by TBARS). Decrease was observed in motility sperm kinetics (total and progressive motility) and reduced lipid peroxidation products in the group treated with 50mM and 100mM. On the other hand, 1mM was similar to control group. In conclusion, higher carnosine concentration (50 and 100mM) apparently promoted impairment in energy production and consequently was harmful to sperm kinetics. Thus, future studies must be performed using different carnosine concentrations and in association with substrates for glycolysis and oxidative phosphorylation.RESUMENLa criopreservación es un proceso clave entre las biotecnologías reproductivas en caninos. Sin embargo, durante la criopreservación espermática se da una generación excesiva de especies reactivas de oxígeno (ROS), lo que lleva a una disminución en la calidad espermática. Por lo tanto, varios medios de congelación utilizando antioxidantes para evitar tales efectos han sido evaluados, aunque la carnosina todavía no se ha utilizada. La carnosina es una proteína presente en el plasma seminal que a diferencia de otros antioxidantes tiene la habilidad de remover productos de la peroxidación lipídica (malondialdehído), que son tan dañinos como los ROS. Por lo tanto, el objetivo de este estudio fue evaluar los efectos de diferentes concentraciones de carnosina durante la congelación espermática en perros. Para este propósito se utilizaron seis perros en edad reproductiva y después de la colectar los eyaculados, las muestras fueron criopreservadas en un diluyente Control (tris, citrato, yema de huevo), Carnosina 1mM, 50mM y 100 mM. Después del descongelado, las muestras fueron evaluadas mediante el análisis computerizado de la motilidad, integridad de membrana plasmática (eosina / nigrosina), integridad del acrosoma (Fast - green / rosa de Bengala), la actividad mitocondrial (3’3 Diaminobenzidina), la integridad del ADN (SCSA) y la evaluación de la resistencia al estrés oxidativo (TBARS). Se observó una disminución en la cinética de los espermatozoides (motilidad total y progresiva) y una reducción de los productos de la peroxidación lipídica en los grupos tratados con 50 mM y 100mM de carnosina. Por otro lado, el grupo con 1 mM de carnosina fue similar al control. En conclusión, una alta concentración de carnosina (50 y 100mM) parece afectar la producción de energía del espermatozoide y por lo tanto es perjudicial para la cinética del espermatozoide. Por lo tanto, futuros estudios deben realizarse utilizando diferentes concentraciones de carnosina y en asociación con sustratos para la glucólisis y la fosforilación oxidativa

Xanthine oxidase inhibitors for prevention of cardiovascular events: a systematic review and meta-analysis of randomized controlled trials

Abstract Background Xanthine oxidase inhibitors (XOI), classified as purine-like (allopurinol and oxypurinol) and non-purine (febuxostat and topiroxostat) XOI, present antioxidant properties by reducing the production of reactive oxygen species derived from purine metabolism. Oxidative stress is an important factor related to endothelial dysfunction and ischemia-reperfusion injury, and may be implicated in the pathogenesis of heart failure, hypertension, and ischemic heart disease. However, there is contradictory evidence regarding the possible cardiovascular (CV) protective effect exerted by XOI. Our objective is to compare the incidence of major adverse cardiovascular events (MACE), mortality, total (TCE) and specific CV events in randomized controlled trials (RCTs) testing XOI against placebo or no treatment. Methods PubMed, EMBASE, Web of Science, Cochrane Central, Lilacs databases were searched from inception to Dec 30 2016, along with hand searching. RCTs including exclusively adult individuals, lasting ≥ 4 weeks, with no language restriction, were eligible. Independent paired researchers selected studies and extracted data. Considering the expected rarity of events, Peto and DerSimonian/Laird odds ratios (OR), the latter in case of heterogeneity, were used for analysis. Random-effects meta-regression was used to explore heterogeneity. Results The analysis of MACE included 81 articles (10,684 patients, 6434 patient-years). XOI did not significantly reduce risk of MACE (ORP = 0.71, 95% CI 0.46–1.09) and death (0.89, 0.59–1.33), but reduced risk of TCE (0.60, 0.44–0.82; serious TCE: 0.64, 0.46 to 0.89), and hypertension (0.54, 0.37 to 0.80). There was protection for MACE in patients with previous ischemic events (0.42, 0.23–0.76). Allopurinol protected for myocardial infarction (0.38, 0.17–0.83), hypertension (0.32, 0.18–0.58), TCE (0.48, 0.31 to 0.75, I2 = 55%) and serious TCE (0.56, 0.36 to 0.86, I2 = 44%). Meta-regression associated increasing dose of allopurinol with higher risk of TCE and serious TCE (P  300 mg/day) may be associated with loss of CV protection

Peripheral Oxidative Stress Biomarkers in Spinocerebellar Ataxia Type 3/Machado–Joseph Disease

Objectives: Spinocerebellar ataxia type 3/Machado–Joseph disease (SCA3/MJD) is a polyglutamine disorder with no current disease-modifying treatment. Conformational changes in mutant ataxin-3 trigger different pathogenic cascades, including reactive oxygen species (ROS) generation; however, the clinical relevance of oxidative stress elements as peripheral biomarkers of SCA3/MJD remains unknown. We aimed to evaluate ROS production and antioxidant defense capacity in symptomatic and presymptomatic SCA3/MJD individuals and correlate these markers with clinical and molecular data with the goal of assessing their properties as disease biomarkers. Methods: Molecularly confirmed SCA3/MJD carriers and controls were included in an exploratory case–control study. Serum ROS, measured by 2′,7′-dichlorofluorescein diacetate (DCFH-DA) as well as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) antioxidant enzyme activities, levels were assessed. Results: Fifty-eight early/moderate stage symptomatic SCA3/MJD, 12 presymptomatic SCA3/MJD, and 47 control individuals were assessed. The DCFH-DA levels in the symptomatic group were 152.82 nmol/mg of protein [95% confidence interval (CI), 82.57–223.08, p < 0.001] higher than in the control and 243.80 nmol/mg of protein (95% CI, 130.64–356.96, p < 0.001) higher than in the presymptomatic group. The SOD activity in the symptomatic group was 3 U/mg of protein (95% CI, 0.015–6.00, p = 0.048) lower than in the presymptomatic group. The GSH-Px activity in the symptomatic group was 13.96 U/mg of protein (95% CI, 5.90–22.03, p < 0.001) lower than in the control group and 20.52 U/mg of protein (95% CI, 6.79–34.24, p < 0.001) lower than in the presymptomatic group and was inversely correlated with the neurological examination score for spinocerebellar ataxias (R = −0.309, p = 0.049). Conclusion: Early/moderate stage SCA3/MJD patients presented a decreased antioxidant capacity and increased ROS generation. GSH-Px activity was the most promising oxidative stress disease biomarker in SCA3/MJD. Further longitudinal studies are necessary to identify both the roles of redox parameters in SCA3/MJD pathophysiology and as surrogate outcomes for clinical trials

Peripheral Oxidative Stress Biomarkers in Spinocerebellar Ataxia Type 3/Machado–Joseph Disease

ObjectivesSpinocerebellar ataxia type 3/Machado–Joseph disease (SCA3/MJD) is a polyglutamine disorder with no current disease-modifying treatment. Conformational changes in mutant ataxin-3 trigger different pathogenic cascades, including reactive oxygen species (ROS) generation; however, the clinical relevance of oxidative stress elements as peripheral biomarkers of SCA3/MJD remains unknown. We aimed to evaluate ROS production and antioxidant defense capacity in symptomatic and presymptomatic SCA3/MJD individuals and correlate these markers with clinical and molecular data with the goal of assessing their properties as disease biomarkers.MethodsMolecularly confirmed SCA3/MJD carriers and controls were included in an exploratory case–control study. Serum ROS, measured by 2′,7′-dichlorofluorescein diacetate (DCFH-DA) as well as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) antioxidant enzyme activities, levels were assessed.ResultsFifty-eight early/moderate stage symptomatic SCA3/MJD, 12 presymptomatic SCA3/MJD, and 47 control individuals were assessed. The DCFH-DA levels in the symptomatic group were 152.82 nmol/mg of protein [95% confidence interval (CI), 82.57–223.08, p &lt; 0.001] higher than in the control and 243.80 nmol/mg of protein (95% CI, 130.64–356.96, p &lt; 0.001) higher than in the presymptomatic group. The SOD activity in the symptomatic group was 3 U/mg of protein (95% CI, 0.015–6.00, p = 0.048) lower than in the presymptomatic group. The GSH-Px activity in the symptomatic group was 13.96 U/mg of protein (95% CI, 5.90–22.03, p &lt; 0.001) lower than in the control group and 20.52 U/mg of protein (95% CI, 6.79–34.24, p &lt; 0.001) lower than in the presymptomatic group and was inversely correlated with the neurological examination score for spinocerebellar ataxias (R = −0.309, p = 0.049).ConclusionEarly/moderate stage SCA3/MJD patients presented a decreased antioxidant capacity and increased ROS generation. GSH-Px activity was the most promising oxidative stress disease biomarker in SCA3/MJD. Further longitudinal studies are necessary to identify both the roles of redox parameters in SCA3/MJD pathophysiology and as surrogate outcomes for clinical trials