Adjuvant Therapy in High-Risk Renal Cell Cancer: A Systematic Review and Meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating risk-benefit for adjuvant postoperative treatments in high-risk renal cell carcinoma by assessing reported disease-free survival (DFS), overall survival (OS), toxicity, and quality of life. METHODS: A literature search was performed in PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials to identify relevant RCTs (from database inception through May 15, 2018). The results of the ATLAS trial were published while writing this manuscript, and the manuscript was updated accordingly. A generic variance-weighted random effects model was used to derive estimates for efficacy and common adverse effects. Heterogeneity was assessed using the Cochran Q statistic and was quantified using the I2 test. RESULTS: Adjuvant therapy with tyrosine kinase inhibitors compared with placebo was observed to have a DFS hazard ratio [HR] of 0.92 (95% CI, 0.83-1.01) and an OS HR of 1.01 (95% CI, 0.89-1.15) (4 RCTs; 4417 patients). Analysis of DFS for sunitinib compared with placebo (n=1909) in the adjuvant setting detected an HR of 0.90 (95% CI, 0.67-1.19). Increased risk of grade 3 or 4 adverse events (relative risk [RR]=2.6; 95% CI, 2.28-2.97), diarrhea (RR=9.89; 95% CI, 4.22-23.14), fatigue (RR=3.11; 95% CI, 1.86-5.18), hypertension (RR=3.63; 95% CI, 2.99-4.41), and palmar/plantar dysesthesia (RR=2.70; 95% CI, 2.47-2.96) was observed. CONCLUSION: Adjuvant vascular endothelial growth factor tyrosine kinase inhibitors in high-risk renal cell carcinoma did not improve OS or DFS, and there was a significant increased risk of toxicity in greater than half of the patients, leading to a decline in quality of life.

A New Tyrosinase Inhibitor from the Red Alga Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae).

A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, and subsequent column chromatography identified three bromophenols: 2,3,6-tribromo-4,5-dihydroxybenzyl methyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). Bromophenols 1 and 3 exhibited potent competitive tyrosinase inhibitory activity against l-tyrosine substrates, with IC50 values of 10.78 ± 0.19 and 2.92 ± 0.04 µM, respectively. Against substrate l-3,4-dihydroxyphenylalanine (l-DOPA), compounds 1 and 3 demonstrated moderate activity, while 2 showed no observable effect. The experimental data were verified by a molecular docking study that found catalytic hydrogen and halogen interactions were responsible for the activity. In addition, compounds 1 and 3 exhibited dose-dependent inhibitory effects in melanin and intracellular tyrosinase levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Compounds 3 and 1 were the most effective tyrosinase inhibitors. In addition, increasing the bromine group number increased the mushroom tyrosinase inhibitory activity.

Lenvatinib: A Review in Hepatocellular Carcinoma.

Lenvatinib (Lenvima®) is an oral small molecule inhibitor of multiple receptor tyrosine kinases, and is approved for the first-line treatment of patients with unresectable hepatocellular carcinoma (HCC) in the USA, EU, Japan and China. The approval of lenvatinib was based on results of the randomized, open-label, multinational, non-inferiority phase III REFLECT trial in patients with unresectable HCC, who had not received treatment for advanced disease. In REFLECT, lenvatinib was non-inferior, but not superior, to sorafenib (current standard of care) for overall survival (OS). However, lenvatinib was associated with significant improvements compared with sorafenib in terms of all secondary endpoints [higher objective response rate (ORR), and longer progression-free survival (PFS) and time to progression (TTP)]. Lenvatinib had a generally manageable tolerability profile in REFLECT, with the most common treatment-emergent adverse events being hypertension, diarrhoea, decreased appetite and decreased weight. Given its non-inferior efficacy to sorafenib and manageable tolerability profile, lenvatinib represents a long-awaited alternative option to sorafenib for the first-line systemic treatment of patients with unresectable HCC. Further clinical experience may be required to fully define the position of lenvatinib in this setting.

Sevoflurane preconditioning induces tolerance to brain ischemia partially via inhibiting thioredoxin-1 nitration.

BACKGROUND: Sevoflurane preconditioning induces brain ischemic tolerance, but the mechanism remains poorly elucidated. Nitration is an important form of post-translational modification in pathological signaling. This study was to investigate the role of thioredoxin-1 (Trx-1) nitration in neuroprotection effect induced by sevoflurane preconditioning in a transient stroke model in rats. METHODS: Adult male Sprague-Dawley rats were preconditioned with 2% sevoflurane or vehicle oxygen exposure, 1 h per day, for 5 consecutive days. At 24 h after the last exposure, rats were subjected to focal brain ischemia induced by middle cerebral artery occlusion (MCAO) for 90 min, followed by 72-h reperfusion. Trx-1 expression and activity, as well as the content of nitrotyrosine at penumbra were detected at 24 h after preconditioning and 2, 8, 24, 72 h after MCAO. Nitrated Trx-1 was examined by immunoprecipitation at 8 h after MCAO. The role of Trx-1 nitration in ischemic tolerance was assessed by administration of nitrated human-Trx-1 prior to MCAO. Neurological scores, brain infarct volumes and TUNEL staining were evaluated at 24 h after reperfusion. RESULTS: Ischemic stroke decreased Trx-1 activity but not the expression in penumbra tissue. The content of nitrotyrosine was elevated after MCAO. Preconditioning with sevoflurane increased Trx-1 activity and reduced its nitration at 8 h after MCAO in comparison with vehicle preconditioning. The decrement of Trx-1 activity was correlated with its nitration level. Exogenous administration of nitrated human-Trx-1 reversed the brain ischemic tolerance of sevoflurane preconditioning, exacerbating brain infarct volume, neurobehavioral defects and apoptosis, while administration of human-Trx-1 had no effect on the sevoflurane preconditioning-induced neuroprotection. CONCLUSION: Ischemic stroke reduces Trx-1 activity via post-translational nitrative modulation in rats. Sevoflurane preconditioning induces brain ischemic tolerance and anti-apoptosis by partially preserving Trx-1 activity via inhibiting nitration.

Protective effect of magnesium acetyltaurate and taurine against NMDA-induced retinal damage involves reduced nitrosative stress.

Purpose: Retinal nitrosative stress associated with altered expression of nitric oxide synthases (NOS) plays an important role in excitotoxic retinal ganglion cell loss in glaucoma. The present study evaluated the effects of magnesium acetyltaurate (MgAT) on changes induced by N-methyl-D-aspartate (NMDA) in the retinal expression of three NOS isoforms, retinal 3-nitrotyrosine (3-NT) levels, and the extent of retinal cell apoptosis in rats. Effects of MgAT with taurine (TAU) alone were compared to understand the benefits of a combined salt of Mg and TAU. Methods: Excitotoxic retinal injury was induced with intravitreal injection of NMDA in Sprague-Dawley rats. All treatments were given as pre-, co-, and post-treatment with NMDA. Seven days post-injection, the retinas were processed for measurement of the expression of NOS isoforms using immunostaining and enzyme-linked immunosorbent assay (ELISA), retinal 3-NT content using ELISA, retinal histopathological changes using hematoxylin and eosin (H&E) staining, and retinal cell apoptosis using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining. Results: As observed on immunohistochemistry, the treatment with NMDA caused a 4.53-fold increase in retinal nNOS expression compared to the PBS-treated rats (p<0.001). Among the MgAT-treated groups, only the pretreatment group showed significantly lower nNOS expression than the NMDA-treated group with a 2.00-fold reduction (p<0.001). Among the TAU-treated groups, the pre- and cotreatment groups showed 1.84- and 1.71-fold reduction in nNOS expression compared to the NMDA-treated group (p<0.001), respectively, but remained higher compared to the PBS-treated group (p<0.01). Similarly, iNOS expression in the NMDA-treated group was significantly greater than that for the PBS-treated group (2.68-fold; p<0.001). All MgAT treatment groups showed significantly lower iNOS expression than the NMDA-treated groups (3.58-, 1.51-, and 1.65-folds, respectively). However, in the MgAT co- and post-treatment groups, iNOS expression was significantly greater than in the PBS-treated group (1.77- and 1.62-folds, respectively). Pretreatment with MgAT caused 1.77-fold lower iNOS expression compared to pretreatment with TAU (p<0.05). In contrast, eNOS expression was 1.63-fold higher in the PBS-treated group than in the NMDA-treated group (p<0.001). Among all treatment groups, only pretreatment with MgAT caused restoration of retinal eNOS expression with a 1.39-fold difference from the NMDA-treated group (p<0.05). eNOS expression in the MgAT pretreatment group was also 1.34-fold higher than in the TAU pretreatment group (p<0.05). The retinal NOS expression as measured with ELISA was in accordance with that estimated with immunohistochemistry. Accordingly, among the MgAT treatment groups, only the pretreated group showed 1.47-fold lower retinal 3-NT than the NMDA-treated group, and the difference was significant (p<0.001). The H&E-stained retinal sections in all treatment groups showed statistically significantly greater numbers of retinal cell nuclei than the NMDA-treated group in the inner retina. However, the ganglion cell layer thickness in the TAU pretreatment group remained 1.23-fold lower than that in the MgAT pretreatment group (p<0.05). In line with this observation, the number of apoptotic cells as observed after TUNEL staining was 1.69-fold higher after pretreatment with TAU compared to pretreatment with MgAT (p<0.01). Conclusions: MgAT and TAU, particularly with pretreatment, reduce retinal cell apoptosis by reducing retinal nitrosative stress. Pretreatment with MgAT caused greater improvement in NMDA-induced changes in iNOS and eNOS expression and retinal 3-NT levels than pretreatment with TAU. The greater reduction in retinal nitrosative stress after pretreatment with MgAT was associated with lower retinal cell apoptosis and greater preservation of the ganglion cell layer thickness compared to pretreatment with TAU.

Polyphenol-Rich Fraction of Parquetina nigrescens Mitigates Dichlorvos-Induced Cardiorenal Dysfunction Through Reduction in Cardiac Nitrotyrosine and Renal p38 Expressions in Wistar Rats.

Parquetina nigrescens is commonly used to treat diseases in humans and animals in developing countries, including Nigeria. This study evaluates the effects of its polyphenol-rich fraction (prf) on dichlorvos-induced cardio- and renal toxicity. There were several factors assessed during this study, including cardiac and renal markers, serum myeloperoxidase and xanthine oxidase, and electrocardiograph (ECG) changes. The changes in electrocardiograph (ECG) were recorded. Immunohistochemistry of cardiac and renal p38 and nitrotyrosine was determined. Dichlorvos exposure caused a significant decrease in L-glutathione (reduced glutathione) and other antioxidant enzymes with increases in malondialdehyde, myeloperoxidase, advanced oxidation protein products, and protein carbonyl levels. It also brought about alterations in microanatomy of the heart and kidneys accompanied by increases in serum creatinine and urea levels. Exposure to dichlorvos induced prolonged QRS interval and shortened QT durations in rats. Immunohistochemistry revealed lower expressions of cardiac nitrotyrosine and renal p38 (mitogen-activated protein kinase; MAPK) in rats treated with prf of P. nigrescens. Combining all, prf of P. nigrescens demonstrated antioxidant as well as protective properties in the heart and kidneys of rats exposed to dichlorvos. It ameliorated dichlorvos-induced cardio- and nephrotoxicity giving credence to its use in ethnomedicine.

Phenelzine reduces the oxidative damage induced by peroxynitrite in plasma lipids and proteins.

Peroxynitrite is a reactive nitrogen species produced in the intravascular compartment from superoxide anion and nitric oxide. Peroxynitrite destroys blood plasma proteins and membranes of red blood cells and of platelets. This explains why excessive production of peroxynitrite contributes to diseases and to ageing. Therapeutics that antagonize peroxynitrite may delay ageing and the progression of disease. We developed an in vitro assay that allows the investigation of the oxidative damage caused by peroxynitrite in the intravascular compartment. This assay correlates the damage with the rate of formation of protein carbonyl groups, 3-nitrotyrosine (3-NT) and thiobarbituric acid reactive substances. Using this assay, we evaluated the ability of phenelzine, a scavenger of reactive aldehydes, to antagonize the effects of peroxynitrite. Herein, we showed that phenelzine significantly decreased the lipid peroxidative damage caused by peroxynitirite in blood plasma and platelets. Moreover, it inhibited carbonyl group and 3-NT formation in blood plasma and platelet proteins.

Chilean berry Ugni molinae Turcz. fruit and leaves extracts with interesting antioxidant, antimicrobial and tyrosinase inhibitory properties.

The knowledge of the biological properties of fruits and leaves of murta (Ugni molinae Turcz.) has been owned by native Chilean culture. The present study investigated the phenolic content, the antioxidant, antimicrobial and anti-tyrosinase activities of different murta fruit and leaves extracts to approach their uses on future food, pharmaceutical and cosmetic applications. Extractions of murta fruit and leaves were carried out under water, ethanol and ethanol 50%. Phenolic content of these extracts was measured through Folin Ciocalteu test and the antioxidant power by four different antioxidant systems (ORAC, FRAP, DPPH and TEAC assays) owing to elucidate the main mechanism of antioxidant. Some flavonoids, such as rutin, isoquercitrin and quercitrin hydrate were identified and quantified through HPLC analysis. Antimicrobial activity was determined measuring minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values against Escherichia coli and Listeria monocytogenes, and the effect of these extracts on L. monocytogenes was confirmed by flow cytometry. Highest contents of polyphenol compounds were obtained in hydroalcoholic extracts (28±1mggallicacid/g dry fruit, and 128±6mggallicacid/g dry leaves). The same trend was found for the values of biological properties: hydroalcoholic extracts showed the strongest activities. Leaves presented higher antioxidant, antimicrobial and anti-tyrosinase properties than murta fruit. Highest antioxidant activity values according to ORAC, FRAP, TEAC and DPPH were 80±8mgTrolox/g, 70±2mgTrolox/g, 87±8mgTrolox/g and 110±12mgTrolox/g, respectively, for murta fruit samples, and 280±10mgTrolox/g, 192±4mgTrolox/g, 286±13mgTrolox/g and 361±13mgTrolox/g, respectively, for murta leaves. These activities were confirmed by HPLC analysis that revealed highest presence of analyzed compounds on leaves hydroalcoholic extract. Regarding to antimicrobial analysis, hydroalcoholic leaves extract presented the highest activity presenting the lowest MIC value for L. monocytogenes (0.07mg/mL). This extract also performed the highest anti-tyrosinase activity (CE50 values of 1.6±0.3 (g/L) and 8.9±1.2 (g/L) for leaves and fruit, respectively).

Strong renal expression of heat shock protein 70, high mobility group box 1, inducible nitric oxide synthase, and nitrotyrosine in mice model of severe malaria

Abstract INTRODUCTION Renal damage is a consequence of severe malaria, and is generally caused by sequestration of Plasmodium falciparum -infected erythrocytes in the renal microcirculation, which leads to obstruction, hypoxia, and ischemia. This triggers high mobility group box 1 (HMGB1) to send a danger signal through toll-like receptors 2 and 4. This signal up-regulates inducible nitric oxide (iNOS) and nitrotyrosine to re-perfuse the tissue, and also increases heat shock protein 70 (HSP70) expression. As no study has examined the involvement of intracellular secondary molecules in this setting, the present study compared the renal expressions of HSP70, HMGB1, iNOS, and nitrotyrosine between mice suffered from severe malaria and normal mice. METHODS C57BL/6 mice were divided into an infected group (intraperitoneal injection of 10 6 P. berghei ANKA) and a non-infected group. Renal damage was evaluated using hematoxylin eosin staining, and immunohistochemistry was used to evaluate the expressions of HSP70, HMGB1, iNOS, and nitrotyrosine. RESULTS Significant inter-group differences were observed in the renal expressions of HSP70, HMGB1, and iNOS (p=0.000, Mann-Whitney test), as well as nitrotyrosine (p=0.000, independent t test). The expressions of HSP70 and HMGB1 were strongly correlated (p=0.000, R=1.000). No correlations were observed between iNOS and HMGB, HMGB1 and nitrotyrosine, HSP70 and nitrotyrosine, or iNOS and nitrotyrosine. CONCLUSIONS It appears that HMGB1, HSP70, iNOS, and nitrotyrosine play roles in the renal damage that is observed in mice with severe malaria. Only HSP70 expression is strongly correlated with the expression of HMGB1.

Nintedanib (Ofev®) para el tratamiento de fibrosis pulmonar idiopática / Nintedanib (Ofev®) in the treatment of idiopathic pulmonary fibrosis

CONTEXTO CLÍNICO: La fibrosis pulmonar idiopática (FPI) es una neumonía intersticial crónica de causa desconocida cuya prevalencia en Argentina es desconocida. En Estados Unidos estiman una tasa de prevalencia en aumento alcanzando 14­63 casos por 100.000 habitantes. Para su diagnóstico se requiere la exclusión de otras entidades clínicas definidas o enfermedades parenquimatosas pulmonares difusas de etiología conocida (enfermedades del tejido conectivo, exposición ambiental u ocupacional, o toxicidad por fármacos), así como la evidencia radiológica de patrón de neumonía intersticial usual y/o su presencia en el examen del tejido pulmonar obtenido mediante biopsia pulmonar quirúrgica. TECNOLOGÍA: El nintedanib (Ofev®) es un inhibidor de las tirosinas quinasa asociadas a los receptores del factor de crecimiento del endotelio vascular (VEGFR, del inglés vascular endothelial growth factor receptors), derivado de plaquetas alfa y beta (PDGFR, del inglés platelet-derived growth factor receptors α and ß) y del factor de crecimiento de fibroblastos (FGFR, del inglés fibroblast growth factor receptors). Su utilización bloquea la señalización intracelular necesaria para la proliferación, migración y transformación de los fibroblastos, lo que constituye el mecanismo esencial de la FPI. OBJETIVO: Evaluar la evidencia disponible acerca de la eficacia, seguridad y aspectos relacionados a las políticas de cobertura de nintedanib en paciente con diagnóstico de fibrosis pulmonar idiopática. MÉTODOS: Se realizó una búsqueda en las principales bases de datos bibliográficas (incluyendo Medline, Cochrane y CRD), en buscadores genéricos de Internet, agencias de evaluación de tecnologias sanitarias y financiadores de salud. Se priorizó la inclusión de revisiones sistemáticas (RS), ensayos clínicos controlados aleatorizados (ECAs), evaluaciones de tecnologías sanitarias y económicas, guías de práctica clínica (GPC) y políticas de cobertura de diversos sistemas de salud cuando estaban disponibles. RESULTADOS: Para el siguiente informe se incluyeron una RS con meta-análisis, un meta-análisis de comparaciones indirectas, cuatro guías de prácticas clínicas y seis documentos referentes a políticas de cobertura. CONCLUSIONES: Evidencia de alta calidad no demostró que el uso de nintedanib en pacientes con fibrosis pulmonar idiopática leve o moderada disminuya la mortalidad al compararlo con la administración de placebo. Su beneficio se limitaría a disminuir el número exacerbaciones y el deterioro de la capacidad vital forzada (CVF). Evidencia de moderada calidad sugiere que su eficacia podría ser similar a la pirfenidona aunque no existen estudios directos entre ambas drogas. Las guías de prácticas clínicas la mencionan como una opción de tratamiento en pacientes com fibrosis pulmonar idiopática leve a moderada. Diferentes financiadores de salud de países desarrollados lo cubren en pacientes con una CVF mayor al 50% y una capacidad de difusión de monóxido de carbono mayor al 35%, en otros casos solamente si el costo es similar a la pirfenidona, o luego de una reducción importante del precio a través de un esquema de negociación.

Blockade of Y177 and Nuclear Translocation of Bcr-Abl Inhibits Proliferation and Promotes Apoptosis in Chronic Myeloid Leukemia Cells.

The gradual emerging of resistance to imatinib urgently calls for the development of new therapy for chronic myeloid leukemia (CML). The fusion protein Bcr-Abl, which promotes the malignant transformation of CML cells, is mainly located in the cytoplasm, while the c-Abl protein which is expressed in the nucleus can induce apoptosis. Based on the hetero-dimerization of FKBP (the 12-kDa FK506- and rapamycin-binding protein) and FRB (the FKBP-rapamycin binding domain of the protein kinase, mTOR) mediated by AP21967, we constructed a nuclear transport system to induce cytoplasmic Bcr-Abl into nuclear. In this study, we reported the construction of the nuclear transport system, and we demonstrated that FN3R (three nuclear localization signals were fused to FRBT2098L with a FLAG tag), HF2S (two FKBP domains were in tandem and fused to the SH2 domain of Grb2 with an HA tag) and Bcr-Abl form a complexus upon AP21967. Bcr-Abl was imported into the nucleus successfully by the nuclear transport system. The nuclear transport system inhibited CML cell proliferation through mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 5 (STAT5) pathways mainly by HF2S. It was proven that nuclear located Bcr-Abl induced CML cell (including imatinib-resistant K562G01 cells) apoptosis by activation of p73 and its downstream molecules. In summary, our study provides a new targeted therapy for the CML patients even with Tyrosine Kinase Inhibitor (TKI)-resistance.

Intravenous iron sucrose reverses anemia-induced cardiac remodeling, prevents myocardial fibrosis, and improves cardiac function by attenuating oxidative/nitrosative stress and inflammation.

BACKGROUND: According to recent clinical trial data, correction of iron deficiency with intravenous (i.v.) iron has favorable outcomes on cardiac function. We evaluated whether i.v. iron treatment of anemic rats has favorable effect on the left ventricular (LV) performance and remodeling and the role of oxidative/nitrosative stress and inflammation in the process. METHODS: After weaning, Sprague-Dawley rats were fed low iron diet for 16weeks, after which the treatment group received five weekly doses of i.v. iron sucrose (10mg Fe/kg body weight). Echocardiography of LV was performed and hematology parameters were assessed before treatment (baseline, day 0) and at the end of the study (day 29). On day 29, rats were sacrificed and extracellular expansion and fibrosis in LV and interventricular septum were evaluated together with oxidative/nitrosative stress, pro-inflammatory, and repair process markers. RESULTS: Although iron sucrose treatment did not fully correct the anemia, it reversed anemia-induced cardiac remodeling as indicated by echocardiographic and tissue Doppler parameters. Treatment with iron sucrose also prevented anemia-induced myocardial fibrosis as indicated by extracellular expansion and fibrosis markers. Anemia-induced inflammation was prevented by iron sucrose as indicated by the levels of proinflammatory (TNF-α, NF-κB65) and repair process markers (HSP27, HSP70). In addition, iron sucrose treatment significantly reduced (p<0.01) anemia-induced oxidative and nitrosative stress. CONCLUSION: Intravenous iron sucrose treatment reversed anemia-induced remodeling of LV, prevented myocardial fibrosis, and improved cardiac function by attenuating oxidative/nitrosative stress and inflammation in the heart.

Active site-directed plasmin inhibitors: Extension on the P2 residue.

Based on the structure of YO-2 [N-(trans-4-aminomethylcyclohexanecarbonyl)-l-Tyr(O-picolyl)-NH-octyl], active site-directed plasmin (Plm) inhibitors were explored. The picolyl moiety in the Tyr(O-picolyl) residue (namely, the P2 residue) was replaced with smaller or larger groups, such as hydrogen, tert-butyl, benzyl, (2-naphthyl)methyl, and (quinolin-2-yl)methyl. Those efforts produced compound 17 {N-(trans-4-aminomethylcyclohexanecarbonyl)-l-Tyr[O-(quinolin-2-yl)methyl]-NH-octyl} [IC50=0.22 and 77µM for Plm and urokinase (UK), respectively], which showed not only 2.4-fold greater Plm inhibition than YO-2, but also an improvement in selectivity (Plm/UK) by 35-fold. The docking experiments of the Plm-17 complexes disclosed that the amino group of the tranexamyl moiety interacted with the side-chain of Asp753 which formed S1 site.

Effects of carnosine, taurine, and betaine pretreatments on diethylnitrosamine-induced oxidative stress and tissue injury in rat liver.

Several chemicals such as N-diethylnitrosamine (DEN) promote hepatocellular cancer in rodents and induce hepatocyte injury. DEN affects the initiation stage of carcinogenesis together with enhanced cell proliferation accompanied by hepatocellular necrosis. DEN-induced hepatocellular necrosis is reported to be related to enhanced generation of reactive oxygen species. Carnosine (CAR), taurine (TAU), and betaine (BET) are known to have powerful antioxidant properties. We aimed to investigate the effects of CAR, TAU, and BET pretreatments on DEN-induced oxidative stress and liver injury in male rats. Rats were given CAR (2 g L-1 in drinking water), TAU (2.5% in chow), and BET (2.5% in chow) for 6 weeks and DEN (200 mg kg-1 intraperitoneally) was given 2 days before the end of this period. Serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and γ-glutamyl transferase activities were determined and a histopathologic evaluation was performed on the liver tissue. Oxidative stress was detected in the liver by measuring malondialdehyde, diene conjugate, protein carbonyl and nitrotyrosine levels, glutathione and glutathione peroxidase levels, and superoxide dismutase and glutathione transferase activities. Pretreatments with CAR, TAU, and BET decreased liver prooxidant status without remarkable changes in antioxidant parameters in DEN-treated rats. Pretreatments with TAU and BET, but not CAR, were also found to be effective to reduce liver damage in DEN-treated rats. In conclusion, TAU, BET, and possibly CAR may have an ameliorating effect on DEN-induced hepatic injury by reducing oxidative stress in rats.

Reduction of radiation­induced nitrative stress in leucocytes and kidney cells of rats upon administration of polyphenolic complex concentrates from red wine.

The research has shown that exposure to ionizing radiation at the dose of 30 cGy leads to the activation of NO-synthase way of nitrogen oxide synthesis, as well as to the accumulation of its stable metabolites and 3'-nitrotyrosine modified proteins in rat peripheral blood leucocytes and the renal cortical layer. NO-synthase activity was preserved at the control value through the consumption of red wine natural polyphenolic complex concentrates by the irradiated animals. The content of proteins modified by tyrosine nitration decreased in the early period of post-radiation exposure due to the influence of the investigated concentrate. Thus the ability of red wine natural polyphenolic complex concentrates to prevent adverse changes in L-arginine/NO system and, therefore, inhibit the development of nitrative stress induced by low doses of ionizing radiation has been proved experimentally.

Oral Glutamine Supplementation Protects Female Mice from Nonalcoholic Steatohepatitis.

BACKGROUND: Genetic factors, a diet rich in fat and sugar, and an impaired intestinal barrier function are critical in the development of nonalcoholic steatohepatitis (NASH). The nonessential amino acid glutamine (Gln) has been suggested to have protective effects on intestinal barrier function but also against the development of liver diseases of various etiologies. OBJECTIVE: The effect of oral Gln supplementation on the development of Western-style diet (WSD)-induced NASH in mice was assessed. METHODS: Female 6- to 8-wk-old C57BL/6J mice were pair-fed a control (C) diet or a WSD alone or supplemented with 2.1 g l-Gln/kg body weight for 6 wk (C+Gln or WSD+Gln). Indexes of liver damage, lipid peroxidation, and glucose metabolism and endotoxin concentrations were measured. RESULTS: Although Gln supplementation had no effect on the loss of the tight junction protein occludin, the increased portal endotoxin and fasting glucose concentrations found in WSD-fed mice, markers of liver damage (e.g., nonalcoholic fatty liver disease activity score and number of neutrophils in the liver) were significantly lower in the WSD+Gln group than in the WSD group (~47% and ~60% less, respectively; P < 0.05). Concentrations of inducible nitric oxide synthase (iNOS) protein and 3-nitrotyrosin protein adducts were significantly higher in livers of WSD-fed mice than in all other groups (~8.6- and ~1.9-fold higher, respectively, compared with the C group; P < 0.05) but did not differ between WSD+Gln-, C-, and C+Gln-fed mice. Hepatic tumor necrosis factor α and plasminogen activator inhibitor 1 concentrations were significantly higher in WSD-fed mice (~1.6- and ~1.8-fold higher, respectively; P < 0.05) but not in WSD+Gln-fed mice compared with C mice. CONCLUSION: Our data suggest that the protective effects of oral Gln supplementation on the development of WSD-induced NASH in mice are associated with protection against the induction of iNOS and lipid peroxidation in the liver.

Ligand binding to the FA3-FA4 cleft inhibits the esterase-like activity of human serum albumin.

The hydrolysis of 4-nitrophenyl esters of hexanoate (NphOHe) and decanoate (NphODe) by human serum albumin (HSA) at Tyr411, located at the FA3-FA4 site, has been investigated between pH 5.8 and 9.5, at 22.0°C. Values of Ks, k+2, and k+2/Ks obtained at [HSA] ≥ 5×[NphOXx] and [NphOXx] ≥ 5×[HSA] (Xx is NphOHe or NphODe) match very well each other; moreover, the deacylation step turns out to be the rate limiting step in catalysis (i.e., k+3 << k+2). The pH dependence of the kinetic parameters for the hydrolysis of NphOHe and NphODe can be described by the acidic pKa-shift of a single amino acid residue, which varies from 8.9 in the free HSA to 7.6 and 7.0 in the HSA:NphOHe and HSA:NphODe complex, respectively; the pK>a-shift appears to be correlated to the length of the fatty acid tail of the substrate. The inhibition of the HSA-Tyr411-catalyzed hydrolysis of NphOHe, NphODe, and 4-nitrophenyl myristate (NphOMy) by five inhibitors (i.e., diazepam, diflunisal, ibuprofen, 3-indoxyl-sulfate, and propofol) has been investigated at pH 7.5 and 22.0°C, resulting competitive. The affinity of diazepam, diflunisal, ibuprofen, 3-indoxyl-sulfate, and propofol for HSA reflects the selectivity of the FA3-FA4 cleft. Under conditions where Tyr411 is not acylated, the molar fraction of diazepam, diflunisal, ibuprofen, and 3-indoxyl-sulfate bound to HSA is higher than 0.9 whereas the molar fraction of propofol bound to HSA is ca. 0.5.

Glabridin, an isoflavan from licorice root, downregulates iNOS expression and activity under high-glucose stress and inflammation.

SCOPE: In females, hyperglycemia abolishes estrogen-vascular protection, leading to inflammation and oxidative stress that are related to diabetes-associated cardiovascular complications. Such knowledge led us to examine the potential of glabridin, as a replacement of estrogen anti-inflammatory activity under high-glucose conditions. METHODS AND RESULTS: In macrophage-like cells, chronic glucose stress (28 and 44 mM) upregulated inducible nitric oxide synthase (iNOS) mRNA expression by 42 and 189%, respectively. Pretreatment with glabridin, under chronic glucose stress, downregulated the LPS-induced nitric oxide secretion and nitrotyrosine formation, by 39 and 21%, respectively. Pretreatment with estradiol did not prevent the LPS-induced nitrotyrosine formation. Furthermore, glabridin, brought about a decrease in the LPS-induced iNOS mRNA expression by 48%, as compared to cells pretreated with estradiol. Glabridin decreased protein levels of liver iNOS by 69% in adult mouse offspring which developed hyperglycemia after early fetal exposure to a saturated fatty acid-enriched maternal diet. Glabridin also decreased liver nitrotyrosine levels in offspring of regular diet-fed mothers after further receiving high-fat diet. CONCLUSION: Such results indicate that glabridin retains anti-inflammatory abilities to regulate the synthesis and activity of iNOS under high-glucose levels, implying that a glabridin supplement may serve as an anti-inflammatory agent in diabetes-related vascular dysfunction.

Magnolol protects neurons against ischemia injury via the downregulation of p38/MAPK, CHOP and nitrotyrosine.

Magnolol is isolated from the herb Magnolia officinalis, which has been demonstrated to exert pharmacological effects. Our aim was to investigate whether magnolol is able to act as an anti-inflammatory agent that brings about neuroprotection using a global ischemic stroke model and to determine the mechanisms involved. Rats were treated with and without magnolol after ischemia reperfusion brain injury by occlusion of the two common carotid arteries. The inflammatory cytokine production in serum and the volume of infarction in the brain were measured. The proteins present in the brains obtained from the stroke animal model (SAM) and control animal groups with and without magnolol treatment were compared. Magnolol reduces the total infarcted volume by 15% and 30% at dosages of 10 and 30mg/kg, respectively, compared to the untreated SAM group. The levels of acute inflammatory cytokines, including interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 were attenuated by magnolol. Magnolol was also able to suppress the production of nitrotyrosine, 4-hydroxy-2-nonenal (4-HNE), inducible NO synthase (iNOS), various phosphorylated p38 mitogen-activated protein kinases and various C/EBP homologues. Furthermore, this modulation of ischemia injury factors in the SAM model group treated with magnolol seems to result from a suppression of reactive oxygen species production and the upregulation of p-Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings confirm the anti-oxidative properties of magnolol, including the inhibition of ischemic injury to neurons; this protective effect seems to involve changes in the in vivo activity of Akt, GSK3ß and NF-κB.

Tyrosine phosphorylation of ß-catenin affects its subcellular localization and transcriptional activity of ß-catenin in Hela and Bcap-37 cells.

In order to investigate the relationship between tyrosine phosphorylation of ß-catenin and transcriptional activity of ß-catenin in Hela and Bcap-37 cells, genistein (a tyrosine kinase inhibitor) was used to inhibit tyrosine phosphorylation in cells. Our results showed the total ß-catenin protein levels were mainly equal in Hela, Bcap-37 and HK-2 cells, ß-catenin was mainly present in nucleus in Hela and Bcap-37cells, while in HK-2 cell ß-catenin was mainly located in cytoplasm. Genistein could inhibit tyrosine phosphorylation of ß-catenin and downregulate nuclear ß-catenin expression in Hela and Bcap-37 cells. In addition, genistein suppressed Ki-67 promoter activity and Ki-67 protein level, thus promoted cell apoptosis. Furthermore, ß-catenin could increase the Ki-67 promoter activity in Hela and Bcap-37 cells. From these findings we conclude that tyrosine phosphorylation of ß-catenin can regulate the cellular distribution of ß-catenin and affect the transcriptional activity of ß-catenin.