Increased insulin resistance due to long COVID is associated with depressive symptoms and partly predicted by the inflammatory response during acute infection

Objective: Some months after the remission of acute COVID-19, some individuals show depressive symptoms, which are predicted by increased peak body temperature (PBT) and decreased blood oxygen saturation (SpO2). The present study aimed to examine data on whether long COVID is associated with increased insulin resistance (IR) in association with neuroimmune and oxidative (NIO) processes during the acute infectious and long COVID phases. Methods: This case-control, retrospective cohort study used the Homeostasis Model Assessment 2 (HOMA2) calculator© to compute β-cell function (HOMA2%B) and insulin sensitivity (HOMA2%S) and resistance (HOMA2-IR) and administered the Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HAMD) to 86 patients with long COVID and 39 controls. Results: Long COVID (3-4 months after the acute infection) is accompanied by increased HOMA2-IR, fasting blood glucose (FBG), and insulin levels; 33.7% of the patients vs. 0% of the controls had HOMA2-IR values > 1.8, suggesting IR. Increased IR was predicted by PBT during acute infection and associated with depressive symptoms above and beyond the effects of NIO pathways (nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 [NLRP3] inflammasome, myeloperoxidase [MPO], protein oxidation). There were no significant associations between increased IR and the activated NIO pathways during long COVID. Conclusion: Long COVID is associated with new-onset IR, which may contribute to onset of depressive symptoms due to long COVID by enhancing overall neurotoxicity.

Suppression of nitrosative stress and inflammation of the knee joint synovium in collagen type ii-induced rheumatoid arthritis by the inhibition of glycogen synthase kinase-3ß / Supresión del estrés nitrosativo e inflamación de la sinovial de la articulación de la rodilla en la artritis reumatoide inducida por colágeno tipo ii mediante la inhibición de la glucógeno sintasa quinasa-3 ß

SUMMARY: Rheumatoid arthritis (RA), an inflammatory autoimmune disease that causes cartilage degradation and tissue destruction, can affect synovial joints such as the knee joint. The link between the nitrosative stress enzyme inducible nitric oxide synthase (iNOS) and the cytokine interleukin-1 (IL-1β) in RA-induced knee joint synovial membrane damage with and without the incorporation of the GSK3β inhibitor TDZD-8 has never been studied. As a result, we used active immunization method with collagen type II (COII) for twenty one days to induce RA in rats. TDZD-8 (1 mg/kg; i.p.) was given daily into matched immunized rats for three weeks after day 21 (COII+TDZD-8). Blood and tissue samples were taken 42 days after immunization. A dramatic increase in rheumatoid factor (RF) blood levels, as well as considerable synovial tissue damage and inflammatory cell infiltration of the synovial membrane, were used to validate the onset of RA following COII immunization. COII immunization increased tissue levels of iNOS protein and IL- 1β mRNA and protein expression, which TDZD-8 suppressed considerably (p<0.0001). Furthermore, there was a significantly (p<0.001) positive correlation between iNOS, inflammatory biomarkers, and RF. We concluded that TDZD-8 reduced RA-induced IL-1β -iNOS axis-mediated arthritis in the rat knee joint synovium.

RESUMEN: La artritis reumatoide (AR), es una enfermedad autoinmune inflamatoria que causa la degradación del cartílago y la destrucción del tejido, pudiendo afectar las articulaciones sinoviales, como la articulación de la rodilla. No se ha estudiado el vínculo entre la óxido nítrico sintasa inducible por la enzima del estrés nitrosativo (iNOS) y la citocina interleucina-1 (IL-1β) en el daño de la membrana sinovial de la articulación de la rodilla provocado por AR con y sin la incorporación del inhibidor de GSK3β TDZD-8. Utilizamos el método de inmunización activa con colágeno tipo II (COII) durante veintiún días para inducir AR en ratas. Se administró TDZD-8 (1 mg/kg; i.p.) diariamente a ratas inmunizadas emparejadas durante tres semanas después del día 21 (COII+TDZD- 8). Se tomaron muestras de sangre y tejido 42 días después de la inmunización. Se observó un gran aumento de los niveles sanguíneos del factor reumatoideo (FR), así como un daño considerable del tejido sinovial e infiltración de células inflamatorias en la membrana sinovial, para validar la aparición de la AR después de la inmunización con COII. La inmunización con COII aumentó los niveles tisulares de la proteína iNOS y la expresión de proteína y ARNm de IL-1β, que TDZD-8 suprimió considerablemente (p<0,0001). Además, hubo una correlación positiva significativa (p<0,001) entre iNOS, biomarcadores inflamatorios y FR. Concluimos que TDZD- 8 redujo la artritis mediada por el eje IL-1β-iNOS inducida por la AR en la sinovial de la articulación de la rodilla de rata.

Effects of Urtica dioica Seeds on Oxidative/ Nitrosative Stress Levels and Myeloperoxidase Activity in Muscle Ischemia/Reperfusion Injury

Abstract The purpose of this study is to evaluate the preventive effects of Urtica dioica (UD) on muscle ischemia/reperfusion (I/R) injury. A total of 27 male Wistar rats were divided into three groups as the control group (1), I/R + saline group (2), and I/R+UD group (3). Group 1 did not receive any treatment. Group 2 was administered a total of 2mL/kg saline (1mL/kg before ischemia and 1 mL/kg after reperfusion), and group 3 was given a total of 2mL of UD (1mL/kg before ischemia and 1mL/kg after reperfusion) as treatment. Saline and UD were administered via intraesophageal canula once a day for five days. At the end of five days, all the rats were exposed to muscle ischemia for 60 min followed by 60 min of reperfusion of the bilateral hindlimbs induced using a tourniquet. Muscle tissue histopathologies were evaluated by light microscopy. Furthermore, oxidative/nitrosative stress biomarkers such as catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), nitrotyrosine (3-NT), nitric oxide (NO), and myeloperoxidase (MPO) as an inflammatory marker in tissue samples were measured. UD treatment significantly decreased oxidative/nitrosative stress biomarker levels and MPO (p<0.05). We established that UD treatment could alleviate muscle injury induced by muscle I/R in rats by inhibiting the inflammation and oxidative/nitrosative stress

Explorando os estresses oxidativo e nitrosativo contra fungos: um mecanismo subjacente à ação de tradicionais antifúngicos e um potencial novo alvo terapêutico na busca por indutores oriundos de fontes naturais / Explorando los estréses oxidativos y nitrosativos contra hongos: un mecanismo subyacente a la acción de los antifúngicos tradicionales y un potencial nuevo objetivo terapéutico en la búsqueda de inductores de fuentes naturales / Exploring the oxidative and nitrosative stresses against fungi: an underlying mechanism beyond the action of traditional antifungal agents and a potential new therapeutic target in searching for inducers from natural sources

RESUMO Objetivo: Nesta revisão sistemática, nós avaliamos o link entre indutores de estresse oxidativo e/ou nitrosativo (EO/EN) com atividade antifúngica, através de uma ação direta sobre a célula fúngica e/ou modulando a resposta de fagócitos contra fungos de interesse médico (incluindo Candida spp., Cryptococcus spp. e Aspergillus spp.). Ainda, foram avaliadas as implicações clínicas deste evento bioquímico, bem como as perspectivas quanto à busca por novos compostos com atividade antifúngica, principalmente, os provenientes de fonte natural e, que explorem a indução de um EO ou EN como parte de seu mecanismo de ação. Metodologia: Foram avaliados artigos, provenientes de diferentes bases de dados e publicados a qualquer período, acessados entre abril e junho de 2017, através da utilização de diferentes descritores. Resultados: Primeiramente, estabelecemos as definições de EO/EN, como sendo o aumento das concentrações de espécies reativas do oxigênio e/ou nitrogênio (ERO/ ERN) quantificado diretamente e, provenientes de fontes fúngicas mitocondriais, Reação de Fenton, retículo endoplasmático ou outras não definidas, e excedendo a capacidade de defesa antioxidante do microrganismo (avaliados por análises de perfis transcriptômicos ou proteômicos ou metabolômicos ou níveis de atividade enzimática). Este aumento de ERO/ERN causando EO/EN é definido por tempo e condições que conduzem a sinalização de apoptose ou reais danos a biomoléculas com perda de função (peroxidação lipídica ou oxidação proteica ou danos ao DNA) e, consequentemente, gerando morte fúngica ou outro efeito antifúngico associado. Portanto, 64 artigos (apenas um publicado antes do ano 2000 e 50 entre 2007-2017) abordam que a indução de EO ou EN na célula fúngica é parte do mecanismo de ação de clássicos agentes antifúngicos (22 publicações), tais como azóis (fluconazol, itraconazol e miconazol), polienos (anfotericina B [AnB]) e equinocandinas (mica-fungina), assim como tal modulação redox tem sido reportada como um importante alvo terapêutico na busca por novos e promissores compostos naturais com atividade antifúngica (32 publicações), que tem respaldo pela grande variedade de indutores que podem provir da natureza. Ainda, compostos que também induzem o burst oxidativo de fagócitos, incluindo AnB, são potencializadores do efeito antifúngico in vivo. Além do efeito antifúngico contra células planctônicas, os efeitos dos EO ou EN sobre biofilmes fúngicos, também têm sido reportados. Tem sido firmado na literatura recente um claro link entre EO ou EN e a atividade antifúngica, tanto para aqueles agentes antifúngicos já utilizados na terapêutica em humanos, quanto para possíveis candidatos a fármaco. Portanto, a indução do EO ou EN como parte do mecanismo de ação de antifúngicos demonstra ser um importante alvo terapêutico, com perspectivas favoráveis sobre os desfechos na prática clínica.

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SUMMARY Aim: In this systematic review, we evaluated the link between inducers of oxidative or nitrosative stresses (OS/NS) and antifungal activity against fungi of medical relevance (including Candida spp., Cryptococcus spp., and Aspergillus spp.), through a direct action on the fungal cell or modulating phagocyte response. Moreover, the clinical implications of this biochemical event, as well as the perspectives, were examined, highlighting the search for new compounds with antifungal activity, mainly those from natural sources and, which explores the induction of OS or NS as part of the mechanism of action. Methodology: Articles from different databases and published at any time were evaluated, between April and June 2017, and using different descriptors. Results: First, a definition of OS and NS was established in which an increase in reactive oxygen or nitrogen species (ROS/ RNS, quantified directly and from mitochondrial, Fenton reaction, endoplasmic reticulum or other fungal sources) should exceed the antioxidant defense capacity of the microorganism (evaluated by transcriptomic or proteomic or metabolomic profiles or enzyme activity levels). These events, by time and conditions delimited, can lead to the signaling of apoptosis or an actual damage toward biomolecules (lipid peroxidation or protein oxidation or DNA damage) and, consequently, they can cause cell death or other associated antifungal effect. Therefore, 64 articles were found, of these, only one was published before 2000 and 50 between 20072017, reporting the induction of OS or NS directly into the fungal cell via an increase in ROS or RNS as part of the mechanism of action of classical antifungal agents (22 publications), such as: azoles (fluconazole, itraconazole, and miconazole), polyenes (amphotericin B, [AnB]), and echinocandins (micafungin). This redox modulation has also been reported as an important therapeutic target in the search for new natural compounds with antifungal activity (32 publications), which is supported for the great variety of inducers from nature. Compounds that also induce the oxidative burst of phagocytes, including AnB, promote a combinatorial antifungal effect in vivo. In addition to the antifungal effect against plank-tonic cells, the relation between OS or NS and antifungal activity against fungal biofilms has also been reported. It has been established in the recent literature a clear link between OS or NS and antifungal effect, during the action of anti-fungal agents already used in the therapy in humans as well as for possible drug candidates. Thus, the induction of OS or NS as part of the mechanism of action proves to be an important therapeutic target with favorable perspectives on the outcomes in clinical practice.

Propolis and Caffeic Acid Phenethyl Ester Attenuates Nitrosative Stress in Lens Tissue in Radiation-induced Cataracts in Rats

ABSTRACT Objective: Eye morbidity is widely observed in patients receiving total body irradiation prior to bone marrow transplantation or radiotherapy for ocular or head and neck cancers. Cataract blindness is the major cause of preventable blindness worldwide, especially in the developing countries. The aim of this study was to investigate whether propolis and caffeic acid phenethyl ester (CAPE) prevent radiation-induced cataractogenesis. Methods: Fifty-four Sprague-Dawley rats were randomly divided into six groups. Group 1 (irradiation (IR) + propolis) received total cranium irradiation and propolis was given orally through an orogastric tube daily. Group 2 (IR+CAPE) received total cranium irradiation plus CAPE intraperitoneally every day. Group 3 (IR) received 5 Gy of gamma irradiation as a single dose to total cranium plus 1 ml saline daily. Group 4 received daily plain saline. Group 5 received daily plain dimethyl sulfoxide. Group 6 (normal control group) did not receive anything. Results: At the end of the 10-day time period, cataracts developed in 80% of the rats in group 3 (IR group). After irradiation, cataract rate drop to 30% and 40% in groups treated with propolis and CAPE, respectively. Nitric oxide synthase activity, nitric oxide (NO•) and peroxynitrite (ONOO-) levels were significantly higher in group 3 compared to all other groups. Conclusion: The results suggest that propolis and CAPE have free radical scavenging activities in the irradiation-induced cataractogenesis, and reduced nitrosative stress markers. Prop-olis was found to be more effective in anticataractogenic effect than CAPE.

Acute effect of passive cycle-ergometry and functional electrical stimulation on nitrosative stress and inflammatory cytokines in mechanically ventilated critically ill patients: a randomized controlled trial

Early mobilization is beneficial for critically ill patients because it reduces muscle weakness acquired in intensive care units. The objective of this study was to assess the effect of functional electrical stimulation (FES) and passive cycle ergometry (PCE) on the nitrous stress and inflammatory cytometry in critically ill patients. This was a controlled, randomized, open clinical trial carried out in a 16-bed intensive care unit. The patients were randomized into four groups: Control group (n=10), did not undergo any therapeutic intervention during the study; PCE group (n=9), lower-limb PCE for 30 cycles/min for 20 min; FES group (n=9), electrical stimulation of quadriceps muscle for 20 min; and FES with PCE group (n=7), patients underwent PCE and FES, with their order determined randomly. The serum levels of nitric oxide, tumor necrosis factor alpha, interferon gamma, and interleukins 6 and 10 were analyzed before and after the intervention. There were no differences in clinical or demographic characteristics between the groups. The results revealed reduced nitric oxide concentrations one hour after using PCE (P<0.001) and FES (P<0.05), thereby indicating that these therapies may reduce cellular nitrosative stress when applied separately. Tumor necrosis factor alpha levels were reduced after the PCE intervention (P=0.049). PCE and FES reduced nitric oxide levels, demonstrating beneficial effects on the reduction of nitrosative stress. PCE was the only treatment that reduced the tumor necrosis factor alpha concentration.

Metabolic syndrome components are associated with oxidative stress in overweight and obese patients

ABSTRACT Objective: The aim of this study is to evaluate the influence of the body mass index (BMI) and the metabolic syndrome (MetS) parameters on oxidative and nitrosative stress in overweight and obese subjects. Subjects and methods: Individuals were divided into three groups: the control group (G1, n = 131) with a BMI between 20 and 24.9 kg/m2, the overweight group (G2, n = 120) with a BMI between 25 and 29.9 kg/m2 and the obese group (G3, n = 79) with a BMI ≥ 30 kg/m2. Results: G3 presented higher advanced oxidation protein products (AOPPs) in relation to G1 and G2 (p = 0.001 and p = 0.011, respectively) whereas G2 and G3 had lower levels of nitric oxide (NO) (p = 0.009 and p = 0.048, respectively) compared to G1. Adjusted for the presence of MetS to evaluate its influence, the levels of AOPPs did not differ between the groups, whereas NO remained significantly lower. Data adjusted by the BMI showed that subjects with higher triacylglycerol levels had higher AOPPs (p = 0.001) and decreased total radical-trapping antioxidant parameter/uric Acid (p = 0.036). Subjects with lower high-density lipoprotein (HDL) levels and patients with higher blood pressure showed increased AOPPs (p = 0.001 and p = 0.034, respectively) and lower NO levels (p = 0.017 and p = 0.043, respectively). Subjects who presented insulin resistance had higher AOPPs (p = 0.024). Conclusions: Nitrosative stress was related to BMI, and protein oxidation and nitrosative stress were related to metabolic changes and hypertension. MetS components were essential participants in oxidative and nitrosative stress in overweight and obese subjects.

Nitrosative stress in human spermatozoa causes cell death characterized by induction of mitochondrial permeability transition-driven necrosis / 亚洲男科学杂志(英文版)

Peroxynitrite is a highly reactive nitrogen species and a potent inducer of apoptosis and necrosis in somatic cells. Peroxynitrite-induced nitrosative stress has emerged as a major cause of impaired sperm function; however, its ability to trigger cell death has not been described in human spermatozoa. The objective here was to characterize biochemical and morphological features of cell death induced by peroxynitrite-mediated nitrosative stress in human spermatozoa. For this, spermatozoa were incubated with and without (untreated control) 3-morpholinosydnonimine (SIN-1), in order to generate peroxynitrite. Sperm viability, mitochondrial permeability transition (MPT), externalization of phosphatidylserine, DNA oxidation and fragmentation, caspase activation, tyrosine nitration, and sperm ultrastructure were analyzed. The results showed that at 24 h of incubation with SIN-1, the sperm viability was significantly reduced compared to untreated control (P < 0.001). Furthermore, the MPT was induced (P < 0.01) and increment in DNA oxidation (P < 0.01), DNA fragmentation (P < 0.01), tyrosine nitration (P < 0.0001) and ultrastructural damage were observed when compared to untreated control. Caspase activation was not evidenced, and although phosphatidylserine externalization increased compared to untreated control (P < 0.001), this process was observed in <10% of the cells and the gradual loss of viability was not characterized by an important increase in this parameter. In conclusion, peroxynitrite-mediated nitrosative stress induces the regulated variant of cell death known as MPT-driven necrosis in human spermatozoa. This study provides a new insight into the pathophysiology of nitrosative stress in human spermatozoa and opens up a new focus for developing specific therapeutic strategies to better preserve sperm viability or to avoid cell death.

Advances on Pathological Significance of Cerebral Microvascular Inflammatory Injury and Drug Discovery / 中山大学学报(医学科学版)

The incidence of acute and chronic cerebrovascular disease is high,whereas effective treatment in clinical practice is still lacking.The discovery of potential drug targets by further understanding the pathogenesis of cerebrovascular disease remains an important strategy.The brain microvasculature plays an important role as a delivery pipeline of oxygen and energy for the brain. The accumulating evidence indicated that cerebral microvascular system have unique structural and functional features,which are different from peripheral vascular system. Cerebral capillaries are important compo-nents of neurovascular units and constitute the blood-brain barrier. The inflammatory responses and oxidative/nitrosative stress are critical mechanisms that cause cerebral microvascular injury and dysfunction. The disease models in combined with in vivo imaging systems can be used to further analyze the spatiotemporal changes of related molecular events.Focusing on how to protect the integrity of brain microvascular structures and functions,this review also summarizes the progress and prospects of drug discovery for acute and chronic cerebrovascular diseases.

A systematic review of observational studies on oxidative/nitrosative stress involvement in dengue pathogenesis / Revisión sistemática de los estudios observacionales sobre el papel del estrés oxidativo-nitrosativo en la patogénesis del dengue

Objective: Our objective was to systematically review the published observational research related to the role of oxidative-nitrosative stress in pathogenesis of dengue. Methods: We searched electronic databases (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) using the term: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide, and nitric oxide synthase. Articles were selected for review by title and abstract excluding letter, review, in vivo and in vitro studies, and duplicates studies. Selected articles were reviewed for study design, original purposes, sample size, main outcomes, methods, and oxidative-nitrosative stress markers values. Results: In total, 4,331 non-duplicates articles were identified from electronic databases searches, of which 16 were eligible for full text searching. Data from the observational studies originate from Asian countries (50%; 8/16), South American countries (31.2%; 5/16), and Central America and the Caribbean countries (18.8%; 3/16). Case-control study was the type of design most common in researches reviewed. The 1997 World Health Organization (WHO) dengue case classification criteria were used in all studies included in this review. Conclusions: Based on published data found in peer-reviewed literature, oxidative and nitrosative stress are demonstrated by changes in plasma levels of nitric oxide, antioxidants, lipid peroxidation and protein oxidation markers in patients with dengue infection. Additionally, elevated serum protein carbonyls and malondialdehyde levels appear to be associated with dengue disease severity.

Objetivo: Sistematizar las evidencias observacionales sobre la relación entre el estrés oxidativo-nitrosativo y la patogénesis del dengue. Métodos: Revisión sistemática de estudios observacionales en las bases de datos (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) utilizando las siguientes palabras clave: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide y nitric oxide synthase. La selección inicial fue realizada a partir del título y resumen excluyéndose: cartas para editor, revisiones, estudios in vivo/in vitro y duplicados. A cada artículo seleccionado, se le revisó el diseño del estudio, objetivo, tamaño de la muestra, resultados principales y niveles plasmáticos de los marcadores de estrés oxidativo-nitrosativo. Resultados: De 4,331 publicaciones encontradas, 16 estudios cumplieron con los criterios de inclusión. El 50% (8/16) de los estudios revisados fueron realizados en países de Sur América, Centro América y del Caribe. El diseño de casos y controles fue el más frecuente. El anterior sistema de clasificación de casos (OMS-1997) fue utilizado en todos los estudios incluidos en esta revisión. Conclusiones: El estrés oxidativo-nitrosativo se encuentra presente en el curso de la infección por virus dengue, demostrado por los cambios en las concentraciones plasmáticas de óxido nítrico, antioxidantes y marcadores de lipoperoxidación y de oxidación de proteínas. Por último, parece existir una asociación entre la elevación de los niveles plasmáticos de los carbonilos proteicos y malondialdehído con la severidad del dengue.

Simultaneous Administration of Dexamethasone and Vitamin E Reversed Experimental Varicocele-induced Impact in testicular tissue in Rats; Correlation with Hsp70-2 Chaperone Expression

ABSTRACTPurpose:This study aimed to investigate the protective effects of isolated and co-administration of vitamin E (VitE) and dexamethasone (DEX) on varicocele (VCL)-induced damages in testicular tissue.Materials and Methods:Wistar rats were divided into five groups (n=6), including; control-sham, non-treated VCL-induced, VitE-treated VCL-induced (VitE, 150 mg/kg, orally), DEX-administrated VCL-induced (DEX, 0.125 mg/kg, i.p.), VitE+DEX-received VCL-induced animals. The antioxidant status analyses, histopathological examinations, hormonal assay and tissue levels of alkaline phosphatase (ALP) were analyzed. The germinal epithelium RNA damage and Leydig cells steroidogenesis were analyzed. Moreover, the Hsp70-2 protein expression was examined based on immunohistochemical and western blot analyses. The sperm parameters, DNA integrity and chromatin condensation were investigated.Results:VitE and DEX in simultaneous form of administration significantly (P<0.05) down-regulated the tissue ALP level and attenuated the VCL-decreased GSH-px, SOD and TAC levels and remarkably (P<0.05) down-regulated the testicular malondialdehyde (MDA) and nitric oxide (NO) contents. The VCL-induced histopathological alterations significantly (P<0.05) improved in VitE and DEX-administrated animals. The VitE and DEX co-administration reduced the VCL-increased RNA damage and elevated the Leydig cells steroidogenic activity. The Hsp70-2 protein level completely (P<0.05) increased in VitE and DEX alone–and-simultaneous-administrated animals. Finally, the VitE and DEX could significantly (P<0.05) improve the VCL-decreased semen quality and improved the sperm DNA integrity and chromatin condensation.Conclusion:Our data suggest that Vit E by up-regulating the antioxidant status and DEX by reducing inflammation-dependent oxidative and nitrosative stresses could improve the VCL-reduced Hsp70-2 chaperone expression and ultimately protected the testicular endocrine activities and promoted the spermatogenesis process.

Estrés oxidative-nitrosativo y dengue: revisión sistemática de estudios in vivo e in vitro / Oxidative-nitrosative stress and dengue disease: a systematic review of in vivo/in vitro studies

Objective: In this systematic review the aim was to summarise the in vivo/in vitro evidence on the role of oxidative-nitrosative stress in pathogenesis of dengue. Methods: We searched electronic databases (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) using the term: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide, and nitric oxide synthase. Articles were selected for review by title and abstract excluding letter, review, epidemiological studies, and duplicates studies. Selected articles were reviewed for used animal model or cell cultures, original purposes, strain of virus or type of antibody, main outcomes, methods, and oxidative-nitrosative stress markers values. Results: In total, 4330 non-duplicates articles were identified from computerized searches of reference databases, of which 32 were eligible for full text searching. The results of in vivo studies were obtained from monkey and knockout and/or wild-type mice. Human peripheral blood mononuclear cells were cell cultures most commonly used in identified in vitro studies, following by human endothelial cells cultures. DENV-2 strains were most used. Conclusions: In conclusion, a large body of in vivo and in vitro evidences showed that oxidative/nitrosative stress can be related to production of pathogenesis-related protein, increased susceptibility of mice to DENV infection, hemorrhage development in mice, proinflammatory cytokines and transcriptional factor expression, and DENV replication in various cell cultures(AU)

Objetivo: sistematizar las evidencias in vivo/in vitro de la participación del estrés oxidativo-nitrosativo en el curso de la infección por virus del dengue. Métodos: revisión sistemática de estudios observacionales en las bases de datos (PubMed, EMBASE, The COCHRANE library, ScienceDirect, Scopus, SciELO, LILACS via Virtual Health Library, Google Scholar) utilizando las siguientes palabras clave: dengue, dengue virus, severe dengue, oxidative stress, nitrosative stress, antioxidants, oxidants, free radicals, oxidized lipid products, lipid peroxides, nitric oxide y nitric oxide synthase. La selección inicial fue realizada a partir del título y resumen excluyéndose: cartas para editor, revisiones, estudios con diseños epidemiológicos y estudios duplicados. A cada artículo seleccionado, se le revisó el objetivo o propósito, cultivos celulares o modelos animales utilizados, cepas víricas o tipo de anticuerpos utilizados, métodos y valores de los marcadores de estrés oxidativo-nitrosativo. Resultados: de 4330 publicaciones encontradas, 32 estudios cumplieron con los criterios de inclusión. Se utilizaron primates no humanos y ratones knockout o tipo salvaje para la obtención de las evidencias in vivo. Los cultivos celulares más utilizados fueron de células mononucleares de sangre periférica y de células endoteliales humanas. Las cepas más utilizadas en los ensayos correspondieron al serotipo 2 del virus dengue. Conclusiones: existen evidencias in vivo/in vitro que muestran la posible asociación entre el estrés oxidativo-nitrosativo con: producción de proteínas relacionadas con la patogénesis del dengue, incremento en la susceptibilidad de ratones por la infección por dengue, desarrollo de hemorragias en modelo de ratón, expresión de citoquinas proinflamatorias y replicación viral en varios cultivos de células tanto humanas como de origen animal(AU)

In vivo antioxidant and antigenotoxic evaluation of an enaminone derivative BDHQ combined with praziquantel in uninfected and Schistosoma mansoni infected mice.

Chemotherapy with praziquantel is the cornerstone of schistosomiasis control, but an oxidative/nitrative stress may occur after short-term treatment and participate in side effects. The aim of this study was to evaluate the antioxidant and antigenotoxic effects of the novel antischistosomal enaminone derivative, 4–hydroxyquinoline (BDHQ), alone or combined with PZQ, in hepatic tissues of uninfected and Schistosoma mansoni infected mice. Uninfected untreated control mice and infected mice were treated with 0 or 500 mg/kg PZQ, 600 mg/kg BDHQ, or PZQ (250 mg/kg) combined with BDHQ (300 mg/kg) for 2 consecutive days. The studied biomarkers, related to oxidative/nitrosative stress and DNA damage were significantly improved in infected mice treated with BDHQ combined with PZQ as compared to either drug alone. This amelioration was accompanied with reduction in hepatic granuloma size and histopathologic lesions. Furthermore, we documented a novel PZQinduced mutation of hepatic mitochondrial genome in uninfected animals.

Antioxidative effects of Kimchi under different fermentation stage on radical-induced oxidative stress

BACKGROUND/OBJECTIVES: Kimchi is a traditional Korean fermented vegetable containing several ingredients. We investigated the protective activity of methanol extract of kimchi under different fermentation stages against oxidative damage. MATERIALS/METHODS: Fresh kimchi (Fresh), optimally ripened kimchi (OptR), and over ripened kimchi (OvR) were fermented until the pH reached pH 5.6, pH 4.3, and pH 3.8, respectively. The radical scavenging activity and protective activity from oxidative stress of kimchi during fermentation were investigated under in vitro and cellular systems using LLC-PK1 cells. RESULTS: Kimchi exhibited strong radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, superoxide anion, and hydroxyl radical. In addition, the free radical generators led to loss of cell viability and elevated lipid peroxidation, while treatment with kimchi resulted in significantly increased cell viability and decreased lipid peroxidation. Furthermore, the protective effect against oxidative stress was related to regulation of cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-kappaB p65, and IkappaB expression. In particular, OvR showed the strongest protective effect from cellular oxidative stress among other kimchi. CONCLUSION: The current study indicated that kimchi, particularly OptR and OvR, played a protective role against free radical-induced oxidative stress. These findings suggest that kimchi is a promising functional food with an antioxidative effect and fermentation of kimchi led to elevation of antioxidative activity.

Influence of tannic acid on contents of 8-OHdG and 3-NT in nephridial tissue of diabetic rats and supernatant of glomerular mesangial cells / 中国免疫学杂志

Objective:To observe the effect of tannic acid on renal morphology and function of diabetes mellitus model rats ,and to explore the mechanism of improving effect of tannic acid from oxidative stress , nitrosative stress angle.Methods: 8 rats were randomly selected from 68 6-week-old male Wistar rats as normal control group and the remaining 60 rats accepted high-sugar and high-fat diet for 4 weeks, then were injected streptozotocin ( STZ, 52 mg/kg ) intraperitoneally in order to manufacture a diabetic rat model.Further the diabetic rats were randomly divided into model group ,aminoguanidine group ,low-dose of tannic acid group and high dose of tannic acid group.The rats in aminoguanidine group were injected aminoguanidine [AG,40 mg/(kg· d)] intraperitoneally, those in low-dose of tannic acid group were injected tannic acid [TA,20 mg/(kg· d)] and those in high-dose of tannic acid group were injected tannic acid [TA,30 mg/(kg· d)].The rats in normal control group and model group were injected normal saline [NS, 30 mg/(kg· d)] and all rats were sacrificed and tissues were derived at the end of the week 10.Morphologic changes of kidney in diabetic rats were observed by HE staining and correlative biochemical indices of renal function were detected by biochemical analyzer.8-hydroxy deoxyguanosine (8-OHdG) and 3-nitrotyrosine (3-NT) content of renal tissue in rats in different groups were detected by ELISA method.Mesangial cells cultured in vitro were treated with high concentration of glucose (30 mmol/L) and AGEs (250 mg/L) and at the same time with different concentration of tannic acid (10,20,40 and 80μmol/L) on the basis of setting corre-sponding control group.The contents of 8-OHdG and 3-NT in the culture supernatant were measured by ELISA method after 48 hours.Results:Tannic acid can effectively improve the renal pathological changes and improve renal function of diabetic rats .The contents of 8-OHdG and 3-NT in kidney tissue homogenate of diabetic rats and in the supernatant of GMC cultured with high glucose or AGEs were all significantly increased and can be reduced by tannic acid.Conclusion:Tannic acid improving the structure and function damage of kidney in diabetic rats might be achieved by oxidative stress and nitrosative stress mechanism .

Evidencias de la participación del peroxinitrito en diversas enfermedades / Role of peroxynitrite anion in different diseases

Peroxynitrite (ONOO-) is a reactive nitrogen specie produced by the reaction between nitric oxide (NO• ) and super-oxide anion (O2.-). NO• is produced by nitric oxide synthase (NOS) and O2.- is formed by the addition of an electron to O2 in enzymatic as well as nonenzymatic way. NADPH oxidase and xanthine oxidase are some of the enzymes involved in O2.-formation. ONOO- is an oxidant specie which is able to modify a great number of biomolecules such as aminoacids, proteins, enzymes and cofactors. ONOO - is able to induce nitration leading to the formation of 3-nytrotyrosine. This change has been widely studied, and although it is not only produced by ONOO-, but also by other reactive nitrogen species, it has been accepted like footprint of ONOO-. The excessive production of reactive nitrogen species is known as nitrosative stress that is able to induce structural damage leading to the loss of cell function. Furthermore, synthetic metalloporphyrins that metabolize ONOO- in a specific way are being used to determine if ONOO- is involved in different diseases, such as Alzheimer, Huntington, diabetes, hypertension, arthritis, colitis, cardiac and renal complications. Finally, these metalloporphyrins may be of potential therapeutic value in diseases related to ONOO- production.

El peroxinitrito (ONOO-) es una especie reactiva de nitrógeno formada por la reacción entre el óxido nítrico (NO•) y el anión superóxido (O2.- ). El NO' es sintetizado por la sintasa de óxido nítrico (NOS) y el O2•- se puede sintetizar de forma no enzimática, por la adición de un electrón al O2 o por medio de diversas enzimas como la NADPH oxidasa y la xantina oxidasa. El ONOO-es una especie oxidante capaz de modificar un gran número de biomoléculas entre las que se encuentran aminoácidos, proteínas, enzimas y cofactores de enzimas. El ONOO- puede inducir nitración de residuos de tirosina promoviendo la formación de 3-nitrotirosina (3-NT). Esta modificación ha sido muy estudiada y aunque no es producida exclusivamente por ONOO- sino también por otras especies reactivas de nitrógeno, se acepta actualmente como una evidencia de la formación de ONOO-. El aumento excesivo de este último, así como de otras especies reactivas de nitrógeno se conoce como estrés nitrosativo y puede causar daño estructural alterando la funcionalidad de las células. Por otra parte, se han desarrollado una serie de metaloporfirinas que descomponen específicamente al ONOO- y éstas han ayudado a determinar que el ONOO - es una especie implicada en enfermedades como Alzheimer, Huntington, diabetes, hipertensión, artritis, colitis y diversas complicaciones cardiacas y renales. Además, estas metaloporfirinas pueden ser de utilidad terapéutica en aquellas enfermedades asociadas a la producción de ONOO-.