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Abstract Background The MTHFR 677C>T variant’s involvement with hyperhomocysteinemia and peripheral arterial disease (PAD) is still unclear. Objectives To evaluate associations between the MTHFR 677C>T (rs1801133) variant and susceptibility to and severity of PAD and homocysteine (Hcy) levels. Methods The study enrolled 157 PAD patients and 113 unrelated controls. PAD severity and anatomoradiological categories were assessed using the Fontaine classification and the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC), respectively. The variant was genotyped using real-time polymerase chain reaction and Hcy levels were determined using chemiluminescence microparticle assay. Results The sample of PAD patients comprised 60 (38.2%) females and 97 (61.8%) males. Patients were older and had higher Hcy than controls (median age of 69 vs. 45 years, pT variant did not differ according to Fontaine or TASC categories. However, Hcy was higher in patients with the CT+TT genotypes than in those with the CC genotype (14.60 µmol/L vs. 12.94 µmol/L, p=0.008). Moreover, patients with the TT genotype had higher Hcy than those with the CC+CT genotypes (16.40 µmol/L vs. 13.22 µmol/L, p=0.019), independently of the major confounding variables. Conclusions The T allele of MTHFR 677C>T variant was associated with higher Hcy levels in PAD patients, but not in controls, suggesting a possible interaction between the MTHFR 677C>T variant and other genetic, epigenetic, or environmental factors associated with PAD, affecting modulation of Hcy metabolism.

Chagas disease (CD), caused by Trypanosoma cruzi, is a neglected tropical disease prevalent in Latin America. Infected patients are treated to eliminate the parasite, reduce the cardiomyopathy risk, and interrupt the disease transmission cycle. The World Health Organization recognizes benznidazole (BZ) and nifurtimox as effective drugs for CD treatment. In the chronic phase, both drugs have low cure rates and serious side effects. T. cruzi infection causes intense tissue inflammation that controls parasite proliferation and CD evolution. Compounds that liberate nitric oxide (NO) (NO donors) have been used as anti-T. cruzi therapeutics. Currently, there is no evidence that nitroxyl (HNO) affects T. cruzi infection outcomes. This study investigated the effects of the HNO donor Angeli’s salt (AS) on C57BL/6 mice infected with T. cruzi (Y strain, 5 × 103 trypomastigotes, intraperitoneally). AS reduced the number of parasites in the bloodstream and heart nests and increased the protective antioxidant capacity of erythrocytes in infected animals, reducing disease severity. Furthermore, in vitro experiments showed that AS treatment reduced parasite uptake and trypomastigote release by macrophages. Taken together, these findings from the murine model and in vitro testing suggest that AS could be a promising therapy for CD.

PurposeAlthough the role of signal transducers and activators of transcription (STAT3) in cachexia due to the association of circulating IL-6 and muscle wasting has been extensively demonstrated, the effect of resistance training on STAT3 in mediating muscle atrophy in tumor-bearing mice is unknown. The aim of this study is to investigate the effects of resistance exercise training on inflammatory cytokines and oxidative-mediated STAT3 activation and muscle loss prevention in tumor-bearing mice.MethodsMale Swiss mice were inoculated with Ehrlich tumor cells and exposed or not exposed to resistance exercise protocol of ladder climbing. Skeletal muscle STAT3 protein content was measured, compared between groups, and tested for possible association with plasma interleukins and local oxidative stress markers. Components of the ubiquitin-proteasome and autophagy pathways were assessed by real-time PCR or immunoblotting.ResultsResistance training prevented STAT3 excessive activation in skeletal muscle mediated by the overabundance of plasma IL-6 and muscle oxidative stress. These mechanisms contributed to preventing the increased key genes and proteins of ubiquitin-proteasome and autophagy pathways in tumor-bearing mice, such as Atrogin-1, LC3B-II, and Beclin-1. Beyond preventing muscle atrophy, RT also prevented strength loss and impaired locomotor capacity, hallmarks of sarcopenia.ConclusionOur results suggest that STAT3 inhibition is central in resistance exercise protective effects against cancer-induced muscle atrophy and strength loss.

Medical gas plasmas are of emerging interest in pre-clinical oncological research. Similar to an array of first-line chemotherapeutics and physics-based therapies already approved for clinical application, plasmas target the tumor redox state by generating a variety of highly reactive species eligible for local tumor treatments. Considering internal tumors with limited accessibility, medical gas plasmas help to enrich liquids with stable, low-dose oxidants ideal for intratumoral injection and lavage. Pre-clinical investigation of such liquids in numerous tumor entities and models in vitro and in vivo provided evidence of their clinical relevance, broadening the range of patients that could benefit from medical gas plasma therapy in the future. Likewise, the application of such liquids might be promising for recurrent BRAF(V600E) papillary thyroid carcinomas, resistant to adjuvant administration of radioiodine. From a redox biology point of view, studying redox-based approaches in thyroid carcinomas is particularly interesting, as they evolve in a highly oxidative environment requiring the capability to cope with large amounts of ROS/RNS. Knowledge on their behavior under different redox conditions is scarce. The present study aimed to clarify resistance, proliferative activity, and the oxidative stress response of human papillary thyroid cancer cells K1 after exposure to plasma-oxidized DMEM (oxDMEM). Cellular responses were also evaluated when treated with different dosages of hydrogen peroxide and the RNS donor sodium nitroprusside (SNP). Our findings outline plasma-oxidized liquids as a promising approach targeting BRAF(V600E) papillary thyroid carcinomas and extend current knowledge on the susceptibility of cells to undergo ROS/RNS-induced cell death.

It has been suggested that nitric oxide (NO) from iNOS source is involved in inflammation and oxidative stress, and hypertension in obese subjects involves an inflammatory process. However, no study evaluated the participation of iNOS inhibition on cardiovascular, autonomic, and inflammatory parameters in obese rats. Obesity was induced by the administration of 4 mg/g body weight of monosodium glutamate (MSG) or equimolar saline (CTR) in newborn rats. On the 60th day, treatment with aminoguanidine (Amino, 50 mg/kg), an iNOS inhibitor, or 0.9% saline, was started. On the 90th day, mean arterial pressure (MAP) and heart rate (HR) were recorded in conscious rats and autonomic modulation was conducted with the CardioSeries software. Plasma samples were collected to assess lipid peroxidation and prostaglandins (PGE2). In addition, iNOS immunohistochemistry in cardiac tissue was evaluated. MSG rats showed hypertension compared to CTR, and Amino treatment did not reverse it. Obese rats presented increased sympathetic and decreased parasympathetic modulation to the heart, reverted by Amino treatment. Plasma PGE2 was increased in obese rats, and Amino treatment decreased. Obese rats presented increased plasma lipoperoxidation, which was decreased after Amino treatment. Also, cardiac iNOS immunohistochemistry was decreased after Amino treatment. Our data suggest that iNOS activation is involved in the systemic and cardiac mechanisms of oxidative stress, inflammation, and autonomic dysfunction derived from obesity.

Infection with the protozoan Trypanosoma cruzi causes Chagas disease and consequently leads to severe inflammatory heart condition; however, the mechanisms driving this inflammatory response have not been completely elucidated. Nitric oxide (NO) is a key mediator of parasite killing in T. cruzi-infected mice, and previous studies have suggested that leukotrienes (LTs) essentially regulate the NO activity in the heart. We used infected 5-lipoxygenase-deficient mice (5-LO−/−) to explore the participation of nitric oxide synthase isoforms, inducible (iNOS) and constitutive (cNOS), in heart injury, cytokine profile, and oxidative stress during the early stage of T. cruzi infection. Our evidence suggests that the cNOS of the host is involved in the resistance of 5-LO−/− mice during T. cruzi infection. iNOS inhibition generated a remarkable increase in T. cruzi infection in the blood and heart of mice, whereas cNOS inhibition reduced cardiac parasitism (amastigote nests). Furthermore, this inhibition associates with a higher IFN-γ production and lower lipid peroxidation status. These data provide a better understanding about the influence of NO-interfering therapies for the inflammatory response toward T. cruzi infection.

Cardiovascular disease (CVD) has emerged as an important cause of death in patients with systemic lupus erythematosus (SLE). Reduced adiponectin and elevated leptin levels may contribute to CVD in SLE patients. The purpose of this study was to verify the effects of fish oil (FO) on adiponectin and leptin in patients with SLE. Biochemical and disease activity analysis were performed. Patients with SLE were divided in two groups: patients who used fish oil for four months and patients who did not use fish oil. Patients with SLE who used FO had a significant decrease in SLE disease activity index (SLEDAI) score (p ˂ 0.023) in relation to baseline. SLE patients who used fish oil had increased adiponectin levels (p ˂ 0.026) and decreased leptin levels (p ˂ 0.024) compared to baseline values, whereas there were no differences in adiponectin and leptin levels in patients with SLE who did not use fish oil. In conclusion, the findings of increased serum adiponectin an decreased leptin levels after 120 days in the fish oil group, reinforce the importance of evaluating prospective studies of fish and fish oil fish ingestion on these adipokines in an attempt to decrease cardiovascular risk factors in patients with SLE.

Citral is a natural compound that has shown cytotoxic and antiproliferative effects on breast and hematopoietic cancer cells; however, there are few studies on melanoma cells. Oxidative stress is known to be involved in all stages of melanoma development and is able to modulate intracellular pathways related to cellular proliferation and death. In this study, we hypothesize that citral exerts its cytotoxic effect on melanoma cells by the modulation of cellular oxidative status and/or intracellular signaling. To test this hypothesis, we investigated the antiproliferative and cytotoxic effects of citral on B16F10 murine melanoma cells evaluating its effects on cellular oxidative stress, DNA damage, cell death, and important signaling pathways, as these pathways, namely, extracellular signal-regulated kinases 1/2 (ERK1/2), AKT, and phosphatidylinositol-3 kinase, are involved in cell proliferation and differentiation. The p53 and nuclear factor kappa B were also investigated due to their ability to respond to intracellular stress. We observed that citral exerted antiproliferative and cytotoxic effects in B16F10; induced oxidative stress, DNA lesions, and p53 nuclear translocation; and reduced nitric oxide levels and nuclear factor kappa B, ERK1/2, and AKT. To investigate citral specificity, we used non-neoplastic human and murine cells, HaCaT (human skin keratinocytes) and NIH-3T3 cells (murine fibroblasts), and observed that although citral effects were not specific for cancer cells, non-neoplastic cells were more resistant to citral than B16F10. These findings highlight the potential clinical utility of citral in melanoma, with a mechanism of action involving the oxidative stress generation, nitric oxide depletion, and interference in signaling pathways related to cell proliferation.

Context Nonsteroidal anti-inflammatory drugs are considered one of the most important causes of reactivation of inflammatory bowel disease. With regard to selective cyclo-oxygenase 2 inhibitors, the results are controversial in experimental colitis as well as in human studies. Objectives The aim this study is to compare nonsteroidal anti-inflammatory drugs effects, selective and non selective cyclo-oxygenase 2 inhibitors, in experimental colitis and contribute to the understanding of the mechanisms which nonsteroidal anti-inflammatory drugs provoke colitis exacerbation. Methods Six groups of rats: without colitis, with colitis, and colitis treated with celecoxib, ketoprofen, indometacin or diclofenac. Survival rates, hemoglobin, plasmatic albumin, colonic tissue of interleukin-1ß, interleukin-6, tumor necrosis factor alpha, prostaglandin E2, catalase, superoxide dismutase, thiobarbituric acid-reactive substances, chemiluminescence induced by tert-butil hydroperoxides, and tissue and plasmatic leukotriene B4 were determined. Results The groups treated with diclofenac or indometacin presented lower survival rates, hemoglobin and albumin, higher tissue and plasmatic leukotriene B4 and tissue superoxide dismutase than the group treated with celecoxib. Ketoprofen presented an intermediary behavior between diclofenac/indometacin and celecoxib, concerning to survival rate and albumin. The groups without colitis, with colitis and with colitis treated with celecoxib showed leukotriene B4 and superoxide dismutase lower levels than the groups treated with nonselective cyclo-oxygenase 2 inhibitors. Conclusions Diclofenac and indometacin presented the highest degree of induced colitis exacerbation with nonsteroidal anti-inflammatory drugs, celecoxib did not show colitis exacerbation, and ketoprofen presented an intermediary behavior between diclofenac/indometacin and celecoxib. These results suggest that leukotriene B4 and superoxide dismutase can be involved in the exacerbation of experimental colitis by nonselective nonsteroidal anti-inflammatory drugs.

Green tea (Camellia sinensis) and its main components, the catechins present several biological activities such as: antioxidant and chemoprotective action against hepatotoxic agent as diethylnitrosamine(DEN), a known cytotoxic substance. This work has the objective to evaluate and understand the green tea extract (GTE) mechanisms of action as a chemoprotector agent. Therefore, tests in vivo with Wistar rats using GTE 2% (2mg/100mL) was taken orally as the only source of water for 35 days. To verify the antioxidant and chemoprotective capacity of GTE, DEN (200mg/kg) was used as a lesion agent. The results indicate that green tea if the dosage close to the ones taken by the population is not able to expressively inhibit the lesion caused for the high dose of DEN, but the results indicated a tendency to chemoprotection, suggesting to green tea may act as a prevention substance even in low dosage in presence of a classically known hepatotoxic agent. O chá verde (Camellia sinensis) e seus principais componentes, as catequinas, apresentam várias atividades biológicas, dentre elas a ação antioxidante e quimioprotetora contra agentes hepatotóxicos, como a dietilnitrosamina (DEN), um conhecido agente citotóxico. Este trabalho tem como objetivo avaliar e compreender os mecanismos da ação do extrato do chá verde (ECV), como agente antioxidante e quimioprotetor. Foram realizados testes in vivo com ratos Wistar machos utilizando o ECV a 2% (2mg/100mL) via oral, como única fonte de água, durante 35 dias. Para verificar a capacidade antioxidante e quimioprotetora do ECV utilizou-se a DEN (200mg/kg) como agente lesivo. Os resultados indicam que o chá verde, nas doses próximas as que são ingeridas pela população, não é capaz de inibir significativamente a lesão causada pela alta dose da DEN, mas os resultados indicaram uma tendência à quimioproteção, sugerindo que o chá verde pode agir como substância preventiva mesmo em baixasdoses, frente a um agente hepatotóxico classicamente conhecido.

Walker-256 tumor is a fast-growing tumor and has been studied under several metabolic aspects associated or not to cachexia. It was observed in our laboratory that animals with Walker-256 tumor, after spontaneous death (usually around the fifteenth day), showed significant pulmonary edema with fluid in the pleural cavity. Some studies have suggested that physical training improves the survival of animals with tumor and minimizes the effects of cachexia. The purpose of our work was to assess the pulmonary edema index as well as the cardiac and skeletal muscle mass, besides the survival of rats with Walker-256 tumor submitted previously to physical training through swimming (N). For this study male Wistar rats (200 to 220 g) were used, submitted to physical training through swimming (1 hour; 5 days a week, four weeks). One day after the training, sedentary rats (C) or trained ones (N) were submitted to inoculation on the right flank of 8 x 107 Walker-256 tumor cells (T). Immediately after spontaneous death of these animals, the pulmonary edema index (PEI), cardiac and skeletal muscle mass (gastrocnemius and soleus) were evaluated. Pulmonary edema was evaluated through the index calculated by the relation between lung and body weights of each animal, and multiplied by 100 (PP/PC x 100) (LEE et al., 2001). Muscle mass (MM) index was calculated similarly. In normal animals the PEI is equal to 0,53±0,02 (n=20). In tumor-bearing rats after spontaneous death the PEI was significantly higher (2,62±0,31, n=18). After the physical training in rats without tumor, the PEI was 0,55±0,03 (n=5). Whereas in tumor-bearing rats previously trained, it was obtained a pulmonary edema index lower than that of the control group with tumor (1,46±0,16, n=5; pO tumor Walker-256 é um carcinoma de crescimento rápido e tem sido estudado sob vários aspectos metabólicos, associados ou não, à caquexia. Foi observado, em nosso laboratório, que em animais portadores de tumor Walker-256 após morte espontânea (geralmente em torno do décimo quinto dia) apresentavam edema pulmonar significativo com presença de líquido na cavidade pleural. Alguns trabalhos têm sugerido que o treinamento físico melhora a sobrevida de animais com tumor e minimiza os efeitos da caquexia. O objetivo de nosso trabalho foi o de avaliar o índice de edema pulmonar e massa muscular esquelética e cardíaca, além da sobrevida de ratos portadores de tumor Walker-256 submetidos previamente a treinamento físico por natação (N). Para este estudo, foram usados ratos Wistar machos (200 a 220g), submetidos ao treinamento físico por natação (1 hora; 5 dias/semana, 4 semanas). Um dia após o treinamento, ratos sedentários (C) ou treinados (N) foram submetidos à inoculação no flanco direito de 8 x 107 células de tumor de Walker 256 (T). Imediatamente após a morte espontânea desses animais, foram avaliados o índice de edema pulmonar (IEP), a massa muscular esquelética (gastrocnêmio e soleus) e cardíaca. O edema pulmonar foi avaliado pelo índice calculado pela relação entre os pesos pulmonar e corporal de cada animal, e multiplicada por 100 (PP/PC x 100) (LEE et al., 2001). O índice de massa muscular (IMM) foi calculado de forma similar. Em animais normais, o IEP é igual a 0,53±0,02 (n=20). Em ratos portadores de tumor após a morte espontânea apresentaram IEP significativamente maior (2,62±0,31, n=18). Após o treinamento físico em animais sem tumor, o IEP foi de 0,55±0,03 (n=5). Já em animais portadores de tumor previamente treinados obteve-se um índice de edema inferior ao grupo controle com tumor (1,46±0,16, n=5; p

Parasites of the genus Leishmania are capable of inhibiting effector functions of macrophages. These parasites have developed the adaptive ability to escape host defenses; for example, they inactivate the NF-κB complex and suppress iNOS expression in infected macrophages, which are responsible for the production of the major antileishmanial substance nitric oxide (NO), favoring then its replication and successful infection. Metal complexes with NO have been studied as potential compounds for the treatment of certain tropical diseases, such as ruthenium compounds, known to be exogenous NO donors. In the present work, the compound cis-[Ru(bpy)2SO3(NO)]PF6, or RuNO, showed leishmanicidal activity directly and indirectly on promastigote forms of Leishmania (Leishmania) amazonensis. In addition, treatment with RuNO increased NO production by reversing the depletion of NO caused by Leishmania. We also found increased expression of Akt, iNOS, and NF-κB in infected and treated macrophages. These results demonstrated that RuNO was able to kill the parasite by NO release and modulate the transcriptional capacity of the cell.

The fact that drugs currently used in the treatment of Leishmania are highly toxic and associated with acquired resistance has promoted the search for new therapies for treating American tegumentary leishmaniasis (ATL). In this study, BALB/c mice were injected in the hind paw with Leishmania (Leishmania) amazonensis and subsequently treated with a combination of nitric oxide (NO) donor (cis-[Ru(bpy) 2imN(NO)](PF6)3) (Ru-NO), given by intraperitoneal injection, and oral Brazilian propolis for 30 days. Ru-NO reached the center of the lesion and increased the NO level in the injured hind paw without lesion exacerbation. Histological and immunological parameters of chronic inflammation showed that this combined treatment increased the efficacy of macrophages, determined by the decrease in the number of parasitized cells, leading to reduced expression of proinflammatory and tissue damage markers. In addition, these drugs in combination fostered wound healing, enhanced the number of fibroblasts, pro-healing cytokines and induced collagen synthesis at the lesion site. Overall, our findings suggest that the combination of the NO donor Ru-NO and Brazilian propolis alleviates experimental ATL lesions, highlighting a new therapeutic option that can be considered for further in vivo investigations as a candidate for the treatment of cutaneous leishmaniasis.

Leishmania amazonensis (L. amazonensis) infection can cause severe local and diffuse injuries in humans, a condition clinically known as American cutaneous leishmaniasis (ACL). Currently, the therapeutic approach for ACL is based on Glucantime, which shows high toxicity and poor effectiveness. Therefore, ACL remains a neglected disease with limited options for treatment. Herein, the in vitro antiprotozoal effect and mechanisms of the diterpene kaurenoic acid [ent-kaur-16-en-19-oic acid] (KA) against L. amazonensis were investigated. KA exhibited a direct antileishmanial effect on L. amazonensis promastigotes. Importantly, KA also reduced the intracellular number of amastigote forms and percentage of infected peritoneal macrophages of BALB/c mice. Mechanistically, KA treatment reestablished the production of nitric oxide (NO) in a constitutive NO synthase- (cNOS-) dependent manner, subverting the NO-depleting escape mechanism of L. amazonensis. Furthermore, KA induced increased production of IL-1β and expression of the inflammasome-activating component NLRP12. These findings demonstrate the leishmanicidal capability of KA against L. amazonensis in macrophage culture by triggering a NLRP12/IL-1β/cNOS/NO mechanism.

Uma única dose de DDT (diclorodifiniltricloroetano) (50 e I00mg/kg) aumentou a atividade metabolizadora de drogas em fígado de ratos. A N-desmetilação da aminopirina aumentou 3 a 4 vezes quando comparada com o controle. Por outro lado, um aumento de 2 vezes foi verificado tanto para a hidroxilação da anilina, como nos níveis de citocromo P4So- O tempo de hipnose barbitúrica provocado pelo pentobarbital sádico foi reduzido em 80% nas duas doses empregadas. Nossos resultados demonstraram que o efeito indutor máximo foi atingido com a dose de 50 mg/kg de DDT. Além disso, revelaram também que DDT exerce um efeito diferencial, na sua capacidade indutora, sobre a atividade da aminopirina N-desmetilase e anilina hidroxilase.

Abstract  The aim of the present work was to compare colonic mucosa and plasmatic oxidative stress measured concomitantly and with different degrees of injury in rats with colitis induced by trinitrobenzene sulfonic acid. Three groups were studied: control group, colitis group, and colitis exacerbated by diclofenac. Enzymatic markers of colon injury showed enhanced activity in both groups with colitis. The colitis group treated with diclofenac presented higher colonic damage score than the other groups. In both groups with colitis, higher values of tert butyl hydroperoxide-initiated-chemiluminescence and thiobarbituric acid-reactive substances in tissue and decreased total radical-trapping antioxidant potential (TRAP) levels in plasma were found. In conclusion, independently of the degree of colonic mucosa injury and inflammation, oxidative stress in tissue occurs as a consequence of pro-oxidants increase, and is not explained by a reduction of antioxidant defenses. In both conditions, TRAP determination decreases in plasma, but not in tissue. [ABSTRACT FROM AUTHOR]