A novel diselenide attenuates the carrageenan-induced inflammation by reducing neutrophil infiltration and the resulting tissue damage in mice.

Selenium-containing compounds have emerged as promising treatment for redox-based and inflammatory diseases. This study aimed to investigate the in vitro and in vivo anti-inflammatory activity of a novel diselenide named as dibenzyl[diselanediyIbis(propane-3-1diyl)] dicarbamate (DD). DD reacted with HOCl (k = 9.2 x 107 M-1s-1), like glutathione (k = 1.2 x 108 M-1s-1), yielding seleninic and selenonic acid derivatives, and it also decreased HOCl formation by activated human neutrophils (IC50=4.6 µM) and purified myeloperoxidase (MPO) (IC50=3.8 µM). However, tyrosine, MPO-I and MPO-II substrates, did not restore HOCl formation in presence of DD. DD inhibited the oxidative burst in dHL-60 cells with no toxicity up to 25 µM for 48h. Next, an intraperitoneal administration of 25, 50, and 75 mg/kg DD decreased total leukocyte, neutrophil chemotaxis, and inflammation markers (MPO activity, lipid peroxidation, albumin exudation, nitrite, TNF-α, IL-1ß, CXCL1/KC, and CXCL2/MIP-2) on a murine model of carrageenan-induced peritonitis. Likewise, 50 mg/kg DD (i.p.) decreased carrageenan-induced paw edema over 5h. Histological and immunohistochemistry analyses of the paw tissue showed decreased neutrophil count, edema area, and MPO, carbonylated, and nitrated protein staining. Furthermore, DD treatment decreased the fMLP-induced chemotaxis of human neutrophils (IC50=3.7 µM) in vitro with no toxicity. Lastly, DD presented no toxicity in a single-dose model using mice (50 mg/kg, i.p.) over 15 days and in Artemia salina bioassay (50 to 2000 µM), corroborating findings from in silico toxicological study. Altogether, these results demonstrate that DD attenuates carrageenan-induced inflammation mainly by reducing neutrophil migration and the resulting damage from MPO-mediated oxidative burst.

Time-Course of Redox Status, Redox-Related, and Mitochondrial-Dynamics-Related Gene Expression after an Acute Bout of Different Physical Exercise Protocols.

We investigated the magnitude of exercise-induced changes in muscular bioenergetics, redox balance, mitochondrial function, and gene expression within 24 h after the exercise bouts performed with different intensities, durations, and execution modes (continuous or with intervals). Sixty-five male Swiss mice were divided into four groups: one control (n = 5) and three experimental groups (20 animals/group), submitted to a forced swimming bout with an additional load (% of animal weight): low-intensity continuous (LIC), high-intensity continuous (HIC), and high-intensity interval (HII). Five animals from each group were euthanized at 0 h, 6 h, 12 h, and 24 h postexercise. Gastrocnemius muscle was removed to analyze the expression of genes involved in mitochondrial biogenesis (Ppargc1a), fusion (Mfn2), fission (Dnm1L), and mitophagy (Park2), as well as inflammation (Nos2) and antioxidant defense (Nfe2l2, GPx1). Lipid peroxidation (TBARS), total peroxidase, glutathione peroxidase (GPx), and citrate synthase (CS) activity were also measured. Lactacidemia was measured from a blood sample obtained immediately postexercise. Lactacidemia was higher the higher the exercise intensity (LIC < HIC < HII), while the inverse was observed for TBARS levels. The CS activity was higher in the HII group than the other groups. The antioxidant activity was higher 24 h postexercise in all groups compared to the control and greater in the HII group than the LIC and HIC groups. The gene expression profile exhibited a particular profile for each exercise protocol, but with some similarities between the LIC and HII groups. Taken together, these results suggest that the intervals applied to high-intensity exercise seem to minimize the signs of oxidative damage and drive the mitochondrial dynamics to maintain the mitochondrial network, similar to low-intensity continuous exercise.

Interaction between cigarette smoke exposure and physical training on inflammatory and oxidative profile in mice muscle.

Regular physical training and cigarette smoke exposure (CSE) have opposite effects on physical performance, antioxidant, and inflammatory profile. However, the interaction between these events is not well studied. We aimed to investigate how regular physical training and CSE interact, and in what is the outcome of this interaction on the physical performance, skeletal muscle antioxidant defense and molecular profile response of pro and anti-inflammatory cytokines. Male C57BL/6 mice were randomly divided into 4 groups (n = 8/group): 1) Sedentary group (SED); 2) 4 weeks of control, followed by 4 weeks of CSE (SED + CSEG); 3) Physically active (PA) along 8 weeks (forced swim training, 5 times a week); 4) Physically active and exposed to the cigarette smoke (PA + CSEG), group submitted to forced swim training for 4 weeks, followed by 4 weeks of concomitant training and CSE. Physical performance was evaluated before and after the experimental period (8 weeks), total peroxidase and glutathione peroxidase (GPx) activities, expression of genes encoding TNF-α, MCP-1, IL1ß, IL-6, IL-10, TGF-ß, HO-1 and the TNF-α/IL-10 ratio were determined from gastrocnemius muscle at the end of experimental period. The CSE attenuated the aerobic capacity adaptation (time to exhaustion in swimming forced test) promoted by physical training and inhibit the improvement in local muscle resistance (inverted screen test). The regular physical training enhanced the antioxidant defense, but the CSE abrogated this benefit. The CSE induced a harmful pro-inflammatory profile in skeletal muscle from sedentary animals whereas the regular physical training induced an opposite adaptation. Likewise, the CSE abolished the protective effect of physical training. Together, these results suggest a negative effect of CSE including, at least in part, the inhibition/attenuation of beneficial adaptations from regular physical training.

Peroxiredoxin AhpC1 protects Pseudomonas aeruginosa against the inflammatory oxidative burst and confers virulence.

Pseudomonas aeruginosa is an opportunistic bacterium in patients with cystic fibrosis and hospital acquired infections. It presents a plethora of virulence factors and antioxidant enzymes that help to subvert the immune system. In this study, we identified the 2-Cys peroxiredoxin, alkyl-hydroperoxide reductase C1 (AhpC1), as a relevant scavenger of oxidants generated during inflammatory oxidative burst and a mechanism of P. aeruginosa (PA14) escaping from killing. Deletion of AhpC1 led to a higher sensitivity to hypochlorous acid (HOCl, IC50 3.2 ± 0.3 versus 19.1 ± 0.2 µM), hydrogen peroxide (IC50 91.2 ± 0.3 versus 496.5 ± 6.4 µM) and the organic peroxide urate hydroperoxide. ΔahpC1 strain was more sensitive to the killing by isolated neutrophils and less virulent in a mice model of infection. All mice intranasally instilled with ΔahpC1 survived as long as they were monitored (15 days), whereas 100% wild-type and ΔahpC1 complemented with ahpC1 gene (ΔahpC1 attB:ahpC1) died within 3 days. A significantly lower number of colonies was detected in the lung and spleen of ΔahpC1-infected mice. Total leucocytes, neutrophils, myeloperoxidase activity, pro-inflammatory cytokines, nitrite production and lipid peroxidation were much lower in lungs or bronchoalveolar liquid of mice infected with ΔahpC1. Purified AhpC neutralized the inflammatory organic peroxide, urate hydroperoxide, at a rate constant of 2.3 ± 0.1 × 106 M-1s-1, and only the ΔahpC1 strain was sensitive to this oxidant. Incubation of neutrophils with uric acid, the urate hydroperoxide precursor, impaired neutrophil killing of wild-type but improved the killing of ΔahpC1. Hyperuricemic mice presented higher levels of serum cytokines and succumbed much faster to PA14 infection when compared to normouricemic mice. In summary, ΔahpC1 PA14 presented a lower virulence, which was attributed to a poorer ability to neutralize the oxidants generated by inflammatory oxidative burst, leading to a more efficient killing by the host. The enzyme is particularly relevant in detoxifying the newly reported inflammatory organic peroxide, urate hydroperoxide.

Tempol reduces inflammation and oxidative damage in cigarette smoke-exposed mice by decreasing neutrophil infiltration and activating the Nrf2 pathway.

Cigarette smoke is a complex mixture capable of triggering inflammation and oxidative damage in animals at pulmonary and systemic levels. Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) reduces tissue injury associated with inflammation in vivo by mechanisms that are not completely understood. Here we evaluated the effect of tempol on inflammation and oxidative damage induced by acute exposure to cigarette smoke in vivo. Male C57BL/6 mice (n = 32) were divided into 4 groups (n = 8 each): 1) control group exposed to ambient air (GC), 2) animals exposed to cigarette smoke for 5 days (CSG), mice treated 3) prior or 4) concomitantly with tempol (50 mg/kg/day) and exposed to cigarette smoke for 5 days. The results showed that the total number of leukocytes and neutrophils increased in the respiratory tract and lung parenchyma of mice exposed to cigarette smoke. Likewise, MPO levels and activity as well as lipid peroxidation and lung protein nitration and carbonylation also increased. Administration of tempol before or during exposure to cigarette smoke inhibited all the above parameters. Tempol also reduced the pulmonary expression of the inflammatory cytokines Il-6, Il-1ß and Il-17 to basal levels and of Tnf-α by approximately 50%. In contrast, tempol restored Il-10 and Tgf-ß levels and enhanced the expression of Nrf2-associated genes, such as Ho-1 and Gpx2. Accordingly, total GPx activity increased in lung homogenates of tempol-treated animals. Taken together, our results show that tempol protects mouse lungs from inflammation and oxidative damage resulting from exposure to cigarette smoke, likely through reduction of leukocyte infiltration and increased transcription of some of the Nrf2-controlled genes.

Avaliação do perfil lipídico, glicêmico, conteúdo de glicogênio hepático ecardíaco em ratos diabéticos suplementados com farinha de casca de maracujá (Passiflora edulis) / Assessment of the profile of lipids, glucose, liver and heart glucogen, in diabetic mice supplemented withpassion-fruit rind flour (Passiflora edulis) / Evaluación del perfil de lípidos, glucosa, contenido de glicógeno hepático y cardíaco, en ratones diabéticoscomplementados con harina de cáscara de maracuyá (Pasiflora edulis)

A ingestão de fibras alimentares está associada a redução do risco das complicações do diabetes mellitus, caracterizado pelos níveis elevados de glicose sangüínea. Com base nisto, o presente estudo propôs verificar o efeito da suplementação com farinha de casca de maracujá (Passiflora edulis) sobre os níveis plasmáticos de glicose, triglicérides, colesterol total e frações, e conteúdo de glicogênio hepático e cardíaco de ratos diabéticos. Utilizou-se 25 ratos, divididos em 5 grupos (n=5): grupo controle (GI) e grupo diabético (GII) que receberam ração comercial, dois grupos diabéticos tratados com ração suplementada com farinha de maracujá nas concentrações de 50 (GIII) e 100% (GIV) da dose correspondente à ingestão diária recomendada (IDR) de fibras, e grupo GV com ração suplementadacom 150% da IDR. Após o tratamento, coletou-se o plasma sangüíneo para análise dos parâmetros bioquímicos. No fígado e no coração, dosou-se o conteúdo de glicogênio. Em relação aos níveis lipídicos, não houve diferença significativa entre os grupos. A glicemia do GIII (137,60 ± 10,24 mg/dL)e GIV (153,60 ± 14,99 mg/dL) foi reduzida quando comparada ao GII (399,20 ± 37,21 mg/dL). O teor de glicogênio hepático e cardíaco, respectivamente, em GIII (22,91 ± 7,78 mg/g e 0,65 ± 0,09 mg/g)e GIV (28,29 ± 7,99 mg/g e 2,1 ± 0,19 mg/g) aumentou significativamente em relação ao GI (7,0 ± 4,71mg/g e 0,12 ± 0,01 mg/g), p<0,05. Conclui-se que a utilização da farinha de casca de maracujá nas concentrações de 50 e 100% da IDR foi efetiva para controle glicêmico e aumento do glicogênio hepático e cardíaco, não sendo efetiva na diminuição de lipídios plasmáticos no período de estudo.

The intake of alimentary fibers is associated to the reduction of the risk of complications with diabetes mellitus, which is characterized by high glucose levels in the blood. Based upon this,the present study aimed to check the effect of supplementation with passion fruit rind flour (Pasiflora edulis) on the glucose plasmatic levels, triglycerides, cholesterol total and fractions, and the hepatic and heart glucogen in diabetic mice. Twenty five mice were used, divided into 5 groups (n=5): control group (GI) and diabetic group (GII) which received commercial ration,two diabetic groups which received ration supplemented with passion fruit flour, 50% (GIII) and100% (GIV) concentrations of the recommended dose of daily fiber intake (RDI), and group(GV) having ration supplemented with 150% of the RDI. After the treatment, blood plasma was collected for the analysis of the biochemical parameters. The content of glucogen in the liver and the heart was quantified. In relation to the lipidic levels no significant difference was found among groups. The glucose level in GIII (137.60 + 10.24 mg/dL) and in GIV (153.60 + 14.99 mg/dL) was reduced when compared to GII (399.20 + 37.21 mg/dL). The level of hepatic and heart glucogen was significantly increased in GIII (22.91 + 7.71 mg/g and 0.65 + 0.09 mg/g) and GVI (28.29 + 7.99 mg/g) when compared to GI (7.0 + 4.71 mg/g and 0.12 + 0.01 mg/g), p<0.05. It was concluded that the use of flour from passion fruit rind in the concentrations of 50% and 100% was effective on the control of blood glucose and the increase of hepatic and heart glucogen, not being effective on the reduction of plasmatic lipids during the period of study.

La ingestión de fibras alimentares está asociada a la reducción del riesgo de complicaciones de la diabetes mellitus, caracterizada por elevados niveles de glucosa en la sangre. Con base en esto, el presente estudio se propuso verificar el efecto de la complementación con harina de cáscara de maracuyá (Pasiflora edulis) sobre los niveles plasmáticos de glucosa, triglicéridos, colesterol total y fracciones, y contenido de glicógeno hepático y cardíaco en ratones diabéticos. Se utilizaron 25 ratones, divididos en 5 grupos (n=5): grupo de controle (GI) y grupo diabético (GII) que recibieron ración comercial, dos grupos diabéticos tratados con ración complementada con harina de maracuyá, en las concentraciones de 50% (GIII) y 100% (IV) de la dosis correspondiente a la ingestión diaria recomendada (IDR) de fibras, y grupo (GV) con ración complementada con 150% de la IDR. Tras el tratamiento se colectó el plasma de la sangre para el análisis de los parámetros bioquímicos. En el hígado y en el corazón se ha dosificado el contenido de glicógeno. Con relación a los niveles lípidos no hubo diferencia significativa entre los grupos. La glicemia del GIII (137,60 + 10,24 mg/dL) y GIV (153,60 + 14,99 mg/dL)se ha reducido cuando comparada con GII (399,20 + 37,21 mg/dL). El contenido de glicógenohepático y cardíaco, respectivamente, en GIII (22,91 + 7,78 mg/g y 0,65 + 0,09 mg/g) y GIV(28,29 + 7,99 mg/g y 2,1 + 0,19 mg/g) ha aumentado significativamente con relación al GI (7,0+ 4,71 mg/g), p<0,05. Se ha concluido que la utilización de la harina de cáscara de maracuyá,en las concentraciones de 50% y 100% de la IDR, fue efectiva para el control de la glucosa y del aumento del glicógeno hepático y cardíaco, no resultando efectivo en la reducción de lípidos plasmáticos durante el periodo del estudio.