Effect of octreotide on oxidative stress in the erythrocyte and kidney tissue in adriamycin-induced experimental nephrotic syndrome model.

INTRODUCTION: Nephrotic syndrome (NS) is one of the reasons of end-stage kidney disease, and elucidating the pathogenesis and offer new treatment options is important. Oxidative stress might trigger pathogenesis systemically or isolated in the kidneys. Octreotide (OCT) has beneficial antioxidant effects. We aimed to investigate the source of oxidative stress and the effect of OCT on experimental NS model. METHODS: Twenty-four non-uremic Wistar albino rats were divided into 3 groups. Control group, 2 mL saline intramuscular (im); NS group, adriamycin 5 mg/kg intravenous (iv); NS treatment group, adriamycin 5 mg/kg (iv) and OCT 200 mcg/kg (im) were administered at baseline (Day 0). At the end of 21 days, creatinine and protein levels were measured in 24-hour urine samples. Erythrocyte and renal catalase (CAT) and thiobarbituric acid reactive substance (TBARS) were measured. Renal histology was also evaluated. RESULTS: There was no significant difference among the 3 groups in terms of CAT and TBARS in erythrocytes. Renal CAT level was lowest in NS group, and significantly lower than the control group. In treatment group, CAT level significantly increased compared with NS group. In terms of renal histology, tubular and interstitial evaluations were similar in all groups. Glomerular score was significantly higher in NS group compared with control group and it was significantly decreased in treatment group compared to NS group. CONCLUSIONS: Oxidative stress in NS might be due to the decrease in antioxidant protection mechanism in kidney. Octreotide improves antioxidant levels and histology in renal tissue and might be a treatment option.

Galectin-3 contributes to acute cardiac dysfunction and toxicity by increasing oxidative stress and fibrosis in doxorubicin-treated mice.

BACKGROUND: Doxorubicin (DOX) leads to cardiovascular toxicity through direct cardiomyocyte injury and inflammation. We aimed to study the role of Galectin-3 (Gal-3), a ß-galactosidase binding lectin associated with inflammation and fibrosis in DOX-induced acute cardiotoxicity in mice. METHODS: Male C57 and Gal-3 knockout (KO) mice were given a single dose of DOX (15 mg/kg, i.p) or placebo. Serum creatine phosphokinase (CPK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and cardiac thiobarbituric acid-reactive substance (TBARS) were measured at 3 days to assess cardiac injury and oxidative stress. Cardiac remodeling and function were studied by echocardiography and catheterization at 7 days. Myocardial fibrosis was quantified in picrosirius red stained slices. RESULTS: Absence of Gal-3 tended to reduce the mortality after DOX. DOX significantly increased CPK, LDH, AST and TBARS while treated Gal-3 KO mice showed reduced injury and oxidative stress. After 7 days, adverse remodeling, fibrosis and dysfunction in treated-C57 mice were severely affected while those effects were prevented by absence of Gal-3. CONCLUSION: In summary, genetic deletion of Gal-3 prevented cardiac damage, adverse remodeling and dysfunction, associated with reduced cardiac oxidative stress and fibrosis. Understanding the contribution of GAL-3 to doxorubicin-induced cardiac toxicity reinforces its potential use as a therapeutic target in patients with several cancer types.

Diazoxide improves muscle function in association with improved dyslipidemia and decreased muscle oxidative stress in streptozotocin-induced diabetic rats.

AIM/INTRODUCTION: Diabetes Mellitus is a chronic degenerative disease, and its main biochemical characteristic is hyperglycemia due to impaired insulin secretion, resistance to peripheral actions of insulin, or both. Hyperglycemia causes dyslipidemia and stimulates oxidative damage, leading to the main symptoms, such as fatigue and culminates in diabetic complications. Previous studies have shown that ATP-sensitive potassium channels counteract muscle fatigue and metabolic stress in healthy mouse models. To determine the effect of diazoxide on muscle strength development during diabetes, we tested the effect of diazoxide in streptozotocin-diabetic rats in muscle function, lipid profile and oxidative stress biomarkers. MATERIALS AND METHODS: Wistar rats were divided into 4 groups of six animals each: (1) Control group, (2) diabetes group, (3) Control group + diazoxide, and (4) Diabetic + diazoxide (DB + DZX). 4 weeks after rats were sacrificed, soleus and extensor digitorum longus muscles (EDL) were extracted to prepare homogenates and serum was obtained for biochemical measurements. Oxidative damage was evaluated by the thiobarbituric acid method and the fluorescent for reactive oxygen species (ROS) probe 2,4-H2DCFDA, respectively. RESULTS: Diabetic rats with diazoxide administration showed an increase in the development of muscle strength in both muscles; in turn, the onset of fatigue was longer compared to the group of diabetic rats without treatment. Regarding the lipid profile, diazoxide decreased total cholesterol levels in the group of diabetic rats treated with diazoxide (x̅46.2 mg/dL) compared to the untreated diabetic group (x̅=104.4 mg/dL); secondly, diazoxide decreased triglyceride concentrations (x̅=105.3 mg/dL) compared to the untreated diabetic rats (x̅=412.2 mg/dL) as well as the levels of very low-density lipoproteins (x̅=20.4 mg/dL vs. x̅=82.44 mg/dL). Regarding the various markers of oxidative stress, the diabetic group treated with diazoxide was able to reduce the concentrations of TBARS and total reactive oxygen species as well as preserve the concentrations of reduced glutathione. CONCLUSION: Diazoxide administration in diabetic rats increases muscle strength development in EDL and soleus muscle, decreases fatigue, reduces cholesterol and triglyceride concentrations and improves oxidative stress parameters such as TBARS, ROS, and glutathione status.

Antioxidant activity of bee products added to water in tebuconazole-exposed fish

An experiment was conducted to evaluate the potential of honey, propolis, and bee pollen for the reversal of lipid peroxidation induced by tebuconazole (TEB) in South American catfish (Rhamdia quelen), in which the concentration of thiobarbituric acid reactive substances (TBARS), the activity of the antioxidant enzyme glutathione-S-transferase (GST) and the concentrations of non-enzymatic antioxidants, reduced glutathione (GSH), ascorbic acid, and non-protein thiols were assessed. Honey (0.125 g L-1) and bee pollen (0.05 g L-1) added to the water reverse the production of TBARS induced by TEB, while propolis demonstrated a pro-oxidant effect, inducing an increase in TBARS production. The data presented herein suggest that the addition of water to honey and bee pollen potentially protects against the oxidative stress caused by agrichemicals.

Um experimento foi conduzido objetivando avaliar o potencial do mel, da própolis e do pólen apícola na reversão da peroxidação lipídica causada pelo fungicida tebuconazole (TEB) na espécie de peixe tropical Rhamdia quelen, avaliando a concentração das substâncias reativas ao ácido tiobarbitúrico (TBARS), a atividade da enzima glutationa-S-transferase (GST) e das concentrações dos antioxidantes glutationa reduzida (GSH), ácido ascórbico e dos tiois não proteicos. O mel adicionado à água na concentração de 0,125g L-1 e o pólen apícola na concentração de 0.05 g L-1reverteram a geração das TBARS causada pela exposição ao TEB, enquanto a própolis demonstrou efeito pró-oxidante, induzindo um aumento na geração das TBARS. Os dados apresentados neste trabalho sugerem o potencial do mel e do pólen apícola adicionados à água como substâncias protetoras contra o estresse oxidativo causado por agroquímicos.

Parámetros inflamatorios en saliva y sangre en niños y adolescentes sanos / Inflammatory parameters in saliva and blood from healthy children and adolescents

En la actualidad se ha mostrado interés en el empleo de la saliva para ser utilizada como una alternativa de diagnóstico, predicción y progresión de diversas enfermedades con relación a otros fluidos corporales. Los objetivos trazados para la realización de este trabajo fueron: correlacionar las concentraciones en saliva y sangre de IL-1, IL-6, TNF-a, sustancias reactivas al ácido tiobarbitúrico y O2- de niños y adolescentes sistémicamente sanos. Se realizó un estudio de corte transversal en 23 niños y adolescentes sanos, entre 4 y 17 años de edad. Se les realizaron evaluaciones clínicas para determinar las condiciones bucales y estudios inmunológicos con el propósito de identificar los niveles de citosinas, a través del ensayo inmunoenzimático indirecto, el O2- por método citoquímico y las sustancias reactivas al ácido tiobarbitúrico, a través del ensayo colorimétrico. Hubo diferencia significativa entre las muestras de saliva y las de sangre periférica respecto a las citosinas y sustancias reactivas al ácido tiobarbitúrico estudiadas. Los resultados fueron: IL-1 en sangre= 1,646 ± 0,13 pg/mL y de IL-1 en saliva= 552,36 ± 75,7 pg/mL; IL-6 en sangre= 3,506 ± 1,85 pg/mL, e IL-6 en saliva= 26,89 ± 9,97 pg/mL. Al analizar el TNF-a en sangre fue de 12,91 ± 3,05 pg/mL y en saliva= 43,56 ± 6,44 pg/mL, las sustancias reactivas al ácido tiobarbitúrico en sangre= 9,46 ± 3,26 nmol/mL y en saliva= 1,26 ± 0,03 nmol/mL. No se observó correlación estadísticamente significativa entre las muestras de sangre y saliva para los valores de IL-1, IL-6 y sustancias reactivas al ácido tiobarbitúrico. En cuanto al TNF-a se evidenció una correlación significativa, r s= 0,78. No se evidenciaron células positivas para el O2- en las muestras estudiadas. Los resultados del análisis de correlación obtenido entre las muestras salivales y séricas, no aportaron evidencias suficientes para sugerir que la saliva pueda ser utilizada como fluido corporal que permita sustituir la determinación sérica de IL-1, IL-6 y sustancias reactivas al ácido tiobarbitúrico. En cuanto al TNF-a se evidenció una correlación significativa, lo cual podría plantear la posible sustitución de muestras séricas por salivales(AU)

At present times, there is interest in the use of saliva as a diagnosis, prediction and progression alternative of different pathologies in relation to the body fluids. To correlate the concentrations of IL-1, IL-6, TNF-a, substances reactive to thiobarbituric acid (RSTBA) and O2- in the saliva and blood of systematically healthy children and adolescents. A cross-sectional study was performed in 23 healthy children and adolescents aged from 4 to 17 underwent to clinical tests to demonstrate the oral conditions and immunological to identify the cytokine levels and the RSTBAs by colorimetry trial. There was a significant difference in saliva samples compared to that of peripheral blood in study cytokines and RSTBAs: IL-1 (blood: 1.646 ± 0.13 pg/mL, saliva: 552.36 ± 75.7 pg/mL; IL-6 (blood: 3.506 ± 1.85 pg/mL, saliva: 26.89 ± 9.97 pg/mL: TNF-a (blood: 12.91 ± 3.05 pg/mL, saliva: 43.56 ± 6.44 pg/mL), RSTBA (blood: 9.46 ± 3.26 nmol/mL, saliva: 1.26 ± 0.03 nmol/mL). There was not a statistically significant difference among blood and saliva samples for IL-1, IL-6 and RSTBA values. As regards TNF-a it was demonstrated a significant correlation, r s= 0.78. There was not evidence of cells positive to O2 in study samples. Results of correlation analysis obtained among the saliva and serum samples not offer evidences that saliva may be used as body fluid allows substituting the serum determination of IL-1, IL-6 and RSTBA. In the case of the TNF-a, there was a significant correlation, which could to propose the possible substitution of serum samples for the salivary ones(AU)

Beneficial role of aminoguanidine on acute cardiomyopathy related to doxorubicin-treatment.

Doxorubicin (DOX) is a broad-spectrum anthracycline antibiotic that has cardiotoxicity as a major side effect. One mechanism of this toxicity is believed to involve the reactive oxygen radical species (ROS); these agents likely account for the pathophysiology of DOX-induced cardiomyopathy. Aminoguanidine (AG) is an effective antioxidant and free radical scavenger which has long been known to protect against ROS formation. We investigated the effects of AG on DOX-induced changes in thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) content. The rats were divided into four groups:1) Control; 2) DOX group; injected intraperitoneally (i.p.) with DOX 20 mg/kg in a single dose 3) AG-treated group; injected i.p. in single dose of 20 mg/kg DOX plus 100 mg/kg AG 1 h before the DOX for 3 days, 4) AG group; injected i.p. with AG 100 mg/kg for 3 days. DOX administration to control rats increased TBARS and decreased GSH levels. AG administration before DOX injection caused significant decrease in TBARS and increase in GSH levels in the heart tissue when compared with DOX only. Morphological changes, including severe myocardial fibrosis and inflammatory cell infiltration were clearly observed in the DOX-treated heart. AG reversed the DOX-induced heart damage. Therefore AG could protect the heart tissue against free radical injury. The application of AG during cancer chemotherapy may attenuate tissue damage and improve the therapeutic index of DOX.

Daytime of sampling, tooth-brushing and ascorbic acid influence salivary thiobarbituric acid reacting substances--a potential clinical marker of gingival status.

BACKGROUND: Salivary thiobarbituric acid reacting substances (TBARS) have been previously shown to correlate with the impairment of gingival tissue. Although the details on the origin and the composition of this heterogeneous group of compounds in saliva are unknown, the potential clinical usefulness makes necessary the studies of factors influencing the salivary TBARS levels. AIM: To observe the effects of daily dynamics, tooth-brushing and ascorbic acid administration on salivary TBARS levels. Subjects and methods. Self-collected samples were obtained from 10 young healthy men collecting samples in the morning, in the afternoon and in the evening during 2 consecutive days. Ascorbic acid (250 mg) was administered orally after the last sampling on day 1 and before every sampling on day 2. Additional sampling was performed before and after tooth-brushing. TBARS levels in saliva specimens were detected spectrofluorometrically. Sialic acid content was measured using a modified method of Warren. RESULTS: Salivary TBARS levels vary significantly during a day (p < 0.001) with highest concentrations in the morning. Both, tooth-brushing (p < 0.05) and short-term antioxidative treatment with ascorbic acid (p < 0.005) decrease salivary TBARS levels. Sialic acid content of saliva is not influenced significantly by any of the investigated factors. CONCLUSION: TBARS levels in saliva are affected by daytime of sampling, tooth-brushing and ascorbic acid pre-treatment. These results must be considered in clinical research using salivary TBARS levels. Sialic acid seems not to be a major component of TBARS in saliva. Further studies should clarify the molecular compounds of salivary TBARS and uncover the role of oral microbial factors.