Glyphosate and Aminomethylphosphonic Acid (AMPA) Modulate Glutathione S-Transferase in Non-Tumorigenic Prostate Cells.

Glyphosate (GLY) was developed in the early 1970s and has become the most used broad-spectrum herbicide in the world so far. Its main metabolite is aminomethylphosphonic acid (AMPA), and the accumulation of GLY and its derivative compounds raises some concerns regarding possible health outcomes. In this study, we aimed to evaluate the effects of GLY and AMPA on prostate cell lines by evaluating cell viability, proliferation, gene and protein expression, and cellular pathways involved in the response to oxidative stress. Our results indicated that GLY and AMPA reduced the cell viability of tumorigenic and non-tumorigenic prostate cell lines only at higher concentrations (10 mM GLY and 20 mM AMPA). In contrast, both compounds increased the clonogenicity of non-tumorigenic PNT2 cells, mainly at concentrations below the IC50 (5 mM GLY and 10 mM AMPA). Moreover, treatment of non-tumorigenic cells with low concentrations of GLY or AMPA for 48 h increased GSTM3 expression at both mRNA and protein levels. In contrast, the treatments decrease the GST activity and induced an increase in oxidative stress, mainly at lower concentrations. Therefore, both compounds can cause cellular damage even at lower concentrations in non-tumorigenic PNT2 cells, mainly affecting cell proliferation and oxidative stress.

Endothelial dysfunction due to the inhibition of the synthesis of nitric oxide: Proposal and characterization of an in vitro cellular model.

The vascular endothelium plays a pivotal role in the maintenance of vascular homeostasis, mediated by vasoactive molecules produced by endothelial cells. The balance between vasoconstrictor and vasodilator biomolecules is what guarantees this equilibrium. Therefore, an increase in the bioavailability of vasoconstrictors along with a reduction in vasodilators may indicate a condition known as endothelial dysfunction. Endothelial dysfunction is marked by an inflammatory process and reduced activity of vasoprotective enzymes, being characterized by some factors like the reduction of the bioavailability of nitric oxide (NO) and increase in the production of reactive oxygen species (ROS), pro-inflammatory and vasoconstrictor molecules. This condition is a predictive marker of several cardiovascular diseases (e.g., atherosclerosis, hypertension, and diabetes). Research is affected by the scarcity of suitable in vitro models that simulate endothelial dysfunction. The goal of this study was to induce an in vitro condition to mimic endothelial dysfunction by inhibiting NO synthesis in cells. Thymus-derived endothelial cells (tEnd.1) were treated with different concentrations of L-NAME (from 1 to 1,000 µM) for different times (12, 24, 48, 72, 96, and 120 h without and with retreatment every 24 h). Cell viability, nitrite concentration, p22phox, NOX2, NOX4, IL-6, and ACE genes expression and lipid peroxidation were evaluated. The results indicate that the treatment with 100 µM L-NAME for 72 h without retreatment reduced NO concentration and NOX4 gene expression while increasing ACE expression, thus mimicking reduced vascular protection and possibly increased vasoconstriction. On the other hand, treatment with 100 µM L-NAME for 96 h with retreatment reduced the concentration of NO and the expression of the p22phox gene while increasing the expression of the IL-6 and ACE genes, mimicking the increase in inflammation and vasoconstriction parameters. Based on these results, we thus propose that both 100 µM L-NAME for 72 h without retreatment and 100 µM L-NAME for 96 h with retreatment may be used as models for in vitro endothelial dysfunction according to the purpose of the study to be conducted.

Jaboticaba (Myrciaria cauliflora) Peel Supplementation Prevents Hepatic Steatosis Through Hypolipidemic Effects and Cholesterol Metabolism Modulation in Diet-Induced Nonalcoholic Fatty Liver Disease Rat Model.

Jaboticaba (Myrciaria cauliflora), a Brazilian fruit, is a good source of dietary fiber and phenolic compounds, which are concentrated mainly in the peel. These compounds have been considered promising in prevention and treatment of hypercholesterolemia and hepatic steatosis. In this study, we investigated the effects of 4% jaboticaba peel powder (JPP) supplementation on cholesterol metabolism and hepatic steatosis in livers of rats fed a high-fat (HF) diet. The rats were fed a standard AIN-93M (control) diet or an HF diet containing 32% lard and 1% cholesterol, both with and without 4% JPP. The M. cauliflora peel composition revealed a low-lipid high-fiber content and phenolic compounds. The phenolic compounds in JPP, tentatively identified by high-performance liquid chromatography and mass spectrometry (HPLC-MS/MS) analysis, were confirmed to contain phenolic acids, flavonoids, and anthocyanins. Moreover, JPP presented significant antioxidant activity in vitro and was not cytotoxic to HepG2 cells, as determined by the lactate dehydrogenase (LDH) assay. After 6 weeks of treatment, our results showed that JPP supplementation increased lipid excretion in feces, reduced serum levels of total cholesterol and nonhigh-density lipoprotein cholesterol, decreased serum aspartate aminotransferase (AST) activity, and attenuated hepatic steatosis severity in rats fed the HF diet. Furthermore, JPP treatment downregulated expression of ACAT-1, LXR-α, CYP7A1, and ABCG5 genes. Therefore, jaboticaba peel may represent a viable dietary strategy to prevent nonalcoholic fatty liver disease as the JPP treatment alleviated hepatic steatosis through improvement of serum lipid profiles and modulation of mRNA expression of genes involved in cholesterol metabolism.

Açai improves non-alcoholic fatty liver disease (NAFLD) induced by fructose.

INTRODUCTION: the excessive consumption of fructose can cause liver damage, characteristic of non-alcoholic fatty liver disease (NAFLD) associated with changes in lipid metabolism and antioxidant defenses. Açai, the fruit of Euterpe oleraceaMart., has demonstrated numerous biological activities, including anti-inflammatory, antioxidant, and lipid metabolism modulating action. OBJECTIVE: we evaluated the benefits of açai supplementation on liver damage caused by replacing starch with fructose in rats. METHODS: thirty male Fischerrats were divided into two groups, the control group (C, 10 animals), which consumed a standard diet (AIN-93M), and the fructose (F, 20 animals) group, which consumed a diet containing 60% of fructose. After eight weeks, 10 animals from the fructose group received 2% of lyophilized açai, and were called the açai fructose group (FA). The animals were fed ad libitumwith these diets for another ten weeks. Serum, hepatic and fecal lipid profile, antioxidant enzymes and carbonylated protein were assessed and histopathological characterization of the liver was performed. RESULTS: açai promoted the reduction of ALT activity in relation to the fructose group (F), reduced alkaline phosphatase to a level similar to that of the control group (C) in relation to the fructose group (F), and reduced catalase activity. The fruit also increased the ratio of total/oxidized glutathione (GSH/GSSG) and reduced the degree of macrovesicular steatosis and the number of inflammatory cells. CONCLUSION: the replacement of starch by fructose during this period was effective in promoting NAFLD. Açai showed attenuating effects on some markers of hepatic steatosis and inflammation.

Açai (Euterpe oleracea Mart.) Upregulates Paraoxonase 1 Gene Expression and Activity with Concomitant Reduction of Hepatic Steatosis in High-Fat Diet-Fed Rats.

Açai (Euterpe oleracea Mart.), a fruit from the Amazon region, has emerged as a promising source of polyphenols. Açai consumption has been increasing owing to ascribed health benefits and antioxidant properties; however, its effects on hepatic injury are limited. In this study, we evaluated the antioxidant effect of filtered açai pulp on the expression of paraoxonase (PON) isoforms and PON1 activity in rats with nonalcoholic fatty liver disease (NAFLD). The rats were fed a standard AIN-93M (control) diet or a high-fat (HF) diet containing 25% soy oil and 1% cholesterol with or without açai pulp (2 g/day) for 6 weeks. Our results show that açai pulp prevented low-density lipoprotein (LDL) oxidation, increased serum and hepatic PON1 activity, and upregulated the expression of PON1 and ApoA-I in the liver. In HF diet-fed rats, treatment with açai pulp attenuated liver damage, reducing fat infiltration and triglyceride (TG) content. In rats receiving açai, increased serum PON1 activity was correlated with a reduction in hepatic steatosis and hepatic injury. These findings suggest the use of açai as a potential therapy for liver injuries, supporting the idea that dietary antioxidants are a promising approach to enhance the defensive systems against oxidative stress.

Carqueja (Baccharis trimera) Protects against Oxidative Stress and ß-Amyloid-Induced Toxicity in Caenorhabditis elegans.

Carqueja (Baccharis trimera) is a native plant found throughout South America. Several studies have shown that Carqueja has antioxidant activity in vitro, as well as anti-inflammatory, antidiabetic, analgesic, antihepatotoxic, and antimutagenic properties. However, studies regarding its antioxidant potential in vivo are limited. In this study, we used Caenorhabditis elegans as a model to examine the antioxidant effects of a Carqueja hydroalcoholic extract (CHE) on stress resistance and lifespan and to investigate whether CHE has a protective effect in a C. elegans model for Alzheimer's disease. Here, we show for the first time, using in vivo assays, that CHE treatment improved oxidative stress resistance by increasing survival rate and by reducing ROS levels under oxidative stress conditions independently of the stress-related signaling pathways (p38, JNK, and ERK) and transcription factors (SKN-1/Nrf and DAF-16/Foxo) tested here. CHE treatment also increased the defenses against ß-amyloid toxicity in C. elegans, in part by increasing proteasome activity and the expression of two heat shock protein genes. Our findings suggest a potential neuroprotective use for Carqueja, supporting the idea that dietary antioxidants are a promising approach to boost the defensive systems against stress and neurodegeneration.

Hypercholesterolemic diet induces hepatic steatosis and alterations in mRNA expression of NADPH oxidase in rat livers.

OBJECTIVE: This study aimed to determine whether a hypercholesterolemic diet induces hepatic steatosis, alterations in mRNA expression of NADPH oxidase subunits, and antioxidant defenses. MATERIALS AND METHODS: Fischer rats were divided into two groups of eight animals according to the treatment, control (C) and hypercholesterolemic diet (H). Those in group C were fed a standard diet (AIN-93M), and those of the group H were fed a hypercholesterolemic diet (25% soybean oil and 1% cholesterol). RESULTS: The hypercholesterolemic diet did not affect body weight, but resulted in the accumulation of lipids in the liver, increased serum activities of aminotransferases and cholesterol levels. Biomarker of lipid peroxidation (TBARS) and mRNA expression of NADPH oxidase subunits p22(phox) and p47(phox) were increased in the liver of animals in group H. Besides, the activity and expression of antioxidant enzymes were altered. CONCLUSION: The results show increased mRNA expression of NADPH oxidase subunits and changes in antioxidant enzyme activities in diet-induced hepatic steatosis.

Hypercholesterolemic diet induces hepatic steatosis and alterations in mRNA expression of NADPH oxidase in rat livers / Dieta hipercolesterolemiante induz esteatose hepática e alterações na expressão de mRNA da NADPH oxidase em fígados de ratos

Objective : This study aimed to determine whether a hypercholesterolemic diet induces hepatic steatosis, alterations in mRNA expression of NADPH oxidase subunits, and antioxidant defenses.Materials and methods : Fischer rats were divided into two groups of eight animals according to the treatment, control (C) and hypercholesterolemic diet (H). Those in group C were fed a standard diet (AIN-93M), and those of the group H were fed a hypercholesterolemic diet (25% soybean oil and 1% cholesterol).Results : The hypercholesterolemic diet did not affect body weight, but resulted in the accumulation of lipids in the liver, increased serum activities of aminotransferases and cholesterol levels. Biomarker of lipid peroxidation (TBARS) and mRNA expression of NADPH oxidase subunits p22phox and p47phox were increased in the liver of animals in group H. Besides, the activity and expression of antioxidant enzymes were altered.Conclusion : The results show increased mRNA expression of NADPH oxidase subunits and changes in antioxidant enzyme activities in diet-induced hepatic steatosis. Arq Bras Endocrinol Metab. 2014;58(3):251-9.

Objetivo Determinar se uma dieta hipercolesterolemiante induz esteatose hepática, alterações na expressão de mRNA da NADPH oxidase e nas defesas antioxidantes.Materiais e métodos : Ratas Fischer foram divididas em dois grupos de oito animais de acordo com o tratamento recebido, controle (C) e hipercolesterolêmico (H). Aquelas do grupo C foram alimentadas com dieta padrão (AIN-93M) e as do grupo H foram alimentadas com dieta hipercolesterolemiante (25% de óleo de soja e 1% de colesterol). As dietas foram oferecidas por oito semanas.Resultados : O grupo H apresentou acúmulo de lipídios no fígado, aumento das atividades de ALT e AST e da concentração de colesterol no soro comparado ao grupo C. O marcador da peroxidação lipídica (TBARS) e os níveis de mRNA das subunidades p47phox da NADPH-oxidase e p22phox foram aumentados no fígado de animais do grupo H, além de alteração da atividade e expressão de enzimas antioxidantes.Conclusão : Os resultados mostram um aumento na expressão de subunidades da NADPH oxidase e alterações na atividade das enzimas antioxidantes na esteatose hepática induzida por dieta hipercolesterolemiante. Arq Bras Endocrinol Metab. 2014;58(3):251-9.

Açaí (Euterpe oleracea Mart.) modulates oxidative stress resistance in Caenorhabditis elegans by direct and indirect mechanisms.

Açaí (Euterpe oleracea Mart.) has recently emerged as a promising source of natural antioxidants. Despite its claimed pharmacological and nutraceutical value, studies regarding the effects of açaí in vivo are limited. In this study, we use the Caenorhabditis elegans model to evaluate the in vivo antioxidant properties of açaí on an organismal level and to examine its mechanism of action. Supplementation with açaí aqueous extract (AAE) increased both oxidative and osmotic stress resistance independently of any effect on reproduction and development. AAE suppressed bacterial growth, but this antimicrobial property did not influence stress resistance. AAE-increased stress resistance was correlated with reduced ROS production, the prevention of sulfhydryl (SH) level reduction and gcs-1 activation under oxidative stress conditions. Our mechanistic studies indicated that AAE promotes oxidative stress resistance by acting through DAF-16 and the osmotic stress response pathway OSR-1/UNC-43/SEK-1. Finally, AAE increased polyglutamine protein aggregation and decreased proteasome activity. Our findings suggest that natural compounds available in AAE can improve the antioxidant status of a whole organism under certain conditions by direct and indirect mechanisms.

High dietary salt decreases antioxidant defenses in the liver of fructose-fed insulin-resistant rats.

In this study we investigated the hypothesis that a high-salt diet to hyperinsulinemic rats might impair antioxidant defense owing to its involvement in the activation of sodium reabsorption to lead to higher oxidative stress. Rats were fed a standard (CON), a high-salt (HS), or a high-fructose (HF) diet for 10 weeks after which, 50% of the animals belonging to the HF group were switched to a regimen of high-fructose and high-salt diet (HFS) for 10 more weeks, while the other groups were fed with their respective diets. Animals were then euthanized and their blood and liver were examined. Fasting plasma glucose was found to be significantly higher (approximately 50%) in fructose-fed rats than in the control and HS rats, whereas fat liver also differed in these animals, producing steatosis. Feeding fructose-fed rats with the high-salt diet triggered hyperinsulinemia and lowered insulin sensitivity, which led to increased levels of serum sodium compared to the HS group. This resulted in membrane perturbation, which in the presence of steatosis potentially enhanced hepatic lipid peroxidation, thereby decreasing the level of antioxidant defenses, as shown by GSH/GSSG ratio (HFS rats, 7.098±2.1 versus CON rats, 13.2±6.1) and superoxide dismutase (HFS rats, 2.1±0.05 versus CON rats, 2.3±0.1%), and catalase (HFS rats, 526.6±88.6 versus CON rats, 745.8±228.7 U/mg ptn) activities. Our results indicate that consumption of a salt-rich diet by insulin-resistant rats may lead to regulation of sodium reabsorption, worsening hepatic lipid peroxidation associated with impaired antioxidant defenses.

Dietary açai modulates ROS production by neutrophils and gene expression of liver antioxidant enzymes in rats.

Açai (Euterpe oleracea Mart.) has recently emerged as a promising source of natural antioxidants. Because increased oxidative stress and impaired antioxidant defense mechanisms are important factors in the development of diabetic complications and many health claims have been reported for açai, the present study was undertaken to evaluate the possible protective effects of açai on the production of reactive oxygen species by neutrophils and on the liver antioxidant defense system in control and streptozotocin-induced diabetic rats. Diet supplementation with 2% açai was found to increase mRNA levels for gamma-glutamylcysteine synthetase and glutathione peroxidase in liver tissue and to decrease reactive oxygen species production by neutrophils. Compared to control animals, diabetic rats exhibited lower levels of mRNA coding for Zn-superoxide dismutase, glutathione peroxidase and gamma-glutamylcysteine synthetase and higher levels of reactive oxygen species production by neutrophils, thiobarbituric acid-reactive substances and carbonyl proteins in hepatic tissues. Although açai supplementation was not effective in restore gene expression of antioxidant enzymes in diabetic rats, it showed a protective effect, decreasing thiobarbituric acid-reactive substances levels and increasing reduced glutathione content in the liver. These findings suggest that açai can modulate reactive oxygen species production by neutrophils and that it has a significant favorable effect on the liver antioxidant defense system under fisiological conditions of oxidative stress and partially revert deleterious effects of diabetes in the liver.