Preventive effects of hesperidin in an experimental model ofs acute lung inflammation.

In this study, we hypothesized that long-term administration of hesperidin can modulate the inflammatory response and oxidative stress in animals submitted to mechanical ventilation (MV). Twenty-five C57BL/6 male mice were divided into 5 groups: control, MV, animals receiving hesperidin in three doses 10, 25 and 50 mg/kg. The animals received the doses of hesperidin for 30 days via orogastric gavage, and at the end of the period the animals were submitted to MV. In animals submitted to MV, increased lymphocyte, neutrophil and monocyte/macrophage cell counts were observed in the blood and airways. Associated to this, MV promoted an increase in inflammatory cytokine levels such as CCL2, IL-12 and TNFα. The daily administration of hesperidin in the three doses prevented the effects caused by MV, which was observed by a lower influx of inflammatory cells into the airways, a reduction in inflammatory markers and less oxidative damage.

N-acetylcysteine modulates redox imbalance and inflammation in macrophages and mice exposed to formaldehyde.

This study aimed to evaluate the protective role of N-acetylcysteine (NAC) in cells and mice exposed to formaldehyde. For the in vitro study, J774A.1 macrophages cells were incubated for 8, 16 and 24 h with formaldehyde or NAC to assess cell viability and reactive oxygen species (ROS). In the in vivo study, C57BL/6 mice (n = 48) were divided into 6 groups: control (CG), vehicle (VG) that received saline by orogastric gavage, a group exposed to formaldehyde 1% (FG) and formaldehyde exposed groups that received NAC at doses of 100, 150 and 200 mg/Kg (FN100, FN150 and FN200) for a period of 5 days. In vitro, formaldehyde promoted a decrease in cell viability and increased ROS, while NAC reduced formaldehyde-induced ROS production. Animals exposed to formaldehyde presented higher leukocyte counts in the blood and in the bronchoalveolar lavage fluid, and promoted secretion of inflammatory markers IL-6, IL-15, and IL-10. The exposure to formaldehyde also promoted redox imbalance and oxidative damage characterized by increased activities of superoxide dismutase, catalase, decreased GSH/GSSG ratio, as well as it increased levels of protein carbonyls and lipid peroxidation. NAC administration after formaldehyde exposure attenuated oxidative stress markers, secretion of inflammatory mediators and lung inflammation. In conclusion, both in in vitro and in vivo models, NAC administration exerted protective effects, which modulated the inflammatory response and redox imbalance, thus preventing the development airway injury induced by formaldehyde exposure.

Chronic Oral Administration of Aluminum Hydroxide Stimulates Systemic Inflammation and Redox Imbalance in BALB/c Mice.

The present study is aimed at investigating the long-term effects of the aluminum hydroxide administration in the small intestine, lung, liver, and kidney of male BALB/c mice. The mice received via orogastric gavage phosphate buffered or 10 mg/kg aluminum hydroxide 3 times a week for 6 months. Administration of aluminum hydroxide decreased hemoglobin, hematocrit, and erythrocyte. In the blood, kidney and liver function markers were evaluated, and long-term administration of aluminum hydroxide led to an increase in AST levels and a decrease in urea levels. The animals exposed to aluminum showed higher lipid and protein oxidation in all the organs analyzed. In relation to the enzymes involved in antioxidant defense, the lungs showed lower superoxide dismutase (SOD) and catalase activity and a lower reduced and oxidized glutathione (GSH/GSSG) ratio. In the liver, aluminum administration led to a decrease in catalase activity and the GSH/GSSG ratio. Lower catalase activity was observed in the small intestine, as well as in the lungs and liver. In addition to alterations in antioxidant defense, increased levels of the chemokine CCL-2 were observed in the lungs, lower levels of IL-10 in the liver and small intestine, and decreased levels of IL-6 in the intestine of the animals that received aluminum hydroxide for 6 months. Long-term exposure to aluminum promoted steatosis in the liver. In the kidneys, mice treated with aluminum presented a decreased glomerular density than in the naive control group. In the small intestine, exposure caused villi shortening. Our results indicate that long-term oral administration of aluminum hydroxide provokes systemic histological damage, inflammation, and redox imbalance.

Effects of a lycopene-layered double hydroxide composite administration in cells and lungs of adult mice.

Lycopene is a natural compound with one of the highest antioxidant activities. Its consumption is associated with lower risks in lung cancer and chronic obstructive pulmonary disease, for example. Experimentally, a murine model demonstrated the ingestion of lycopene, which reduced the damage in lungs caused by cigarette smoke. Since lycopene is highly hydrophobic, its formulations in supplements and preparations for laboratory assays are based on oils, additionally, bioavailavility is low. We developed a lycopene layered double hydroxide (Lyc-LDH) composite, which is capable of transporting lycopene aqueous media. Our objective was to evaluate the cytotoxicity of Lyc-LDH and the intra-cellular production of reactive oxygen species (ROS) in J774A.1 cells. Also, in vivo assays were conducted with 50 male C57BL/6 mice intranasally treated with Lyc-LDH 10 mg/kg (LG10), Lyc-LDH 25 mg/kg (LG25) and Lyc-LDH 50 mg/kg (LG50) during five days compared against a vehicle (VG) and control (CG) group. The blood, bronchoalveolar lavage fluid (BALF) and lung tissue were analyzed. The results revealed that Lyc-LDH composite attenuated intracellular ROS production stimulated with lipopolysacharide. In BALF, the highest doses of Lyc-LDH (LG25 and LG50) promoted influx of macrophages, lymphocytes, neutrophils and eosinophils compared to CG and VG. Also, LG50 increased the levels of IL-6 and IL-13, and promoted the redox imbalance in the pulmonary tissue. On the contrary, low concentrations did not produce significative effects. In conclusion, our results suggest that intranasal administration of high concentrations of Lyc-LDH induces inflammation as well as redox status changes in the lungs of healthy mice, however, results with low concentrations open a promising way to study LDH composites as vehicles for intranasal administration of antioxidant coadjuvants.

Long-term e-cigarette aerosol exposure causes pulmonary emphysema in adult female and male mice.

This study aimed to evaluate long-term exposure to conventional cigarette smoke (CC) and electronic cigarette (EC) aerosol in adult male and female C57BL/6 mice. Forty-eight C57BL/6 mice were used, male (n = 24) and female (n = 24), both were divided into three groups: control, CC and EC. The CC and EC groups were exposed to cigarette smoke or electronic cigarette aerosol, respectively, 3 times a day for 60 consecutive days. Afterwards, they were maintained for 60 days without exposure to cigarettes or electronic cigarette aerosol. Both cigarettes promoted an influx of inflammatory cells to the lung in males and females. All animals exposed to CC and EC showed an increase in lipid peroxidation and protein oxidation. There was an increase of IL-6 in males and females exposed to EC. The IL-13 levels were higher in the females exposed to EC and CC. Both sexes exposed to EC and CC presented tissue damage characterized by septal destruction and increased alveolar spaces compared to control. Our results demonstrated that exposure to CC and EC induced pulmonary emphysema in both sexes, and females seem to be more susceptible to EC.

Acute Outcomes of Cigarette Smoke and Electronic Cigarette Aerosol Inhalation in a Murine Model.

Cigarette smoking throughout life causes serious health issues in the lungs. The electronic cigarette (E-Cig) use increased, since it was first introduced in the world. This research work compared the short-term exposure consequences to e-cigarette vapor and cigarette smoke in male mice. Forty-five C57BL/6 mice were randomized into control (C) in an ambient air exposition cigarette smoke (CS) and aerosol electronic cigarette (EC), both were exposed to 120 puffs, 3 times/day during five days. Then, in the experimental protocol, the euthanized mice had their tissues removed for analysis. Our study showed that CS and EC resulted in higher cell influx into the airways, and an increase in macrophage counts in CS (209.25 ± 7.41) and EC (220.32 ± 8.15) when compared to C (108.40 ± 4.49) (p < 0.0001). The CS (1.92 ± 0.23) displayed a higher pulmonary lipid peroxidation as opposed to C (0.93 ± 0.06) and EC (1.23 ± 0.17) (p < 0.05). The EC (282.30 ± 25.68) and CS (368.50 ± 38.05) promoted increased levels of interleukin 17 when compared to C (177.20 ± 10.49) (p < 0.05). The EC developed shifts in lung histoarchitecture, characterized by a higher volume density in the alveolar air space (60.21; 55.00-65.83) related to C (51.25; 18.75-68.75) and CS (50.26; 43.75-62.08) (p =0.002). The EC (185.6 ± 9.01) presented a higher respiratory rate related to CS (133.6 ± 10.2) (p < 0.002). Therefore, our findings demonstrated that the short-term exposure to e-cig promoted more acute inflammation comparing to cigarette smoke in the ventilatory parameters of the animals.

The deleterious impact of exposure to different inhaled anesthetics is time dependent.

In this study, the effects of exposure to isoflurane, sevoflurane and desflurane on the oxidative response and inflammation at different times was analyzed in the lungs of adult C57BL/6 mice. 120 animals were divided into 3 groups (n = 40): Isoflurane (ISO), Sevoflurane (SEV) and Desflurane (DES) and exposed to these anesthetics for 1 h (n = 10), 2 h (n = 10) and 3 h (n = 10), at a minimum alveolar concentration (MAC) equal to 1. The control group (CG) (n = 10) was exposed to ambient air. 24 h after the experimental protocol, the animals were euthanized and the bronchoalveolar lavage fluid (BALF), blood and lung tissue samples were collected. In the BALF, animals exposed to isoflurane for 2 h and 3 h showed a greater influx of leukocytes, especially macrophages compared to the CG. The ISO3h had lower leukocyte counts in the peripheral blood compared to CG, ISO1h and ISO2h. There was an increase in CCL-2 levels in the ISO3h compared to the CG. Superoxide dismutase activity was higher in ISO1h compared to CG. The activity of catalase was higher in the ISO1h and ISO2h compared to the CG. The lipid peroxidation, as well as carbonylated protein were higher in the ISO3h compared to the CG (p < 0.05). Similar results were observed in the exposure of SEV and DES compared to inflammation and redox imbalance in different periods. This study demonstrated that time is a determinant to promote a local and systemic inflammatory response to different inhalational anesthetics in a healthy murine model.

Protein restriction during pregnancy affects lung development and promotes oxidative stress and inflammation in C57 BL/6 mice offspring.

OBJECTIVES: The present study aimed to evaluate the effects of maternal protein restriction during pregnancy on the lungs of 1-d and 31-d old offspring of C57BL/6 mice. METHODS: The C57BL/6 mice (8-10 wk) were used for breeding. After pregnancy confirmation, female mice were randomly divided into a control group (CG) receiving a standard diet (22% protein) and a protein-restriction group (PRG) receiving a low-protein diet (6% protein). In the low-protein diet, protein was replaced by carbohydrate. After parturition, female mice that received the low-protein diet were fed the standard diet. Male offspring were euthanized 1 d and 31 d after birth for subsequent analysis. We evaluated the effects of a protein-restricted diet during gestation in pulmonary organogenesis, lung oxidative stress, and pulmonary inflammatory response of the offspring. RESULTS: PRG mice 1 d after birth showed lower body and lung mass, length, relative mass, lung density, and erythrocyte count compared with CG mice. There was an increase in alveolar airspace density and a higher mean linear intercept (Lm), greater oxidative damage, and inflammation in PRG mice compared with CG mice. At 31 d after birth, PRG mice had lower body mass, length, and lung mass values compared with CG mice. PRG mice showed greater recruitment of inflammatory cells to the airways. In addition, there was increased collagen deposition in the lungs, altered inflammatory mediators, and greater oxidative damage compared with CG mice. CONCLUSIONS: Protein restriction during pregnancy reduces the body weight of offspring and promotes inflammation and oxidative stress, resulting in a simplification of the lung structure.

Quercetin Improves Pulmonary Function and Prevents Emphysema Caused by Exposure to Cigarette Smoke in Male Mice.

Chronic obstructive pulmonary disease (COPD) is the major cause of morbidity and mortality worldwide, and cigarette smoke is a key factor in the development of COPD. Thus, the development of effective therapies to prevent the advancement of COPD has become increasingly essential. We hypothesized that quercetin protects lungs in mice exposed to long-term cigarette smoke. Thirty-five C57BL/6 mice were exposed to cigarette smoke (12 cigarettes per day) for 60 days and pretreated with 10 mg/kg/day of quercetin via orogastric gavage. After the experimental protocol, the animals were euthanized and samples were collected for histopathological, antioxidant defense, oxidative stress and inflammatory analysis. The animals exposed to cigarette smoke showed an increase in respiratory rate and hematological parameters, cell influx into the airways, oxidative damage and inflammatory mediators, besides presenting with alterations in the pulmonary histoarchitecture. The animals receiving 10 mg/kg/day of quercetin that were exposed to cigarette smoke presented a reduction in cellular influx, less oxidative damage, reduction in cytokine levels, improvement in the histological pattern and improvement in pulmonary emphysema compared to the group that was only exposed to cigarette smoke. These results suggest that quercetin may be an agent in preventing pulmonary emphysema induced by cigarette smoke.

Effects in vitro and in vivo of hesperidin administration in an experimental model of acute lung inflammation.

Mechanical ventilation (MV) is a tool used in critical patient care. However, it can trigger inflammatory and oxidative processes capable of causing or aggravating lung injuries, which is known as ventilator-induced lung injury (VILI). Hesperidin is a flavonoid with antioxidant and anti-inflammatory properties in various diseases. The role of hesperidin in the process triggered by MV is poorly studied. Thus, we hypothesize hesperidin could protect the lung of mice submitted to mechanical ventilation. For that, we evaluated cell viability and reactive oxygen species (ROS) formation in macrophages using different hesperidin concentrations. We observed hesperidin did not reduce cell viability, however; it attenuated the production of intracellular ROS in cells stimulated with lipopolysaccharide (LPS). We further evaluated the effects of hesperidin in vivo in animals submitted to MV. In the bronchoalveolar lavage fluid, there were higher levels of macrophage, lymphocyte and neutrophil counts in animals submitted to MV, indicating an inflammatory process. In the lung tissue, MV induced oxidative damage and increased myeloperoxidase activity, though the antioxidant enzyme activity decreased. MV also induced the production of the inflammatory mediators CCL-2, TNF-α and IL-12. Pretreatment with hesperidin resulted in less recruitment of inflammatory cells to the airways and less oxidative damage. Also, it reduced the formation of CCL-2 and IL-12. Our results show pretreatment with hesperidin can protect the lungs of mice submitted to mechanical ventilation by modulating the inflammatory response and redox imbalance and may act to prevent MV injury.

The effects of different ventilatory modes in female adult rats submitted to mechanical ventilation.

This study aimed to analyze the effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) modes in female Wistar rats. 18 Wistar female adult rats were divided into three groups: control (CG), pressure-controlled ventilation (PCVG), and volume-controlled ventilation (VCVG). PCVG and VCVG were submitted to MV for one hour with a tidal volume (TV) of 8 mL/Kg, respiratory rate of 80 breaths/min, and positive end-expiratory pressure of 0 cmH2O. At the end of the experiment, all animals were euthanized. The neutrophils and lymphocytes influx to lung were higher in VCVG and PCVG compared to CG. The activities of superoxide dismutase, catalase and myeloperoxidase were higher in PCVG compared to CG. There was an increase in lipid peroxidation and protein oxidation in PCVG compared to CG. The levels of CCL3 and CCL5 were higher in PCVG compared to CG. In conclusions, the PCV mode promoted structural changes in the lung parenchyma, redox imbalance and inflammation in healthy adult female rats submitted to MV.

Sigh maneuver protects healthy lungs during mechanical ventilation in adult Wistar rats.

Mechanical ventilation (MV) is a tool used for the treatment of patients with acute or chronic respiratory failure. However, MV is a non-physiological resource, and it can cause metabolic disorders such as release of pro-inflammatory cytokines and production of reactive oxygen species. In clinical setting, maneuvers such as sigh, are used to protect the lungs. Thus, this study aimed to evaluate the effects of sigh on oxidative stress and lung inflammation in healthy adult Wistar rats submitted to MV. Male Wistar rats were divided into four groups: control (CG), mechanical ventilation (MVG), MV set at 20 sighs/h (MVG20), and MV set at 40 sighs/h (MVG40). The MVG, MVG20, and MVG40 were submitted to MV for 1 h. After the protocol, all animals were euthanized and the blood, bronchoalveolar lavage fluid, and lungs were collected for subsequent analysis. In the arterial blood, MVG40 presented higher partial pressure of oxygen and lower partial pressure of carbon dioxide compared to control. The levels of bicarbonate in MVG20 were lower compared to CG. The neutrophil influx in bronchoalveolar lavage fluid was higher in the MVG compared to CG and MVG40. In the lung parenchyma, the lipid peroxidation was higher in MVG compared to CG, MVG20, and MVG40. Superoxide dismutase and catalase activity were higher in MVG compared to CG, MVG20, and MVG40. The levels of IL-1, IL-6, and TNF in the lung homogenate were higher in MVG compared to CG, MVG20, and MVG40. The use of sigh plays a protective role as it reduced redox imbalance and pulmonary inflammation caused by MV.

Exogenous surfactant prevents hyperoxia-induced lung injury in adult mice.

BACKGROUND: In addition to the risk of developing ventilator-induced lung injury, patients with ARDS are at risk of developing hyperoxic injury due the supra-physiological oxygen supplementation clinically required to reverse hypoxemia. Alterations of endogenous surfactant system participate in the pulmonary dysfunction observed in ARDS. Administration of exogenous surfactant could have protective effects during hyperoxia. METHODS: Male BALB/c mice (8-10 weeks), a strain highly sensitive to hyperoxia, received the exogenous surfactant-containing protein SP-B and SP-C by intranasal instillation 12 h before starting 24 h of exposure to hyperoxia in an inhalation chamber and were compared to mice receiving hyperoxia alone and to controls subjected to normoxia. RESULTS: Compared to the hyperoxia group, the administration of exogenous surfactant was able to reduce lung inflammation through a reduction in the influx of neutrophils and inflammatory biomarkers such as TNF, IL-17, and HMGB1 expression. The antioxidant activity prevented oxidative damage by reducing lipid peroxidation and protein carbonylation and increasing superoxide dismutase activity when compared to the hyperoxia group. CONCLUSION: Our results offer new perspectives on the effects and the mechanism of exogenous surfactant in protecting the airway and lungs, in oxygen-rich lung microenvironment, against oxidative damage and aggravation of acute inflammation induced by hyperoxia.

High-Fat Diet Increases HMGB1 Expression and Promotes Lung Inflammation in Mice Subjected to Mechanical Ventilation.

This study aims to evaluate the effects of a high-fat diet and mechanical ventilation on the pulmonary and systemic inflammatory response in C57BL/6 mice. Male C57BL/6 mice were divided into two groups: one received a standard diet, and the other received a high-fat diet. After 10 weeks, the groups were further divided into two groups each: control group (CG), mechanical ventilation group (MVG), diet group (DG), and diet mechanical ventilation group (DMVG). MVG and DMVG underwent mechanical ventilation for 60 minutes. All animals were euthanized for subsequent analysis. Animals receiving a high-fat diet presented higher body mass, adipose index, and greater adipocyte area. In the lung, the expression of HMGB1 was greater in DG and DMVG than in CG and MVG. CCL2 and IL-22 levels in MVG and DMVG were increased compared to those in CG and DG, whereas IL-10 and IL-17 were decreased. Superoxide dismutase activity was higher in MVG and DMVG than in CG. Catalase activity was lower in DG than in CG, and in MV groups, it was lower than that in CG and DG. MV and obesity promote inflammation and pulmonary oxidative stress in adult C57BL/6 mice.