Botanical formulation HX110B ameliorates PPE-induced emphysema in mice via regulation of PPAR/RXR signaling pathway.

Chronic obstructive pulmonary disease (COPD), an inflammatory lung disease, causes approximately 3 million deaths each year; however, its pathological mechanisms are not fully understood. In this study, we examined whether HX110B, a mixture of Taraxacum officinale, Dioscorea batatas, and Schizonepeta tenuifolia extracts, could suppress porcine pancreatic elastase (PPE)-induced emphysema in mice and its mechanism of action. The therapeutic efficacy of HX110B was tested using a PPE-induced emphysema mouse model and human bronchial epithelial cell line BEAS-2B. In vivo data showed that the alveolar wall and air space expansion damaged by PPE were improved by HX110B administration. HX110B also effectively suppresses the expression levels of pro-inflammatory mediators including IL-6, IL-1ß, MIP-2, and iNOS, while stimulating the expression of lung protective factors such as IL-10, CC16, SP-D, and sRAGE. Moreover, HX110B improved the impaired OXPHOS subunit gene expression. In vitro analysis revealed that HX110B exerted its effects by activating the PPAR-RXR signaling pathways. Overall, our data demonstrated that HX110B could be a promising therapeutic option for COPD treatment.

Anti-inflammatory effect of Anadenanthera colubrina var. cebil (Griseb.) Altschul in experimental elastase-induced pulmonary emphysema in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal plants have shown promise in the search for new treatments of pulmonary emphysema. Anadenanthera colubrina, a species native to the Caatinga biome in northeastern Brazil, is widely recognized and traditionally employed in the treatment of pulmonary diseases. Many studies corroborate popular knowledge about the medicinal applications of A. colubrina, which has demonstrated a remarkable variety of pharmacological properties, however, its anti-inflammatory and antioxidant properties are highlighted. AIM OF THE STUDY: The objective of this study was to investigate the anti-inflammatory potential of the crude hydroethanolic extract of A. colubrina var. cebil (Griseb.) Altschul on pulmonary emphysema in rats as well as to determine its potential genotoxic and cytotoxic effects using the micronucleus assay. MATERIALS AND METHODS: The stem bark of the plant was collected in Pimenteiras-PI and sample was extracted by maceration using 70% ethanol. A portion of the extract underwent phytochemical analyses using TLC and HPLC. In this study, 8-week-old, male Wistar rats weighing approximately ±200 g was utilized following approval by local ethics committee for animal experimentation (No. 718/2022). Pulmonary emphysema was induced through orotracheal instillation of elastase, and treatment with A. colubrina extract or dexamethasone (positive control) concomitantly during induction. Twenty-eight days after the initiation of the protocol, plasma was used for cytokine measurement. Bronchoalveolar lavage (BAL) was used for leukocyte count. After euthanasia, lung samples were processed for histological analysis and quantification of oxidative stress markers. The micronucleus test was performed by evaluating the number of polychromatic erythrocytes (PCE) with micronuclei (MNPCE) to verify potential genotoxic effects of A. colubrina. A differential count of PCE and normochromatic erythrocytes (NCE) was performed to verify the potential cytotoxicity of the extract. Parametric data were subjected to normality analysis and subsequently to analysis of variance and Tukey or Dunnett post-test, non-parametric data were treated using the Kruskal-Wallis test with Dunn's post-test for unpaired samples. P value < 0.05 were considered significant. RESULTS: The A. colubrina extract did not show a significant increase in the number of MNPCE (p > 0.05), demonstrating low genotoxicity. No changes were observed in the PCE/NCE ratio of treated animals, compared with the vehicle, suggesting low cytotoxic potential of the extract. A significant reduction (p < 0.05) in neutrophilic inflammation was observed in the lungs of rats treated with the extract, evidenced by presence of these cells in both the tissue and BAL. The extract also demonstrated pulmonary antioxidant activity, with a significant decrease (p < 0.05) in myeloperoxidase, malondialdehyde, and nitrite levels. TNFα, IL-1ß, and IL-6 levels, as well as alveolar damage, were significantly reduced in animals treated with A. colubrina extract. Phytochemical analyses identified the presence of phenolic compounds and hydrolysable tannins in the A. colubrina extract. CONCLUSIONS: The findings of this study highlights the safety of the hydroethanolic extract of Anadenanthera colubrina, and demonstrates its potential as a therapeutic approach in the treatment of emphysema. The observed properties of this medicinal plant provide an optimistic outlook in the development of therapies for the treatment of pulmonary emphysema.

Astaxanthin attenuates cigarette smoke-induced small airway remodeling via the AKT1 signaling pathway.

BACKGROUND: Astaxanthin (AXT) is a keto-carotenoid with a variety of biological functions, including antioxidant and antifibrotic effects. Small airway remodeling is the main pathology of chronic obstructive pulmonary disease (COPD) and is caused by epithelial-to-mesenchymal transition (EMT) and fibroblast differentiation and proliferation. Effective therapies are still lacking. This study aimed to investigate the role of AXT in small airway remodeling in COPD and its underlying mechanisms. METHODS: First, the model of COPD mice was established by cigarette smoke (CS) exposure combined with intraperitoneal injection of cigarette smoke extract (CSE). The effects of AXT on the morphology of CS combined with CSE -induced emphysema, EMT, and small airway remodeling by using Hematoxylin-eosin (H&E) staining, immunohistochemical staining, and western blot. In addition, in vitro experiments, the effects of AXT on CSE induced-EMT and fibroblast function were further explored. Next, to explore the specific mechanisms underlying the protective effects of AXT in COPD, potential targets of AXT in COPD were analyzed using network pharmacology. Finally, the possible mechanism was verified through molecular docking and in vitro experiments. RESULTS: AXT alleviated pulmonary emphysema, EMT, and small airway remodeling in a CS combined with CSE -induced mouse model. In addition, AXT inhibited the EMT process in airway cells and the differentiation and proliferation of fibroblasts. Mechanistically, AXT inhibited myofibroblast activation by directly binding to and suppressing the phosphorylation of AKT1. Therefore, our results show that AXT protects against small airway remodeling by inhibiting AKT1. CONCLUSIONS: The present study identified and illustrated a new food function of AXT, indicating that AXT could be used in the therapy of COPD-induced small airway remodeling.

Rice Bran Oil Improves Emphysema in Cigarette Smoke Extract-Induced Mice through Anti-Inflammatory and Antioxidative Effects.

Lung inflammation and alveolar enlargement are the major pathological conditions of chronic obstructive pulmonary disease (COPD) patients. Rice bran oil (RBO), a natural anti-inflammatory and antioxidative agent, has been used for therapeutic purposes in several inflammatory diseases. This study aimed to investigate the anti-inflammatory and antioxidative effect of RBO on a cigarette smoke extract (CSE)-induced emphysema model in mice. The results indicated that CSE significantly induced airspace enlargement in mouse lung. Increased inflammatory cells, macrophage, and TNF-alpha levels in bronchoalveolar lavage fluid (BALF) were noticed in CSE-treated mice. RBO (low and high dose)-supplemented mice showed decreased total BALF inflammatory cell, macrophage, and neutrophil numbers and TNF-alpha levels (p < 0.05). Additionally, the administration of RBO decreased the mean linear alveolar intercept (MLI) in the CSE-treated group. Additionally, RBO treatment significantly increased the total antioxidant capacity in both mouse BALF and serum. However, RBO did not have an effect on the malondialdehyde (MDA) level. These findings suggested that RBO treatment ameliorates lung inflammation in a CSE-induced emphysema mice model through anti-inflammatory and antioxidant pathways. Therefore, the supplementation of RBO could be a new potential therapeutic to relieve the severity of COPD.

Persistence of emphysema following cessation of cigarette smoke exposure requires a susceptibility factor.

Chronic obstructive pulmonary disease (COPD) is caused by cigarette smoke (CS) exposure but can often be progressive even in former smokers. Exposure of mice to CS for 22 wk causes emphysema, but whether emphysema persists after cessation of CS exposure is not clear. The purpose of this study was to determine whether emphysema persists in mice following a recovery period of 22 wk and whether a susceptibility factor, such as deficiency in the Bcl-2-interacting killer (Bik), is required for this persistence. Therefore, bik+/+ and bik-/- mice at 6-10 wk of age were exposed to 250 mg/m3 total particulate matter of CS or filtered air (FA) for 3 or 22 wk and were kept in FA for an additional 22 wk. Lungs were lavaged to quantify inflammatory cells, and sections were stained with hematoxylin and eosin to assess severity of emphysema. Exposure to CS for 3 wk increased the number of inflammatory cells in bik-/- mice compared with bik+/+ mice but not at 22 wk of exposure. At 22 wk of CS exposure, extent of emphysema was similar in bik+/+ and bik-/- mice. However, when mice were exposed to CS over the first 22 wk and were kept in FA for an additional 22 wk, emphysema remained similar in bik+/+ mice but was enhanced in bik-/- mice. These findings link increased inflammation with persistent emphysematous changes even after smoking cessation and demonstrate that a preexisting susceptibility condition is required to sustain enhanced emphysema that was initiated by long-term CS exposure.NEW & NOTEWORTHY Exposure of mice to cigarette smoke (CS) for 22 wk causes emphysema, but whether emphysema persists after an additional period of 6 mo after cessation of CS exposure has not been reported. In addition, the role of preexisting susceptibility in enhancing the persistence of CS-induced emphysema after exposure to CS has stopped has not been shown. The present study shows that a preexisting susceptibility must be present to enhance CS-induced emphysema after cessation of CS exposure.

Alpha-7 Nicotinic Receptor Agonist Protects Mice Against Pulmonary Emphysema Induced by Elastase.

Pulmonary emphysema is a primary component of chronic obstructive pulmonary disease (COPD), a life-threatening disorder characterized by lung inflammation and restricted airflow, primarily resulting from the destruction of small airways and alveolar walls. Cumulative evidence suggests that nicotinic receptors, especially the α7 subtype (α7nAChR), is required for anti-inflammatory cholinergic responses. We postulated that the stimulation of α7nAChR could offer therapeutic benefits in the context of pulmonary emphysema. To investigate this, we assessed the potential protective effects of PNU-282987, a selective α7nAChR agonist, using an experimental emphysema model. Male mice (C57BL/6) were submitted to a nasal instillation of porcine pancreatic elastase (PPE) (50 µl, 0.667 IU) to induce emphysema. Treatment with PNU-282987 (2.0 mg/kg, ip) was performed pre and post-emphysema induction by measuring anti-inflammatory effects (inflammatory cells, cytokines) as well as anti-remodeling and anti-oxidant effects. Elastase-induced emphysema led to an increase in the number of α7nAChR-positive cells in the lungs. Notably, both groups treated with PNU-282987 (prior to and following emphysema induction) exhibited a significant decrease in the number of α7nAChR-positive cells. Furthermore, both groups treated with PNU-282987 demonstrated decreased levels of macrophages, IL-6, IL-1ß, collagen, and elastic fiber deposition. Additionally, both groups exhibited reduced STAT3 phosphorylation and lower levels of SOCS3. Of particular note, in the post-treated group, PNU-282987 successfully attenuated alveolar enlargement, decreased IL-17 and TNF-α levels, and reduced the recruitment of polymorphonuclear cells to the lung parenchyma. Significantly, it is worth noting that MLA, an antagonist of α7nAChR, counteracted the protective effects of PNU-282987 in relation to certain crucial inflammatory parameters. In summary, these findings unequivocally demonstrate the protective abilities of α7nAChR against elastase-induced emphysema, strongly supporting α7nAChR as a pivotal therapeutic target for ameliorating pulmonary emphysema.

Understanding the modulations of glycero-lysophospholipids in an elastase-induced murine emphysema model.

BACKGROUND: Increasing evidence indicates that bioactive lipid mediators are involved in chronic obstructive pulmonary disease (COPD) pathogenesis. Recently, glycero-lysophospholipids, such as lysophosphatidic acid (LysoPA) and lysophosphatidylserine (LysoPS), have been recognized as significant inflammation-related lipid mediators. However, their association with COPD remains unclear. METHODS: We used an elastase-induced murine emphysema model to analyze the levels of lysophospholipids and diacyl-phospholipids in the lungs. Additionally, we assessed the expression of LysoPS-related genes and published data on smokers. RESULTS: In the early phase of an elastase-induced murine emphysema model, the levels of LysoPS and its precursor (phosphatidylserine [PS]) were significantly reduced, without significant modulations in other glycero-lysophospholipids. Additionally, there was an upregulation in the expression of lysoPS receptors, specifically GPR34, observed in the lungs of a cigarette smoke-exposed mouse model and the alveolar macrophages of human smokers. Elastase stimulation induces GPR34 expression in a human macrophage cell line in vitro. CONCLUSIONS: Elastase-induced lung emphysema affects the LysoPS/PS-GPR34 axis, and cigarette smoking or elastase upregulates GPR34 expression in alveolar macrophages. This novel association may serve as a potential pharmacological target for COPD treatment.

Development of different degrees of elastase-induced emphysema in mice: a randomized controlled experimental study

Introduction: Mouse models of emphysema are important tools for testing different therapeutic strategies. The aim of this study was to develop a mouse model of emphysema induced by different doses of elastase in order to produce different degrees of severity. Methods: Thirty female mice (C57BL/6) were used in this study. Different doses of porcine pancreatic elastase were administered intratracheally once a week for four weeks, as follows: 0.1 U (n=8), 0.15 U (n=7), and 0.2 U (n=7). Control mice (n=8) received 50 microL of sterile saline solution intratracheally. Lung mechanics were analyzed by plethysmography. Mean linear intercept and volume fraction occupied by collagen and elastic fibers were determined. Results: An increase in lung resistance was observed with 0.2 U of elastase [median (P-25-P75): 2.02 (1.67; 2.34) cmH2O.s/mL], as well as a decrease in tidal volume and minute ventilation. Peak expiratory flow increased significantly in the groups treated with 0.15 U and 0.2 U of elastase. Mean linear intercept was higher with 0.15 U and 0.2 U of elastase, with destruction of alveolar walls [median (P-25-P75): 30.31 (26.65-43.13) microm and 49.49 (31.67-57.71) microm respectively]. The volume fraction occupied by collagen and elastic fibers was lower in the group receiving 0.2 U of elastase. Conclusion: Four intratracheal instillations of 0.2 U of elastase once a week induced changes in lung function and histology, producing an experimental model of severe pulmonary emphysema, whereas 0.15 U resulted in only histological changes.

O envolvimento do estresse oxidativo e nitrosativo em modelo de doença pulmonar obstrutiva crônica (DPOC) induzido por elastase / The involvement of oxidative and nitrosative stress in model of chronic obstructive pulmonary disease (COPD) induced by elastase

Este estudo buscou investigar o papel do estresse oxidativo e nitrosativo no enfisema pulmonar induzido por elastase. Foram utilizados camundongos machos C57BL/6 submetidos a dois modelos de indução do enfisema por elastase pancreática suína (PPE): intratraqueal (i.t.) e intranasal (i.n.). No modelo intratraqueal a PPE foi instilada nas doses de 0,05 U ou 0,05 U/camundongo para avaliação temporal do enfisema 7, 14 e 21 dias após instilação de PPE. Em outra etapa, o papel da iNOS foi avaliado através da sua inibição farmacológica por aminoguanidina (AMG) 1% na água de beber ou pela sua exclusão genética em camundongos deficientes em iNOS que tiveram o enfisema induzido por 0,5 U PPE i.t. após 21 dias. No modelo intranasal a dose de PPE foi 3 U/camundongo para avaliação temporal do enfisema (1, 7, 14 e 21 dias após PPE). O papel do estresse oxidativo e nitrosativo foi avaliado com diferentes tratamentos antioxidantes na água de beber: tempol, apocinina+alopurinol, n-acetilcisteína, vitamina C+E, e aminoguanidina durante os 21 dias de indução do enfisema. Os grupos controles foram submetidos à instilação de salina. Lavado broncoalveolar, imunoensaios, análises bioquímicas de estresse oxidativo e ensaios morfométricos foram realizados nos pulmões dos animais. O enfisema foi histologicamente alcançado em 21 dias após 0,5 U PPE i.t., evidenciado pelo aumento do diâmetro alveolar médio - Lm e da densidade de volume dos espaços alveolares - Vvair em comparação ao grupo controle. TNF-a foi aumentado em 7 e 14 dias após 0,05 U PPE comparados ao controle, concomitante com a redução de IL-10 nos mesmos períodos, comparados ao controle. O estresse oxidativo foi observado na fase inicial do enfisema, com aumento dos níveis de nitrito, TBARS e superóxido dismutase no grupo 7 dias após 0,5 U PPE (i.t.) quando comparados ao controle ao passo que no modelo intranasal as alterações típicas do estresse foram vistas no grupo 1 dia após 3 U de PPE. Atividade da glutationa ...

This study investigated the role of oxidative and nitrosative stress in elastase-induced pulmonary emphysema. C57BL/6 male mice were used submitted to two models of emphysema induced by porcine pancreatic elastase (PPE): intratracheal (i.t.) and intranasal (i.n.). In the intratracheal model PPE was instilled at doses of 0.05 U or 0.5 U/mouse (i.t.) to temporal evaluation of emphysema 7, 14 and 21 days post-PPE instillation. Others sets of experiments, the role of iNOS was evaluated through its pharmacology inhibition by 1% aminoguanidine (AMG) into the drinking water or bt iNOS genetic exclusion in iNOS-deficient mice which had induced emphysema by 0.5 U PPE i.t. after 21 days. In the intranasal model the PPE dose was 3 U/mouse to temporal evaluation of emphysema (1, 7, 14 and 21 days after PPE). The role of oxidative and nitrosative stress was evaluated using different antioxidant treatments into the drinking water: tempol, apocynin+allopurinol, N-acetylcysteine, vitamin C+E and aminoguanidine during the 21 days of emphysema induction. Control groups were instilled with saline. Bronchoalveolar lavage, immunoassays, biochemical analysis of oxidative stress and morphometric tests were performed in the lungs of animals. The emphysema was histologically reached 21 days after 0.5 U PPE, as evidenced by an increase in alveolar diameter - Lm and volume density of the alveolar spaces - Vvair compared to the control group. TNF-a was increased in 7 and 14 days after 0.5 U PPE compared to the control, concomitant with reduction of IL-10 at the same time-points compared to the control. Oxidative stress was observed in the early stages of emphysema, with increased levels of nitrite, TBARS and superoxide dismutase in group 7 days after 0.5 U PPE (i.t.) compared to the control, while in the intranasal model the typical stress alterations were seen in group 1 day after 3 U PPE. Glutathione peroxidase activity was increased in all PPE groups (i.t.). Exposure to 0.5 U PPE ...

Elastase-induced pulmonary emphysema: insights from experimental models

Several distinct stimuli can be used to reproduce histological and functional features of human emphysema, a leading cause of disability and death. Since cigarette smoke is the main cause of emphysema in humans, experimental researches have attempted to reproduce this situation. However, this is an expensive and cumbersome method of emphysema induction, and simpler, more efficacious alternatives have been sought. Among these approaches, elastolytic enzymes have been widely used to reproduce some characteristics of human cigarette smoke-induced disease, such as: augmentation of airspaces, inflammatory cell influx into the lungs, and systemic inflammation. Nevertheless, the use of elastase-induced emphysema models is still controversial, since the disease pathways involved in elastase induction may differ from those occurring in smoke-induced emphysema. This indicates that the choice of an emphysema model may impact the results of new therapies or drugs being tested. The aim of this review is to compare the mechanisms of disease induction in smoke and elastase emphysema models, to describe the differences among various elastase models, and to establish the advantages and disadvantages of elastase-induced emphysema models. More studies are required to shed light on the mechanisms of elastase-induced emphysema.

Diversos estímulos podem ser utilizados para reproduzir características histológicas e funcionais do enfisema humano, uma das principais causas de incapacidade e morte. Uma vez que a fumaça de cigarro é a principal causa de enfisema em humanos, estudos experimentais têm tentado reproduzir esta situação. No entanto, esse é um método dispendioso e complicado para a indução do enfisema e, alternativas mais simples e eficazes, têm sido pesquisadas. Entre essas abordagens, enzimas elastolíticas vêm sendo amplamente utilizadas para reproduzir algumas das características do enfisema humano, tais como: aumento dos espaços aéreos, influxo de células inflamatórias nos pulmões e inflamação sistêmica. Entretanto, o uso de modelos de enfisema induzido por elastase permanece controverso, uma vez que as vias de ação da doença envolvidas na indução com elastase podem diferir das que ocorrem no enfisema induzido pelo fumo. Isso indica que a escolha de um modelo de enfisema pode influenciar os resultados de novas terapias ou drogas a serem testadas. O objetivo desta revisão é comparar os mecanismos da indução da doença em modelos de enfisema por fumaça e elastase, descrever as diferenças entre os vários modelos de elastase e, estabelecer as vantagens e desvantagens dos modelos de enfisema por elastase. Mais estudos são necessários para elucidar os mecanismos relacionados ao enfisema induzido por elastase.

Respiratory mechanics do not always mirror pulmonary histological changes in emphysema

OBJECTIVE: To verify the accordance of functional and morphometric parameters during the development of emphysema. METHODS: BALB/c mice received a nasal drop of either papain or saline solution and were studied after 1, 3, 15, 28, and 40 days. Functional parameters, such as airway resistance, tissue damping, and tissue elastance, were analyzed. To evaluate the structural changes and possible mechanisms involved in this disease, we measured the mean linear intercept, the volume proportions of elastic and collagen fibers, the number of macrophages, the numbers of cells expressing metalloprotease 12 and 8-isoprostane in lung parenchyma. RESULTS: We only observed decreases in tissue elastance and tissue damping on the 28th day, with a concomitant increase in the mean linear intercept, indicating the presence of emphysema. However, only the mean linear intercept values remained increased until the 40th day. The volume proportion of collagen fibers was increased from the 15th day to the 40th day, whereas the volume proportion of elastic fibers was only increased on the 40th day. The number of macrophages increased beginning on the 1st day. The expression of metalloproteinase 12 was increased from the 3rd day until the 40th day. However, 8-isoprostane expression was only increased on the 1st and 3rd days. CONCLUSIONS: In this study, morphometric parameters were found to be more reliable for detecting the presence of emphysema than the functional parameters measured by respiratory mechanics. Further investigations are necessary to understand how the extracellular matrix remodeling observed in the lung parenchyma could be involved in this process.

Participação do L-NAME, da L-arginina e da N-acetilcisteína no enfisema pulmonar induzido por fumaça de cigarro em camundongos / Participation of L-NAME, L-arginine and N-acetylcysteine in pulmonary emphysema induced by cigarette smoke in mice

O óxido nítrico (NO) constitui um dos mais importantes mediadores intra e extracelulares e tem sido descrita sua participação tanto em processos biológicos como patológicos. Nosso objetivo foi verificar se o aumento ou a diminuição do óxido nítrico apresenta um efeito benéfico na proteção do tecido pulmonar no enfisema pulmonar induzido por fumaça de cigarro em camundongos. Para tanto, utilizamos o L-NAME (inibidor do NO), a L-arginina (substrato para a formação do NO) e os comparamos com a N-acetilcisteína (utilizada no tratamento da DPOC). Foram utilizados 65 camundongos C57BL/6 machos. Cinquenta animais foram divididos em grupos controle, fumaça de cigarro (FC), fumaça de cigarro + L-NAME (FC+LN), fumaça de cigarro + L-arginina (FC+LA), fumaça de cigarro + N-acetilcisteína (FC+NAC) (n=10, por grupo). Durante sessenta dias 40 animais foram expostos a 12 cigarros comerciais por dia, 3 vezes ao dia. Os grupos controle e FC foram submetidos à gavagens orogástricas com o veículo. Os grupos FC+LN, FC+LA, FC+NAC receberam gavagens diárias de L-NAME (60 mg/kg), L-arginina (120 mg/kg) ou NAC (200 mg/kg) respectivamente. Quinze animais (n=5, por grupo) foram expostos ao ar ambiente e tratados apenas com L-NAME, L-arginina e NAC. Realizamos a análise do perfil das células do lavado broncoalveolar após o sacrifício. O pulmão direito foi removido para as análises histológicas do alargamento dos espaços aéreos determinado pela medida do diâmetro alveolar médio (Lm) e da densidade de superfície (Sv) dos septos alveolares. Os pulmões esquerdos foram removidos e homogeneizados para a as análises da atividade enzimática (SOD, CAT e MPO) e do sistema glutationa (GSH/GSSG), para a análise dos valores de nitrito e da expressão de 4-HNE, MMP-12, NE, TIMP-1, TIMP-2. Nossos resultados apontam que o L-NAME tem uma ação voltada para a matriz extracelular (via protease-antiprotease), enquanto que a L-arginina possui uma ação voltada para os oxidantes, assim como a NAC...

Nitric oxide (NO) represents one of the most important intra and extracellular mediators/messengers. It takes part in both biologic and pathologic processes. This study aimed to verify NO role in pulmonary emphysema induced by cigarette smoke (CS) in mice. So L-NAME (LN) (a NO inhibitos) and L-arginine (LA) (a substract for NO formation) were analyzed and compared to N-acetylcysteine (NAC) (which is used in COPD treatment). A total of 65 C57BL/6 male mice were used. Fifty of them were divided in control, cigarette smoke (CS), cigarette smoke + L-NAME (CS+LN), cigarette smoke + L-arginin (CS+LA) and cigarette smoke + N-acetylcysteine (CS+NAC) groups (n=10, each group). Forty animals were exposed to 12 commercial cigarettes 3 times a day for sixty days. Control and CS groups were submitted to orogastric gavages with saline. FC+LN, FC+LA, FC+NAC groups received daily gavages with L-NAME (60 mg/kg), L-arginine (120 mg/kg) and NAC (200 mg/kg) respectively. Fifteen animals (n=5, each group)were exposed to ambient air and treated with L-NAME, L-arginine and NAC alone. Cell profile of bronchoalveolar lavage was analyzed and the right lung was removed in order to perform histological analysis of air space enlargement. This was done measuring median alveolar diameter (Lm) and total alveolar septal volume (Sv) of alveolar septa. Left lungs were removed and homogenized to perform enzymatic activity (SOD, CAT and MPO) and glutathione ratio analysis (GSH/GSSG). Besides it, nitrite values and the expression of 4-HNE, MMP-12, NE, TIMP-1 and TIMP-2 were also performed. L-arginine administration favored NO production and release, while L-NAME use inhibited. Briefly, we suggest L-NAME action to be directed to extracellular matrix (via proteinase-antiproteinase), while L-arginine action is directed to oxidants, similar to NAC. Our results showed that NAC acts raising glutathione levels which interfere directly with oxidants (via oxidant-antioxidant) while L-arginine acts...

O efeito da exposição a níveis ambientais de material particulado no desenvolvimento do enfisema pulmonar em camundongos / Effects of exposure to ambient level of particulate matter on the development of pulmonary emphysema

Neste estudo investigamos os efeitos da exposição crônica a níveis ambientais de material particulado (PM) no desenvolvimento de enfisema pulmonar. Camundongos receberam instilação de solução de papaína ou de salina e permaneceram em duas câmaras: uma que recebia ar ambiente e outra que possuía filtros em sua entrada de ar para PM. O grupo instilado com solução de papaína e exposto a níveis ambientais de PM apresentou aumento do intercepto linear médio, da densidade de fibras de colágeno e da expressão de isoprostano-8 no tecido pulmonar comparado ao grupo instilado com solução de papaína e que foi mantido na câmara com filtros (p=0,002; p<0,05 e p=0,002, respectivamente). A exposição ao PM piorou o enfisema e o estresse oxidativo pode ser um dos mecanismos envolvidos nesta resposta.

We investigated the effects of chronic exposure to ambient levels of particulate matter (PM) on the development of emphysema in mice. Mice received either papain or normal saline and were kept in two chambers: one received ambient air and the other had filters for PM. Lungs from papain-treated mice exposed to ambient air presented greater values of mean linear intercept than papain-treated mice kept in the chamber with filtered air (p=0.002). There was an increase in the density of collagen fibers and in the expression of 8-isoprostane in pulmonary tissue of papain-treated mice that remained in the chamber with ambient air (p<0.05 and p=0.002, respectively). Exposure to urban levels of PM worsens protease-induced emphysema and an increase in oxidative stress may be involved in this response.

Avaliação das alterações anatômicas cardíacas secundárias ao enfisema pulmonar: estudo experimental em ratos / Evaluation of the cardiac anatomical alterations secondary to the pulmonary emphysema: experimental study in rats

Analisamos as alterações cardíacas pós-indução de enfisema por instilação de papaína. Foram avaliados 75 ratos (grupos papaína e controle), sacrificados 30, 60, 90, 120 ou 180 dias pós-instilação. Foram realizados: gasometria do sangue arterial, avaliação morfométrica cardíaca e pulmonar. A papaína produziu destruição alveolar compatível com enfisema, sem repercussão nas trocas gasosas. Ventrículo direito e septo interventricular não apresentaram alterações significativas. Houve redução da área do ventrículo esquerdo, 90 dias pós-indução, e discreto espessamento de sua parede / Evaluation of the cardiac anatomical alterations secondary to the pulmonary emphysema: experimental study in rats. Cardiac alterations post-induction emphysema by instillation of papain were analyzed. Seventy-five rats (groups papain and control), sacrificed 30, 60, 90, 120 or 180 days post-instillation were evaluated. Arterial blood gases, cardiac and pulmonary morphometrical analysis were performed. Papain administration produced alveolar destruction compatible with emphysema, without arterial blood gases changes. Right ventricle and interventricular septum didn't show alterations. There were left ventricular area decrease (90 days post-induction) and light thickness increase of its wall...

Efeito da atividade física sobre a evolução do enfisema pulmonar: um estudo experimental em ratos Wistar / Effects of physical activity on the development pulmonar emphysema in rats: experimental study in rats Wistar

O propósito da presente investigação foi avaliar o papel da atividade física no desenvolvimento de enfisema induzido por papaina em ratos. Para tanto, ratos Wistar foram radomicamente divididos em quatro grupos (n = 10 para cada grupo) que receberam, respectivamente, infusão intra-traqueal de papaína (6 mg em 1 ml de NaCI 0,9 por cento) ou veículo e foram submetidos ou não ao protocolo de exercício em uma esteira ergométrica. Os ratos exercitaram-se a 13,3 m/min, 6 dias por semana, durante 9 semanas (o tempo de exercício foi aumentado gradualmente, de 10 a 35 min) / The purpose of the present study was to evaluate the role of exercise trainning on the development of papain-induced emphysema in rats. Wistar rats were randomly assigned to four groups (n = 10 for each group) that receiveid, respectively, intratracheal infusion of papain (6 mg in 1 ml NaCI 0,9 per cent) or vehicle and were submitted or not to a protocol of exercise on a treadmill...

Modelo experimental de enfisema pulmonar em ratos induzido por papaína / Papain-induced experimental pulmonary emphysema model in rats

Objetivo: Com a finalidade de estabelecer uma linha de pesquisa em cirurgia redutora de volume pulmonar, foi proposta a reprodução de um modelo experimental de enfisema em ratos através da instilação intratraqueal de papaína. Métodos: Foi feita a instilação orotraqueal de papaína (20mg/kg) dissolvida em 3,5ml/kg de solução fisiológica a 0,9 por cento. Após 40 dias da instilação, os animais foram submetidos a mecânica ventilatória, com medidas de elastância e resistência do sistema respiratório, e sacrificados com retirada dos pulmões. O tecido pulmonar dos animais foi analisado qualitativamente com coloração de hematoxilina-eosina e submetido à análise morfométrica com medida do diâmetro alveolar médio. O tecido pulmonar foi também submetido à coloração de resorcina-fucsina, para identificação de fibras elásticas, que foram quantificadas em septos alveolares através de análise digital de imagem. Resultados: A análise histológica dos pulmões dos animais submetidos à instilação de papaína mostrou um enfisema pan-acinar, com rotura de septos alveolares e hiperdistensão alveolar. A análise morfométrica revelou médias superiores de diâmetro alveolar médio nos pulmões dos animais submetidos à papaína (149,08mim e 100,56mim), em comparação com o grupo de solução fisiológica (64,08mim e 75,90mim). A quantificação de fibras elásticas de septos alveolares de animais tratados com papaína foi 70 por cento menor do que a de animais submetidos à solução fisiológica. A mecânica ventilatória não mostrou diferença na resistência do sistema respiratório de animais submetidos à papaína ou à solução fisiológica. Já no caso da elastância do sistema respiratório, esta foi menor nos animais do grupo com papaína, em comparação com o grupo com solução fisiológica, demonstrando comportamento funcional do grupo com papaína compatível com enfisema pulmonar, apresentando diminuição da capacidade de recolhimento elástico do tecido pulmonar. Conclusão: Foi possível reproduzir um modelo experimental de enfisema pulmonar pan-acinar em ratos, através da instilação de papaína pela árvore respiratória, com comprovação funcional e morfológica

Enfisema pulmonar experimental en la rata: fenómenos inflamatorios y progresión del daño pulmonar / Experimental pulmonary emphysema in the rat: inflammatory phenomena and progression of lung damage

Background: Although the hamster model of elastase induced emphysema is well characterized, the rat model has received less attention. Aim: To evaluate the effect of a single intratracheal elastase dose on lung pathological changes of Sprague-Dawley rats. Material and methods: Rats were injected with a single intratracheal elastase dose of 28 U/100 g body weight or saline and studied 7, 15, 30 and 365 days after injection. Results: Forty percent of rats died in the first 48 hours after injection, six were sacrificed at 7 days, 6 at 15 days, 7 at 30 days and 12 at 365 days. Progressive centroacinar emphysema was found from day 7 after elastase, with a persistent inflammatory reaction in the vicinity of emphysematous areas. Conclusions: Present findings differ from the panacinar emphysema described in the hamster using a similar elastase dose

Estudo da morfometria e expressão de AgNOR no epitélio do trato aerodigestivo superior e respiratório no fumo passivo em ratos / Study of morphometry and AgNOR expression in the epithelium of the upper aerodigestive tract and respiratory in secondhand smoke in rats

O conceito de “campo de cancerização” no trato aerodigestivo superior define que o epitélio das diversas regiões anatômicas deste trato se comporta como uma única cobertura de mucosa na resposta à agressão de um agente carcinogênico em comum. Foram utilizados 26 ratos machos Wistar adultos, divididos em 4 grupos: grupo I (controle) com oito ratos não expostos à fumaça do tabaco; grupos II, III e IV, constituídos de seis ratos, expostos à fumaça do cigarro durante quatro, oito e doze semanas, respectivamente. Formamos uma população de roedores fumantes passivos. Os animais desenvolveram enfisema pulmonar tempo dependente (p=0,0002), utilizado como parâmetro do grau de intoxicação a que foram submetidos. Analisamos todo o epitélio do trato aerodigestivo superior e respiratório dos ratos: cavidade oral, orofaringe, esôfago, laringe e brônquio. Realizamos a morfometria da espessura do epitélioç, da paraqueratina e da queratina e a expressão de AgNOR como índice de atividade e de proliferação celular. O modelo experimental de fumante passivo de intoxicação no rato foi eficiente; os carcinógenos do cigarro inalados passivamente agridem as mucosas da cavidade oral, da orofaringe, do esôfago, da laringe e do brônquio, em um mesmo instante de tempo; o modelo experimental aponta as células-alvo a serem estudadas, e mostra a necessidade de estudos com marcadores do ciclo celular, de apoptose celular e da glutationa (oxidante), para avaliar a teoria do “campo de cancerização”. Demonstramos experimentalmente como se comporta o epitélio do trato aerodigestivo superior e respiratório do rato em resposta à agressão pelo tabaco. O modelo experimental fornece substrato para o estudo do “campo de cancerização”