Treatment of stable COPD: antioxidants

Association of the ACE2-Angiotensin1-7-Mas axis with lung damage caused by cigarette smoke exposure: a systematic review

Through the Mas receptor, angiotensin-(1-7) [Ang-(1-7)] has been shown to have a key role in the development of lung inflammation. This systematic review (SR) sought to identify the relationship between lung damage brought on by exposure to cigarette smoke (CS) and the ACE2-Ang-(1-7)-Mas pathway. In this investigation, relevant keywords were used to search PubMed (MEDLINE), Scopus (Elsevier), and Institute for Scientific Information (ISI) Web of Science up to December 2022. Nine studies were chosen because they satisfied the inclusion/exclusion criteria. The majority of research concluded that exposure to CS increased the risk of lung damage. Smoking cigarettes is the main cause of COPD because it causes massive amounts of reactive oxygen and nitrogen species to enter the lungs, which stimulate the production of inflammatory cytokines like IL-1 β, IL-6, and TNF-α, as well as the invasion of inflammatory cells like neutrophils and macrophages. These findings support the renin-angiotensin system's (RAS) involvement in the pathophysiology of smoking-induced damage. Additionally, via stimulating pro-inflammatory mediators, aberrant RAS activity has been linked to lung damage. Lung inflammation's etiology has been shown to be significantly influenced by the protective known RAS arm ACE2-Ang-(1-7)-Mas. In conclusion, these are important for informing policymakers to pass legislation limiting the use of smoking and other tobacco to prevent their harmful effects.

The Effect of Ocimum basilicum L. and Its Main Ingredients on Respiratory Disorders: An Experimental, Preclinical, and Clinical Review

Ocimum basilicum L. (O. basilicum) and its constituents show anti-inflammatory, immunomodulatory, and antioxidant effects. The plant has been mainly utilized in traditional medicine for the treatment of respiratory disorders. In the present article, effects of O. basilicum and its main constituents on respiratory disorders, assessed by experimental and clinical studies, were reviewed. Relevant studies were searched in PubMed, Science Direct, Medline, and Embase databases using relevant keywords including “Ocimum basilicum,” “basilicums,” “linalool,” “respiratory disease,” “asthma,” “obstructive pulmonary disease,” “bronchodilatory,” “bronchitis,” “lung cancer,” and “pulmonary fibrosis,” and other related keywords.The reviewed articles showed both relieving and preventing effects of the plant and its ingredients on obstructive pulmonary diseases such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory disorders such as bronchitis, aspergillosis tuberculosis, and lung cancer. The results of the reviewed articles suggest the therapeutic potential of O. basilicum and its constituent, linalool, on respiratory disorders.

Traditional Uses, Nutritional and Pharmacological Potentials of Clerodendrum volubile

Clerodendrum volubile is an underutilized leafy vegetable consumed in some parts of Nigeria. The interest in C. volubile has continued to increase due to its multipurpose values, including traditional uses, nutritional properties, and some therapeutic potentials; however, the pharmacological prospects of the plant are yet to be fully explored. Therefore, in the present review, different databases such as PubMed, Scopus, Web of Science, Google Scholar, etc. were explored to retrieve publications used to write this review. The pharmacological potentials of C. volubile, such as anticancer, antioxidant, antiviral, antimicrobial, anti-inflammatory, hepatoprotective, antidiabetic, and anti-hypertensive properties, were highlighted. The toxicological potential of the plant is also discussed. Proposed mechanisms that underline its biological activities include modulation of redox homeostasis, leading to decreased oxidative stress; down-regulation of matrix metalloproteinase-9 (MMP-9) expression; inhibition of key enzymes implicated in diabetes mellitus, hypertension, and neurological diseases; and inhibition of oxidative burst and inflammatory cytokines. Furthermore, the prospect of endophytes from C. volubile as a bioresource to produce novel therapeutic agents, as well as the development of nanotherapeutics from the plant extracts and its phytoconstituents, are discussed. In conclusion, C. volubile possesses an enormous number of possible pharmacological properties and therapeutic potentials waiting to be explored.

Nutritional value, micronutrient and antioxidant capacity of some green leafy vegetables commonly used by southern coastal people of Bangladesh

Southern coastal people of Bangladesh are highly vulnerable to food insecurity and malnutrition due to coastal flooding, deforestation and increased soil salinity. A number of green leafy vegetables are found in the southern coastal belt being traditionally eaten as daily basis by local people. But they are unaware of nutritional and medicinal use of these vegetables. To contribute to their wider utilization, five common vegetables namely Hibiscus sabdariffa, Trianthema portulacastrum, Diplazium esculentum, Heliotropium indicum L. and Hygrophila auriculata were selected for analysis of nutritional proximate, micronutrients and antioxidant potential. Nutritional properties were analyzed in terms of moisture, pH, protein, lipid, ash, fibre, minerals and carbohydrate. Total flavonoid, tannin and antioxidant capacity were evaluated using established protocols. The results demonstrated that collected plants are rich in carbohydrate, fibre, proteins, moisture and ash content but low in lipid content. The mineral elements were high with remarkable amount of Na (19.9–21.5 mg/gm), K (7.9–13.5 mg/gm) and P (1.0–1.8 mg/gm). All the samples were found to have considerable amount of flavonoid (90.6–144.5 mg QE/gm) and tannin content (26.8–57.2 mg GAE/gm). The IC₅₀ value of DPPH and superoxide radical scavenging was the lowest for H. indicum (37.1 and 83.4 μg/ml, respectively) whereas T. portulacastrum possessed high reducing power (IC₅₀ 53.7 μg/ml). Among the five investigated species, T. portulacastrum and H. indicum were found to have good nutritional and antioxidant properties, thus can be promoted as a significant source of nutritional and antioxidant food supplements.

Activity of Antioxidant Enzymes in the Tumor and Adjacent Noncancerous Tissues of Non-Small-Cell Lung Cancer

Lung tissue is directly exposed to high oxygen pressure, as well as increased endogenous and exogenous oxidative stress. Reactive oxygen species (ROS) generated in these conditions play an important role in the initiation and promotion of neoplastic growth. In response to oxidative stress, the antioxidant activity increases and minimizes ROS-induced injury in experimental systems. The aim of the present study was to evaluate the activity of antioxidant enzymes, such as superoxide dismutase (SOD; isoforms: Cu/ZnSOD and MnSOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST), along with the concentration of malondialdehyde (MDA) in tumor and adjacent noncancerous tissues of two histological types of NSCLC, i.e., adenocarcinoma and squamous cell carcinoma, collected from 53 individuals with surgically resectable NSCLC. MDA concentration was similar in tumors compared with adjacent noncancerous tissues. Tumor cells had low MnSOD activity, usually low Cu/ZnSOD activity, and almost always low catalase activity compared with those of the corresponding tumor-free lung tissues. Activities of GSH-related enzymes were significantly higher in tumor tissues, irrespective of the histological type of cancer. This pattern of antioxidant enzymes activity could possibly be the way by which tumor cells protect themselves against increased oxidative stress.

Crocin attenuates cigarette smoke-induced lung injury and cardiac dysfunction by anti-oxidative effects: the role of Nrf2 antioxidant system in preventing oxidative stress

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has been emerging as a great health problem in world. Cigarette smoke is known to cause oxidative stress and deplete glutathione (GSH) levels. Nuclear erythroid-related factor 2 (Nrf2) is involved in transcriptional regulation of glutamate-cysteine ligase catalytic subunit (GCLc). Antioxidant compounds may be of therapeutic value in monitoring disease progression. Crocin demonstrates antioxidant and anti-inflammatory functions. The aim of this study was to investigate the protective role of crocin against CSE-mediated oxidative stress, inflammatory process, Nrf2 modifications and impairment of cardiac function in rats with COPD.

METHODS

Eighty rats were divided into four groups: Control, Cigarette smoke exposure (CSE), Crocin, Crocin+CS. Each group was divided into the two parts: 1) to evaluate lung inflammatory and oxidative process, 2) to evaluate the effect of Cigarette smoke induced-lung injuries on cardiac electrocardiogram (such as heart rate and QRS complex) and hemodynamic parameters (such as perfusion pressure and left ventricular developed pressure).

RESULTS

CSE rats showed a significant increase in cotinine concentration (17.24 ng/ml), and inflammatory parameters and a decrease in PO2 (75.87 mmHg) and expression of PKC (0.86 fold), PI3K (0.79 fold), MAPK (0.87 fold), Nrf2 (0.8 fold) and GCLc (0.75 fold) genes, antioxidant activity, and finally cardiac abnormalities in electrocardiogram and hemodynamic parameters. Co-treatment whit crocin could restore all these values to normal levels.

CONCLUSIONS

CS induced-COPD in rat model provides evidence that chronic CS exposure leads to lung injury and mediated cardiac dysfunction. Crocin co-treatment by modulating of Nrf2 pathway protected lung injury caused by COPD and its related cardiac dysfunction. In this study, we showed the importance of Nrf2 activators as a therapeutic target for the development of novel therapy for lung oxidative injuries.

Pentagalloyl glucose increases elastin deposition, decreases reactive oxygen species and matrix metalloproteinase activity in pulmonary fibroblasts under inflammatory conditions

Emphysema is characterized by degradation of lung alveoli that leads to poor airflow in lungs. Irreversible elastic fiber degradation by matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) activity leads to loss of elasticity and drives the progression of this disease. We investigated if a polyphenol, pentagalloyl glucose (PGG) can increase elastin production in pulmonary fibroblasts. We also studied the effect of PGG treatment in reducing MMP activity and ROS levels in cells. We exposed rat pulmonary fibroblasts to two different types of inflammatory environments i.e., tumor necrosis factor-α (TNF-α) and cigarette smoke extract (CSE) to mimic the disease. Parameters like lysyl oxidase (LOX) and elastin gene expression, MMP-9 activity in the medium, lysyl oxidase (LOX) activity and ROS levels were studied to assess the effect of PGG on pulmonary fibroblasts. CSE inhibited lysyl oxidase (LOX) enzyme activity that resulted in a decreased elastin formation. Similarly, TNF-α treated cells showed less elastin in the cell layers. Both these agents caused increase in MMP activity and ROS levels in cells. However, when supplemented with PGG treatment along with these two inflammatory agents, we saw a significant increase in elastin deposition, reduction in both MMP activity and ROS levels. Thus PGG, which has anti-inflammatory, anti-oxidant properties coupled with its ability to aid in elastic fiber formation, can be a multifunctional drug to potentially arrest the progression of emphysema.

Predictors' factors of nutritional status of male chronic obstructive pulmonary disease patients

Chronic obstructive pulmonary disease (COPD) is a systemic disease that leads to weight loss and muscle dysfunction resulting in an increase in mortality. This study aimed to determine the prevalence rate of malnutrition and nutritional status and also factors associated with nutritional status. A total of 149 subjects were involved in the cross-sectional study. The study was conducted at two medical centers in Kuala Lumpur, Malaysia. The results of the study showed that malnutrition was more prevalent (52.4%) in the subjects with severe stages of COPD as compared to mild and moderate COPD stages (26.2%) (P < 0.05). Fat-free mass depletion as assessed using fat-free mass index (FFMI) affected 41.9% of the subjects. Plasma vitamin A, peak expiratory flow (PEF), and handgrip were the predictors for body mass index (BMI) (R(2) = 0.190, P < 0.001). Plasma vitamin A and force expiratory volume in one second (FEV(1)) were the predictors of FFMI (R(2) = 0.082, P = 0.007). BMI was the predictor of respiratory factors, that is, FEV(1)% predicted (R(2) = 0.052, P = 0.011). It can be concluded that there is a need to identify malnourished COPD patients for an appropriate nutrition intervention.

Current perspectives of oxidative stress and its measurement in chronic obstructive pulmonary disease

Cigarette smoking, the principal aetiology of chronic obstructive pulmonary disease (COPD) in the developed countries, delivers and generates oxidative stress within the lungs. This imbalance of oxidant burden and antioxidant capacity has been implicated as an important contributing factor in the pathogenesis of COPD. Oxidative processes and free radical generation orchestrate the inflammation, mucous gland hyperplasia, and apoptosis of the airway lining epithelium which characterises COPD. Pivotal oxidative stress/pro-inflammatory molecules include reactive oxygen species such as the superoxides and hydroxyl radicals, pro-inflammatory cytokines including leukotrienes, interleukins, tumour necrosis factor alpha, and activated transcriptional factors such as nuclear factor kappa-B and activator protein 1. The lung has a large reserve of antioxidant agents such as glutathione and superoxide dismutase to counter oxidants. However, smoking also causes the depletion of antioxidants, which further contributes to oxidative tissue damage. The downregulation of antioxidant pathways has also been associated with acute exacerbations of COPD. The delivery of redox-protective antioxidants may have preventative and therapeutic potential of COPD. Although these observations have yet to translate into common clinical practice, preliminary clinical trials and studies of animal models have shown that interventions to counter this oxidative imbalance may have potential to better manage COPD. There is, thus, a need for the ability to monitor such interventions and exhaled breath condensate is rapidly emerging as a novel and noninvasive approach in the sampling of airway epithelial lining fluid which could be used for repeated analysis of oxidative stress and inflammation in the lungs.

Superoxide dismutase-loaded PLGA nanoparticles protect cultured human neurons under oxidative stress

The objective of our study was to investigate the neuroprotective efficacy of superoxide dismutase (SOD), loaded in poly(D,L-lactide co-glycolide; PLGA) nanoparticles (NPs), in cultured human neurons challenged with hydrogen peroxide (H(2)O(2))-induced oxidative stress. We hypothesized that the protected and sustained intracellular delivery of SOD encapsulated in NPs would demonstrate better neuroprotection from oxidative stress than either SOD or pegylated SOD (PEG-SOD) in solution. SOD-NPs (approximately 81 +/- 4 nm in diameter, 0.9% w/w SOD loading) released the encapsulated SOD in an active form with 8.2% cumulative release during the first 24 h, followed by a slower release thereafter. The results demonstrated that PLGA-NPs are compatible with human neurons, and the neuroprotective effect of SOD-NPs is dose-dependent, with efficacy seen at >100 U SOD, and less significant effects at lower doses. Neither SOD (25-200 U) nor PEG-SOD (100 U) in solution demonstrated the neuroprotective effect under similar conditions. The neuroprotective effect of SOD-NPs was seen up to 6 h after H(2)O(2)-induced oxidative stress, but the effect diminished thereafter. Confocal microscopic studies demonstrated better intracellular neuronal uptake of the encapsulated model protein (fluorescein isothiocyanate-labeled BSA) than the protein in solution. Thus, the mechanism of efficacy of SOD-NPs appears to be due to the stability of the encapsulated enzyme and its better neuronal uptake after encapsulation.

Black tea prevents cigarette smoke-induced apoptosis and lung damage

Background

Cigarette smoking is a major cause of lung damage. One prominent deleterious effect of cigarette smoke is oxidative stress. Oxidative stress may lead to apoptosis and lung injury. Since black tea has antioxidant property, we examined the preventive effect of black tea on cigarette smoke-induced oxidative damage, apoptosis and lung injury in a guinea pig model.

Methods

Guinea pigs were subjected to cigarette smoke exposure from five cigarettes (two puffs/cigarette) per guinea pig/day for seven days and given water or black tea to drink. Sham control guinea pigs were exposed to air instead of cigarette smoke. Lung damage, as evidenced by inflammation and increased air space, was assessed by histology and morphometric analysis. Protein oxidation was measured through oxyblot analysis of dinitrophenylhydrazone derivatives of the protein carbonyls of the oxidized proteins. Apoptosis was evidenced by the fragmentation of DNA using TUNEL assay, activation of caspase 3, phosphorylation of p53 as well as over-expression of Bax by immunoblot analyses.

Results

Cigarette smoke exposure to a guinea pig model caused lung damage. It appeared that oxidative stress was the initial event, which was followed by inflammation, apoptosis and lung injury. All these pathophysiological events were prevented when the cigarette smoke-exposed guinea pigs were given black tea infusion as the drink instead of water.

Conclusion

Cigarette smoke exposure to a guinea pig model causes oxidative damage, inflammation, apoptosis and lung injury that are prevented by supplementation of black tea.