Protective effects of ascorbic acid and calcitriol combination on airway remodelling in ovalbumin-induced chronic asthma

Antioxidant supplementation during treatment of outpatient dogs with parvovirus enteritis ameliorates oxidative stress and attenuates intestinal injury: A randomized controlled trial

A prospective randomized controlled clinical study was conducted to determine whether antioxidant supplementation as an adjunct therapy alters hemogram, oxidative stress, serum intestinal fatty acid binding protein-2 (IFABP-2) level, fecal viral load, clinical score (CS) and survivability in outpatient canine parvovirus enteritis (CPVE) dogs. The dogs with CPVE were randomized to one of the five treatment groups: supportive treatment (ST) alone, ST with N-acetylcysteine (ST+NAC), resveratrol (ST+RES), coenzyme Q10 (ST+CoQ10) or ascorbic acid (ST+AA). The primary outcome measures were reduction of CS and fecal HA titre, and enhancement of survivability. Secondary outcome measures were reduction of oxidative stress indices and IFABP-2 level from day 0 to day 7. The mean CS and HA titre were significantly (P < 0.05) decreased from day 0 to 7 in ST and all antioxidant groups. The supplementations of NAC, RES and AA along with ST markedly (P < 0.05) reduced the concentrations of malondialdehyde, nitric oxide and IFABP-2 on day 7 as compared to ST alone. Additionally, NAC and RES supplementations markedly (P < 0.05) improved the total leukocyte count and neutrophil count in CPVE-affected dogs. NAC and RES could serve as better antioxidants for the amelioration of oxidative stress in CPVE but, the antioxidants did not confer any additional benefits in reduction of CS, fecal HA tire, or survivability when compared with ST alone.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

The effects of vitamin C on respiratory, allergic and immunological diseases: an experimental and clinical-based review

Vitamin C is used in modern medicine supplements for treatment of various disorders associated with oxidative stress, inflammation and immune dysregulation. In this review article, experimental and clinical results regarding the effects of vitamin C on respiratory immunologic, and allergic diseases are reviewed. Various databases and appropriate keywords are used to search the effect of vitamin C on respiratory diseases until the end of May 2022. Books, theses and articles were included. These studies assessed the effects of vitamin C on respiratory disorders including asthma, chronic obstructive pulmonary disease (COPD), lung infection and lung cancer. Vitamin C showed relaxant effect on tracheal smooth muscle via various mechanisms. The preventive effects of vitamin C were mediated by antioxidant, immunomodulatory and anti-inflammatory mechanisms in the experimental animal models of different respiratory diseases. Some clinical studies also indicated the effect of vitamin C on lung cancer and lung infections. Therefore, vitamin C could be used a preventive and/or relieving therapy in respiratory diseases.

-Sitosterol inhibits ovalbumin-induced asthma-related inflammation by regulating dendritic cells

AIM

To investigate the effects of β-sitosterol (B-SIT) and the underlying mechanisms of action in an ovalbumin-induced rat model of asthma.

METHODS

The pathological and morphological changes in lung and tracheal tissues were observed by H&E, PAS, and Masson's staining. The levels of IgE, TNF-α, and IFN-γ in the bronchoalveolar lavage fluid (BALF) and those of IL-6, TGF-β1, and IL-10 in serum were measured by ELISA. The relative expression levels of IL-5, IL-13, IL-21, CD11c, CD80, and CD86 mRNA in lung tissue were examined by RT-qPCR. Flow cytometry was performed to assess the levels of immune cells, including macrophages and neutrophils in spleen tissue and Th cells, Tc cells, NK cells, and DCs in peripheral blood. The protein expression levels of CD68, MPO, CD11c, CD80, and CD86 were detected by western blotting or immunohistochemistry.

RESULTS

B-SIT improved the injury in OVA-induced pathology, decreased the levels of inflammatory factors of IgE, TNF-α, IL-6, TGF-β1, IL-5, IL-13, and IL-21 and increased the levels of IFN-γ and IL-10. In addition, B-SIT decreased the number of macrophages and neutrophils and the relative expression levels of CD68 and MPO in the spleen. Moreover, B-SIT increased the number of Th cells, Tc cells, NK cells, and DCs in peripheral blood and upregulated the levels of CD11c, CD80, and CD86 in the spleen and lung.

CONCLUSION

B-SIT improved symptoms in a rat model of asthma likely via the inhibition of inflammation by regulating dendritic cells.

Syndecan-1 Amplifies Ovalbumin-Induced Airway Remodeling by Strengthening TGFβ1/Smad3 Action

Syndecan-1 (SDC-1) is a transmembrane proteoglycan of heparin sulfate that can regulate various cell signal transduction pathways in the airway epithelial cells and fibroblasts. Airway epithelial cells and human bronchial fibroblasts are crucial in airway remodeling. However, the importance of SDC-1 in the remodeling of asthmatic airways has not been confirmed yet. The present study was the first to uncover SDC-1 overexpression in the airways of humans and mice with chronic asthma. This study also validated that an increase in SDC-1 expression was correlated with TGFβ1/Smad3-mediated airway remodeling in vivo and in vitro. A small interfering RNA targeting SDC-1 (SDC-1 siRNA) and homo-SDC-1 in pcDNA3.1 (pc-SDC-1) was designed to assess the effects of SDC-1 on TGFβ1/Smad3-mediated collagen I expression in Beas-2B (airway epithelial cells) and HLF-1 (fibroblasts) cells. Downregulation of the SDC-1 expression by SDC-1 siRNA remarkably attenuated TGFβ1-induced p-Smad3 levels and collagen I expression in Beas-2B and HLF-1 cells. In addition, SDC-1 overexpression with pc-SDC-1 enhanced TGFβ1-induced p-Smad3 level and collagen I expression in Beas-2B and HLF-1 cells. Furthermore, the levels of p-Smad3 and collagen I induced by TGFβ1 were slightly increased after the addition of the recombinant human SDC-1 protein to Beas-2B and HLF-1 cells. These findings in vitro were also confirmed in a mouse model. A short hairpin RNA targeting SDC-1 (SDC-1 shRNA) to interfere with SDC-1 expression considerably reduced the levels of p-Smad3 and remodeling protein (α-SMA, collagen I) in the airways induced by ovalbumin (OVA). Similarly, OVA-induced p-Smad3 and remodeling protein levels in airways increased after mice inhalation with the recombinant mouse SDC-1 protein. These results suggested that SDC-1 of airway epithelial cells and fibroblasts plays a key role in the development of airway remodeling in OVA-induced chronic asthma.

Oxidative Stress Promotes Corticosteroid Insensitivity in Asthma and COPD

Corticosteroid insensitivity is a key characteristic of patients with severe asthma and COPD. These individuals experience greater pulmonary oxidative stress and inflammation, which contribute to diminished lung function and frequent exacerbations despite the often and prolonged use of systemic, high dose corticosteroids. Reactive oxygen and nitrogen species (RONS) promote corticosteroid insensitivity by disrupting glucocorticoid receptor (GR) signaling, leading to the sustained activation of pro-inflammatory pathways in immune and airway structural cells. Studies in asthma and COPD models suggest that corticosteroids need a balanced redox environment to be effective and to reduce airway inflammation. In this review, we discuss how oxidative stress contributes to corticosteroid insensitivity and the importance of optimizing endogenous antioxidant responses to enhance corticosteroid sensitivity. Future studies should aim to identify how antioxidant-based therapies can complement corticosteroids to reduce the need for prolonged high dose regimens in patients with severe asthma and COPD.

Nephroprotection through Modifying the Apoptotic TNF-α/ERK1/2/Bax Signaling Pathway and Oxidative Stress by Long-term Sodium Hydrosulfide Administration in Ovalbumin-induced Chronic Asthma

Asthma is one of the most common respiratory diseases in the world. Nevertheless, it is reported that inflammation induced by asthma is not only restricted to the lung and may cause damaging effects on remote organs. Therefore, this study was designed to investigate the beneficial effects of long-term sodium hydrosulfide (NaHS) administration on lung inflammation and oxidative stress markers to protect the kidney during chronic asthma. BALB/c mice were divided into three groups (n = 5-7): control, asthma and NaHS. Except the control group, sensitization and challenge were performed with ovalbumin. The NaHS group intraperitoneally received 14 μmol/kg NaHS 30 min before each challenge. 24 h after the last challenge, samples of bronchoalveolar lavage fluid (BALF), plasma, lung and kidney tissues were collected. NaHS administration significantly decreased total white blood cell count, percentages of eosinophils, neutrophils and macrophages and increased percentage of lymphocytes. Administration of NaHS considerably decreased the levels of BALF interleukin-13, plasma tumor necrosis factor-alpha (TNF-α), lung malondialdehyde (MDA) and lung phosphorylated nuclear factor-kappa B (p-NF-κB) expression and scores of peribronchial inflammatory cell infiltration, goblet cell hyperplasia and subepithelial fibrosis and increased the activity of lung superoxide dismutase (SOD). The MDA levels and expressions of p-ERK1/2 and Bax were decreased and SOD activity and expressions of Bcl-2 and p-Akt were significantly increased in kidney tissues by NaHS administration. Administration of NaHS decreased renal oxidative stress indices and reduced apoptosis by the inhibition of TNF-α/ERK1/2/Bax. Therefore, H₂S may have an essential role in renal protection during asthma.

An overview of high-mobility group box 1, a potent pro-inflammatory cytokine in asthma

High-mobility group box 1 (HMGB1), also called amphoterin, HMG1 and p30, is a highly conserved protein between different species that has various functions in nucleus such as stabilization of nucleosome formation, facilitation of deoxyribonucleic acid (DNA) bending and increasing the DNA transcription, replication and repair. It has also been indicated that HMGB1 acts as a potent pro-inflammatory cytokine with increasing concentrations in acute and chronic inflammatory diseases. Asthma is a common chronic respiratory disease associated with high morbidity and mortality rates. One central characteristic in its pathogenesis is airway inflammation. Considering the inflammatory role of HMGB1 and importance of inflammation in asthma pathogenesis, a better understanding of this protein is vital. This review describes the structure, cell surface receptors, signaling pathways and intracellular and extracellular functions of HMGB1, but also focuses on its inflammatory role in asthma. Moreover, this manuscript reviews experimental and clinical studies that investigated the pathologic role of HMGB1.