Cycloastragenol alleviates airway inflammation in asthmatic mice by inhibiting autophagy

Using UPLC-LTQ-Orbitrap-MS and HPLC-CAD to Identify Impurities in Cycloastragenol, Which Is a Pre-Clinical Candidate for COPD

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease that has become the third leading cause of death worldwide. Cycloastragenol (CAG), which is the genuine sapogenin of the main active triterpene saponins in Astragali radix, is a bioavailable pre-clinical candidate for chronic obstructive pulmonary disease (COPD), and it was investigated in our previous study. In order to progress medical research, it was first efficiently produced on a 2.5-kg scale via Smith degradation from astragaloside IV (AS-IV). Simultaneously, since the impurity profiling of a drug is critical for performing CMC documentation in pre-clinical development, a study on impurities was carried out. As these structures do not contain chromophores and possess weak UV absorption characteristics, HPLC-CAD and UPLC-LTQ-Orbitrap-MS were employed to carry out the quality control of the impurities. Then, column chromatography (CC), preparative thin-layer chromatography (PTLC), and crystallization led to the identification of 15 impurities from CAG API. Among these impurities, compounds 1, 4, 9, 10, 14, and 15 were elucidated via spectroscopic analysis, and 2-3, 5-8, and 11-13 were putatively identified. Interestingly, the new compounds 9 and 14 were rare 10, 19-secocycloartane triterpenoids that displayed certain anti-inflammatory activities against LPS-induced lymphocyte cells and CSE-induced MLE-12 cells. Additionally, a plausible structural transformation pathway of the degradation compounds from CAG or AS IV was proposed. The information obtained will provide a material basis to carry out the quality control and clinical safety assurance of API and related prescriptions. Reasonable guidance will also be provided regarding the compounds with weak UV absorption characteristics.

PLDδ, auxin, and H2O2 mediated the allelopathic effect of cycloastragenol on root growth in Arabidopsis

Cycloastragenol (CAG) is a tetra-cyclic triterpenoid allelochemical. It has been widely studied in animals but rarely in plants. Here, we reported that a model allelochemical CAG inhibited primary root elongation of Arabidopsis by reducing the sizes of both the meristem and elongation zones. Phospholipase Dδ(PLDδ), hydrogen peroxide (H₂O₂), and auxin affected this process. After treatment with CAG, the expression of PLDδ and the activity of the Phospholipase D(PLD) enzyme increased in WT. Mutants analysis demonstrated that PLDδ negatively regulated the primary root elongation by CAG treatment. CAG treatment stimulated the accumulation of H₂O₂ in roots. The production of H₂O₂ was derived from cell wall peroxidase. Mutants analysis showed that PLDδ positively regulated the production of H₂O₂ by CAG treatment. CAG also decreased auxin content in the root tip by affecting the expression of auxin synthesis-related genes. PLDδ was involved in the auxin reduction mediated by CAG, but H₂O₂ did not participate in this process. In conclusion, PLDδ, auxin, and H₂O₂ mediated the inhibition of primary root growth by CAG in Arabidopsis.

Mechanistic study of salidroside on ovalbumin-induced asthmatic model mice based on untargeted metabolomics analysis

Salidroside (SAL) is a natural component derived from Rhodiola rosea and is well known for its wide range of biological activities such as its anti-inflammatory and anti-oxidative properties. However, its effects and mechanisms of action related to asthma have not been well explored yet. Recent studies have found that changes in host metabolism are closely related to the progression of asthma. Many natural components can ameliorate asthma by affecting host metabolism. The use of untargeted metabolomics can allow for a better understanding of the metabolic regulatory mechanisms of herbs on asthma. This study aimed to demonstrate the anti-asthmatic effects and metabolic regulatory mechanisms of SAL. In this study, the therapeutic effects of SAL on asthmatic mice were tested at first. Secondly, the effects of SAL on the airway inflammatory reaction, oxidative stress, and airway remodeling were investigated. Finally, untargeted metabolomics analysis was used to explore the influence of SAL on lung metabolites. The results showed that SAL had a significant therapeutic effect on asthmatic model mice. Moreover, SAL treatment lowered interleukin (IL)-4, IL-5, and IL-13 levels but elevated interferon gamma (IFN-γ) and IL-10 levels in bronchoalveolar lavage fluid (BALF). Additionally, it also increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and decreased methane dicarboxylic aldehyde (MDA) levels in the lungs. Besides, SAL-treated mice showed decreased expression of smooth muscle actin (α-SMA), matrix metallopeptidase 2 (MMP2), matrix metallopeptidase 9 (MMP9), and transforming growth factor-beta 1 (TGF-β1) in the lung. Untargeted metabolomics analysis showed 31 metabolites in the lungs that were influenced by SAL. These metabolites were related to pyrimidine metabolism, steroid hormone biosynthesis, and tricarboxylic acid (TCA) cycle. In conclusion, SAL treatment can reduce the inflammatory response, oxidative stress, and airway remodeling in asthmatic model mice. The mechanism of SAL in the treatment of asthma may be related to the regulation of pyrimidine metabolism, steroid hormone biosynthesis, and the TCA cycle. Further studies can be carried out using targeted metabolomics and in vitro models to deeply elucidate the anti-inflammatory and anti-oxidative mechanisms of SAL on asthma based on regulating metabolism.

New insights into autophagy in inflammatory subtypes of asthma

Asthma is a heterogeneous airway disease characterized by airway inflammation and hyperresponsiveness. Autophagy is a self-degrading process that helps maintain cellular homeostasis. Dysregulation of autophagy is involved in the pathogenesis of many diseases. In the context of asthma, autophagy has been shown to be associated with inflammation, airway remodeling, and responsiveness to drug therapy. In-depth characterization of the role of autophagy in asthma can enhance the understanding of the pathogenesis, and provide a theoretical basis for the development of new biomarkers and targeted therapy for asthma. In this article, we focus on the relationship of autophagy and asthma, and discuss its implications for asthma pathogenesis and treatment.

TMT-Based Quantitative Proteomic Analysis Reveals Downregulation of ITGAL and Syk by the Effects of Cycloastragenol in OVA-Induced Asthmatic Mice

BACKGROUND

Cycloastragenol (CAG) has been reported to alleviate airway inflammation in ovalbumin- (OVA-) induced asthmatic mice. However, its specific mechanisms remain unclear.

OBJECTIVE

This study is aimed at investigating the effects of CAG on asthma, comparing its efficacy with dexamethasone (DEX), and elucidating the mechanism of CAG's regulation.

METHODS

The asthma mouse model was induced by OVA. CAG at the optimal dose of 125 mg/kg was given every day from day 0 for 20-day prevention or from day 14 for a 7-day treatment. We observed the preventive and therapeutic effects of CAG in asthmatic mice by evaluating the airway inflammation, AHR, and mucus secretion. Lung proteins were used for TMT-based quantitative proteomic analysis to enunciate its regulatory mechanisms.

RESULTS

The early administration of 125 mg/kg CAG before asthma happened prevented asthmatic mice from AHR, airway inflammation, and mucus hypersecretion, returning to nearly the original baseline. Alternatively, the administration of CAG during asthma also had the same therapeutic effects as DEX. The proteomic analysis revealed that the therapeutical effects of CAG were associated with 248 differentially expressed proteins and 3 enriched KEGG pathways. We then focused on 3 differentially expressed proteins (ITGAL, Syk, and Vav1) and demonstrated that CAG treatment downregulated ITGAL, Syk, and Vav1 by quantitative real-time PCR, western blot analysis, and immunohistochemical staining.

CONCLUSION

These findings suggest that CAG exerts preventive and protective effects on asthma by inhibiting ITGAL, Syk, and the downstream target Vav1.

Adding Chinese Herbal Medicine to Routine Care is Associated With a Lower Risk of Rheumatoid Arthritis Among Patients With Asthma: A Population-Based Retrospective Cohort Study

Objective: Due to the shared pathogenesis of asthma and rheumatoid arthritis (RA), patients with asthma were found to have a higher risk of RA. While the benefits and safety of Chinese herbal medicine (CHM) for asthma have been reported, the scientific evidence regarding its effect on RA is limited. This longitudinal cohort study aimed to determine the relation between CHM use and RA risk in patients with asthma.

Methods: Using the nationwide claims data, we enrolled 33,963 patients 20–80 years of age who were newly diagnosed with asthma and simultaneously free of RA between 2000 and 2007. From this sample, we utilized propensity score matching to create sets of participants as treatment and control groups, which comprised 13,440 CHM users and 13,440 non-CHM users. The incidence rate and hazard ratio (HR) for RA between the two groups were estimated at the end of 2013. A Cox proportional hazards model was constructed to examine the impact of the CHM use on the risk of RA.

Results: The cumulative incidence of RA was substantially lower in the CHM user group. In the follow-up period, 214 patients in the CHM user group (1.92 per 1,000 person-years) and 359 patients in the non-CHM user group (2.92 per 1,000 person-years) developed RA (adjusted HR = 0.63, 95% confidence interval: 0.54–0.75). Of the commonly-prescribed formulae, nine CHM products were associated with a lower RA risk: Xiao-Qing-Long-Tang, Ma-Xing-Gan-Shi-Tang, Ding-Chuan-Tang, Xin-Yi-Qing-Fei-Tang, Bei Mu, Jie Geng, Xing Ren, Da Huang, and San Chi.

Conclusion: This study found that patients with asthma who received CHM treatment, in addition to the conventional therapy, had a lower risk of RA. Use of CHM treatment may be integrated into conventional therapy to reduce subsequent RA risk among asthma patients.

Aerosol Inhalation of Heat-Killed Clostridium butyricum CGMCC0313-1 Alleviates Allergic Airway Inflammation in Mice

Epidemiological studies have shown that exposure to beneficial microorganisms can reduce the risk of asthma, but the clinical use of live probiotics is controversial due to the risk of infection. As heat-killed probiotics can also exhibit immunomodulatory activity, this study is aimed at investigating whether heat-killed Clostridium butyricum (HKCB) CGMCC0313-1 could reduce allergic airway inflammation in an ovalbumin-induced mouse model. Mice received aerosol inhalation of HKCB, oral administration of HKCB, or oral administration of live Clostridium butyricum (CB) during sensitization. Bronchoalveolar lavage fluid cell number, histology, and levels of the cytokines interferon-gamma and IL-4, the autophagy-related proteins LC3B, Beclin1, and p62, and members of the nuclear factor kappa B (NF-κB)/NLRP3 inflammasome signaling pathway were examined. Our results demonstrated that aerosol inhalation of HKCB, oral HKCB administration, and oral live CB administration alleviated allergic airway inflammation and mucus secretion in allergic mice. Aerosol inhalation of HKCB was the most effective method; it restored the Th1/Th2 balance, ameliorated autophagy, and inhibited the NF-κB/NLRP3 inflammasome signaling pathway in the lungs of allergic mice. Thus, aerosol inhalation of HKCB could be a promising strategy for the prevention or treatment of asthma.

The Role and Mechanisms of Traditional Chinese Medicine for Airway Inflammation and Remodeling in Asthma: Overview and Progress

Asthma as an individual disease has blighted human health for thousands of years and is still a vital global health challenge at present. Though getting much progress in the utilization of antibiotics, mucolytics, and especially the combination of inhaled corticosteroids (ICS) and long-acting β-agonists (LABA), we are confused about the management of asthmatic airway inflammation and remodeling, which directly threatens the quality of life for chronic patients. The blind addition of ICS will not benefit the remission of cough, wheeze, or sputum, but to increase the risk of side effects. Thus, it is necessary to explore an effective therapy to modulate asthmatic inflammation and airway remodeling. Traditional Chinese Medicine (TCM) has justified its anti-asthma effect in clinical practice but its underlying mechanism and specific role in asthma are still unknown. Some animal studies demonstrated that the classic formula, direct exacts, and natural compounds isolated from TCM could significantly alleviate airway structural alterations and exhibit the anti-inflammatory effects. By investigating these findings and data, we will discuss the possible pathomechanism underlined airway inflammation and remodeling in asthma and the unique role of TCM in the treatment of asthma through regulating different signaling pathways.

Amino Acid Solute Carrier Transporters in Inflammation and Autoimmunity

The past decade exposed the importance of many homeostasis and metabolism related proteins in autoimmunity disease and inflammation. Solute carriers (SLCs) are a group of membrane channels that can transport amino acids, the building blocks of proteins, nutrients, and neurotransmitters. This review summarizes the role of SLCs amino acid transporters in inflammation and autoimmunity disease. In detail, the importance of Glutamate transporters SLC1A1, SLC1A2, and SLC1A3, mainly expressed in the brain where they help prevent glutamate excitotoxicity, is discussed in the context of central nervous system disorders such as multiple sclerosis. Similarly, the cationic amino acid transporter SLC7A1 (CAT1), which is an important arginine transporter for T cells, and SLC7A2 (CAT2), essential for innate immunity. SLC3 family proteins, which bind with light chains from the SLC7 family (SLC7A5, SLC7A7 and SLC7A11) to form heteromeric amino acid transporters, are also explored to describe their roles in T cells, NK cells, macrophages and tumor immunotherapies. Altogether, the link between SLC amino acid transporters with inflammation and autoimmunity may contribute to a better understanding of underlying mechanism of disease and provide novel potential therapeutic avenues. Significance Statement SIGNIFICANCE STATEMENT In this review, we summarize the link between SLC amino acid transporters and inflammation and immune responses, specially SLC1 family members and SLC7 members. Studying the link may contribute to a better understanding of related diseases and provide potential therapeutic targets and useful to the researchers who have interest in the involvement of amino acids in immunity.