Atractylodin Suppresses TGF-β-Mediated Epithelial-Mesenchymal Transition in Alveolar Epithelial Cells and Attenuates Bleomycin-Induced Pulmonary Fibrosis in Mice

Chinese medicine as a therapeutic option for pulmonary fibrosis: Clinical efficacies and underlying mechanisms

ETHNIC PHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis (PF) is a fibrotic interstitial lung disease caused by continuous damage and excessive repair of alveolar epithelial cells, the pathogenesis of which is not fully understood. At present, the incidence of PF has increased significantly around the world. The therapeutic arsenals against PF are relatively limited, with often poor efficacy and many adverse effects. As a conventional and effective therapeutic strategy, traditional Chinese medicine (TCM) has been widely applied in treating lung fibrosis for thousands of years in China. Due to the multi-ingredient, multi-target characteristics, Chinese medicines possess promising clinical benefits for PF treatment.

AIM OF THIS REVIEW

This review aims to systematically analyze the clinical efficacy of Chinese medicine on PF, and further summarize the relevant mechanisms of Chinese medicine treating PF in preclinical studies, in order to provide a comprehensive insight into the beneficial effects of Chinese medicines on PF.

METHODS

Eight major Chinese and English databases were searched from database inception up to October 2022, and all randomized clinical trials (RCTs) investigating the effects of Chinese medicine intervention on effectiveness and safety in the treatment of PF patients were included. Subsequently, preclinical studies related to the treatment of PF in Chinese medicine, including Chinese medicine compounds, Chinese herbal materials and extracts, and Chinese herbal formulas (CHFs) were searched through PubMed and Web of science to summarize the related mechanisms of Chinese medicine against PF.

RESULTS

A total of 56 studies with 4019 patients were included by searching the relevant databases. Total clinical efficacy, pulmonary function, blood gas analysis, lung high resolution CT (HRCT), 6 min walk test (6-MWT), St George's Respiratory Questionnaire (SGRQ) scores, clinical symptom scores, TCM syndrome scores and other outcome indicators related to PF were analyzed. Besides, numerous preclinical studies have shown that many Chinese medicine compounds, Chinese herbal materials and extracts, and CHFs play a preventive and therapeutic role in PF by reducing oxidative stress, ameliorating inflammation, inhibiting epithelial-mesenchymal transition and myofibroblasts activation, and regulating autophagy and apoptosis.

CONCLUSION

Chinese medicines show potential as supplements or substitutes for treating PF. And studies on Chinese medicines will provide a new approach to better management of PF.

Anthelmintic nitazoxanide protects against experimental pulmonary fibrosis

BACKGROUND AND PURPOSE

Nitazoxanide is a therapeutic anthelmintic drug. Our previous studies found that nitazoxanide and its metabolite tizoxanide activated adenosine 5'-monophosphate-activated protein kinase (AMPK) and inhibited signal transducer and activator of transcription 3 (STAT3) signals. As AMPK activation and/or STAT3 inhibition are targets for treating pulmonary fibrosis, we hypothesized that nitazoxanide would be effective in experimental pulmonary fibrosis.

EXPERIMENTAL APPROACH

The mitochondrial oxygen consumption rate of cells was measured by using the high-resolution respirometry system Oxygraph-2K. The mitochondrial membrane potential of cells was evaluated by tetramethyl rhodamine methyl ester (TMRM) staining. The target protein levels were measured by using western blotting. The mice pulmonary fibrosis model was established through intratracheal instillation of bleomycin. The examination of the lung tissues changes were carried out using haematoxylin and eosin (H&E), and Masson staining.

KEY RESULTS

Nitazoxanide and tizoxanide activated AMPK and inhibited STAT3 signalling in human lung fibroblast cells (MRC-5 cells). Nitazoxanide and tizoxanide inhibited transforming growth factor-β1 (TGF-β1)-induced proliferation and migration of MRC-5 cells, collagen-I and α-smooth muscle cell actin (α-SMA) expression, and collagen-I secretion from MRC-5 cells. Nitazoxanide and tizoxanide inhibited epithelial-mesenchymal transition (EMT) and inhibited TGF-β1-induced Smad2/3 activation in mouse lung epithelial cells (MLE-12 cells). Oral administration of nitazoxanide reduced the bleomycin-induced mice pulmonary fibrosis and, in the established bleomycin-induced mice, pulmonary fibrosis. Delayed nitazoxanide treatment attenuated the fibrosis progression.

CONCLUSIONS AND IMPLICATIONS

Nitazoxanide improves the bleomycin-induced pulmonary fibrosis in mice, suggesting a potential application of nitazoxanide for pulmonary fibrosis treatment in the clinic.

Progress in Understanding the Role and Therapeutic Targets of Polarized Subtypes of Macrophages in Pulmonary Fibrosis

Pulmonary fibrosis represents the advanced phase of diverse pulmonary ailments, and at present, a definitive cure for these ailments is lacking. Furthermore, underlying mechanisms causative of these ailments remain elusive. Macrophages are immune cells that resist external stimuli in the early stages after birth. These cells can polarize into the classically (M1) and alternatively (M2) activated macrophages. When stimulated owing to the presence of toxic factors, M1 macrophages produce several pro-inflammatory factors, which mediate the inflammatory injury response of the alveolar tissue. The secretion of diverse growth factors by M2 macrophages contributes to the pathogenesis of aberrant alveolar structural fibrosis and remodeling. The abnormal activity of M2 macrophages is considered a critical factor in the formation of pulmonary fibrosis. In this mini-review, to highlight the clinical implications of research studies, we summarize the role and therapeutic targets of polarized subtypes of macrophages in pulmonary fibrosis and the role of targeting macrophages for the treatment of pulmonary fibrosis.

TRPA1: A promising target for pulmonary fibrosis?

Pulmonary fibrosis is a disease characterized by progressive scar formation and the ultimate manifestation of numerous lung diseases. It is known as "cancer that is not cancer" and has attracted widespread attention. However, its formation process is very complex, and the mechanism of occurrence has not been fully elucidated. Current research has found that TRPA1 may be a promising target in the pathogenesis of pulmonary fibrosis. The TRPA1 channel was first successfully isolated in human lung fibroblasts, and it was found to have a relatively concentrated distribution in the lungs and respiratory tract. It is also involved in various acute and chronic inflammatory processes of lung diseases and may even play a core role in the progression and/or prevention of pulmonary fibrosis. Natural ligands targeting TRPA1 could offer a promising alternative treatment for pulmonary diseases. Therefore, this review delves into the current understanding of pulmonary fibrogenesis, analyzes TRPA1 biological properties and regulation of lung disease with a focus on pulmonary fibrosis, summarizes the TRPA1 molecular structure and its biological function, and summarizes TRPA1 natural ligand sources, anti-pulmonary fibrosis activity and potential mechanisms. The aim is to decipher the exact role of TRPA1 channels in the pathophysiology of pulmonary fibrosis and to consider their potential in the development of new therapeutic strategies.

Authenticating the geographic origins of Atractylodes lancea rhizome chemotypes in China through metabolite marker identification

Introduction

Atractylodes lancea is widely distributed in East Asia, ranging from Amur to south-central China. The rhizome of A. lancea is commonly used in traditional Chinese medicine, however, the quality of products varies across different regions with different geochemical characteristics.

Method

This study aimed to identify the chemotypes of A. lancea from different areas and screen for chemical markers by quantifying volatile organic compounds (VOCs) using a targeted metabolomics approach based on GC-MS/MS.

Results

The A. lancea distributed in Hubei, Anhui, Shaanxi, and a region west of Henan province was classified as the Hubei Chemotype (HBA). HBA is characterized by high content of β-eudesmol and hinesol with lower levels of atractylodin and atractylon. In contrast, the Maoshan Chemotype (MA) from Jiangsu, Shandong, Shanxi, Hebei, Inner Mongolia, and other northern regions, exhibited high levels of atractylodin and atractylon. A total of 15 categories of VOCs metabolites were detected and identified, revealing significant differences in the profiles of terpenoid, heterocyclic compound, ester, and ketone among different areas. Multivariate statistics indicated that 6 compounds and 455 metabolites could serve as candidate markers for differentiating A. lancea obtained from the southern, northern, and Maoshan areas.

Discussion

This comprehensive analysis provides a chemical fingerprint of selected A. lancea. Our results highlight the potential of metabolite profiling combined with chemometrics for authenticating the geographical origin of A. lancea.

A systematic review of the research progress of traditional Chinese medicine against pulmonary fibrosis: from a pharmacological perspective

Pulmonary fibrosis is a chronic progressive interstitial lung disease caused by a variety of etiologies. The disease can eventually lead to irreversible damage to the lung tissue structure, severely affecting respiratory function and posing a serious threat to human health. Currently, glucocorticoids and immunosuppressants are the main drugs used in the clinical treatment of pulmonary fibrosis, but their efficacy is limited and they can cause serious adverse effects. Traditional Chinese medicines have important research value and potential for clinical application in anti-pulmonary fibrosis. In recent years, more and more scientific researches have been conducted on the use of traditional Chinese medicine to improve or reduce pulmonary fibrosis, and some important breakthroughs have been made. This review paper systematically summarized the research progress of pharmacological mechanism of traditional Chinese medicines and their active compounds in improving or reducing pulmonary fibrosis. We conducted a systematic search in several main scientific databases, including PubMed, Web of Science, and Google Scholar, using keywords such as idiopathic pulmonary fibrosis, pulmonary fibrosis, interstitial pneumonia, natural products, herbal medicine, and therapeutic methods. Ultimately, 252 articles were included and systematically evaluated in this analysis. The anti-fibrotic mechanisms of these traditional Chinese medicine studies can be roughly categorized into 5 main aspects, including inhibition of epithelial-mesenchymal transition, anti-inflammatory and antioxidant effects, improvement of extracellular matrix deposition, mediation of apoptosis and autophagy, and inhibition of endoplasmic reticulum stress. The purpose of this article is to provide pharmaceutical researchers with information on the progress of scientific research on improving or reducing Pulmonary fibrosis with traditional Chinese medicine, and to provide reference for further pharmacological research.

Cellular and Molecular Mechanisms in Idiopathic Pulmonary Fibrosis

The respiratory system is a well-organized multicellular organ, and disruption of cellular homeostasis or abnormal tissue repair caused by genetic deficiency and exposure to risk factors lead to life-threatening pulmonary disease including idiopathic pulmonary fibrosis (IPF). Although there is no clear etiology as the name reflected, its pathological progress is closely related to uncoordinated cellular and molecular signals. Here, we review the advances in our understanding of the role of lung tissue cells in IPF pathology including epithelial cells, mesenchymal stem cells, fibroblasts, immune cells, and endothelial cells. These advances summarize the role of various cell components and signaling pathways in the pathogenesis of idiopathic pulmonary fibrosis, which is helpful to further study the pathological mechanism of the disease, provide new opportunities for disease prevention and treatment, and is expected to improve the survival rate and quality of life of patients.

Losartan enhances the suppressive effect of pirfenidone on the bleomycin-induced epithelial-mesenchymal transition and oxidative stress in A549 cell line

Objectives

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease. Despite the promising anti-fibrotic effect, the toleration of pirfenidone (PFD) by the patients in full dose is low. Combination therapy is a method for enhancing the therapeutic efficiency of PFD and decreasing its dose. Therefore, the present study evaluated the effect of a combination of losartan (LOS) and PFD on oxidative stress parameters and the epithelial-mesenchymal transition (EMT) process induced by bleomycin (BLM) in human lung adenocarcinoma A549 cells.

Materials and Methods

The non-toxic concentrations of BLM, LOS, and PFD were assessed by the MTT assay. Malondialdehyde (MDA) and anti-oxidant enzyme activity including catalase (CAT) and superoxide dismutase (SOD) were assessed after co-treatment. Migration and western blot assays were used to evaluate EMT in BLM-exposed A549 after single or combined treatments.

Results

The combination treatment exhibited a remarkable decrease in cellular migration compared with both single and BLM-exposed groups. Furthermore, the combination treatment significantly improved cellular anti-oxidant markers compared with the BLM-treated group. Moreover, combined therapy markedly increased epithelial markers while decreasing mesenchymal markers.

Conclusion

This in vitro study revealed that the combination of PFD with LOS might be more protective in pulmonary fibrosis (PF) than single therapy because of its greater efficacy in regulating the EMT process and oxidative stress. The current results might offer a promising therapeutic strategy for the future clinical therapy of lung fibrosis.

The Anti-Rheumatic Drug, Leflunomide, Induces Nephrotoxicity in Mice via Upregulation of TGFβ-Mediated p53/Smad2/3 Signaling

Recent studies indicated renal toxicity and interstitial nephritis in patients receiving leflunomide (LEFN), but the exact mechanism is still unknown. The transforming growth factor β (TGFβ)/p53/Smad2/3 pathway crucially mediates renal fibrosis. We aimed to assess the nephrotoxic effect of LEFN in mice and the possible role of TGFβ-stimulated p53/SMAD2/3 signaling. The study design involved distributing sixty male albino mice into four groups: (i) vehicle-treated mice, (ii) LEFN (2.5 mg/kg), (iii) LEFN (5 mg/kg), and (iv) LEFN (10 mg/kg). The drug was given orally every 48 h and continued for 8 weeks. Blood samples were then taken from mice for the determination of kidney function parameters. Right kidneys were used for histopathologic staining and immunohistochemistry, whereas left kidneys were frozen and used for Western blot analysis of the target proteins, p-p53 and Smad2/3. Results indicated that chronic administration of LEFN in mice resulted in a four- and nine-fold increase in serum urea and creatinine levels, respectively. Kidney specimens stained with hematoxylin and eosin or periodic acid–Schiff showed significant histopathological manifestations, such as cellular irregularity, interstitial congestion, and moderate lymphocytic inflammatory infiltrate in mice treated with LEFN. Western blotting indicated upregulation of the p-p53/Smad2/3 proteins. LEFN, especially in the highest dose (10 mg/kg), produced prominent nephrotoxicity in mice. This toxicity is mediated through stimulating fibrotic changes through TGFβ-stimulated p53/Smad2/3 signaling and induction of glomerular and tubular apoptosis. An improved understanding of LEFN-induced nephrotoxicity would have great implications in the prediction, prevention, and management of leflunomide-treated rheumatic patients, and may warrant further clinical studies for following up these toxidromes.

Atractylodin Induces Apoptosis and Inhibits the Migration of A549 Lung Cancer Cells by Regulating ROS-Mediated Signaling Pathways

Atractylodin (ATR) has anticancer effects on some tumor cells by inducing apoptosis, but its mechanism in lung cancer remains unclear. This study investigates the inhibitory effect of ATR on A549 lung cancer cells. Cell viability was detected by the Cell Counting Kit-8 assay, and results showed that ATR could significantly inhibit the proliferation of A549 cells. Apoptosis was detected by Annexin V-FITC/PI staining, and apoptosis rate and mitochondrial membrane potential were detected by flow cytometry. Results showed that the effect of ATR on the apoptosis of A549 cells was negatively correlated with the change in mitochondrial membrane potential. Western blot analysis showed that ATR regulated apoptosis induced by mitogen-activated protein kinase, signal transducer and activator of transcription 3, and nuclear factor kappa B signaling pathways. Analyses of reactive oxygen species (ROS), cell cycle, and cell migration showed that ATR induced intracellular ROS accumulation as an initiation signal to induce cell cycle arrest regulated by the AKT signaling pathway and cell migration inhibition regulated by the Wnt signaling pathway. Results showed that ATR can inhibit cell proliferation, induce cell apoptosis, induce cell cycle arrest, and inhibit the migration of A549 cells (p < 0.05 was considered statistically significant, * p < 0.05, ** p < 0.01 and *** p < 0.001).