The role of natural products in the prevention and treatment of pulmonary fibrosis: a review

Role of TRIM59 in regulating PPM1A in the pathogenesis of silicosis and the intervention effect of tanshinone IIA

This study examines the involvement of TRIM59 in silica-induced pulmonary fibrosis and explores the therapeutic efficacy of Tanshinone IIA (Tan IIA). In vivo experiments conducted on rats with silica-induced pulmonary fibrosis unveiled an increase in TRIM59 levels and a decrease in PPM1A levels. Subsequent investigations using in vitro silicosis cell models demonstrated that modulation of TRIM59 expression significantly impacts silicosis fibrosis, influencing the levels of PPM1A and activation of the Smad2/3 signaling pathway. Immunofluorescence and co-immunoprecipitation assays confirmed the interaction between TRIM59 and PPM1A in fibroblasts, wherein TRIM59 facilitated the degradation of PPM1A protein via proteasomal and ubiquitin-mediated pathways. Furthermore, employing a rat model of silica-induced pulmonary fibrosis, Tan IIA exhibited efficacy in mitigating lung tissue damage and fibrosis. Immunohistochemical analysis validated the upregulation of TRIM59 and downregulation of PPM1A in silica-induced pulmonary fibrosis, which Tan IIA alleviated. In vitro studies elucidated the mechanism by which Tan IIA regulates the Smad2/3 signaling pathway through TRIM59-mediated modulation of PPM1A. Treatment with Tan IIA in silica-induced fibrosis cell models resulted in concentration-dependent reductions in fibrotic markers and attenuation of relevant protein expressions. Tan IIA intervention in silica-induced fibrosis cell models mitigated the TRIM59-induced upregulation of fibrotic markers and enhanced PPM1A expression, thereby partially reversing Smad2/3 activation. Overall, the findings indicate that while overexpression of TRIM59 may activate the Smads pathway by suppressing PPM1A expression, treatment with Tan IIA holds promise in counteracting these effects by inhibiting TRIM59 expression.

Resveratrol Alleviates Liver Fibrosis Induced by Long-Term Inorganic Mercury Exposure through Activating the Sirt1/PGC-1α Signaling Pathway

Liver disease has become an important risk factor for global health. Resveratrol (Res) is a natural polyphenol which is widely found in foods and has a variety of biological activities. This study investigated the role of the microbiota-gut-liver axis in the Res relieving the liver fibrosis induced by inorganic mercury exposure. Twenty-eight mice were divided into four groups (n = 7) and treated with mercuric chloride and/or Res for 24 weeks, respectively. The results showed that Res mitigated the ileum injury induced by inorganic mercury and restrained LPS and alcohol entering the body circulation. Network pharmacological and molecular analyses showed that Res alleviated oxidative stress, metabolism disorders, inflammation, and hepatic stellate cell activation in the liver. In conclusion, Res alleviates liver fibrosis induced by inorganic mercury via activating the Sirt1/PGC-1α signaling pathway and regulating the microbial-gut-liver axis, particularly, increasing the relative enrichment of Bifidobacterium in the intestinal tract.

Specneuzhenide improves bleomycin-induced pulmonary fibrosis in mice via AMPK-dependent reduction of PD-L1

BACKGROUND

Pulmonary fibrosis (PF) is an escalating global health issue, characterized by rising rates of morbidity and mortality annually. Consequently, further investigation of potential damage mechanisms and potential preventive strategies for PF are warranted. Specnuezhenide (SPN), a prominent secoiridoid compound derived from Ligustrum lucidum Ait, exhibits anti-inflammatory and anti-oxidative capacities, indicating the potential therapeutic actions on PF. However, the underlying mechanisms of SPN on PF remain unclear.

PURPOSE

This work was aimed at investigating the protective actions of SPN on PF and the potential mechanism.

METHODS

In vivo, mice were administrated with bleomycin (BLM) to establish PF model. PF mice were treated with SPN (45/90 mg/kg) by gavage. In vitro, we employed TGF-β1 (10 ng/mL)-induced MLE-12 and PLFs cells, which then were treated with SPN (5, 10, 20 µM). DARTS assay, biofilm interference experiment and molecular docking were performed to investigate the molecular target of SPN.

RESULTS

In vivo, we found SPN treatment improved survival rate, alleviated pathological changes through reducing BLM-induced extracellular matrix (ECM) deposition, as well as BLM-induced epithelial-mesenchymal transition (EMT). In vitro, SPN inhibited EMT and lung fibroblast transdifferentiation. Mechanistically, SPN activated the AMPK protein to decrease the abnormally high level of PD-L1. Furthermore, the compound C, known as an AMPK inhibitor, exhibited a significant hindrance to the inhibition of SPN on TGF-β1-caused fibroblast transdifferentiation and proliferation. This outcome could be attributed to the fact that compound C could eliminate the inhibitory effects of SPN on PD-L1 expression. Interestingly, DARTS assay, biofilm interference experiment and molecular docking results all indicated that SPN could bind to AMPK, which suggested that SPN might be a potential agonist targeting AMPK protein.

CONCLUSION

Altogether, the results in our work illustrated that SPN promoted AMPK-dependent reduction of PD-L1 protein, contributing to the inhibition of fibrosis progression. Thus, SPN may represent a potential AMPK agonist for PF treatment.

Integrated mRNA-miRNA transcriptome profiling of blood immune responses potentially related to pulmonary fibrosis in forest musk deer

Background

Forest musk deer (FMD, Moschus Berezovskii) is a critically endangered species world-widely, the death of which can be caused by pulmonary disease in the farm. Pulmonary fibrosis (PF) was a huge threat to the health and survival of captive FMD. MicroRNAs (miRNAs) and messenger RNAs (mRNAs) have been involved in the regulation of immune genes and disease development. However, the regulatory profiles of mRNAs and miRNAs involved in immune regulation of FMD are unclear.

Methods

In this study, mRNA-seq and miRNA-seq in blood were performed to constructed coexpression regulatory networks between PF and healthy groups of FMD. The hub immune- and apoptosis-related genes in the PF blood of FMD were explored through Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Further, protein-protein interaction (PPI) network of immune-associated and apoptosis-associated key signaling pathways were constructed based on mRNA-miRNA in the PF blood of the FMD. Immune hub DEGs and immune hub DEmiRNAs were selected for experimental verification using RT-qPCR.

Results

A total of 2744 differentially expressed genes (DEGs) and 356 differentially expressed miRNAs (DEmiRNAs) were identified in the PF blood group compared to the healthy blood group. Among them, 42 DEmiRNAs were negatively correlated with 20 immune DEGs from a total of 57 correlations. The DEGs were significantly associated with pathways related to CD molecules, immune disease, immune system, cytokine receptors, T cell receptor signaling pathway, Th1 and Th2 cell differentiation, cytokine-cytokine receptor interaction, intestinal immune network for IgA production, and NOD-like receptor signaling pathway. There were 240 immune-related DEGs, in which 186 immune-related DEGs were up-regulated and 54 immune-related DEGs were down-regulated. In the protein-protein interaction (PPI) analysis of immune-related signaling pathway, TYK2, TLR2, TLR4, IL18, CSF1, CXCL13, LCK, ITGB2, PIK3CB, HCK, CD40, CD86, CCL3, CCR7, IL2RA, TLR3, and IL4R were identified as the hub immune genes. The mRNA-miRNA coregulation analysis showed that let-7d, miR-324-3p, miR-760, miR-185, miR-149, miR-149-5p, and miR-1842-5p are key miRNAs that target DEGs involved in immune disease, immune system and immunoregulation.

Conclusion

The development and occurrence of PF were significantly influenced by the immune-related and apoptosis-related genes present in PF blood. mRNAs and miRNAs associated with the development and occurrence of PF in the FMD.

Preclinical evidence using synthetic compounds and natural products indicates that AMPK represents a potential pharmacological target for the therapy of pulmonary diseases

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a highly conserved eukaryotic enzyme discovered as a key regulator of cellular energy homeostasis, with anti-inflammation, antioxidative stress, anticancer, and antifibrosis beneficial effects. AMPK is dysregulated in human pulmonary diseases such as acute lung injury, nonsmall cell lung cancer, pulmonary fibrosis, chronic obstructive pulmonary disease, and asthma. This review provides an overview of the beneficial role of natural, synthetic, and Chinese traditional medicines AMPK modulators in pulmonary diseases, and highlights the role of the AMPK signaling pathway in the lung, emphasizing the importance of finding lead compounds and drugs that can target and modulate AMPK to treat the lung diseases.

Liensinine, a Novel and Food-Derived Compound, Exerts Potent Antihepatoma Efficacy via Inhibiting the Kv10.1 Channel

Plant metabolites from natural product extracts offer unique advantages against carcinogenesis in the development of drugs. The target-based virtual screening from food-derived compounds represents a promising approach for tumor therapy. In this study, we performed virtual screening to target the presumed inhibitor-binding pocket and identified a highly potent Kv10.1 inhibitor, liensinine (Lien), which can inhibit the channel in a dose-dependent way with an IC50 of 0.24 ± 0.07 μM. Combining molecular dynamics simulations with mutagenesis experiments, our data show that Lien interacts with Kv10.1 by binding with Y539, T543, D551, E553, and H601 in the C-linker domain of Kv10.1. In addition, the interaction of sequence alignment and 3D structural modeling revealed differences between the C-linker domain of the Kv10.1 channel and the Kv11.1 channel. Furthermore, antitumor experiments revealed that Lien suppresses the proliferation and migration of HCC both in vitro and in vivo. In summary, the food-derived compound, Lien, may serve as a lead compound for antihepatoma therapeutic drugs targeting Kv10.1.

The Peptide DHα-(4-pentenyl)-ANPQIR-NH2 Exhibits Antifibrotic Activity in Multiple Pulmonary Fibrosis Models Induced by Particulate and Soluble Chemical Fibrogenic Agents

Interstitial lung diseases (ILDs) are a group of restrictive lung diseases characterized by interstitial inflammation and pulmonary fibrosis. The incidence of ILDs associated with exposure to multiple hazards such as inhaled particles, fibers, and ingested soluble chemicals is increasing yearly, and there are no ideal drugs currently available. Our previous research showed that the novel and low-toxicity peptide DHα-(4-pentenyl)-ANPQIR-NH2 (DR3penA) had a strong antifibrotic effect on a bleomycin-induced murine model. Based on the druggability of DR3penA, we sought to investigate its effects on respirable particulate silicon dioxide (SiO2)- and soluble chemical paraquat (PQ)-induced pulmonary fibrosis in this study by using western blot, quantitative reverse-transcription polymerase chain reaction (RT-qPCR), immunofluorescence, H&E and Masson staining, immunohistochemistry, and serum biochemical assays. The results showed that DR3penA alleviated the extent of fibrosis by inhibiting the expression of fibronectin and collagen I and suppressed oxidative stress and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Further study revealed that DR3penA may mitigate pulmonary fibrosis by negatively regulating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and mitogen-activated protein kinase (MAPK) pathway. Unexpectedly, through the conversion of drug bioavailability under different routes of administration, DR3penA exerted antifibrotic effects equivalent to those of the positive control drug pirfenidone (PFD) at lower doses. In summary, DR3penA may be a promising lead compound for various fibrotic ILDs. SIGNIFICANCE STATEMENT: Our study verified that DHα-(4-pentenyl)-ANPQIR-NH2 (DR3penA) exhibited positive antifibrotic activity in pulmonary fibrosis induced by silicon dioxide (SiO2) particles and soluble chemical paraquat (PQ) and demonstrated a low-dose advantage compared to the small-molecule drug pirfenidone (PFD). The peptide DR3penA can be further developed for the treatment of multiple fibrotic lung diseases.

Corydaline binds to a druggable pocket of hEAG1 channel and inhibits hepatic carcinoma cell viability

Ether-à-go-go (EAG) potassium channels play a crucial role in the regulation of neuronal excitability and cancer progression, rendering them potential drug targets for cancer therapy. However, the scarcity of information regarding the selection sites on hEAG1 has posed a challenge in the discovery of new hEAG1 inhibitors. In this study, we introduced a novel natural product, corydaline, which selectively inhibits the hEAG1 channel without sensitivity to other KCNH channels. The IC50 of corydaline for the hEAG1 channel was 11.3 ± 0.6 μM, whereas the IC50 for hEAG2 and hERG1 were 73.6 ± 9.9 μM and 111.4 ± 8.5 μM, respectively. Molecular dynamics simulations together with site-directed mutagenesis, have unveiled that the site corydaline forms interactions with Lys217, Phe273, Pro276, Trp295 and Arg366, situated within the intracellular transmembrane segments S1-S4 of the voltage-sensor domain, be considered a novel drug pocket for hEAG1. Additionally, the intergaration of sequence alignment and 3D structural modeling revealed differences between the voltage sensor domain of hEAG1 channel and other EAG channels, suggesting the feasibility of a VSD modulation approach that could potentially lead to the selective inhibition of hEAG1 channels. Furthermore, antitumor experiments demonstrated that corydaline can inhibit the proliferation and migration of hepatic carcinoma cells by targeting hEAG1. The identification of this novel druggable pocket offers the possibility for drug screening against diseases linked to abnormal hEAG1 channels.

Tangeretin attenuates bleomycin-induced pulmonary fibrosis by inhibiting epithelial-mesenchymal transition via the PI3K/Akt pathway

Background: Pulmonary fibrosis (PF) is a terminal pathological change in a variety of lung diseases characterized by excessive deposition of extracellular matrix, for which effective treatment is lacking. Tangeretin (Tan), a flavonoid derived from citrus, has been shown to have a wide range of pharmacological effects. This study aimed to investigate the role and potential mechanisms of Tan on pulmonary fibrosis. Methods: A model of pulmonary fibrosis was established by administering bleomycin through tracheal drip, followed by administering Tan or pirfenidone through gavage. HE and Masson staining were employed to assess the extent of pulmonary fibrosis. Subsequently, Western blot, enzyme-linked immunosorbent assay (ELISA), RNA sequencing, and immunohistochemistry techniques were employed to uncover the protective mechanism of Tan in PF mice. Furthermore, A549 cells were stimulated with TGF-β1 to induce epithelial-mesenchymal transition (EMT) and demonstrate the effectiveness of Tan in mitigating PF. Results: Tan significantly ameliorated bleomycin-induced pulmonary fibrosis, improved fibrotic pathological changes, and collagen deposition in the lungs, and reduced lung inflammation and oxidative stress. The KEGG pathway enrichment analysis revealed a higher number of enriched genes in the PI3K/Akt pathway. Additionally, Tan can inhibit the EMT process related to pulmonary fibrosis. Conclusion: Taken together, the above research results indicate that Tan suppresses inflammation, oxidative stress, and EMT in BLM-induced pulmonary fibrosis via the PI3K/Akt pathway and is a potential agent for the treatment of pulmonary fibrosis.

Regulatory Cues in Pulmonary Fibrosis-With Emphasis on the AIM2 Inflammasome

Pulmonary fibrosis (PF) is a chronic lung disorder characterized by the presence of scarred and thickened lung tissues. Although the Food and Drug Administration approved two antifibrotic drugs, pirfenidone, and nintedanib, that are currently utilized for treating idiopathic PF (IPF), the clinical therapeutic efficacy remains unsatisfactory. It is crucial to develop new drugs or treatment schemes that combine pirfenidone or nintedanib to achieve more effective outcomes for PF patients. Understanding the complex mechanisms underlying PF could potentially facilitate drug discovery. Previous studies have found that the activation of inflammasomes, including nucleotide-binding and oligomerization domain (NOD)-like receptor protein (NLRP)1, NLRP3, NOD-like receptor C4, and absent in melanoma (AIM)2, contributes to lung inflammation and fibrosis. This article aims to summarize the cellular and molecular regulatory cues that contribute to PF with a particular emphasis on the role of AIM2 inflammasome in mediating pathophysiologic events during PF development. The insights gained from this research may pave the way for the development of more effective strategies for the prevention and treatment of PF.

Gracillin relieves pulmonary fibrosis by suppressing the STAT3 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Pulmonary fibrosis (PF) is a persistent and refractory illness accompanied by inflammation and fibrosis. Gracillin, a natural steroidal saponin, is one of the components of Dioscorea quinqueloba which has been used in herbal medicines for treating some inflammatory diseases. Therefore, it may be a potential drug candidate for PF management.

AIM OF THE STUDY

This study aims to elucidate and verify the anti-pulmonary fibrosis effect of gracillin.

METHODS

We established an in vivo model of PF by treatment of mice with bleomycin (BLM) and an in vitro model by treatment of NIH-3T3 cells with TGF-β1. Pathological changes to the structure of lung tissue, pulmonary function, inflammatory exudation of bronchoalveolar lavage fluid (BALF) and deposition of collagen were detected in vivo, and extracellular matrix (ECM) deposition and migration were evaluated in vitro. The significance of gracillin on STAT3 phosphorylation and nuclear translocation were evaluated by western blotting, immunohistochemistry and immunofluorescence assays. The STAT3 transcriptional activity was quantified with a dual-luciferase reporter assay. Recovery experiments were performed by plasmid-directed overexpression of STAT3.

RESULTS

We found that gracillin could improve pulmonary function, reduce lung inflammation and mitigate collagen deposition to ameliorate BLM-induced PF in mice. Gracillin also suppressed TGF-β1-induced increases in ECM deposition biomarkers, including COL1A1, fibronectin, α-SMA, N-cad and vimentin, and repressed migration in NIH-3T3 cells. Additionally, gracillin suppressed the phosphorylation, nuclear translocation and transcriptional action of STAT3. Furthermore, the decreased ECM deposition and migration upon gracillin treatment were abrogated upon overexpression of STAT3 in NIH-3T3 cells.

CONCLUSIONS

Gracillin protects against PF by inhibiting the STAT3 axis, providing a safe and efficacious approach to treating PF.

A comprehensive overview of Artemisinin and its derivatives as anticancer agents

Artemisinin is the crucial ingredient of artemisia annua, a traditional Chinese medicine used for the therapy of malaria in China for hundreds of years. In recent years, the anticancer properties of artemisinin and its derivatives have also been reported. This review has summarized the research and development of artemisinin and its derivatives as anticancer agents, which included both natural and synthetic monomers as well as their dimers. In addition, it highlights the antitumor effects of artemisinin and its derivatives after site-modification or after transformation to a nano-delivery system. Moreover, we have further explored their potential mechanisms of action and also discussed the clinical trials of ARTs used to treat cancer, which will facilitate in further development of novel anticancer drugs based on the scaffold of artemisinin.

Tocotrienol-Rich Fractions Offer Potential to Suppress Pulmonary Fibrosis Progression

Although pulmonary fibrosis (PF) is considered a rare disease, the incidence thereof has increased steadily in recent years, while a safe and effective cure remains beyond reach. In this study, the potential of tocotrienol-rich fractions (TRF) and carotene to alleviate PF was explored. PF was induced in Sprague-Dawley rats via a single intratracheal bleomycin (BLM) (5 mg/kg) instillation. These rats were subsequently treated with TRF, carotene, pirfenidone (Pir) and nintedanib (Nin) for 28 days via gavage administration, whereafter histopathological performance, biochemical functions and molecular alterations were studied in the lung tissues. Our results showed that TRF, carotene, Nin and Pir all ameliorated PF by reducing inflammation and resisting oxidative stress to varying degrees. The related mechanisms involved the TGF-β1/Smad, PI3K/Akt and NF-κB signaling pathways. Ultimately, our findings revealed that, when combined with TRF, the therapeutic effects of Nin and Pir on PF were enhanced, indicating that TRF may, indeed, provide promising potential for use in combination therapy in the treatment of PF.

MicroRNA let-7f-5p regulates PI3K/AKT/COX2 signaling pathway in bacteria-induced pulmonary fibrosis via targeting of PIK3CA in forest musk deer

Background

Recent studies have characterized that microRNA (miRNA) is a suitable candidate for the study of bleomycin/LPS-induced pulmonary fibrosis, but the knowledge on miRNA in bacteria-induced pulmonary fibrosis (BIPF) is limited. Forest musk deer (Moschus berezovskii, FMD) is an important endangered species that has been seriously affected by BIPF. We sought to determine whether miRNA exist that modulates the pathogenesis of BIPF in FMD.

Methods

High-throughput sequencing and RT-qPCR were used to determine the differentially expressed miRNAs (DEmiRNAs) in the blood of BIPF FMD. The DEmiRNAs were further detected in the blood and lung of BIPF model rat by RT-qPCR, and the targeting relationship between candidate miRNA and its potential target gene was verified by dual-luciferase reporter activity assay. Furthermore, the function of the candidate miRNA was verified in the FMD lung fibroblast cells (FMD-C1).

Results

Here we found that five dead FMD were suffered from BIPF, and six circulating miRNAs (miR-30g, let-7f-5p, miR-27-3p, miR-25-3p, miR-9-5p and miR-652) were differentially expressed in the blood of the BIPF FMD. Of these, let-7f-5p showed reproducibly lower level in the blood and lung of the BIPF model rat, and the expression levels of PI3K/AKT/COX2 signaling pathway genes (PIK3CA, PDK1, Akt1, IKBKA, NF-κB1 and COX2) were increased in the lung of BIPF model rats, suggesting that there is a potential correlation between BIPF and the PI3K/AKT/COX2 signaling pathway. Notably, using bioinformatic prediction and experimental verification, we demonstrated that let-7f-5p is conserved across mammals, and the seed sequence of let-7f-5p displays perfect complementarity with the 3' UTR of PIK3CA gene and the expression of the PIK3CA gene was regulated by let-7f-5p. In order to determine the regulatory relationship between let-7f-5p and the PI3K/AKT/COX2 signaling pathway in FMD, we successfully cultured FMD-C1, and found that let-7f-5p could act as a negative regulator for the PI3K/Akt/COX2 signaling pathway in FMD-C1. Collectively, this study not only provided a study strategy for non-invasive research in pulmonary disease in rare animals, but also laid a foundation for further research in BIPF.

18β-Glycyrrhetinic acid monoglucuronide (GAMG) alleviates single-walled carbon nanotubes (SWCNT)-induced lung inflammation and fibrosis in mice through PI3K/AKT/NF-κB signaling pathway

Carbon nanotubes (CNTs) have become far and wide used in a number of technical and merchant applications as a result of substantial advances in nanotechnology, therein single-walled carbon nanotubes (SWCNT) are one of the most promising nanoparticles. Inhaling CNTs has been linked to a variety of health problems, including lung fibrosis. Glycyrrhetinic acid 3-O-mono-β-D-glucuronide (GAMG), a natural sweetener, has anti-inflammatory and antioxidant capacities. The purpose of this study was to evaluate the potential for GAMG to alleviate SWCNT-induced lung inflammation and fibrosis. During days 3-28 after SWCNT intratracheal administration, we observed a remarkable increase of IL-1β, IL-6 and TNF-α in bronchoalveolar lavage fluid (BALF) on day 3 and collagen deposition on day 28. GAMG treatment remarkably ameliorated SWCNT-induced pulmonary fibrosis and attenuated SWCNT-induced inflammation and collagen deposition, and suppressed the activation of PI3K/AKT/NF-κB signaling pathway in the lungs. Therefore, GAMG has a therapeutic potential for the treatment of SWCNT-induced pulmonary fibrosis. Targeting PI3K/AKT/NF-κB signaling pathway may be a potential therapeutic approach to treat pulmonary fibrosis in mice with SWCNT.

The Role of Nrf2 in Pulmonary Fibrosis: Molecular Mechanisms and Treatment Approaches

Pulmonary fibrosis is a chronic, progressive, incurable interstitial lung disease with high mortality after diagnosis and remains a global public health problem. Despite advances and breakthroughs in understanding the pathogenesis of pulmonary fibrosis, there are still no effective methods for the prevention and treatment of pulmonary fibrosis. The existing treatment options are imperfect, expensive, and have considerable limitations in effectiveness and safety. Hence, there is an urgent need to find novel therapeutic targets. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a central regulator of cellular antioxidative responses, inflammation, and restoration of redox balance. Accumulating reports reveal that Nrf2 activators exhibit potent antifibrosis effects and significantly attenuate pulmonary fibrosis in vivo and in vitro. This review summarizes the current Nrf2-related knowledge about the regulatory mechanism and potential therapies in the process of pulmonary fibrosis. Nrf2 orchestrates the activation of multiple protective genes that target inflammation, oxidative stress, fibroblast–myofibroblast differentiation (FMD), and epithelial–mesenchymal transition (EMT), and the mechanisms involve Nrf2 and its downstream antioxidant, Nrf2/HO−1/NQO1, Nrf2/NOX4, and Nrf2/GSH signaling pathway. We hope to indicate potential for Nrf2 system as a therapeutic target for pulmonary fibrosis.

Study on the molecular mechanisms of tetrandrine against pulmonary fibrosis based on network pharmacology, molecular docking and experimental verification

Aims

This study aims to screen the potential targets of tetrandrine (Tet) against pulmonary fibrosis (PF) based on network pharmacological analysis, molecular docking and experimental verification.

Main methods

The network pharmacology methods were employed to predict targets, construct Tet-PF-intersection target-pathway networks, and screen the candidate targets. The molecular docking was performed using AutoDockTools1.5.6. TGF-β1-induced human lung adenocarcinoma A549 cells were used as an in vitro experimental verification model, taking dexamethasone (Dex) as the positive control, to verify the effects of Tet on the mRNA expression of the candidate targets.

Key findings

Six candidate targets were predicted based on network pharmacology and molecular docking, namely PIK3CA, PDPK1, RAC1, PTK2, KDR, and RPS6KB1. The experimental verification results showed that Dex and Tet presented quite different pharmacological effects. Specifically, compared with the model group, both Dex and Tet (5 μΜ) significantly increased the mRNA expression of PIK3CA and KDR (P < 0.001). Dex up-regulated the mRNA expression of PDPK1 and RAC1, while Tet (1.25 μΜ) down-regulated (P < 0.001). Dex up-regulated the mRNA expression of PTK2, but Tet had no effect. Dex down-regulated RPS6KB1 mRNA expression, while Tet (5 μΜ) up-regulated (P < 0.01).

Significance

Combined with the results of theoretical calculation and experimental verification, and considering the roles of these targets in the pathogenesis of PF, Tet might antagonize PF by acting on PDPK1 and RAC1. The results of this study will provide scientific reference for the prevention and clinical diagnosis and treatment of PF.

Potential “Therapeutic” Effects of Tocotrienol-Rich Fraction (TRF) and Carotene “Against” Bleomycin-Induced Pulmonary Fibrosis in Rats via TGF-β/Smad, PI3K/Akt/mTOR and NF-κB Signaling Pathways

Background: Pulmonary fibrosis (PF) is a chronic, progressive, and, ultimately, terminal interstitial disease caused by a variety of factors, ranging from genetics, bacterial, and viral infections, to drugs and other influences. Varying degrees of PF and its rapid progress have been widely reported in post-COVID-19 patients and there is consequently an urgent need to develop an appropriate, cost-effective approach for the prevention and management of PF. Aim: The potential “therapeutic” effect of the tocotrienol-rich fraction (TRF) and carotene against bleomycin (BLM)-induced lung fibrosis was investigated in rats via the modulation of TGF-β/Smad, PI3K/Akt/mTOR, and NF-κB signaling pathways. Design/Methods: Lung fibrosis was induced in Sprague-Dawley rats by a single intratracheal BLM (5 mg/kg) injection. These rats were subsequently treated with TRF (50, 100, and 200 mg/kg body wt/day), carotene (10 mg/kg body wt/day), or a combination of TRF (200 mg/kg body wt/day) and carotene (10 mg/kg body wt/day) for 28 days by gavage administration. A group of normal rats was provided with saline as a substitute for BLM as the control. Lung function and biochemical, histopathological, and molecular alterations were studied in the lung tissues. Results: Both the TRF and carotene treatments were found to significantly restore the BLM-induced alterations in anti-inflammatory and antioxidant functions. The treatments appeared to show pneumoprotective effects through the upregulation of antioxidant status, downregulation of MMP-7 and inflammatory cytokine expressions, and reduction in collagen accumulation (hydroxyproline). We demonstrated that TRF and carotene ameliorate BLM-induced lung injuries through the inhibition of apoptosis, the induction of TGF-β1/Smad, PI3K/Akt/mTOR, and NF-κB signaling pathways. Furthermore, the increased expression levels were shown to be significantly and dose-dependently downregulated by TRF (50, 100, and 200 mg/kg body wt/day) treatment in high probability. The histopathological findings further confirmed that the TRF and carotene treatments had significantly attenuated the BLM-induced lung injury in rats. Conclusion: The results of this study clearly indicate the ability of TRF and carotene to restore the antioxidant system and to inhibit proinflammatory cytokines. These findings, thus, revealed the potential of TRF and carotene as preventive candidates for the treatment of PF in the future.

Natural Product-Based Potential Therapeutic Interventions of Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a disease-refractive lung condition with an increased rate of mortality. The potential factors causing PF include viral infections, radiation exposure, and toxic airborne chemicals. Idiopathic PF (IPF) is related to pneumonia affecting the elderly and is characterized by recurring scar formation in the lungs. An impaired wound healing process, defined by the dysregulated aggregation of extracellular matrix components, triggers fibrotic scar formation in the lungs. The potential pathogenesis includes oxidative stress, altered cell signaling, inflammation, etc. Nintedanib and pirfenidone have been approved with a conditional endorsement for the management of IPF. In addition, natural product-based treatment strategies have shown promising results in treating PF. In this study, we reviewed the recently published literature and discussed the potential uses of natural products, classified into three types-isolated active compounds, crude extracts of plants, and traditional medicine, consisting of mixtures of different plant products-in treating PF. These natural products are promising in the treatment of PF via inhibiting inflammation, oxidative stress, and endothelial mesenchymal transition, as well as affecting TGF-β-mediated cell signaling, etc. Based on the current review, we have revealed the signaling mechanisms of PF pathogenesis and the potential opportunities offered by natural product-based medicine in treating PF.

Targeting Oxidative Stress as a Therapeutic Approach for Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease characterized by an abnormal reepithelialisation, an excessive tissue remodelling and a progressive fibrosis within the alveolar wall that are not due to infection or cancer. Oxidative stress has been proposed as a key molecular process in pulmonary fibrosis development and different components of the redox system are altered in the cellular actors participating in lung fibrosis. To this respect, several activators of the antioxidant machinery and inhibitors of the oxidant species and pathways have been assayed in preclinical in vitro and in vivo models and in different clinical trials. This review discusses the role of oxidative stress in the development and progression of IPF and its underlying mechanisms as well as the evidence of oxidative stress in human IPF. Finally, we analyze the mechanism of action, the efficacy and the current status of different drugs developed to inhibit the oxidative stress as anti-fibrotic therapy in IPF.

Nano-designed CO donor ameliorates bleomycin-induced pulmonary fibrosis via macrophage manipulation

Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible interstitial pulmonary disease due to chronic inflammatory responses. The prognosis of IPF is very poor, however, the therapeutic options are very limited. Previously we developed a polymeric micellar drug delivery system of carbon monoxide (CO) that is a pivotal anti-inflammatory gaseous molecule, i.e., SMA/CORM2, which exhibited therapeutic potentials against dextran sulfate sodium (DSS)-induced mouse colitis and acetaminophen (APAP) induced liver injury. Along this line, here we investigate the applicability of SMA/CORM2 on IPF using a bleomycin (BLM)-induced pulmonary fibrosis model. Severe inflammation and the consequent pulmonary fibrosis were triggered by BLM, whereas SMA/CORM2 treatment remarkably suppressed the inflammation progression and ameliorated the formation of fibrosis. CO is the effector molecule of SMA/CORM2, which exerted the therapeutic/protective effect mostly through suppressing the reprogramming of anti-inflammatory macrophages as revealed by the decreased expressions of CD206 and arginase-1 that were remarkably upregulated by BLM exposure. The suppression of macrophage polarization accompanied the downregulated hypoxia-inducible factor-1α (HIF-1α) and its target molecule heme oxygenase-1 (HO-1), suggesting a HIF-1α/HO-1 pathway for modulating macrophage reprogramming. As the downstream event of anti-inflammatory macrophage polarization, the alveolar epithelial to mesenchymal transition that is the major source of myofibroblast, the hallmark of IPF, was significantly suppressed by SMA/CORM2 via a TGF-β/Smad2/3 pathway. Compared to native CORM2 of equivalent dose, SMA/CROM2 exhibited a much better protective effect indicating its superior bioavailability as an enhanced permeability and retention (EPR) effect-based nanomedicine. We thus anticipate the application of SMA/CORM2 as a therapeutic candidate for IPF as well as other inflammatory diseases and disorders.

Poria cocos polysaccharides attenuate chronic nonbacterial prostatitis by targeting the gut microbiota: Comparative study of Poria cocos polysaccharides and finasteride in treating chronic prostatitis

Finasteride is an antiandrogenic drug used for the clinical treatment of chronic nonbacterial prostatitis (CNP). Recently, we reported the anti-CNP activity of Poria cocos polysaccharides (PPs) in a rat model. In this study, we compared the differences between PPs and finasteride in treating CNP, especially their effects on the gut microbiota. Results showed that both PPs and finasteride significantly reduced the prostate weight and prostate index of CNP rats, and improved the histological damages in the inflamed prostate. Moreover, PPs and finasteride inhibited the production of pro-inflammatory cytokines (TNF-α, IL-2 and IL-8) and androgens (dihydrotestosterone and testosterone). By 16S rDNA sequencing, PPs and finasteride were found to reprogram the gut microbiota into distinct profiles. Further analysis presented that PPs but not finasteride recovered CNP-induced changes in the gut microbiota, including Ruminococcaceae NK4A214 group, uncultured bacterium f Ruminococcaceae, Ruminiclostridium 9, Phascolarctobacterium, Coriobacteriaceae UCG-002 and Oribacterium. LDA effect size (LEfSe) analysis revealed that PPs recovered the gut microbiota by targeting Ruminococcaceae NK4A214 group. Our results suggested that PPs alleviated CNP via different mechanisms from finasteride, especially by regulating the gut microbiota, which offers therapeutic target for the treatment of CNP.

Pharmacologic Activities of Plant-Derived Natural Products on Respiratory Diseases and Inflammations

Respiratory inflammation is caused by an air-mediated disease induced by polluted air, smoke, bacteria, and viruses. The COVID-19 pandemic is also a kind of respiratory disease, induced by a virus causing a serious effect on the lungs, bronchioles, and pharynges that results in oxygen deficiency. Extensive research has been conducted to find out the potent natural products that help to prevent, treat, and manage respiratory diseases. Traditionally, wider floras were reported to be used, such as Morus alba, Artemisia indica, Azadirachta indica, Calotropis gigantea, but only some of the potent compounds from some of the plants have been scientifically validated. Plant-derived natural products such as colchicine, zingerone, forsythiaside A, mangiferin, glycyrrhizin, curcumin, and many other compounds are found to have a promising effect on treating and managing respiratory inflammation. In this review, current clinically approved drugs along with the efficacy and side effects have been studied. The study also focuses on the traditional uses of medicinal plants on reducing respiratory complications and their bioactive phytoconstituents. The pharmacological evidence of lowering respiratory complications by plant-derived natural products has been critically studied with detailed mechanism and action. However, the scientific validation of such compounds requires clinical study and evidence on animal and human models to replace modern commercial medicine.

Mangostanin Derivatives as Novel and Orally Active Phosphodiesterase 4 Inhibitors for the Treatment of Idiopathic Pulmonary Fibrosis with Improved Safety

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease, and its incidence rate is rapidly rising. However, effective therapies for the treatment of IPF are still lacking. Phosphodiesterase 4 (PDE4) inhibitors were reported to be potential anti-fibrotic agents, but their clinical use was hampered by side effects like emesis and nausea. Herein, structure-based hit-to-lead optimizations of natural mangostanin resulted in the novel and orally active PDE4 inhibitor 18a with potent inhibitory affinity (IC50 = 4.2 nM), favorable physico-chemical properties, and a different binding pattern from roflumilast. Emetic activity tests on dogs demonstrated that 18a cannot cause emesis even at an oral dose of 10 mg/kg, whereas rolipram had severe emetic effects at an oral dose of 1 mg/kg. Finally, the oral administration of 18a (10 mg/kg) exhibited comparable anti-pulmonary fibrosis effects with pirfenidone (150 mg/kg) in a bleomycin-induced IPF rat model, indicating its potential as a novel anti-IPF agent with improved safety.

The Mechanism and Effect of Autophagy, Apoptosis, and Pyroptosis on the Progression of Silicosis

Silicosis remains one of the most severe pulmonary fibrotic diseases worldwide, caused by chronic exposure to silica dust. In this review, we have proposed that programmed cell death (PCD), including autophagy, apoptosis, and pyroptosis, is closely associated with silicosis progression. Furthermore, some autophagy, apoptosis, or pyroptosis-related signaling pathways or regulatory proteins have also been summarized to contribute greatly to the formation and development of silicosis. In addition, silicosis pathogenesis depends on the crosstalk among these three ways of PCD to a certain extent. In summary, more profound research on these mechanisms and effects may be expected to become promising targets for intervention or therapeutic methods of silicosis in the future.

Natural Products, Alone or in Combination with FDA-Approved Drugs, to Treat COVID-19 and Lung Cancer

As a public health emergency of international concern, the highly contagious coronavirus disease 2019 (COVID-19) pandemic has been identified as a severe threat to the lives of billions of individuals. Lung cancer, a malignant tumor with the highest mortality rate, has brought significant challenges to both human health and economic development. Natural products may play a pivotal role in treating lung diseases. We reviewed published studies relating to natural products, used alone or in combination with US Food and Drug Administration-approved drugs, active against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and lung cancer from 1 January 2020 to 31 May 2021. A wide range of natural products can be considered promising anti-COVID-19 or anti-lung cancer agents have gained widespread attention, including natural products as monotherapy for the treatment of SARS-CoV-2 (ginkgolic acid, shiraiachrome A, resveratrol, and baicalein) or lung cancer (daurisoline, graveospene A, deguelin, and erianin) or in combination with FDA-approved anti-SARS-CoV-2 agents (cepharanthine plus nelfinavir, linoleic acid plus remdesivir) and anti-lung cancer agents (curcumin and cisplatin, celastrol and gefitinib). Natural products have demonstrated potential value and with the assistance of nanotechnology, combination drug therapies, and the codrug strategy, this "natural remedy" could serve as a starting point for further drug development in treating these lung diseases.