Cardamonin attenuates phorbol 12-myristate 13-acetate-induced pulmonary inflammation in alveolar macrophages

Cardamonin protects against diabetic cardiomyopathy by activating macrophage NRF2 signaling through molecular interaction with KEAP1

Diabetic cardiomyopathy (DCM) contributes to a large proportion of heart failure incidents in the diabetic population, but effective therapeutic approaches are rare. Cardamonin (CAD), a flavonoid found in Alpinia, possesses anti-inflammatory and anti-oxidative activities. Here we report a profound protective effect of CAD on DCM in a mouse model of type 2 diabetes induced by streptozotocin and a high-fat diet, in which gavage with CAD improved hyperglycemia and glucose intolerance and mitigated diabetic cardiac injuries including cardiac dysfunction, hypertrophy, apoptotic cell death and infiltration of inflammatory cells, especially M1 polarized macrophages. To verify whether CAD could protect against cardiomyocyte injury through inhibiting macrophage M1 polarization, M1 polarized macrophages were treated with CAD, followed by washing out and co-culturing with cardiomyocytes, showing that CAD remarkably inhibited macrophage M1 polarization and the following cardiomyocyte injury, along with activation of the nuclear factor erythroid 2-related factor 2 (NRF2) antioxidant signaling pathway. Molecular docking and surface plasmon resonance assays found Kelch-like ECH-associated protein 1 (KEAP1) as the molecular target of CAD. Both CAD and the Kelch domain inhibitor Ki696 promoted the nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2). This work may provide CAD as a novel NRF2 activator in future interventions for DCM.

Cardamonin inhibits silicosis development through the PI3K-AKT signaling pathway

Silicosis is one of the most severe occupational diseases characterized by inflammatory cell infiltration, fibroblasts activation, and fibrosis in the lung. However, specific drug treatments are lacking. Cardamonin (CDM) has been reported to possess antitumor, anti-inflammatory/fibrotic effects. While, the effect of CDM on the progression of silicosis remains unknown. In this study, we established a SiO2-M stimulated fibroblast cell model, and explored the antifibrotic effect of CDM and the related molecular mechanism using WB, RT-qPCR, and immunofluorescence. The results indicate that CDM inhibits SiO2-M-induced fibroblast activation, proliferation, and migration. Furthermore, a silicosis mouse model was established through injecting silica suspension intratracheally. The results revealed that CDM retards the progression of pulmonary fibrosis. The RNA sequencing results suggest that the antifibrotic effect of CDM may be mediated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway. In conclusion, the results of this study demonstrate that CDM inhibits the development of silicosis via the PI3K-AKT signaling pathway, which could provide guidance for the development of drugs for silicosis treatment.

Cardamonin inhibits the expression of inflammatory mediators in TNF-α-stimulated human periodontal ligament cells

OBJECTIVE

Periodontis is a chronic inflammatory disease induced by periodontopathogenic bacteria. The excessive immune response caused by persistent bacterial infection leads to alveolar bone resorption and ultimately tooth loss. Cardamonin is a biologically active substance that is found in the Zingiberaceae family, such as Alpinia zerumbet, and is classified as a natural chalcone. There have been no attempts to use cardamonin for the treatment of periodontitis, and no reports have examined the effects of cardamonin on periodontal tissue component cells. The aim of this study was to analyze effects of cardamonin on expression of inflammation mediators produced by TNFα-stimulated human periodontal ligament cells (HPDLCs), including its effects on signal transduction molecules.

METHODS

Cytokine and chemokine levels were measured by ELISA. Protein expression in HPDLCs and activations of signal transduction pathway were determined by Western blotting.

RESULTS

Our results indicate that cardamonin suppresses C-C motif chemokine ligand (CCL)2, CCL20, C-X-C motif chemokine ligand (CXCL)10, and interleukin (IL)-6 production and intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 expression in TNF-α-stimulated HPDLCs. In addition, cardamonin induced the expression of the antioxidant enzyme, Heme Oxygenase (HO)-1, in HPDLCs. Furthermore, cardamonin suppressed TNF-α-stimulated c-Jun N-terminal kinase (JNK), nuclear factor (NF)-κB, and signal transducer and activator of transcription (STAT)3 signaling pathways in HPDLCs.

CONCLUSION

We show that cardamonin reduces inflammatory mediator production by inhibiting the activation of several signaling pathways in this manuscript.

Cardamonin decreases inflammatory mediator expression in IL-1β-stimulated human periodontal ligament cells

BACKGROUND

Cardamonin is classified as a natural chalcone, and has been reported to possess various bioactive effects. However, there have been limited attempts to utilize cardamonin in the treatment of periodontitis. This study aimed to investigate whether cardamonin has anti-inflammatory effects on human periodontal ligament cells (HPDLCs), which are a component cell of periodontal tissue. Specifically, the study seeks to determine whether cardamonin affects the expression of inflammatory mediators, such as cytokines and adhesion molecules, induced by interleukin-1β (IL-1β) in HPDLCs, as well as the signaling pathways activated by IL-1β.

METHODS

Cytokine and chemokine levels in supernatants of HPDLCs were measured by ELISA. Western blot analysis was used to measure protein expression and signal transduction pathway activation in HPDLCs.

RESULTS

We found that IL-1β-induced CC chemokine ligand (CCL)2, CCL5, CCL20, CXC-chemokine ligand (CXCL)10, and interleukin (IL)-6 production and intercellular adhesion molecule (ICAM)-1 and cyclooxygenase (COX)-2 expression in HPDLCs were suppressed by cardamonin treatment. We also found that cardamonin suppressed IL-1β-activated nuclear factor (NF)-κB pathway, and the phosphorylation of signal transducer and activator of transcription (STAT)3. Furthermore, cardamonin treatment enhanced the expression of the antioxidant enzymes, heme oxygenase (HO)-1 and NAD(P)H dehydrogenase [quinone] 1 (NQO1), in HPDLCs.

CONCLUSION

In this study, we found that cardamonin could suppress the production of inflammatory mediators in HPDLCs as well as the activation of several signaling pathways induced by IL-1β treatment.

Cardamonin targets KEAP1/NRF2 signaling for protection against atherosclerosis

Atherosclerosis (AS)-induced cardiovascular disease is a leading cause of death worldwide. To date, there is still a lack of effective approaches for AS intervention. Cardamonin (CAD) is a bioactive food component, but its effect on AS is unknown. In this work, CAD was investigated for its effect on AS using low-density lipoprotein receptor knockout mice and tumor necrosis factor-alpha (TNF-α)-stimulated endothelial cells (ECs). After a 12-week intervention, CAD was found to significantly prevent AS formation in the aortic root and aortic tree, reduce the necrotic core area, and inhibit aortic inflammation and oxidative stress. Moreover, CAD quenched TNF-α-provoked inflammation and oxidative stress in ECs. RNA-sequencing identified nuclear factor erythroid-2 related factor 2 (NFE2L2, NRF2)/heme oxidase 1 (HO1) signaling to be drastically activated by CAD. CAD is a known activator of the aryl hydrocarbon receptor (AHR) which is a transcription factor of the NFE2L2 gene. Surprisingly, AHR was not required for CAD's action on the activation of NRF2/HO1 signaling since AHR gene silencing did not reverse this effect. Furthermore, a molecular docking assay showed a strong binding potential of CAD to the Kelch domain of the Kelch-like ECH-associated protein 1 (KEAP1) which sequesters NRF2 in the cytoplasm. Both CAD and the Kelch domain inhibitor Ki696 promoted NRF2 nuclear translocation, whereas the combination of CAD and Ki696 did not yield a greater effect compared with either CAD or Ki696, confirming the interaction of CAD with the Kelch domain. This work provides an experimental basis for CAD as a novel and effective bioactive food component in future AS interventions.

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.