Gomisin N Decreases Inflammatory Cytokine Production in Human Periodontal Ligament Cells

Zerumbone modulates the expression of inflammatory mediators and antioxidant enzymes in TNF-α-stimulated human periodontal ligament cells

OBJECTIVES

Periodontal disease is a chronic inflammatory disease caused by periodontopathogenic bacteria, and its progression leads to periodontal tissue destruction and tooth loss. Zerumbone is a bioactive substance found in ginger (Zingiber zerumbet) and is known to have bioactive effects such as anticancer effects, but there have been no attempts to use it for periodontitis treatment. In addition, there have been no reports examining its effects on periodontal tissue component cells. In this experiment, we aimed to determine whether zerumbone affects the production of inflammatory mediators induced by tumor necrosis factor (TNF)-α in human periodontal ligament cells (HPDLCs), including its effects on signaling pathways.

METHODS

HPDLCs were stimulated by TNF-α (10 ng/ml) with or without zerumbone (6.25, 12.5, or 25 µM). Cytokine production in supernatant was determined using ELISA. Activation of signal transduction pathways and intracellular protein expression were investigated using the western blot analysis.

RESULTS

Zerumbone significantly suppressed TNF-α-induced production of CC chemokine ligand 2 (CCL2), CCL20, CXC chemokine ligand 10 (CXCL10), and interleukin-6 (IL-6) in HPDLCs. In addition, zerumbone decreased intercellular adhesion molecule-1 (ICAM-1) and cyclooxygenase-2 (COX-2) expression in TNF-α-stimulated HPDLCs. Furthermore, zerumbone suppressed activation of nuclear factor (NF)-κB and signal transducer and activator of transcription 3 (STAT3) pathways in TNF-α-treated HPDLCs. Finally, zerumbone enhanced the production of heme oxygenase-1 (HO-1), an antioxidant enzyme, in HPDLCs.

CONCLUSION

These results suggest that zerumbone suppressed the production of several inflammatory mediators by inhibiting the NF-κB and STAT3 pathways in HPDLCs.

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.

Gomisin N attenuated cerebral ischemia-reperfusion injury through inhibition of autophagy by activating the PI3K/AKT/mTOR pathway

BACKGROUND

Ischemic stroke is a major global cause of mortality and permanent disability.  Studies have shown that autophagy is essential to maintain cell homeostasis and inevitably lead to neuronal damage after cerebral ischemia. Gomisin N (GN), lignin isolated from Schisandra chinensis, possesses multiple pharmacological activities. However, there is no research on the potential of GN for neuroprotection in ischemic stroke.

PURPOSE

The current work aimed to explore the potential therapeutic possibilities of GN on ischemic stroke and investigate the underlying molecular mechanisms.

STUDY DESIGN

The neuroprotective effects of GN on PC12 cells induced by oxygen glucose deprivation/reoxygenation (OGD/R) and mice with middle cerebral artery occlusion/reperfusion (MCAO/R) injury were investigated.

METHODS

On day 3 after ischemia, the infarct volume and neurological function were assessed. The level of autophagy was measured in vivo and in vitro using Transmission electron microscopy (TEM) and Monodansylcadaverine (MDC) staining. The interaction between GN and PI3K/AKT/mTOR pathway was investigated by molecular docking. Additionally, the expressions of critical proteins in the PI3K/AKT/mTOR signaling pathway and autophagy markers were determined by western blotting.

RESULTS

In compared to the Model group, GN might considerably improve the neurological and locomotor function following a stroke, as well as lower the volume of the cerebral infarct volume and the number of autophagosomes. GN therapy may suppress autophagy by activating the PI3K/Akt/mTOR signaling pathway in the penumbra. In vitro, MDC and TEM results showed that GN treatment obviously suppressed autophagy. Meanwhile, GN downregulated LC3II/LC3I expression ratio while upregulated the p62 expression level. In further studies, GN dramatically boosted the expression ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR proteins in PC12 cells following OGD/R damage. However, the PI3K inhibitor (LY294002) reversed the increase of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR expression ratio induced by GN administration. Also, LY294002 significantly partially attenuated GN induced reduction of autophagy and increase of cell viability compared with GN treatment alone.

CONCLUSIONS

Here, we first demonstrate the neuroprotective effects of GN on MCAO mice and OGD/R induced PC12 cells injury. A possible mechanism by which GN prevents ischemic stroke is proposed: GN could restrain autophagy by stimulating the PI3K/AKT/mTOR signaling pathways. More effects and mechanisms of GN on the rehabilitation of ischemic stroke are worthy to be explored in the future.

Long non-coding RNA SNHG5 mediates periodontal inflammation through the NF-κB signaling pathway

AIM

We investigated the role of the long non-coding RNA (lncRNA), small nucleolar RNA host gene 5 (SNHG5), in the pathogenesis of periodontitis.

MATERIALS AND METHODS

A ligature-induced periodontitis mouse model was established, and gingival tissues from patients with periodontitis and healthy controls were collected. Inflammatory cytokines were detected using qRT-PCR and western blotting analyses. Direct interactions between SNHG5 and p65 were detected by RNA pull-down and RNA immunoprecipitation assays. Micro-computed tomography, hematoxylin and eosin staining, and immunohistochemical staining were used to measure periodontal bone loss.

RESULTS

SNHG5 expression was downregulated in human and mouse periodontal tissues compared to that in the healthy controls. In vitro experiments demonstrated that SNHG5 significantly ameliorated tumor necrosis factor-α (TNFα)-induced inflammation. Mechanistically, SNHG5 directly binds to the nuclear factor-kappa B (NF-κB) p65 subunit and inhibits its translocation, thereby suppressing the NF-κB signaling pathway activation and reducing the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 inflammasome expression. Locally injecting si-SNHG5 aggravated the periodontal destruction.

CONCLUSION

This study revealed that SNHG5 mediates periodontal inflammation through the NF-κB signaling pathway, providing a potential therapeutic target for periodontitis treatment. This article is protected by copyright. All rights reserved.

Nobiletin Decreases Inflammatory Mediator Expression in Tumor Necrosis Factor-Stimulated Human Periodontal Ligament Cells

Nobiletin, a biologically active substance in the skin of citrus fruits, has been reported to be an effective anti-inflammatory, anticancer, and antimicrobial agent. In this study, we aimed to examine the anti-inflammatory effects of nobiletin on tumor necrosis factor- (TNF-) stimulated human periodontal ligament cells (HPDLCs). Our results demonstrated that nobiletin treatment could decrease the expressions of inflammatory cytokines (C-X-C motif chemokine ligand (CXCL)10, C-C motif chemokine ligand (CCL)2, and interleukin- (IL-) 8), matrix metalloproteinases (MMPs) (MMP1 and MMP3), and prostaglandin-endoperoxide synthase 2 (PTGS2) in TNF-stimulated HPDLCs. Moreover, we revealed that nobiletin could inhibit the activation of nuclear factor- (NF-) κB and protein kinase B (AKT1) pathways in TNF-stimulated HPDLCs. Furthermore, nobiletin treatment enhanced nuclear factor, erythroid 2 like 2 (NFE2L2) and heme oxygenase 1 (HMOX1) expressions in TNF-stimulated HPDLCs. In conclusion, these findings suggest that nobiletin can inhibit inflammatory responses in TNF-stimulated HPDLCs by inhibiting NF-κB and AKT1 activations and upregulating the NFE2L2 and HMOX1 expression.

Nobiletin Inhibits Inflammatory Reaction in Interleukin-1β-Stimulated Human Periodontal Ligament Cells

The immune response in periodontal lesions is involved in the progression of periodontal disease. Therefore, it is important to find a bioactive substance that has anti-inflammatory effects in periodontal lesions. This study aimed to examine if nobiletin, which is found in the peel of citrus fruits, could inhibit inflammatory responses in interleukin (IL)-1β-stimulated human periodontal ligament cells (HPDLCs). The release of cytokines (IL-6, IL-8, CXCL10, CCL20, and CCL2) and matrix metalloproteinases (MMP-1 and MMP-3) was assessed by ELISA. The expression of cell adhesion molecules (ICAM-1and VCAM-1) and the activation of signal transduction pathways (nuclear factor (NF)-κB, mitogen-activated protein kinases (MAPKs) and protein kinase B (Akt)) in HPDLCs were detected by Western blot analysis. Our experiments revealed that nobiletin decreased the expression of inflammatory cytokines, cell adhesion molecules, and MMPs in IL-1β-stimulated HPDLCs. Moreover, we revealed that nobiletin treatment could suppress the activation of the NF-κB, MAPKs, and Akt pathways. These findings indicate that nobiletin could inhibit inflammatory reactions in IL-1β-stimulated HPDLCs by inhibiting multiple signal transduction pathways, including NF-κB, MAPKs, and Akt.

Pharmacodynamic effects and molecular mechanisms of lignans from Schisandra chinensis Turcz. (Baill.), a current review

Fruit of Schisandra chinensis Turcz. (Baill.) (S. chinensis) is a traditional herbal medicine widely used in China, Korea, and many other east Asian countries. At present, S. chinensis commonly forms Chinese medicinal formulae with other herbal medicines to treat liver disease and neurological disease in clinical. Modern researches indicated that lignans were the main active ingredients of S. chinensis with high content and novel dibenzocyclooctadiene skeletal structure, exhibited considerable antioxidant, anti-inflammatory, and neuroprotective properties. Additionally, some of these lignans also showed certain potentials in anti-cancer, anti-fibrosis, and other effects. In the current review, we summarize literature reported lignans from S. chinensis in the past five years, and highlight the molecular mechanisms of lignans in exerting their biological functions. Also, we point out some deficiencies of existing researches and discuss the future direction of lignans study.

Sudachitin Inhibits Matrix Metalloproteinase-1 and -3 Production in Tumor Necrosis Factor-α-Stimulated Human Periodontal Ligament Cells

Sudachitin, a polymethoxylated flavonoid found in the skin of Citrus sudachi, is a biologically active substance. The aim of this study was to examine whether sudachitin could be used to inhibit the expression of matrix metalloproteinase (MMP)-1 and MMP-3, which are involved in the destruction of periodontal tissues in periodontal lesions, in tumor necrosis factor (TNF)-α-stimulated human periodontal ligament cells (HPDLC). Sudachitin suppressed TNF-α-induced MMP-1 and MMP-3 production in HPDLC. On the other hand, it enhanced tissue inhibitor of metalloproteinase (TIMP)-1 expression. The level of Akt phosphorylation in the TNF-α-stimulated HPDLC was decreased by sudachitin treatment. Moreover, an Akt inhibitor reduced MMP-1 and MMP-3 production and increased TIMP-1 production. These findings indicate that sudachitin reduces MMP-1 and MMP-3 production in TNF-α-stimulated HPDLC by inhibiting the Akt pathway.