Anti-Inflammatory and Protective Effects of Juncus effusus L. Water Extract on Oral Keratinocytes

Periodontitis is a chronic inflammatory disease caused by periodontopathogenic bacteria that form biofilms in periodontal pockets. The gingival epithelium acts as the first physical barrier in fighting attacks by periodontopathogenic pathogens, such as the primary etiological agent Porphyromonas gingivalis, and various exogenous chemicals, as well as regulates the local innate immune responses. Therefore, the development of novel oral care products to inhibit inflammatory reactions caused by bacterial infection and protect the gingival epithelium is necessary. Juncus effusus L. has generally been used as an indigenous medicine, such as a diuretic, an antipyretic, and an analgesic, in ancient practice. In this study, we examined the effects of a water extract from J. effusus L. on the inhibition of the inflammatory reaction elicited by bacterial infection and protection of the oral epithelium by chemical irritation. Pretreatment of oral epithelial cells with the water extract from J. effusus L. significantly reduced P. gingivalis or its lipopolysaccharide- (LPS-) mediated production of chemokines (interleukin-8 and C-C-chemokine ligand20) in a concentration-dependent manner with comparable to or greater effects than epigallocatechin gallate and protected oral epithelial cells from injury by chemical irritants, cetylpyridinium chloride, and benzethonium chloride. Moreover, the water extract from J. effusus L. in the presence of antimicrobial agents or antifibrinolytics already used as ingredients in mouthwash could significantly reduce the production of chemokines from P. gingivalis LPS-stimulated oral epithelial cells in a concentration-dependent manner. These findings suggest that the water extract from J. effusus L. is potentially useful for oral care to prevent oral infections, such as periodontal infections, and maintain oral epithelial function.

Effect of human secretory calcium-binding phosphoprotein proline-glutamine rich 1 protein on Porphyromonas gingivalis and identification of its active portions

The mouth environment comprises the second most significant microbiome in the body, and its equilibrium is critical in oral health. Secretory calcium-binding phosphoprotein proline-glutamine rich 1 (SCPPPQ1), a protein normally produced by the gingival epithelium to mediate its attachment to teeth, was suggested to be bactericidal. Our aim was to further explore the antibacterial potential of human SCPPPQ1 by characterizing its mode of action and identifying its active portions. In silico analysis showed that it has molecular parallels with antimicrobial peptides. Incubation of Porphyromonasgingivalis, a major periodontopathogen, with the full-length protein resulted in decrease in bacterial number, formation of aggregates and membrane disruptions. Analysis of SCPPPQ1-derived peptides indicated that these effects are sustained by specific regions of the molecule. Altogether, these data suggest that human SCPPPQ1 exhibits antibacterial capacity and provide new insight into its mechanism of action.

Case Report: A Case of Hereditary Gingival Fibromatosis With a High Level of Human β Defensins in Gingival Epithelium

Hereditary gingival fibromatosis [HGF, (MIM 135300)], a rare benign oral condition, has several adverse consequences such as aesthetic changes, malocclusion, speech impediments, and abnormal dentition. However, relatively few studies have addressed the beneficial effects of thick gingival tissues in resisting external stimuli. In this report, we present a unique case of a family affected by HGF that manifests as a ‘healthy’ gingiva. Human β-defensins (hBDs) are known to play a pivotal role in the clearance and killing of various microbes, and contribute to maintaining a healthy oral environment, which is currently emerging research area. However, the expression pattern and localisation of hBDs in patients with HGF have not yet been reported. hBD-2 and hBD-3 in the pedigree we collected had relatively elevated expression. High hBD levels in the gingival tissue of patients from the family may be beneficial in protecting oral tissue from external stimuli and promoting periodontal regeneration, but their role and the mechanisms underlying HGF need to be clarified.

Regulation of the unfolded protein response transducer IRE1α by SERPINH1 aggravates periodontitis with diabetes mellitus via prolonged ER stress

Background The hyperglycemic microenvironment induced by diabetes mellitus aggravates the inflammatory response, in which the inositol-requiring enzyme-1α (IRE1α) signal transduction pathway of the unfolded protein response (UPR) participates. This study aimed to investigate the mechanism by which hyperglycemia regulates the IRE1α signaling pathway and affects endoplasmic reticulum (ER) homeostasis in human gingival epithelium in periodontitis with diabetes mellitus (DP). Methods Human gingival epithelium samples from healthy subjects, subjects with periodontitis and subjects with DP were collected, in vitro cultures of human gingival epithelial cells were challenged with a hyperglycemic microenvironment to observe the effects of diabetes on periodontal inflammation and to assess UPR-IRE1α signaling in human gingival epithelium in DP. Subsequently, RNA sequencing (RNA-seq) data was analyzed to investigate the expression of ER-related genes in human gingival epithelium. Furthermore, to explore the key role of serpin family H member 1 (SERPINH1) in the regulation of UPR-IRE1α signaling in a hyperglycemic microenvironment, experiments in SERPINH1-knockdown and SERPINH1-overexpression models were established in vitro. Results Diabetes causes a hyperinflammatory response in human gingival epithelium, which accelerates periodontal inflammation. A hyperglycemic microenvironment inhibited the inositol-requiring enzyme-1α / X-box binding protein 1 (IRE1α/XBP1) axis, decreased the expression of glucose regulated protein 78 (GRP78), and ultimately impaired the UPR, causing ER stress to be prolonged or more severe in human gingival epithelium. The RNA-seq and experiments revealed that the mechanism by which periodontitis is aggravated in individuals with diabetes mellitus may involve decreased SERPINH1 expression. SERPINH1 might act as an activator of IRE1α, maintaining human gingival epithelium homeostasis, suppressing nuclear factor-κB signaling pathway and reducing NOD-like receptor, pyrin domain containing protein 3 (NLRP3) and interleukin-1 beta (IL-1β) expression by preventing prolonged ER stress induced by high-glucose conditions. Conclusion Regulation of the UPR transducer IRE1α by SERPINH1 alleviates DP by mitigating prolonged ER stress.

Effectiveness of an 810-nm Diode Laser in Addition to Non-surgical Periodontal Therapy in Patients With Chronic Periodontitis: A Randomized Single-Blind Clinical Trial

Introduction: This study evaluated the effectiveness of an 810-nm diode laser as an adjunct to scaling and root planning (SRP) in improving periodontal parameters in patients with chronic periodontitis. Methods: This randomized clinical trial consisted of 36 patients (16 females and 20 males) with chronic periodontitis and pocket depths of 4-6 mm. The quadrants were randomly divided into two sides; one side of each patient was selected as the laser group (SRP + laser) and the other side served as the control group (SRP alone). An 810-nm diode laser was applied in the laser side to remove the outer gingival epithelium (1.5 W, CW) as well as the inner epithelium of the periodontal pockets (1 W, CW). The clinical parameters including bleeding on probing (BOP), probing depth (PD), plaque index (PI), and clinical attachment level (CAL) were measured at baseline and 6 and 18 weeks after therapy. Results: In both groups, there was a significant improvement in BOP, PD, PI and CAL over the course of the experiment (P<0.001). Significantly lower BOP was found in the SRP + laser group than the SRP alone group after 6 and 18 weeks of intervention (P<0.05). The difference in other parameters was not significant between the two groups, neither at 6 nor at 18 weeks after the treatment (P>0.05). Conclusion: Within the limitations of this study, the association of the diode laser with standard non-surgical periodontal therapy (SRP) provided minimal additional benefits for patients with moderate chronic periodontitis.

Prevalence of Gingival Pigmentation and its Association with Gingival Biotype and Skin Colour

Introduction: The facial appearance depends on several oral and extraoral factors including colour of facial skin and pigmentation of gingival epithelium. The colour of the gingiva varies among individuals and is thought to be associated with cutaneous pigmentation which ranges from light to dark brown or black colour. Objective: To assess the prevalence of physiological gingival pigmentation, gingival biotype and their association with skin colur in Nepalese subjects visiting Kantipur Dental College and Hospital (KDCH). Methods: This was an analytical cross-sectional study which was carried out from February 2020 to June 2020 in all patients of age-group 16 to 80 years visiting the Department of Periodontics at KDCH after ethical approval. Patients were recruited by convenience sampling and examined thoroughly to find out gingival biotype and extent of gingival pigmentation intraorally as well as skin colour extraorally. Results: In this study, 210 patients were examined among which, 105 (50%) were males and 105 (50%) were females. Out of 210, 33 (15.7%) had pink tissue without pigmentation, 84 (40%) had pigmentation only in attached gingiva, 58 (27.6%) in attached gingiva and interdental papilla, 32 (15.2%) had diffuse pigmentation involving all parts of gingiva, 2 (1%) had in marginal gingiva only, and 1 (0.5%) in marginal gingiva and interdental papilla. Conclusion: A strong association was found between gingival pigmentation and facial skin colour in present study (P <0.001). Establishing the pattern of gingival pigmentation in Nepalese population will help to choose a specific depigmentation therapy that will harmonise with skin colour.

Unique Clinical Features of Hereditary Gingival Fibromatosis Withelevated Expression of Human β-Defensin-2 and -3 in Gingival Epithelia

Background: Hereditary gingival fibromatosis (HGF), a rare benign oral condition, has several adverse consequences such as aesthetic changes, malocclusion, speech impediments, and abnormal dentition . H owever, relatively few studies have addressed the beneficial effects of thick gingival tissues on resisting external stimuli. Patients with HGF commonly manifest a ‘healthy’ gingiva , and the aetiology and pathogenesis of this condition remain unclear. H uman β-defensins (hBDs) are known to play a pivotal role in the clearance and killing of various microbes and contribute to maintaining a harmonious oral environment, which is currently an emerg ing research focus. We previously performed an immunohistochemi cal analysis of gingival tissues from a multigenerational family with non-syndromic HGFs (NHGF) . However , the expression pattern and localisation of hBD-2 and - 3 in patients with NHGF has not been reported. Methods: Gingival tissue was paraffin embedding, sectioned, and then the expression and localisation of hBD-2 and -3 in the gingival epithelium of patients with HGF and normal individuals were compared using immunohistochemistry (IHC) with descriptive and quantitative analysis. Results: The immunohistochemical staining showed a statistically significant increase in hBD-2 and 3 in gingiva l tissue derived from patients with HGF. Conclusion: Our current findings provide evidence to support the novel hypothesis that certain gene mutations of the HGF lead to relatively elevated expression levels of hBDs, which may be beneficial in protect ing oral tissue from external stimuli and promot ing periodontal regeneration.

Fabrication and Characterization of Collagen/PVA Dual-Layer Membranes for Periodontal Bone Regeneration

Guided tissue regeneration (GTR) is a promising treatment for periodontal tissue defects, which generally uses a membrane to build a mechanical barrier from the gingival epithelium and hold space for the periodontal regeneration especially the tooth-supporting bone. However, existing membranes possess insufficient mechanical properties and limited bioactivity for periodontal bone regenerate. Herein, fish collagen and polyvinyl alcohol (Col/PVA) dual-layer membrane were developed via a combined freezing/thawing and layer coating method. This dual-layer membrane had a clear but contact boundary line between collagen and PVA layers, which were both hydrophilic. The dual membrane had an elongation at break of 193 ± 27% and would undergo an in vitro degradation duration of more than 17 days. Further cell experiments showed that compared with the PVA layer, the collagen layer not only presented good cytocompatibility with rat bone marrow-derived mesenchymal stem cells (BMSCs), but also promoted the osteogenic genes (RUNX2, ALP, OCN, and COL1) and protein (ALP) expression of BMSCs. Hence, the currently developed dual-layer membranes could be used as a stable barrier with a stable degradation rate and selectively favor the bone tissue to repopulate the periodontal defect. The membranes could meet the challenges encountered by GTR for superior defect repair, demonstrating great potential in clinical applications.