Periodontitis In Rats Research Articles

Time-Responsive Activity of Engineered Bacteria for Local Sterilization and Biofilm Removal in Periodontitis.

Periodontitis is a highly prevalent and common condition in people of all ages, however, existing drugs to treat periodontitis have difficulty penetrating complex biofilms. Here, we report a biofilm-penetrating probiotic hybrid strategy for the treatment of periodontitis. It consists of therapeutic probiotics of E. coli Nissle 1917, which can produce antimicrobial peptides and hydrogen, and is coated with D-amino acids that can penetrate biofilms. After the fusion of D-amino acids with the biofilm, EcN entered the plaque biofilm and produced antimicrobial peptides to kill porphyromonas gingivalis and eliminate periodontitis under the action of hydrogen. The efficacy of EcN@DA-D in biofilm penetration and treatment of periodontitis was demonstrated in a rat model of periodontitis. In addition, the clinical combination to construct a rat periodontitis model by using clinical tissue has a significant therapeutic effect. In conclusion, EcN@DA-D offers a promising topical treatment for periodontitis without developing detectable pathogen resistance and side effects.

Bioinspired Glycopeptide Hydrogel Reestablishing Bone Homeostasis through Mediating Osteoclasts and Osteogenesis in Periodontitis Treatment.

Irreversible alveolar bone resorption is one of the important clinical manifestations of periodontitis, which is initiated by a plaque biofilm and exacerbated by the imbalance of osteoclast activity and osteogenesis, affecting a patient's masticatory function and resulting in a high recurrence rate of periodontitis. Herein, to reestablish bone homeostasis in periodontitis, a minocycline hydrochloride (MH)-loaded glycopeptide hydrogel (MH/GRWgel) is fabricated to mediate alveolar bone absorption through sequential antibacterial and RANKL-blocking activities. GRWgel shows an ECM-like fibrous and porous microstructure serving as a scaffold for cell proliferation and differentiation and holds the merits including injectability, self-healing properties, and good biocompatibility. After injection in situ, MH is released rapidly from the hydrogel in the early stage, demonstrating a potent antimicrobial effect to combat the biofilm in the deep periodontal pocket. Moreover, MH/GRWgel exhibits a high specific binding efficiency with RANKL to suppress osteoclast maturation by shielding the RANKL/RANK interaction and enhancing osteogenic differentiation, thereby synergistically regulating bone homeostasis. In the rat periodontitis model, MH/GRWgel significantly curtails periodontitis progression through antimicrobial activity, inhibition of alveolar bone resorption, and promotion of bone regeneration, which is superior to the treatment of a commercial gel. These findings suggest that MH/GRWgel with superiority in regulating bone homeostasis provides a promising therapeutic strategy for periodontitis.

Protective effect of carvacrol hydrogel on the alveolar bone in rats with periodontitis.

This study aimed to investigate the protective effect and mechanism of carvacrol hydrogel on the alveolar bone in rats with periodontitis. A thermosensitive hydrogel supported by carvacrol was prepared using poloxamer and hydroxypropyl methyl cellulose as matrix. SD rats were randomly divided into blank group, periodontitis group, blank hydrogel group, and low-, medium-, and high-dose hydrogel groups. The periodontitis symptoms and the CT structure of the alveolar bone were observed. The changes in liver, spleen, kidney, and periodontal tissues were observed. The related indexes of bone metabolism in serum were detected. The expression of osteoprotegerin (OPG) and nuclear transcription factor-κB (NF-κB) pathway proteins was determined by Western blot. The levels of inflammatory factors were assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Carvacrol hydrogel had good slow release, biocompatibility, and cell adhesion. The periodontitis of rats in the carvacrol hydrogel group was significantly alleviated, the expression of OPG protein in gingival tissue was significantly increased (P<0.01), and the levels of receptor activator of NF-κB ligand (RANKL), receptor activator of NF-κB (RANK), NF-κB protein, and inflammatory factors were significantly decreased (P<0.01). Carvacrol hydrogel can regulate the OPG and NF-κB pathways, reduce alveolar bone absorption, and improve periodontal inflammation.

27-Hydroxycholesterol contributes to hypercholesterolemia-associated aggravation of apical periodontitis in ovariectomized rats and raloxifene counteracts its action.

The influence of hypercholesterolemia on the development of apical periodontitis (AP) is inconclusive. Recent studies revealed that cholesterol metabolite 27-hydoxycholesterol (27HC) can affect cellular responses to bacterial infections and oestrogen status and raloxifene may influence its action. Herein, we aimed to examine the impact of 27HC on production of inflammatory mediators by macrophages and the regulatory function of raloxifene. The contribution of 27HC to AP development and the therapeutic effect of raloxifene were evaluated in a rat model. Murine macrophages J774 cells were used. The expression of inducible nitric oxide synthase (iNOS) was examined by Western blot. The concentrations of C-C motif chemokine ligand (CCL) 2 and 27HC were assessed by enzyme-linked immunosorbent assay. Colorimetric assay was used to evaluate cholesterol levels. Experimental AP was induced in ovariectomized (OVX) or un-operated rats receiving high-fat/high-cholesterol diet (HFHCD) or normal diet (ND). Micro-computed tomography and immunohistochemistry were employed to evaluate disease severity and the therapeutic effect of raloxifene. Cholesterol enhanced 27HC production in macrophages. 27HC induced iNOS and CCL2 synthesis by macrophages and estradiol suppressed the responses. In our animal model of AP, HFHCD plus OVX significantly augmented serum and lesion tissue levels of 27HC (p < .05 versus the ND group). Lesion size, infiltration of CD68+ cells, and iNOS+ monocytes were increased in parallel with 27HC accumulation. Raloxifene inhibited pro-inflammatory effects of 27HC on macrophages and suppressed AP progression in HFHCD/OVX rats (p < .05 versus the vehicle control group). Our results suggested that 27HC contributes to AP aggravation associated with hypercholesterolemia. Oestrogen deficiency may both enhance 27HC production and exacerbate its downstream action.

Supramolecular Composite Hydrogel Loaded with CaF2 Nanoparticles Promotes the Recovery of Periodontitis Bone Resorption.

Treatments to reduce periodontal inflammation and rescue periodontitis bone resorption have been of interest to researchers. Bone tissue engineering materials have been gradually used in the treatment of bone defects, but periodontal bone tissue regeneration still faces challenges. Considering the biocompatibility factor, constructing bionic scaffolds with natural extracellular matrix properties is an ideal therapeutic pathway. Based on the pathological mechanism of periodontitis, in this study, short peptide and nanometer inorganic particles were comingled to construct NapKFF-nano CaF2 supramolecular composite hydrogels with different ratios. Material characterization experiments confirmed that the composite hydrogel had suitable mechanical properties and a three-dimensional structure that can function in the resorption region of the alveolar bone and provide spaces for cell proliferation and adhesion. The release of low concentrations of fluoride and calcium ions has been shown to have positive biological effects in both in vivo and in vitro experiments. Vitro experiments confirmed that the composite hydrogel had good biocompatibility and promoted osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Microbiological experiments confirmed that the composite hydrogel inhibited the activity of periodontal pathogenic bacteria. In animal studies, composite hydrogel applied to periodontitis rats in vivo can effectively repair alveolar bone resorption. This composite hydrogel has a simple preparation method and is inexpensive to produce, yet it has antibacterial and osteogenesis-promoting incremental effects, which makes it well suited for the treatment of periodontitis bone resorption, providing a new strategy for periodontal bone tissue engineering.

Effect of chronic alcohol consumption on oral microbiota in rats with periodontitis.

The imbalance of oral microbiota can contribute to various oral disorders and potentially impact general health. Chronic alcohol consumption beyond a certain threshold has been implicated in influencing both the onset and progression of periodontitis. However, the mechanism by which chronic alcohol consumption affects periodontitis and its association with changes in the oral microbial community remains unclear. This study used 16S rRNA gene amplicon sequencing to examine the dynamic changes in the oral microbial community of rats with periodontitis influenced by chronic alcohol consumption. Twenty-four male Wistar rats were randomly allocated to either a periodontitis (P) or periodontitis + alcohol (PA) group. The PA group had unrestricted access to alcohol for 10 weeks, while the P group had access to water only. Four weeks later, both groups developed periodontitis. After 10 weeks, serum levels of alanine aminotransferase and aspartate aminotransferase in the rats' serum were measured. The oral swabs were obtained from rats, and 16S rRNA gene sequencing was conducted. Alveolar bone status was assessed using hematoxylin and eosin staining and micro-computed tomography. Rats in the PA group exhibited more severe periodontal tissue damage compared to those in the periodontitis group. Although oral microbial diversity remained stable, the relative abundance of certain microbial communities differed significantly between the two groups. Actinobacteriota and Desulfobacterota were more prevalent at the phylum level in the PA group. At the genus level, Cutibacterium, Tissierella, Romboutsia, Actinomyces, Lawsonella, Anaerococcus, and Clostridium_sensu_stricto_1 were significantly more abundant in the PA group, while Haemophilus was significantly less abundant. Additionally, functional prediction using Tax4Fun revealed a significant enrichment of carbohydrate metabolism in the PA group. Chronic alcohol consumption exacerbated periodontitis in rats and influenced the composition and functional characteristics of their oral microbiota, as indicated by 16S rRNA gene sequencing results. These microbial alterations may contribute to the exacerbation of periodontitis in rats due to chronic alcohol consumption.

Periodontal host-modulation therapy with avocado/soybean unsaponifiables in rats with arthritis.

The aim of this study was to evaluate the effect of the avocado/soybean unsaponifiables (ASU) in the treatment of induced periodontitis in rats with experimental arthritis. Sixty rats were randomly assigned to 4 groups according to the type of treatment and the systemic condition of the animals: CTR-S: healthy animals in which saline solution (SS) was administered; ASU-S: healthy animals in which ASU (0.6 mg/kg) was administered; AR/ASU-S: animals with induced arthritis in which ASU was administered; AR-S: animals with induced arthritis in which SS was administered. Periodontitis was induced by ligatures, maintained for 15 days. Subsequently, the treatment was performed by scaling with hand instruments. The SS and ASU were administered daily by gavage until euthanasia of the animals that occurred at 7, 15 or 30 days after the scaling procedure (N.=5 animals/group). Bone resorption, inflammatory infiltrate composition, and osteoclastogenesis were assessed. The AR-S group had greater bone loss, smaller amounts of fibroblasts and larger amounts of inflammatory cells than all other groups. In addition, the AR-S group had greater osteoclastogenesis in relation to the healthy animal groups. The use of ASU improved the healing pattern after treatment for experimental periodontitis in animals with arthritis reducing the periodontal bone loss.

Induced Periodontitis in Rats With Three Ligature Types: An Exploratory Study.

The placement of ligatures in the cervical area of rat molars is considered as a predictable model to induce periodontitis. The present explorative study aimed to compare the efficacy of metal wires (MWs), without or with sandblasting, versus silk ligatures (SLs) in inducing periodontal bone loss in rats. Twenty-four Wistar rats were randomly divided into three groups of eight rats that received three different types of ligatures (MW, sandblasted wire [SMW], and SL) around their first right mandibular molar, while the contralateral tooth was left without the ligature and served as a control. Bone loss was assessed by measuring the distance from the cementoenamel junction (CEJ) to the bone crest at the distal aspect of the first molar on central mesiodistal sections generated from micro-CT scans taken 24 and 35 days after ligature placement. In the SL group, only in two rats the ligatures were retained until the end of the 24-day period; in all other animals, the ligatures were lost at some time point. In the SMW, the ligatures were retained only for the 24-day period. In the MW group, no ligatures were lost. Irrespective of the group or experimental period, the difference in the crestal bone level between ligated and control teeth was in most cases z < 0.20 mm, that is, in 19 out of 25 pairs of teeth. In a few cases, the bone crest was more apically located at the control teeth compared to the ligated ones (four cases each, during both 24- and 35-day experimental periods). Bone loss was minimal during the experimental period, with no significant differences between the test and control teeth, or among the three types of ligatures. MWs, not even roughened, do not seem to be a better alternative to SLs for inducing bone loss in the experimental periodontitis model in the rat. This assumption, however, has to be confirmed in a larger, well-powered study.

The role of uncoupling protein 2 in experimental periodontitis-associated renal injury in rats.

This study aims to explore changes in uncoupling protein 2 (UCP2) in experimental periodontitis-associated renal injury induced by ligation and investigate the effect of UCP2 on renal injury induced by periodontitis. Twelve Wistar male rats were randomly divided into two groups: control and periodontitis groups. A periodontal model was built by ligating the maxillary first molars area with 0.2 mm orthodontic ligature wire. After 8 weeks, the intraoral condition of the rats was observed and periodontal clinical indices such as gingival bleeding index (BI), periodontal probing depth (PD), and tooth mobility (TM) were detected. The maxillary bone was scanned by Micro CT to observe the alveolar bone resorption. The tissue mineral density (TMD), bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular bone separation (Tb.Sp) were recorded, and the distance from the enamel bone boundary to the alveolar crest (CEJ-ABC) of the maxillary first molar was measured. The oxidative stress indexes such as malondialdehyde, glutathione (GSH), and superoxide dismutase (SOD) were detected using frozen rat kidney tissue. The gene expression of UCP2, nuclear factor erythroid 2-related factor 2 (Nrf2), and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) was observed by quantitative real-time polymerase chain reaction (qRT-PCR) test. The gingival tissue of the rats was used for immunohistochemical staining to observe the expression of the UCP2 protein. The fixed rat kidney tissue was used for hematoxylin-eosin (HE), periodic acid-schiff (PAS), MitoSOX Red, JC-1, and immunohistochemical staining to observe the renal histopathology, the level of reactive oxygen species (ROS), the level of mitochondrial membrane potential, and the expression of UCP2, Nrf2, and PGC-1α protein. Rat serum was collected to detect renal function indices, namely, blood urea nitrogen (BUN), creatinine (Cre), and albumin (Alb). Compared with the control group, the periodontitis group showed red, swollen, and soft gingival tissue, with gingival probing bleeding, periodontal PD increased, tooth loosening, alveolar bone resorption, decreased TMD, BMD, BV/TV, and Tb.Th indices, and increased Tb.Sp index, CEJ-ABC, and gingival UCP2 protein expression. Compared with the control group, the levels of MDA and ROS in the kidney tissue of periodontitis rats and the gene and protein expression of UCP2 increased, and the levels of MMP, GSH, and SOD and the gene and protein expression of Nrf2 and PGC-1α decreased. Renal functional indices, namely, BUN, Cre, and Alb, were not significantly different between the two groups. UCP2 may play a role in renal injury induced by periodontitis through oxidative stress.

CORM-3 Inhibits the Inflammatory Response of Human Periodontal Ligament Fibroblasts Stimulated by LPS and High Glucose.

Diabetes has been recognized as an independent risk factor for periodontitis. Increasing evidences indicate that hyperglycemia aggravates inflammatory response of human periodontal ligament cells (hPDLCs). Carbon monoxide-releasing molecule-3 (CORM-3) is a water-soluble compound that can release carbon monoxide (CO) in a controllable manner. CORM-3 has been shown the anti-inflammatory effect in different cell lineages. We stimulated periodontal ligament cells with LPS and high glucose. The expression of inflammatory cytokine was detected by ELISA. RT-qPCR, Western blot and immunofluorescence were used to detect the expression of TLR2, TLR4, RAGE and the activation of NF-κB pathway. We performed silencing and overexpression treatment of RAGE targeting the role of RAGE. We performed the immunostaining of paraffin sections of the periodontitis model in diabetes rats. The results showed that CORM-3 significantly inhibited the expression of inflammatory cytokine in hPDLCs stimulated with LPS and high glucose. CORM-3 also inhibited LPS and high glucose-induced expression of RAGE/NF-κB pathway and TLR2/TLR4/NF-κB pathway. Silence of RAGE resulted in significantly decreased expression of proteins above. Overexpression of RAGE significantly enhanced the expression of these factors. CORM-3 abrogated the effect of RAGE partially. In animal model, CORM-3 suppressed the inflammatory response of periodontal tissues in experimental periodontitis of diabetic rats. Our research proved CORM-3 reduced the inflammatory response via RAGE/NF-κB pathway and TLR2/TLR4/NF-κB pathway in the process of high glucose exacerbated periodontitis. These findings demonstrated the role of RAGE in the process of high glucose exacerbated periodontitis and suggested that CORM3 be a potential therapeutic strategy for the treatment of diabetes patients with periodontitis.

Increase Toll-like receptors 2 and 4 in apical periodontitis of rats with chronic liver disease.

The aim of this study was to evaluate the influence of liver fibrosis (LF) on the expression of Toll-like receptors (TLR) 2 and 4 in apical periodontitis (AP) in Wistar rats. Forty Wistar rats were allocated in the following groups (n = 10): C-control; AP-apical periodontitis; LF-liver fibrosis; AP + LF-rats with AP and LF. LF and AP were induced by established methodologies. Histological, bacteriological, and immunohistochemical analyses were performed according to pre-established scores. For comparisons between AP and AP + LF groups, the Mann-Whitney test was used (P < .05). The livers of the LF and AP + LF groups showed generalized portal inflammatory infiltrate and collagen fibers confirming the presence of LF. Histopathological analysis in the maxilla of the AP + LF group showed areas of necrosis comprising the entire dental pulp and periapical tissue surrounded by a more intense inflammatory infiltrate than observed in the AP group (P = 0.032). A significant number of specimens in the AP + LF group showed microorganisms beyond the apical foramen adhered to the extraradicular biofilm, demonstrating greater invasion compared to the AP group (P = .008). Immunohistochemical analysis showed a large number of cells immunoreactive for TLR2 and TLR4 in the AP + LF group, compared to the AP group (P < 0.05). Liver fibrosis favors the inflammation and contamination of microorganisms in apical periodontitis and triggers the expression of TLR2 and TLR4, modulating innate immunity response in periapical lesions.

Effects of the DL76 Antagonist/Inverse Agonist of Histamine H3 Receptors on Experimental Periodontitis in Rats: Morphological Studies.

Periodontitis preceded by gingivitis is the most common form of periodontal disease and occurs due to the interaction of microorganisms present in the complex bacterial aggregates of dental plaque biofilm and their metabolism products with periodontal tissues. Histamine is a heterocyclic biogenic amine acting via four types of receptors. Histamine H3 receptors act as presynaptic auto/heteroreceptors to regulate the release of histamine and other neurotransmitters. Since the nervous system is able to regulate the progression of the inflammatory process and bone metabolism, the aim of this study was to investigate the effects of DL76, which acts as an antagonist/inverse agonist of H3 receptors, on the course of experimental periodontitis. This study was conducted in 24 mature male Wistar rats weighing 245-360 g, aged 6-8 weeks. A silk ligature was placed on the second maxillary molar of the right maxilla under general anesthesia. From the day of ligating, DL76 and 0.9% NaCl solutions were administered subcutaneously for 28 days in the experimental and control groups, respectively. After the experiment, histopathological, immunohistochemical and radiological examinations were performed. Ligation led to the development of the inflammatory process with lymphocytic infiltration, increased epithelial RANKL and OPG expression as well as bone resorption. DL76 evoked a reduction in (1) lymphocytic infiltration, (2) RANKL and OPG expression as well as (3) bone resorption since the medians of the mesial and distal interdental spaces in the molars with induced periodontitis were 3.56-fold and 10-fold lower compared to the corresponding values in saline-treated animals with periodontitis. DL76 is able to inhibit the progression of experimental periodontitis in rats, as demonstrated by a reduction in the inflammatory cell infiltration, a decrease in the RANKL/RANK OPG pathway expression and a reduction in the alveolar bone resorption.

Mitochondrial biogenesis disorder and oxidative damage promote refractory apical periodontitis in rat and human.

To elucidate whether mitochondrial biogenesis disorder and damage from oxidative stress promote refractory apical periodontitis (RAP) in rat and human. Twenty Enterococcus faecalis-induced RAPs were established in the maxillary first molars of male Wistar rats. Concurrently, 12 periapical lesion specimens from patients presenting with RAP were obtained by apicoectomy. Radiographic examination and histologic analysis were conducted to evaluate periapical bone tissue destruction and morphological changes. The expression of key regulators of mitochondrial biogenesis, PGC-1α and Nrf2, were detected by immunohistochemistry and double immunofluorescence staining, Western blot and real-time PCR were also assayed. Mitochondrial ROS (mtROS) was identified by MitoSOX staining. Mitochondrial function was detected by the quantification of ATP production, mitochondrial DNA (mtDNA) copy number and activities of mitochondrial respiratory chain complexes. Furthermore, mitochondrial oxidative stress was evaluated by the determination of 3-nitrotyrosine (3-NT), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-deoxyguanosine (8-OHdG) expression levels, as well as malondialdehyde (MDA) expression and antioxidant capacity. Student's t-test was performed to determine significance between the groups; p < .05 was considered significant. In the maxilla, significantly more bone resorption, greater number of periapical apoptotic cells and Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were observed in the RAP group compared with the control group (p < .01). PGC-1α and Nrf2 were significantly reduced in rat and human RAP lesions compared to the control group (p < .01) at both the mRNA and protein levels. Double immunofluorescence analysis of PGC-1α or Nrf2 with TOMM20 also indicated that mitochondrial biogenesis was impaired in RAP group (p < .01). Additionally, mitochondrial dysfunction was observed in RAP group, as reflected by increased mtROS, decreased ATP production, reduced mtDNA copy number and complexes of the mitochondrial respiratory chain. Finally, the expression levels of mitochondrial oxidative stress markers, 3-NT, 4-HNE and 8-OHdG, were significantly increased in the RAP group (p < .01). Consistent with this, systemic oxidative damage was also present in the progression of RAP, including increased MDA expression and decreased antioxidant activity (p < .01). Mitochondrial biogenesis disorder and damage from oxidative stress contribute to the development of RAP.

Physical training minimizes immunological dysfunction, oxidative stress and tissue destruction on experimental periodontitis in rats

Physical training minimizes immunological dysfunction, oxidative stress and tissue destruction on experimental periodontitis in rats

Anti-Inflammatory Activity of No-Ozone Cold Plasma in Porphyromonas gingivalis Lipopolysaccharide-Induced Periodontitis Rats.

Periodontitis is an inflammatory disease caused by Porphyromonas gingivalis (P. gingivalis) in the oral cavity. This periodontal disease causes damage to the periodontal ligament and alveolar bone and can cause tooth loss, but there is no definite treatment yet. In this study, we investigated the possibility of using no-ozone cold plasma to safely treat periodontitis in the oral cavity. First, human gingival fibroblasts (HGFs) were treated with P. gingivalis-derived lipopolysaccharide (PG-LPS) to induce an inflammatory response, and then the anti-inflammatory effect of NCP was examined, and a study was conducted to identify the mechanism of action. Additionally, the anti-inflammatory effect of NCP was verified in rats that developed an inflammatory response similar to periodontitis. When NCP was applied to PG-LPS-treated HGFs, the activities of inflammatory proteins and cytokines were effectively inhibited. It was confirmed that the process of denaturing the medium by charged particles of NCP is essential for the anti-inflammatory effect of NCP. Also, it was confirmed that repeated treatment of periodontitis rats with NCP effectively reduced the inflammatory cells and osteoclast activity. As a result, this study suggests that NCP can be directly helpful in the treatment of periodontitis in the future.

Role of connexin 43 in a rat model of periodontitis-induced renal injury.

This study aims to investigate the role of gap junction mediated by connexin 43 (Cx43) in renal injury induced by periodontitis in rats. Twelve SPF-grade Wistar male rats were divided into a control group and a periodontitis group by using a completely random number table method, with six rats in each group. The control group rats were not treated, while the periodontitis group rats were subjected to wire ligation of the neck of their bilateral maxillary first molars to construct a periodontitis model. After 8 weeks of modeling, the rats were examined for clinical indicators of the periodontium. micro-CT scanning of the maxilla reconstructed its 3D structure and analyzed the absorption of alveolar bone. Histopathological changes in periodontal and renal tissues were detected. MitoSOX red reagent was used to determine reactive oxygen species (ROS) content in renal tissues. A biochemical reagent kit was used to detect serum oxidative stress biomarkers. Real-time fluorescent quantitative-polymerase chain reaction (qRT-PCR) was employed to determine Cx43, nuclear factor kappa-B (NF-κB) , interleukin (IL)-1β, IL-6, BCL2-Associated X (Bax), B-lymphomatoma-2 gene (Bcl-2), and Caspase-3 mRNA were determined. Western blot analysis was used to detect Cx43, NF-κB, IL-1β, Bax, Bcl-2 and Caspase-3 protein. micro-CT 3D reconstruction showed significant bone resorption of the first molar alveolar bone in the periodontitis group rats and decreased height of the alveolar ridge. The distance from the enamel cementum boundary to the top of the alveolar ridge in the periodontitis group was significantly higher than that inthe control group. The histopathological results showed a large number of inflammatory cells that infiltrated the periodontal tissue of the periodontitis group, and the alveolar bone was significantly absorbed. Rats in the periodontitis group also exhibited mild thickening of the glomerular basement membrane, dilation of the Bowman's capsule, and destruction of the brush-like edge of the renal tubules in the renal tissue. The MitoSOX red staining results showed a significant increase in ROS content in the renal tissue of the periodontitis group. The biochemical test results showed that the levels of superoxide dismutase and glutathione in the serum of rats with periodontitis decreased, while that of malondialdehyde increased. The results of qRT-PCR and Western blot showed that the expression levels of Cx43, IL-1β, IL-6, Bax, Caspase-3 mRNA and Cx43, IL-1β, NF-κB, Bax, Caspase-3 proteins in the periodontitis group significantly increased compared with those in the control group, while the expression levels of Bcl-2 mRNA and protein decreased. Periodontitis may activate NF-κB signaling molecules by upregulating the expression of Cx43 in rat kidney tissues, leading to increased levels of inflammation and apoptosis and ultimately inducing kidney injury.

PSO/SDF-1 composite hydrogel promotes osteogenic differentiation of PDLSCs and bone regeneration in periodontitis rats

Periodontitis is an inflammatory disease characterized by the destruction of periodontal tissues, and the promotion of bone tissue regeneration is the key to curing periodontitis. Psoralen is the main component of Psoralea corylifolia Linn, and has multiple biological effects, including anti-osteoporosis and osteogenesis. We constructed a novel hydrogel loaded with psoralen (PSO) and stromal cell-derived factor-1 (SDF-1) for direct endogenous cell homing. This study aimed to evaluate the synergistic effects of PSO/SDF-1 on periodontal bone regeneration in patients with periodontitis. The results of CCK8, alkaline phosphatase (ALP) activity assay, and Alizarin Red staining showed that PSO/SDF-1 combination treatment promoted cell proliferation, chemotaxis ability, and ALP activity of PDLSCs. qRT-PCR and western blotting showed that the expression levels of alkaline phosphatase (ALP), dwarf-associated transcription factor 2 (RUNX2), and osteocalcin (OCN) gene were upregulated. Rat periodontal models were established to observe the effect of local application of the composite hydrogel on bone regeneration. These results proved that the PSO/SDF-1 combination treatment significantly promoted new bone formation. The immunohistochemical (IHC) results confirmed the elevated expression of ALP, RUNX2, and OCN osteogenic genes. PSO/SDF-1 composite hydrogel can synergistically regulate the biological function and promote periodontal bone formation. Thus, this study provides a novel strategy for periodontal bone regeneration.

Oroxylin A inhibits inflammatory cytokines in periodontitis via HO‑1.

Periodontal disease is a common infectious disease that can lead to the loss of teeth. Hower how to effectively suppress the inflammation with medication is unclear. The aim of the present study was to investigate the anti‑inflammatory effect of Oroxylin A in periodontitis and its potential role through heme oxygenase‑1 (HO‑1). Primary rat gingival fibroblasts (RGFs) were cultured using the tissue block method and identified by immunofluorescence. Following lipopolysaccharide (LPS) stimulation of RGFs, Oroxylin A was administered at 50, 100, 200 or 400 µg/ml. Reverse transcription‑quantitative PCR was used to assess mRNA expression of cyclooxygenase (COX)‑2, TNF‑α, RANKL and osteoprotegerin (OPG). Western blotting was used to detect protein expression levels of COX ‑2, TNF‑α, RANKL and OPG. Following HO‑1 knockdown, the same treatment was performed. The expression of COX‑2 in rat gingival tissue was observed by immunohistochemistry. One‑way analysis of variance and Student's t test were used for statistical analysis. Oroxylin A downregulated mRNA expression of COX‑2, TNF‑α, RANKL and OPG in LPS‑induced RGFs. With increase of Oroxylin A dose, the expression of HO‑1 was gradually upregulated. When HO‑1 was knocked down, Oroxylin A did not downregulate the expression of COX‑2, TNF‑α, RANKL and OPG in LPS‑induced RGFs. Immunohistochemical results showed that expression of COX‑2 was downregulated by Oroxylin A, and the expression of TNF‑α, RANKL and OPG were also downregulated. Oroxylin A decreased expression of inflammatory cytokines in LPS‑induced RGFs and had a good inhibitory effect on periodontitis in rats.

Sulfated Chitosan-Modified CuS Nanocluster: A Versatile Nanoformulation for Simultaneous Antibacterial and Bone Regenerative Therapy in Periodontitis.

Periodontitis, a prevalent chronic inflammatory disease worldwide, is triggered by periodontopathogenic bacteria, resulting in the progressive destruction of periodontal tissue, particularly the alveolar bone. To effectively address periodontitis, this study proposed a nanoformulation known as CuS@MSN-SCS. This formulation involves coating citrate-grafted copper sulfide (CuS) nanoparticles with mesoporous silica (MSNs), followed by surface modification using amino groups and sulfated chitosan (SCS) through electrostatic interactions. The objective of this formulation is to achieve efficient bacteria removal by inducing ROS signaling pathways mediated by Cu2+ ions. Additionally, it aims to promote alveolar bone regeneration through Cu2+-induced pro-angiogenesis and SCS-mediated bone regeneration. As anticipated, by regulating the surface charges, the negatively charged CuS nanoparticles capped with sodium citrate were successfully coated with MSNs, and the subsequent introduction of amine groups using (3-aminopropyl)triethoxysilane was followed by the incorporation of SCS through electrostatic interactions, resulting in the formation of CuS@MSN-SCS. The developed nanoformulation was verified to not only significantly exacerbate the oxidative stress of Fusobacterium nucleatum, thereby suppressing bacteria growth and biofilm formation in vitro, but also effectively alleviate the inflammatory response and promote alveolar bone regeneration without evident biotoxicity in an in vivo rat periodontitis model. These findings contribute to the therapeutic effect on periodontitis. Overall, this study successfully developed a nanoformulation for combating bacteria and facilitating alveolar bone regeneration, demonstrating the promising potential for clinical treatment of periodontitis.

The Effect of Coffee Consumption on the Level of Adrenalin Blood Serum in the Periodontitis Model: An In Vivo Study

Background: Adrenalin was supposed to have an anti-inflammatory effect; hence adrenalin concentration in blood serum might be lower in inflammatory diseases. Coffee contains caffeine that is thought to have the potency to increase adrenalin secretion in inflammatory diseases. This study aimed to analyze the effect of coffee consumption on adrenalin blood levels in periodontitis rat model. Methods: This in vivo experimental study used the post-test-only control group design. Wistar male rats (Rattus novergicus) were divided into four groups (four rats/group) i.e. 1) Periodontitis (no coffee), 2) periodontitis + coffee, 3) Coffee (no periodontitis), 4) Control (no coffee, no periodontitis). The periodontitis rat model was made by injecting periodontitis bacteria Phorpyromonas gingivalis in the buccal mucosa of the lower molar tooth three times a week for 4 weeks. A single dose (0.6 mL d–1) of ground coffee infusion (equal to one cup per day for humans) was given to each rat in the coffee group, for 28 d. At the end of the study, all of the rats were sacrificed and blood was drawn intra-cardially. Blood serum adrenalin concentration was analyzed using Enzyme-linked immunosorbent assay (Elisa). Results: The Periodontitis group showed significantly lower serum adrenalin (p&lt; 0.05) than others. Coffee consumption in periodontitis rats affected a significantly higher adrenalin blood serum level (p &lt; 0.05). Conclusion: Coffee consumption could replenish the level of blood serum adrenalin which decreases in periodontitis. Further studies are needed to elucidate the modulation mechanism of coffee-adrenalin-inflammation.