Preventive effects of systemic Pistacia eurycarpa Yalt. administration on alveolar bone loss and oxidative stress in rats with experimental periodontitis

OBJECTIVE

This study aimed to investigate the effects of systemic administration of P. eurycarpa Yalt. plant extract on alveolar bone loss and oxidative stress biomarkers in gingival tissue in a rat model of experimental periodontitis.

METHODOLOGY

32 male Wistar albino rats, weighing 200-250 g, were divided into four groups (n=8): Healthy control (HC), Experimental periodontitis control (EPC), Experimental periodontitis 400 mg/kg (EP400), Experimental periodontitis 800 mg/kg (EP800). Experimental periodontitis was induced using the ligating method. Distilled water was administered to the HC and EPC groups and the plant extract was administered to the EP400 and EP800 groups by oral gavage at doses of 400 mg/kg and 800 mg/kg, respectively. The rats were sacrificed on the 15th day. The values of glutathione peroxidase GSH-Px, malondialdehyde (MDA), superoxide dismustase (SOD), interleukin-1β (IL-1β), interleukin-10 (IL-10), total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI) in the gingival tissues were analyzed by ELISA tests. Alveolar bone loss was assessed using micro-CT images of the maxilla.

RESULTS

Although the IL-1β, TOS, OSI results of the healthy control group were lower than those of the other groups, the TAS values were higher (p<0.05). No significant difference was found in the biochemical parameters among the EPC, EP400, and EP800 groups (p>0.05). Alveolar bone loss was significantly reduced in the extract groups compared to the EPC group (p<0.001).

CONCLUSION

Within the limitations of this study, it was observed that the systemic P. eurycarpa extract application reduced alveolar bone loss in a rat model of experimental periodontitis. Further studies are needed to elucidate the beneficial effects of P. eurycarpa.

The Emerging Role of Salivary Oxidative Stress Biomarkers as Prognostic Markers of Periodontitis: New Insights for a Personalized Approach in Dentistry

Periodontitis is a multifactorial and infective oral disease that leads to the destruction of periodontal tissues and tooth loss. Although the treatment of periodontitis has improved recently, the effective treatment of periodontitis and the periodontitis-affected periodontal tissues is still a challenge. Therefore, exploring new therapeutic strategies for a personalized approach is urgent. For this reason, the aim of this study is to summarize recent advances and the potential of oxidative stress biomarkers in the early diagnosis and personalized therapeutic approaches in periodontitis. Recently, ROS metabolisms (ROMs) have been studied in the physiopathology of periodontitis. Different studies show that ROS plays a crucial role in periodontitis. In this regard, the reactive oxygen metabolites (ROMs) started to be searched for the measures of the oxidizing capacity of the plasma understood as the total content of oxygen free radicals (ROS). The oxidizing capacity of plasma is a significant indicator of the body's oxidant state as well as homocysteine (Hcy), sulfur amino acid, which has pro-oxidant effects as it favors the production of superoxide anion. More specifically, the thioredoxin (TRX) and peroxiredoxin (PRX) systems control reactive oxygen species (ROS), such as superoxide and hydroxyl species, to transduce redox signals and change the activities of antioxidant enzymes to remove free radicals. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), among other antioxidant enzymes, change their activity when ROS are produced in order to neutralize free radicals. The TRX system is triggered and transduces redox signals to do this.

Periodontal Inflammation and Systemic Diseases: An Overview

Periodontitis is a common inflammatory disease of infectious origins that often evolves into a chronic condition. Aside from its importance as a stomatologic ailment, chronic periodontitis has gained relevance since it has been shown that it can develop into a systemic condition characterized by unresolved hyper-inflammation, disruption of the innate and adaptive immune system, dysbiosis of the oral, gut and other location's microbiota and other system-wide alterations that may cause, coexist or aggravate other health issues associated to elevated morbi-mortality. The relationships between the infectious, immune, inflammatory, and systemic features of periodontitis and its many related diseases are far from being fully understood and are indeed still debated. However, to date, a large body of evidence on the different biological, clinical, and policy-enabling sources of information, is available. The aim of the present work is to summarize many of these sources of information and contextualize them under a systemic inflammation framework that may set the basis to an integral vision, useful for basic, clinical, and therapeutic goals.

New tendencies in non-surgical periodontal therapy

The aim of this review was to update the evidence of new approaches to non-surgical therapy (NSPT) in the treatment of periodontitis. Preclinical and clinical studies addressing the benefits of adjunctive antimicrobial photodynamic therapy, probiotics, prebiotics/synbiotics, statins, pro-resolving mediators, omega-6 and -3, ozone, and epigenetic therapy were scrutinized and discussed. Currently, the outcomes of these nine new approaches, when compared with subgingival debridement alone, did not demonstrate a significant added clinical benefit. However, some of these new alternative interventions may have the potential to improve the outcomes of NSPT alone. Future evidence based on randomized controlled clinical trials would help clinicians and patients in the selection of different adjunctive therapies.

Development of a thermosensitive statin loaded chitosan-based hydrogel promoting bone healing

Statins have been proposed as potential adjuvant to periodontal treatment due to their pleiotropic properties. A new thermosensitive chitosan hydrogel loaded with statins (atorvastatin and lovastatin) nanoemulsions was synthesized to allow a spatially controlled local administration of active compounds at lesion site. Spontaneous nano-emulsification method was used to synthesize statins loaded nanoemulsions. In vitro, atorvastatin and lovastatin loaded nanoemulsions were cytocompatible and were able to be uptake by oral epithelial cells. Treatment of Porphyromonas gingivalis infected oral epithelial cells and gingival fibroblasts with atorvastatin and lovastatin loaded nanoemulsions decreased significantly pro-inflammatory markers expression (TNF-α and IL-1β) and pro-osteoclastic RANKL. Nevertheless, such treatment induced the expression of Bone sialoprotein 2 (BSP2) in osteoblast emphasizing the pro-healing properties of atorvastatin and lovastatin nanoemulsions. In vivo, in a calvarial bone defect model (2 mm), treatment with the hydrogel loaded with atorvastatin and lovastatin nanoemulsions induced a significant increase of the neobone formation in comparison with systemic administration of statins. This study demonstrates the potential of this statins loaded hydrogel to improve bone regeneration and to decrease soft tissue inflammation. Its use in the specific context of periodontitis management could be considered in the future with a reduced risk of side effects.

Effects of ABCG2 and SLCO1B1 gene variants on inflammation markers in patients with hypercholesterolemia and diabetes mellitus treated with rosuvastatin

PURPOSE

Dysregulation of angiogenesis and inflammation play important roles in the development of atherosclerosis. Rosuvastatin (RST) was widely used in atherosclerosis therapy. Genetic variations of transporters may affect the rosuvastatin concentration in plasma and reflect different clinical treatment. The aim of this study was to explore the drug transport related single-nucleotide polymorphisms (SNPs) on RST pharmacokinetic and the further on pro-angiogenic and pro-inflammatory factors.

METHODS

A total of 269 Chinese patients with hypercholesterolemia and diabetes mellitus were enrolled. They were treated with RST to lower cholesterol. The plasma concentration of RST was determined using a validated UPLC-MS/MS method. Seven single-nucleotide polymorphisms (SNPs) in six genes were genotyped using the Sanger dideoxy DNA sequencing method. The serum concentrations of inflammation markers were determined using ELISA kits.

RESULTS

ABCG2 421C > A (rs2231142) and SLCO1B1 521 T > C (rs4149056) variations were highly associated with plasma concentrations of RST (P < 0.01, FDR < 0.05). The serum MCP-1, sVCAM-1, and TNF-α levels were significantly different between the ABCG2 421C > A and SLCO1B1 521 T > C genetic variation groups (P < 0.01). RST concentration was negatively correlated with sVCAM-1 concentration (r = 0.150, P = 0.008).

CONCLUSION

ABCG2 421C > A (rs2231142) and SLCO1B1 521 T > C (rs4149056) genetic variants affect RST concentration significantly and potentially affect serum levels of pro-inflammatory and pro-angiogenic markers. The effects on anti-inflammation might not be related to high plasma exposure of RST.

Contribution of Statins towards Periodontal Treatment: A Review

The pleiotropic effects of statins have been evaluated to assess their potential benefit in the treatment of various inflammatory and immune-mediated diseases including periodontitis. Herein, the adjunctive use of statins in periodontal therapy in vitro, in vivo, and in clinical trials was reviewed. Statins act through several pathways to modulate inflammation, immune response, bone metabolism, and bacterial clearance. They control periodontal inflammation through inhibition of proinflammatory cytokines and promotion of anti-inflammatory and/or proresolution molecule release, mainly, through the ERK, MAPK, PI3-Akt, and NF-κB pathways. Moreover, they are able to modulate the host response activated by bacterial challenge, to prevent inflammation-mediated bone resorption and to promote bone formation. Furthermore, they reduce bacterial growth, disrupt bacterial membrane stability, and increase bacterial clearance, thus averting the exacerbation of infection. Local statin delivery as adjunct to both nonsurgical and surgical periodontal therapies results in better periodontal treatment outcomes compared to systemic delivery. Moreover, combination of statin therapy with other regenerative agents improves periodontal healing response. Therefore, statins could be proposed as a potential adjuvant to periodontal therapy. However, optimization of the combination of their dose, type, and carrier could be instrumental in achieving the best treatment response.

Calcitonin gene‑related peptide reduces Porphyromonas gingivalis LPS‑induced TNF‑α release and apoptosis in osteoblasts

Periodontal diseases comprise mixed bacterial infections mainly caused by Gram‑negative anaerobic bacteria. Lipopolysaccharides (LPS) are important virulence factors and periodontal pathogens, which change local cytokine levels and promote osteoblast apoptosis, thereby leading to an imbalance in bone remodeling mechanisms and accelerating bone loss. Calcitonin gene‑related peptide (CGRP) is a vasoactive neuropeptide that is released from sensory nerves and has a positive effect on osteoblast proliferation and differentiation. In addition, this small molecule peptide is an important immune regulator in the inflammatory response. The aim of the present study was to assess the in vitro effects of CGRP on Porphyromonas gingivalis (Pg)LPS‑induced osteoblast apoptosis. Osteoblast cultures were stimulated either with various concentrations of PgLPS (0, 25, 50, 100, 500 and 1,000 ng/ml) for 48 h or with 500 ng/ml PgLPS for various lengths of time (0, 6, 12, 24, 48 and 72 h). The PgLPS‑stimulated cells were pretreated with different concentrations of CGRP (0, 1, 10, 100 and 1,000 nM) and cell viability and apoptotic rates were measured by Cell Counting kit‑8 assays and flow cytometry, respectively. CGRP, cleaved (c)‑Caspase‑8 and c‑Caspase‑3 protein expression levels were analyzed by western blotting. Changes in cytokine expression levels, which included tumor necrosis factor (TNF)‑α, interleukin (IL)‑1β, IL‑6, monocyte chemotactic protein (MCP)‑1 and MCP‑2, were measured by ELISA. PgLPS was demonstrated to inhibit osteoblast viability and promote apoptosis in a time‑ and concentration‑dependent manner. CGRP expression was revealed to reduce PgLPS‑induced cytostatic activity and apoptosis in osteoblasts. CGRP also suppressed the PgLPS‑induced release of TNF‑α and inhibited the activation of c‑Caspase‑3 and c‑Caspase‑8, thus preventing apoptosis in osteoblasts. CGRP may be an important neuropeptide in bone remodeling and may reduce osteoblast apoptosis in inflammatory conditions. These results may provide a solid foundation for CGRP to serve as a new target for the treatment of periodontitis.