Effects of gold nanoparticles combined with human β-defensin 3 on the alveolar bone loss of periodontitis in rat

Background Nanomaterials of biomedicine and tissue engineering have been proposed for the treatment of periodontitis in recent years. This study aimed to investigate the effects of gold nanoparticles (AuNPs) combined with human β-defensin 3 (hBD3) on the repair of the alveolar bones of experimental periodontitis in rats. Methods A model of experimental periodontitis was established by ligation of the maxillary second molars with silk thread in rats, which were treated with or without AuNPs combined with hBD3. Micro‐computerized tomography (micro-CT) scanning, enzyme-linked immunosorbent assay, and histological and immunohistochemical staining, including alkaline phosphatase (ALP), osteoprotegerin (OPG), tartrate-resistant acid phosphatase (TRAP), and receptor activator of NF-κB ligand (RANKL), were used to analyze the samples. Results Micro-CT demonstrated that the alveolar bone resorption was significantly reduced after the treatment with AuNPs combined with hBD3. Levels of TNF-α and IL-6 were decreased markedly compared with the ligation group. H&E and Masson staining showed that AuNPs combined with hBD3 group had less inflammatory cell infiltration, collagen fibrosis and fracture, but higher calcification in the new bone tissue. Moreover, the administration of AuNPs combined with hBD3 increased the expression levels of ALP and OPG (related to bone formation) while decreasing the expression levels of TRAP and RANKL (related to bone resorption) expression. Conclusions AuNPs combined with hBD3 had a protective effect on the progression of experimental periodontitis in rats and played a certain role in suppressing osteoclastogenesis and alleviating the inflammatory destruction of periodontitis along with the promotion of bone repair.

Protective Effect of Resveratrol against the Alveolar Bone Loss in Rats with Experimental Periodontitis and Acts Positively on the IL-17

The resveratrol is a polyphenol known for its health benefits, which includes the ability to interfere in the osteoblastogenesis, which may foster adverse immunomodulators effects in the host response to periodontal disease. In the present study we evaluated the appearance of periodontal tissues of rats with experimentally induced periodontitis, by using resveratrol. Twenty-four male Wistar rats were used, in which half of the animals received a ligature around the first lower molars, then forming the groups with experimental periodontitis. Next, four groups were created: 1) Control Group (CON); 2) The Ligature Group (LIG); 3) Group Resveratrol (RSV); 4) Ligature-Resveratrol Group (LIG-RSV). The animals of the Resveratrol groups were daily dosed with 10 mg/kg of body weight of polyphenol orally, during four weeks. After 105 days of experimental period, euthanasia was performed. The results showed a significantly lower alveolar bone loss (p<0.05) in animals that received resveratrol, and still, the polyphenol was able to reduce concentration of interleukin 17 (IL-17) in the groups dosed with it. Our conclusion is that dosing rats with experimental periodontitis with resveratrol could cause a protective effect on the alveolar bone loss, in addition to act positively on the IL-17.

Quercetin effects on adaptive immune response in experimental periodontitis of bacterial-immune genesis

In the article was studied the effects of flavonol quercetin on indices of adaptive immune response in experimental animals on the 14th day of the experimental bacterial-immune periodontitis development. Indices of immune protection were determined by the relative number of lymphocytes with CD3+, CD4+, CD8+, CD19+, CD16+ and immunoregulatory index (CD4+ / CD8+) in intact animals and on the 14th day of inflammatory process development in periodontal tissues as well as the therapeutic effects of flavonol quercetin. As a result of the study, characterized changes associated with the activity of both the cell-mediated and humoral-immune response were found, both in the development of experimental periodontitis, and apply of flavonol. In particular, there was an increase in the animal’s blood relative amount of CD8+, CD16+ cells on the 14th day, and content of CD3+, CD4+, CD19+ was decreased. In this case, the immunoregulatory index (CD4+ / CD8+) as an important index of immunological activity was decreased. The apply of flavonol quercetin in the period development of bacterial-immune periodontitis animals functional activity of the T-cell line of the immune system was increased, as evidenced percentage increase of B- and T-cells due to T-helper cells decrease as well as T-killers content during this period of inflammatory reaction in the periodontal complex, in comparison with animals, which were not treated.

Dynamics of changes in nonspecific resistance of guinea pigs under conditions of formation of experimental periodontitis and immobilization stress

The aim of our study was to determine the phagocytic activity of leukocytes and nitrosine tetrazolium test (NST - test) in the dynamics of experimental periodontitis (EP) and immobilization stress (IS). It is established in the work that the indicators studied by us, namely phagocytic number, phagocytic index and NST - test increase on the 3 rd, 5 th and 15 th days of our experiment. The above tests have a high diagnostic value and allow to characterize the degree of activity of the inflammatory process and determine the participation of individual parts of the body's defense mechanisms. The obtained results make it possible to express the opinion that polymorphonuclear leukocytes take an active part in the formation of EP and IS, as well as indicate the stimulation of metabolic processes in leukocytes.

Evaluation of endogenous intoxication indicators in the dynamics of experimental periodontitis and immobilization stress

The aim of our work was to investigate the peculiarities of changes in endogenous intoxication rates: medium mass molecules (MMM) and erythrocyte intoxication index (EII) in the blood of guinea pigs in the formation of combined pathology - experimental periodontitis (EP) and immobilization stress (IS).The results of biochemical studies showed that at all stages of development of combined pathology - experimental periodontitis and immobilization stress there is a consistent increase in the degree of endogenous intoxication, which dominated on the 15th day of the experiment, namely increased content of medium mass molecules (МMМ254 , MMM280) and EII in the blood by 58.5% (p≤0.05), 80.3% (p≤0.05) and 95.7% (p≤0.05), respectively, compared with the first group of animals is a clear manifestation of the formation of endogenous intoxication. These changes are obviously the result of insufficient elimination of toxic products on the background of the inflammatory process in periodontal tissues and stress.

Novel Preosteoclast Populations in Obesity-Associated Periodontal Disease

Although there is a clear relationship between the degree of obesity and periodontal disease incidence, the mechanisms that underpin the links between these conditions are not completely understood. Understanding that myeloid-derived suppressor cells (MDSCs) are expanded during obesity and operate in a context-defined manner, we addressed the potential role of MDSCs to contribute toward obesity-associated periodontal disease. Flow cytometry revealed that in the spleen of mice fed a high-fat diet (HFD), expansion in monocytic MDSCs (M-MDSCs) significantly increased when compared with mice fed a low-fat diet (LFD). In the osteoclast differentiation assay, M-MDSCs isolated from the bone marrow of HFD-fed mice showed a larger number and area of osteoclasts with a greater number of nuclei. In the M-MDSCs of HFD-fed mice, several osteoclast-related genes were significantly elevated when compared with LFD-fed mice according to a focused transcriptomic platform. In experimental periodontitis, the number and percentage of M-MDSCs were greater, with a significantly larger increase in HFD-fed mice versus LFD-fed mice. In the spleen, the percentage of M-MDSCs was significantly higher in HFD-fed periodontitis-induced (PI) mice than in LFD-PI mice. Alveolar bone volume fraction was significantly reduced in experimental periodontitis and was further decreased in HFD-PI mice as compared with LFD-PI mice. The inflammation score was significantly higher in HFD-PI mice versus LFD-PI mice, with a concomitant increase in TRAP staining for osteoclast number and area in HFD-PI mice over LFD-PI mice. These data support the concept that M-MDSC expansion during obesity to become osteoclasts during periodontitis is related to increased alveolar bone destruction, providing a more detailed mechanistic appreciation of the interconnection between obesity and periodontitis.