Chalcone T4, a novel chalconic compound, inhibits inflammatory bone resorption in vivo and suppresses osteoclastogenesis in vitro

Antimicrobial and anti-biofilm activity of a mucoadhesive hydrogel functionalized with aminochalcone on titanium surfaces and in Galleria mellonella model: In vitro and in vivo study

Peri-implantitis associated with dental implants shares characteristics with destructive periodontal diseases. Both conditions are multifactorial and strongly correlated with the presence of microorganisms surrounding the prostheses or natural dentition. This study aimed to evaluate the antimicrobial activity and toxicity of a mucoadhesive hydrogel functionalized with aminochalcone (HAM-15) against Aggregatibacter actinomycetemcomitans, Fusobacterium periodonticum, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, and Candida albicans. Various experiments were conducted to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC), as well as the antibiofilm potential and toxicity in human gingival fibroblasts and a G. mellonella animal model. Infection and treatment studies were also performed in G. mellonella. The results demonstrated that both aminochalcone (AM-15) and the aminochalcone-functionalized hydrogel (HAM-15) exhibited antimicrobial activity, with MICs ranging from 7.8 to 31.2 μg/mL for the tested strains. Treatment with HAM-15 at 300 μg/mL reduced the monospecies biofilm of C. albicans and P. gingivalis by 7 log10 and 6 log10, respectively, and the mixed-species biofilm of these microorganisms by 7 log10 and 8 log10, respectively. Regarding toxicity, HAM-15 showed cytotoxic effects on human gingival fibroblasts at high concentrations, but in the G. mellonella model, survival was 70 % at a dose of 1 mg/mL. Additionally, AM-15, when administered after larval infection, protected 90 % of the animals (p < 0.05). These results suggest that AM-15 is a promising candidate for the prevention and treatment of anaerobic infections and yeasts, demonstrating significant antimicrobial efficacy and an acceptable safety profile in experimental models.

Exploring the Impact of Biological Agents on Protecting Against Experimental Periodontitis: A Systematic Review of Animal-Based Studies

Aim: This systematic review was aimed at addressing the focused question: What is the protective potential of biological agents against alveolar bone resorption during the progression of experimental periodontitis (EP)? Material and Methods: The study protocol was registered in the Open Science Framework database (doi:10.17605/OSF.IO/3P2HY). A comprehensive literature search was conducted across PubMed, Web of Science, Cochrane Library, Scopus, and Embase databases up to December 2023. Inclusion criteria consisted of preclinical studies in animal models of EP that examined the effects of biological agents on preventing periodontal bone loss and reducing tissue inflammation. Studies were excluded if they (i) used non-EP animal models; (ii) focused on antimicrobial agents; (iii) centered on prebiotics or probiotics; (iv) evaluated compounds not classified as biologicals; or (v) included randomized clinical trials, clinical studies, or reviews. Eligibility was determined based on the PI/ECOs framework, and study quality was assessed using the SYRCLE risk-of-bias tool. Results: After screening an initial pool of 5236 records from databases, registries, and hand searches, 39 studies met the inclusion criteria. A total of 23 biological agents were evaluated across these studies. The majority of studies employed the ligature-induced model of EP to test the effectiveness of biologicals as preventive or therapeutic interventions. The dosage of biological agents and the duration of disease induction varied depending on the EP model. In all studies, the main outcome-alveolar bone loss, a hallmark of EP-was significantly inhibited by biological agents, which also reduced proinflammatory mediators when compared to untreated controls. A key strength of this review is the high number of studies included, most of which were classified as having low risk of bias. However, a notable limitation is the absence of a meta-analysis, the short follow-up periods in the included studies, and the heterogeneity among the compound dosages and route of administration. Conclusion: This systematic review demonstrates that biological agents are effective in reducing bone loss and mitigating inflammation during EP progression. Randomized clinical trials are needed to confirm these findings in human populations.

Local Application of a New Chalconic Derivative (Chalcone T4) Reduces Inflammation and Oxidative Stress in a Periodontitis Model in Rats

Chalcones are phenolic compounds with biological properties. This study had the aim to evaluate the effects of topical administration of a new synthetic chalcone, Chalcone T4, in an animal model of periodontitis induced by ligature. Forty rats were distributed in the following experimental groups: negative control (without periodontitis and topical application of distilled water), positive control (periodontitis and topical application of distilled water), chalcone I and II (periodontitis and topical application of 0.6 mg/mL and 1.8 mg/mL, respectively). Chalcone or distilled water was administered into the gingival sulcus of the first molars daily for 10 days, starting with the ligature installation. The following outcomes were evaluated: alveolar bone loss (µCT and methylene blue dye staining), quantification of osteoclasts (histomorphometry), cell infiltrate and collagen content (stereometry), gene expression of mediators (Nfact11, Tnf-α, Mmp-13, iNos, Sod and Nrf2) by (RT-qPCR); expression of BCL-2 and Caspase-1 (immunohistochemistry). Chalcone T4 inhibited bone resorption and prevented collagen matrix degradation. Reduction in the expression of inflammatory markers (Nfact11, Tnf-α, Mmp-13, and Caspase-1), attenuation of oxidative stress (iNOS reduction, and increase in Sod), and pro-apoptotic effect of the compound (BCL-2 reduction), were associated its effects on periodontal tissues. Topical application of Chalcone T4 prevented bone resorption and inflammation, demonstrating potential in the adjunctive treatment of periodontitis.

Chemopreventive and Biological Strategies in the Management of Oral Potentially Malignant and Malignant Disorders

Oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) represent a significant global health burden due to their potential for malignant transformation and the challenges associated with their diagnosis and treatment. Chemoprevention, an innovative approach aimed at halting or reversing the neoplastic process before full malignancy, has emerged as a promising avenue for mitigating the impact of OPMD and OSCC. The pivotal role of chemopreventive strategies is underscored by the need for effective interventions that go beyond traditional therapies. In this regard, chemopreventive agents offer a unique opportunity to intercept disease progression by targeting the molecular pathways implicated in carcinogenesis. Natural compounds, such as curcumin, green tea polyphenols, and resveratrol, exhibit anti-inflammatory, antioxidant, and anti-cancer properties that could make them potential candidates for curtailing the transformation of OPMD to OSCC. Moreover, targeted therapies directed at specific molecular alterations hold promise in disrupting the signaling cascades driving OSCC growth. Immunomodulatory agents, like immune checkpoint inhibitors, are gaining attention for their potential to harness the body's immune response against early malignancies, thus impeding OSCC advancement. Additionally, nutritional interventions and topical formulations of chemopreventive agents offer localized strategies for preventing carcinogenesis in the oral cavity. The challenge lies in optimizing these strategies for efficacy, safety, and patient compliance. This review presents an up to date on the dynamic interplay between molecular insights, clinical interventions, and the broader goal of reducing the burden of oral malignancies. As research progresses, the synergy between early diagnosis, non-invasive biomarker identification, and chemopreventive therapy is poised to reshape the landscape of OPMD and OSCC management, offering a glimpse of a future where these diseases are no longer insurmountable challenges but rather preventable and manageable conditions.

Ugonin L inhibits osteoclast formation and promotes osteoclast apoptosis by inhibiting the MAPK and NF-κB pathways

Bone loss is a major issue for patients with osteoporosis, arthritis, periodontitis, and bone metastasis; however, anti-resorption drugs used to treat bone loss have been linked to a variety of adverse effects. Helminthostachys zeylanica (L.) Hook, belonging to the family Ophioglossaceae, is commonly used in traditional Chinese medicine to treat inflammation and liver problems. In the current study, ugonin L extracted from H. zeylanica was shown to reduce the receptor activator of nuclear factor kappa beta ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells in a concentration-dependent manner. Ugonin L treatment also inhibited the mRNA expression of osteoclast markers. Ugonin L was also shown to promote cell apoptosis in mature osteoclasts and suppress RANKL-induced ERK, p38, JNK, and NF-κB activation. Taken together, ugonin L appears to be a promising candidate for the development of novel anti-resorption therapies.

Design, synthesis and anti-Tb evaluation of chalcone derivatives as novel inhibitors of InhA

A series of halogenated chalcone derivatives were designed and developed for anti-tubercular activity. Novel molecules were designed and in-silico screening were performed using admetSAR, SwissADME, and Osiris Property Explorer. From the initial filter the top 10 compounds were docked using the Autodock tool 1.5.6. and the binding energies of the docked compounds were higher than the standard drugs Isoniazid.and Ethionamide. Based on the in-silico and docking results, the top halogenated chalcones were synthesized and characterized using FT-IR, mass spectrometry, 1H, and 13C NMR spectroscopy. The chalcones were further evaluated for anti-tubercular activity using MABA against the H37Rv strain. Among the series of compounds, DK12 and DK14 showed potent in-vitro activity, with MICs of 0.8 µg/ml, in comparison with 1.6 µg/ml of the first-line drug Isoniazid. Further molecular dynamics simulations studies for 100 ns revealed that the key interaction with TYR 158 were observed in both DK12 and DK14 in the InhA active site. The compound DK12 further showed significant interactions with PHE 149 and ARG 153 residues and is a hit molecule among the series. Further DK12 and DK14 does not show any significance toxicity. The compounds DK12 needs to be optimized and further investigation to be carried out against InhA.Communicated by Ramaswamy H. Sarma.

Chalcone T4 Inhibits RANKL-Induced Osteoclastogenesis and Stimulates Osteogenesis In Vitro

Chalcones are phenolic compounds produced during the biosynthesis of flavonoids that have numerous biological activities, including anti-inflammatory, antioxidant and anticancer. In this in vitro study, we investigate a newly synthesized chalcone (Chalcone T4) in the context of bone turnover, specifically on the modulation of osteoclast differentiation and activity and osteoblast differentiation. Murine macrophages (RAW 264.7) and pre-osteoblasts (MC3T3-E1) were used as models of osteoclasts and osteoblasts, respectively. Differentiation and activity osteoclasts were induced by RANKL in the presence and absence of non-cytotoxic concentrations of Chalcone T4, added in different periods during osteoclastogenesis. Osteoclast differentiation and activity were assessed by actin ring formation and resorption pit assay, respectively. Expression of osteoclast-specific markers (Nfatc1, Oscar, Acp5, Mmp-9 and Ctsk) was determined by RT-qPCR, and the activation status of relevant intracellular signaling pathways (MAPK, AKT and NF-kB) by Western blot. Osteoblast differentiation and activity was induced by osteogenic culture medium in the presence and absence of the same concentrations of Chalcone T4. Outcomes assessed were the formation of mineralization nodules via alizarin red staining and the expression of osteoblast-related genes (Alp e Runx2) by RT-qPCR. Chalcone T4 reduced RANKL-induced osteoclast differentiation and activity, suppressed Oscar, Acp5 and Mmp-9 expression, and decreased ERK and AKT activation in a dose-dependent manner. Nfact1 expression and NF-kB phosphorylation were not modulated by the compound. Mineralized matrix formation and the expression of Alp and Runx2 by MC3T3-E1 cells were markedly stimulated by Chalcone T4. Collectively, these results demonstrate that Chalcone T4 inhibits in osteoclast differentiation and activity and stimulates osteogenesis, which indicates a promising therapeutic potential in osteolytic diseases.

Local administration of curcumin-loaded nanoparticles enhances periodontal repair in vivo

The aim was to assess the influence of local application of curcumin-loaded nanoparticles on an experimental model of periodontal repair. Periodontitis was induced by ligatures on both lower first molars of rats. After 15 days, ligatures were removed ("treatment") and animals were randomly allocated to three experimental groups (n = 8/group): (i) 0.05 mg/ml curcumin-loaded nanoparticles, (ii) empty nanoparticles (vehicle control), and (iii) sterile saline (negative control). Experimental treatments were administered locally on days 0, 3, 5, 7, 9, and 11 after ligature removal. Animals were euthanized at 7 and 14 days. Bone repair was assessed by microcomputer tomography (µCT). Histological sections were stained with hematoxylin/eosin (H/E), Picrosirius Red, and Masson's trichrome. Expression of Runx-2 was studied by immunohistochemistry. Gene expression of Itgam, Arg1, and Inos was assessed by RT-qPCR. At 7 days, there was increased gene expression of Itgam and Arg1 and of the relative expression of Arg1/Inos in curcumin-treated animals, but no difference in any other outcomes. At 14 days, curcumin-loaded nanoparticles significantly increased bone repair and collagen content, as well as the number of osteocytes, percentage of extracellular matrix, and expression of Runx2. The results demonstrate that local administration of curcumin-loaded nanoparticles enhanced tissue repair in an experimental model of periodontal repair. Nanoparticle-encapsulated curcumin enhances early post-treatment repair of periodontal tissues.

Pharmacological Therapies for the Management of Inflammatory Bone Resorption in Periodontal Disease: A Review of Preclinical Studies

Periodontitis, a highly prevalent multicausal chronic inflammatory and destructive disease, develops as a result of complex host-parasite interactions. Dysbiotic bacterial biofilm in contact with the gingival tissues initiates a cascade of inflammatory events, mediated and modulated by the host's immune response, which is characterized by increased expression of several inflammatory mediators such as cytokines and chemokines in the connective tissue. If periodontal disease (PD) is left untreated, it results in the destruction of the supporting tissues around the teeth, including periodontal ligament, cementum, and alveolar bone, which lead to a wide range of disabilities and poor quality of life, thus imposing significant burdens. This process depends on the differentiation and activity of osteoclasts, the cells responsible for reabsorbing the bone tissue. Therefore, the inhibition of differentiation or activity of these cells is a promising strategy for controlling bone resorption. Several pharmacological drugs that target osteoclasts and inflammatory cells with immunomodulatory and anti-inflammatory effects, such as bisphosphonates, anti-RANK-L antibody, strontium ranelate, cathepsin inhibitors, curcumin, flavonoids, specialized proresolving mediators, and probiotics, were already described to manage inflammatory bone resorption during experimental PD progression in preclinical studies. Meantime, a growing number of studies have described the beneficial effects of herbal products in inhibiting bone resorption in experimental PD. Therefore, this review summarizes the role of several pharmacological drugs used for PD prevention and treatment and highlights the targeted action of all those drugs with antiresorptive properties. In addition, our review provides a timely and critical appraisal for the scientific rationale use of the antiresorptive and immunomodulatory medications in preclinical studies, which will help to understand the basis for its clinical application.