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Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods:Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: Royal jelly concentrations of 25% or higher can inhibit bacterial growth; however, subinhibitory concentrations could increase pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.

Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods: Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: The royal jelly concentration of 25% or higher inhibits bacterial growth; however, the subinhibitory concentration increases pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.

Calcium is one of the most important minerals needed during hard tissue development. The preparation of this material into nano-sized particle is carried out to enhance the bioavailability and distribution of calcium in the body. Lack of calcium during odontogenesis causes defect in enamel such as hypoplasia and hypomineralization. During amelogenesis, after secretion of organic matrices, enamel mineralization will start in the presence of calcium. The objective of this study was to determine the effect of nano calcium supplementation during pregnancy on enamel development. In this study, 3-month-old female Sprague Dawley were mated and divided into three groups: nano calcium group (A), micro calcium group (B), and negative control group (C). The treatment was started on day 1 of pregnancy to day 1 after birth by intragastric administration method. The mandibles of 6 pups from each group were collected and stained with hematoxylin and eosin. Examination was conducted using microscope. Enamel deposition was measured using Optilab Image Raster® and the data collected was analyzed using t-test. Histological section of mandibular right first molar on Sprague Dawley newborn pups showed that enamel was observed on day 1 after birth but only on the group treated with nano calcium and micro calcium. Statistical analysis performed showed that the difference between the two groups was significant (p

Aim: Gingivitis has been defined as the reversible dental plaque-induced inflammation of the gingiva without detectable bone loss or clinical attachment loss. It is frequently encountered in dental practice and affected people of all ages and describes the condition of the dental soft tissue. There is always a correlation between the presence of calculus and the prevalence of gingivitis. The aim of this clinical study was to assess the efficacy of anticalculus mouthwash on reduction of plaque and calculus with and without professional intervention. Materials and Methods: A total of 40 volunteers with clinical signs of moderate gingivitis were selected and after a washout period of 2 weeks divided into groups, with and without any professional intervention. The patients were instructed to use anticalculus mouth twice daily. Clinical assessment was carried out using the plaque index based on Silness and Loe method, gingival index based on Loe and Silness method, and calculus index of Oral Hygiene Index-Simplified at baseline, 1 month, and 2-month days of the anticalculus mouthwash use. Statistically analysis was carried out using the Kruskal–Wallis and Mann–Whitney test for comparative analysis. Results: The study proved that anticalculus mouthwash was effective in lowering all the clinical scores both with and without any professional intervention. However, the optimal results were achieved when combined with professional scaling. Conclusion: Anticalculus mouthwash is effective in controlling plaque-induced gingivitis and lowering clinical scores.

Porphyromonas gingivalis and Escherichia coli lipopolysaccharide (LPS) have been shown to induce alveolar bone resorption in the rat. The progress and distribution of bone resorption associated with periodontal disease is modified by local and systemic factors. The aim of this study was to determine the effect of a site specific, local application of P. gingivalis and E. coli LPS on alveolar bone in the rat. It appears that the injection of P. gingivalis and E. coli LPS has both a local and systemic effect on alveolar bone activity in the rat. Loss of alveolar bone height and an increase in osteoclast cell numbers were observed on both the injected and non-injected sides of the maxilla in animals injected with P. gingivalis and E. coli LPS at the dosages and time intervals examined.

OBJECTIVE: To determine whether treatments with high-density lipoprotein (HDL) may alter the lipopolysaccharide (LPS)-induced alveolar bone resorption in rats. MATERIALS AND METHODS: Rats were injected with 500 μg of LPS from Escherichia coli at the alveolar mucosa of lower right first molar once every 2 days for 8 days. The negative and positive control were injected with phosphate buffered saline (PBS) and LPS alone, respectively. In HDL-treated animals various concentration of HDL were injected immediately before, after the third or the final LPS injection. The bone sections were stained with tartrate-resistant acid phosphatase (TRAP) and the numbers of both osteoclasts and preosteoclasts and the levels of alveolar bone resorption were assessed. RESULTS: The numbers of both osteoclasts and preosteoclasts and the levels of alveolar bone resorption in animals treated with HDL before or during LPS injections were lower than those in the positive control, but higher than those in the negative control, regardless of HDL doses. Similar results were also observed in animals treated with 250 and 500 μg of HDL after the final LPS injection. Only treatments with 1000 μg of HDL after LPS injections completely reduced the number of both osteoclasts and preosteoclasts, but only partially decreased the alveolar bone resorption. CONCLUSION: HDL treatments partially reduced the LPS-induced alveolar bone resorption in vivo in rats, suggesting that HDL may neutralize the ability of LPS to induce alveolar bone resorption.

– The aim of this study was to determine whether treatment with fish oil may alter the periapical bone resorption following pulp exposure in rats. Untreated and pulp-exposed animals served as the negative and positive control, respectively. Other pulp-exposed animals were orally treated with fish oil at different concentrations and frequencies. Periapical tissue sections were stained with tartrate-resistant acid phosphatase (TRAP), and then the numbers of both periapical osteoclasts and preosteoclasts were determined. The levels of bone resorption were assessed using the osteoclast–bone interface (OBI) index. The results showed that no differences between the numbers of both osteoclasts and preosteoclasts in the fish oil-treated animals and the negative control at day 14 could be found. Similarly, the periapical bone resorption in the animals treated with fish oil for 14 days significantly reduced to the levels of that in the negative control. The results of the present study, therefore, suggest that oral treatment with fish oil may inhibit bone resorption following pulp exposure in rats and hence, may have a therapeutic modality for inflamed periradicular tissue.

The aims of this study were to determine how Prostaglandin E-2 (PGE(2)) locally applied affected the immunodistribution of latent transforming growth factor-beta 1 (TGF-beta 1), and how the eicosanoid modified TGF-beta 1 release and TGF-beta receptors gene expression in Cultured osteoblasts. PGE(2) locally delivered on the rat mandible at doses of 0.1 and 0.05 mg/day, but not 0.025 mg/ day, over 20 days significantly increased latent TGF-beta 1 immunodistribution (P < 0.001), comparing with a placebo-treated group. Cultured osteoblasts stimulated with 10(-5) or 10(-7) M PGE(2) significantly varied the level of activated TGF-beta 1 released into supernatants at different experimental periods compared with negative and positive controls. TGF-beta receptor type I gene expression was significantly increased in osteoblasts (P < 0.01) after 10 days of treatment with 10(-5) and 10(-7) M PGE(2), whereas 10(-3) M PGE(2) produced the opposite effect. It is Concluded that PGE(2) may stimulate bone deposition by affecting TGF-beta pathway. This effect on the pathway appears to be dose-dependent. (c) 2006 Elsevier Ltd. All rights reserved.