Alpha-mangostin suppresses IL-6 and IL-8 expression in P. gingivalis LPS-stimulated human gingival fibroblasts.

This study aims to investigate the effect of alpha-mangostin on interleukin (IL)-6 and IL-8 expression in human gingival fibroblasts (HGFs). HGFs were challenged with Porphyromonas gingivalis LPS and then treated with various concentrations of alpha-mangostin. The cytotoxicity was determined using MTS assay and cytokine expressions were evaluated by Real-time PCR and ELISA. The results showed that 5 µg/ml P. gingivalis LPS and alpha-mangostin at 1 µg/ml or less did not affect the viability of HGFs. Alpha-mangostin reduced IL-6 and IL-8 mRNA and protein in P. gingivalis LPS-stimulated HGFs. These findings suggested that alpha-mangostin might be used as an adjunct to the periodontal therapy.

Non-overlapping functions of Nck1 and Nck2 adaptor proteins in T cell activation.

BACKGROUND: Signalling by the T cell antigen receptor (TCR) results in the activation of T lymphocytes. Nck1 and Nck2 are two highly related adaptor proteins downstream of the TCR that each contains three SH3 and one SH2 domains. Their individual functions and the roles of their SH3 domains in human T cells remain mostly unknown. RESULTS: Using specific shRNA we down-regulated the expression of Nck1 or Nck2 to approximately 10% each in Jurkat T cells. We found that down-regulation of Nck1 impaired TCR-induced phosphorylation of the kinases Erk and MEK, activation of the AP-1 and NFAT transcription factors and subsequently, IL-2 and CD69 expression. In sharp contrast, down-regulation of Nck2 hardly impacts these activation read-outs. Thus, in contrast to Nck2, Nck1 is a positive regulator for TCR-induced stimulation of the Erk pathway. Mutation of the third SH3 domain of Nck1 showed that this domain was required for this activity. Further, TCR-induced NFAT activity was reduced in both Nck1 and Nck2 knock-down cells, showing that both isoforms are involved in NFAT activation. Lastly, we show that neither Nck isoform is upstream of p38 phosphorylation or Ca2+influx. CONCLUSIONS: In conclusion, Nck1 and Nck2 have non-redundant roles in human T cell activation in contrast to murine T cells.

Antimicrobial Activity of Roselle-capped​ Silver​ Nanochip on Aggregatibacter actinomycetemcomitans.

OBJECTIVES: This article aimed to study the effects of the​ roselle-capped​ silver​ nanochip​ ​(SNP-Ro​ chip)​ against Aggregatibacter actinomycetemcomitans, and the toxicity of this film on fibroblast cells to develop this SNP-Ro chip into a local chemical for the treatment of periodontitis in the future. MATERIALS AND METHODS: Using a microwave-assisted synthesis method, silver​ nanoparticles (SNPs) were prepared from a silver nitrate solution and roselle extract as a reducing and capping agent. Then, SNP-Ro chips were fabricated by mixing a solution of SNP-Ro with alginate gel. The antimicrobial effect of the synthesized SNP-Ro chips was performed by the disc diffusion technique and time kill assay. The cytotoxic effect was also determined by the MTS assay. STATISTICAL ANALYSIS: One-way analysis of variance (ANOVA) and Scheffe's method were used to analyze the data for this experiment. RESULTS: All three ratios of the SNP-Ro chip produced inhibition zones ranging between 18.75 ± 2.08 and 19.03 ± 2.25 mm. In studying the killing time, the three groups of the SNP-Ro chips completely eradicated A. actinomycetemcomitans within 180 minutes. The percentage of the viable SNP-Ro chip-treated human gingival fibroblasts (HGFs) were significantly increased when compared with the alginate chip-treated cells (p < 0.05). CONCLUSION: This study developed a new method for the deposition of SNPs in alginate gel to make a thin small chip for the sustained release of the SNPs in a periodontal lesion. Therefore, the SNP-Ro chip has the potential to be developed as an adjunctive locally delivered antimicrobial agent in periodontal therapy.

Morus alba Stem Extract Suppresses Matrix Metalloproteinases (MMP)-1, MMP-9, and Tissue Inhibitors of Metalloproteinase (TIMP)-1 Expression via Inhibition of IκBα Degradation Induced by Porphyromonas gingivalis LPS Signal in THP-1 Cells.

OBJECTIVES: The aim of this study is to evaluate the inhibitory effects of M. alba stem extract (MSE) on the expression of matrix metalloproteinases (MMP)-1, MMP-9, and tissue inhibitors of metalloproteinase (TIMP)-1 in Porphyromonas gingivalis lipopolysaccharide (LPS)-activated-acute monocytic leukemia cell line (THP-1). MATERIALS AND METHODS: THP-1 cells were treated with noncytotoxic concentrations of MSE combined with 1 µg/mL of P. gingivalis LPS. The mRNA levels of MMP-1, MMP-9, and TIMP-1 were evaluated via quantitative real-time polymerase chain reaction. The secreted proteins in the culture media were detected by enzyme-linked immunosorbent assay. The degradation of inhibitor of kappa B-alpha (IκBα) protein was tracked by Western blotting. STATISTICAL ANALYSIS: Comparisons in experiments were analyzed with analysis of variance followed by Tukey honestly significant difference comparison test. RESULTS: Twenty and 40 µg/mL of MSE significantly downregulated MMP-1 and MMP-9 genes and protein expression but upregulated the gene expression of TIMP-1 (p < 0.05). P. gingivalis LPS induced degradation of IκBα, while addition of MSE (20 and 40 µg/mL) increased IκBα cytosolic levels. MSE was able to suppress the P. gingivalis LPS-induced MMPs expression and also increased the gene expression of TIMP-1 via the inhibition of the cytoplasmic IκBα degradation in THP-1 cells. CONCLUSIONS: The present observations suggest that MSE exerted a positive effect on the regulatory mechanism between MMPs and TIMP, which is an important implication for the therapeutic potential of MSE in periodontitis.

Antibacterial and Anti-inflammatory Potential of Morus alba Stem Extract.

BACKGROUND: Periodontitis, a chronic inflammatory disease, is the leading cause of tooth loss in adults. Evidence for the anti inflammatory activity of M. alba Stem Extract (MSE) in periodontal disease is limited. OBJECTIVE: The study aimed to investigate the inhibitory effect of MSE on the growth of periodontopathic bacteria and expression of interleukin (IL)-6 and IL-8 in Porphyromonas gingivalis Lipopolysaccharide (LPS)-stimulated human Periodontal Ligament (hPDL) fibroblasts. METHODS: The antimicrobial activities of MSE were tested against P. gingivalis and Actinobacillus actinomycetemcomitans by the disk diffusion, the minimum inhibitory concentration and the minimal bactericidal concentration methods. Cytotoxicity of P. gingivalis LPS and MSE on hPDL fibroblasts was determined by MTS assay. The expression of cytokines (IL-6 and IL-8) mRNA and proteins in hPDL fibroblasts was measured using the reverse transcription-qPCR and enzyme-linked immunosorbent assay, respectively. RESULTS: MSE exhibited antibacterial activities against P. gingivalis and A. actinomycetemcomitans with the zones of inhibition of 10.00 ± 0.33 mm and 17.33 ± 0.58 mm, respectively. MIC and MBC values for MSE against P. gingivalis were 62.5 µg/ml. The MIC and MBC values against A. actinomycetemcomitans were 250 µg/mL and 500 µg/ml, respectively. P. gingivalis LPS was shown to mediate the expression of pro-inflammatory cytokines in hPDL fibroblasts. However, treatment with MSE concentrations of 2.5 and 5.0 µg/ml significantly suppressed P. gingivalis LPS-induced IL-6 and IL-8 mRNA and protein expression (p< 0.05). CONCLUSION: The present study demonstrates that MSE has antibacterial activity against two putative periodontal pathogens. MSE suppressed IL-6 and IL-8 expression in P. gingivalis LPS-stimulated hPDL fibroblasts, indicating a possible anti-inflammatory effect. Thus, it is a potential adjunctive agent for the treatment of periodontitis.