Anti-Inflammation of N-Benzyl-4-Bromobenzamide in Lipopolysaccharide-Induced Human Gingival Fibroblasts.

OBJECTIVE: To evaluate the effect of N-benzyl-4-bromobenzamide (NBBA) on lipopolysaccharide (LPS)-induced IL-6 and prostaglandin E2 (PGE2) production in human gingival fibroblasts (HGFs). MATERIAL AND METHODS: The benzamide compound was synthesized. The condition for IL-6 production of HGFs after induction with LPS was optimized. The HGFs were incubated with NBBA (10 µg/ml) for 30 min before LPS (1 µg/ml) was added. After 24 h of incubation time, the culture media were harvested and their IL-6 and PGE2 contents were determined using an enzyme-linked immunosorbent assay. Prednisolone (PDS) and NS-398 were used as positive controls. Statistical analysis of the IL-6 and PGE2 contents was performed using the ANOVA test followed by the Tukey multiple-comparisons test to compare replicate means. p < 0.001 was considered statistically significant. RESULTS: The maximum IL-6 production was achieved when HGFs were exposed to 1 µg/ml of LPS for 24 h, which was inhibited by the IL-6 immunosuppressant PDS. The benzamide compound, NBBA, exhibited a potent anti-IL-6 activity with inhibition of 35.6 ± 0.5%, significantly different from in the LPS-induced HGFs (p < 0.001). In addition, it inhibited 75.6 ± 0.52% PGE2 production. Cell viability was not significantly affected by treatment with NBBA at a concentration <10 µg/ml (p < 0.001). CONCLUSIONS: NBBA exhibited an inhibitory effect on the production of IL-6 and PGE2 in LPS-induced HGFs. It could serve as a compound with inhibiting inflammatory activity in periodontal disease.

Synthesis of bis, tris and tetra(dihydrocaffeoyl)polyamine conjugates as antibacterial agents against VRSA.

Bis, tris and tetra(dihydrocaffeoyl)polyamine conjugates were synthesized using solid phase synthesis technique. These compounds were screened for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) (11 strains) and vancomycin-resistant S. aureus (VRSA) (4 strains). Bis, tris and tetra(dihydrocaffeoyl)polyamine analogues showed antibacterial activity against VRSA which were better than the reference drugs, vancomycin. Tetra(dihydrocaffeoyl)polyamine conjugate exhibited the highest activity. These compounds showed no cytotoxicity against vero cells.

A sensitive direct ELISA for detection of prostaglandin E2.

In order to improve the indirect ELISA for detection of PGE(2), a modified direct ELISA technique was developed to measure PGE(2) in cell culture supernatants. An evaluation of three types of coating buffer showed that PGE(2) was adsorbed efficiently to the solid phase using the gelatin phosphate buffer. The sensitivity of the assay was increased by employing polyclonal rabbit anti-PGE(2) antibody dilution of 1/100 and 1% skimmed milk as a blocking solution, with the detection limit of 7.8-500 ng/well. The within-run and between-run coefficients of variation (CV) ranges were 3.2-3.7% and 3.4-3.8%, respectively. A linear standard curve was observed over the range of 0.078-5 microg/mL with a coefficient of determination (r(2)) of 0.99. Our results indicated that the developed direct ELISA was sensitive and suitable for a quick determination of PGE(2) levels from cell culture supernatants.

Antibacterial pterocarpans from Erythrina subumbrans.

Seven pterocarpans, erybraedin B (1), erybraedin A (2), phaseollin (3), erythrabyssin II (4), erystagallin A (5), erythrabissin-1 (6) and erycristagallin (7), two flavanones, 5-hydroxysophoranone (8) and glabrol (9), and one isoflavone, erysubin F (10), were isolated from the stems of Erythrina subumbrans (Leguminosae). Their structures were identified by means of spectroscopy. This is the first report of the isolation of the non-alkaloidal compounds from Erythrina subumbrans and the observed dehydration of 6a-hydroxypterocarpans 5 and 6 in CDCl(3) to the corresponding pterocarpenes 11 and 12, respectively. Compounds 8 and 9 were isolated for the first time from the genus Erythrina. Compounds 2 and 4 exhibited the highest degree of activity against Streptococcus strains with an MIC range of 0.78-1.56 microg/ml, whereas compound 7 exhibited the highest degree of activity against Staphylococcus strains, including drug-resistant strains (MRSA and VRSA), with an MIC range of 0.39-1.56 microg/ml. Interestingly, compounds 2, 4, 5 and 7 were more active against several strains of Streptococcus and Staphylococcus than the standard antibiotics vancomycin and oxacillin. Compound 7 showed the highest level of activity against all VRSA strains tested, with an MIC range of 0.39-1.56 microg/ml, which were resistant to both antibiotics. These compounds may prove to be potent phytochemical agents for antibacterial activity, especially against the MRSA and VRSA strains.

Bioactive constituents of the root bark of Artocarpus rigidus subsp. rigidus.

Investigation of the chemical constituents of the root bark of Artocarpus rigidus BLUME subsp. rigidus has led to the isolation of six, structurally diverse phenolic compounds. These included two new compounds with modified skeletons, the flavonoid 7-demethylartonol E (1) and the chromone artorigidusin (2), together with four known phenolic compounds, the xanthone artonol B (3), the flavonoid artonin F (4), the flavonoid cycloartobiloxanthone (5), and the xanthone artoindonesianin C (6). Compounds 1, 4, and 5 exhibited antiplasmodial activity against Plasmodium falciparum. All compounds showed antimycobacterial activity against Mycobacterium tuberculosis, with 4 being the most active compound (MIC 6.25 microg/ml). Compounds 5 and 6 were active against KB cells, whereas 2, 5, and 6 showed varying toxicity to BC cells. Compounds 1-3, 5, and 6 were active in the NCI-H187 cytotoxicity assay, with 3 being the most active compound (IC(50) 1.26 microg/ml).

Solid-phase synthesis and antibacterial activity of hydroxycinnamic acid amides and analogues against methicillin-resistant Staphylococcus aureus and vancomycin-resistant S. aureus.

A library of hydroxycinnamic acid amides (HCAAs) and analogues were synthesized using solid-phase synthesis technique. These compounds were screened for antibacterial against methicillin-resistant Staphylococcus aureus (MRSA) (11 strains) and vancomycin-resistant S. aureus (VRSA) (4 strains). Dihydrocaffeoyl analogues showed activity against VRSA which were better than the reference drugs, vancomycin and oxacillin. These compounds also exhibited antibacterial activity against MRSA, which were more potent than oxacillin.

Antimycobacterial and antioxidant flavones from Limnophila geoffrayi.

The chloroform extract of the aerial part of Limnophila geoffrayi showed antimycobacterial and antioxidant activities. Bioassay-guided fractionation has led to the isolation of the flavones nevadensin (5,7-dihydroxy-6,8,4'-trimethoxyflavone, 1) and isothymusin (6,7-dimethoxy-5,8,4'-trihydroxyflavone, 2). Both compounds 1 and 2 exhibited inhibition activity against Mycobacterium tuberculosis, with equal MIC value of 200 microg/mL. Only compound 2 exhibited antioxidant activity against the radical scavenging ability of DPPH, with the IC50 value of 7.7 microg/mL. The crude hexane, chloroform and methanol extracts as well as the pure compounds 1 and 2 did not exhibit mutagenic activity in the Bacillus subtilis recassay.

Generation of gingival T cell lines/clones specific with Porphyromonas gingivalis pulsed dendritic cells from periodontitis patients.

OBJECTIVES AND BACKGROUND: It is well documented that in periodontitis lesions, most infiltrated gingival T cells are antigen-specific memory T cells. These cells play an important role as regulators and effector cells in the pathogenesis of periodontitis. In this study, we used dendritic cells (DCs) as antigen-presenting cells to generate human gingival T cell lines and clones specific for Porphyromonas gingivalis from periodontitis patients. METHODS: Autologous DCs were derived from the patients' adherent monocytes using granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4. Lymphocytes were isolated from gingival biopsies using collagenase enzyme digestion and the number was increased by subsequent culturing in IL-2-containing medium. T cells were then negatively sorted using flow cytometry, cocultured with P. gingivalis-pulsed DCs and subsequently expanded in the culture medium containing IL-2. T cells were kept viable and active by periodic exposure to antigen-pulsed DCs. The specificity of the T cell lines was tested against four plaque bacteria: P. gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia and Actinomyces viscosus. The established T cell lines were then cloned. Three P. gingivalis-specific T cell lines and 12 gingival T cell clones were generated. They all showed good specificity against P. gingivalis but not to other plaque bacteria. RESULTS: All T cell clones were positive for CD4 and the majority of them produced interferon gamma, but a minimal or negligible amount of IL-5. CONCLUSIONS: The data obtained clearly showed that monocyte-derived DCs could be used as powerful antigen-presenting cells to generate antigen-specific T cells from periodontitis tissues.