ABSTRACT
BACKGROUND: We have previously reported that azulene-related compounds, and alkaline extract of Sasa senanensis Rehder potently inhibited nitric oxide (NO) production by lipopolysaccharide (LPS)-stimulated mouse macrophages. We investigated here whether they can inhibit pro-inflammatory cytokine production, by activated human gingival fibroblast (HGF). MATERIALS AND METHODS: HGF was established from the periodontal tissues of extracted tooth. Viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Production of Prostaglandin E(2) (PGE(2)) and cytokines was determined by enzyme immunoassay, and enzyme-linked immunosorbent assay, respectively. RESULTS: Interleukin (IL)-1ß did not inhibit, but rather slightly stimulated the growth of HGF cells. IL-1ß stimulated the production of PGE(2), IL-6, IL-8 and monocyte chemotactic protein-1 very potently, but not that of nitric oxide and tumor necrosis factor-α. Native LPS and synthetic lipid A from E. coli and P. gingivalis was much less stimulatory. Dexamethasone, not indomethacin, was an efficient inhibitor of IL-8 production. Among five azulene-related compounds, benzo[b]cyclohepta[e][1,4]thiazine most potently inhibited the IL-8 production by HGF cells, as well as NO production by activated RAW264.7 cells. The alkaline extract of Sasa senanensis Rehder significantly inhibited IL-8 production, without affecting the cell viability. CONCLUSION: The present system may be applicable for use in the search for anti-gingivitis substances.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Fibroblasts/drug effects , Gingiva/pathology , Interleukin-1beta/pharmacology , Plant Extracts/pharmacology , Anti-Inflammatory Agents/isolation & purification , Antioxidants/pharmacology , Ascorbic Acid/pharmacology , Cell Line, Tumor , Chromatography, Gel , Drug Evaluation, Preclinical , Drug Synergism , Humans , Interleukin-1beta/physiology , Plant Extracts/isolation & purification , Plant Leaves/chemistry , Radiation-Protective Agents/isolation & purification , Radiation-Protective Agents/pharmacology , Sasa/chemistry , Ultraviolet RaysABSTRACT
We have previously investigated a total of 173 azulene-, tropolone- and azulenequinone-related compounds for their tumor-specificity and anti-inflammatory activity. In this study, we selected six compounds that showed tumor-specific cytotoxicity (referred to as group I compounds) and five compounds that inhibited nitric oxide production by activated macrophages (referred to as group II compounds) to investigate their possible hormetic and anti-radiation effects. We have established three oral normal cell type, human gingival fibroblast HGF-1, pulp cell HPC-1 and periodontal ligament fibroblast HPLF-1, from extracted teeth and periodontal tissue. These normal cells expressed p53 protein, regardless of the growth stage (either at growing or near confluent phase), more than oral squamous cell carcinoma cell line (HSC-2). Group I compounds slightly stimulated the growth of HPL-1 cells only at restricted durations and concentrations, but did not affect that of HGF-1 and HPC-1 cells, suggesting the minor hormetic effects displayed by these compounds. We established a new evaluation system for UV-induced cellular damage using an intact HSC-2 cell system in which sodium ascorbate (vitamin C) and gallic acid, but not N-acetyl-l-cysteine nor catalase, exerted protective effects. Three group I compounds and two group II compounds significantly protected the cells from UV-induced injury, suggesting their possible anti-UV effect.
