Combined Treatment of Heteronemin and Tetrac Induces Antiproliferation in Oral Cancer Cells.

BACKGROUND: Heteronemin, a marine sesterterpenoid-type natural product, possesses an antiproliferative effect in cancer cells. In addition, heteronemin has been shown to inhibit p53 expression. Our laboratory has demonstrated that the thyroid hormone deaminated analogue, tetrac, activates p53 and induces antiproliferation in colorectal cancer. However, such drug mechanisms are still to be studied in oral cancer cells. METHODS: We investigated the antiproliferative effects by Cell Counting Kit-8 and flow cytometry. The signal transduction pathway was measured by Western blotting analyses. Quantitative PCR was used to evaluate gene expression regulated by heteronemin, 3,3',5,5'-tetraiodothyroacetic acid (tetrac), or their combined treatment in oral cancer cells. RESULTS: Heteronemin inhibited not only expression of proliferative genes and Homo Sapiens Thrombospondin 1 (THBS-1) but also cell proliferation in both OEC-M1 and SCC-25 cells. Remarkably, heteronemin increased TGF-ß1 expression in SCC-25 cells. Tetrac suppressed expression of THBS-1 but not p53 expression in both cancer cell lines. Furthermore, the synergistic effect of tetrac and heteronemin inhibited ERK1/2 activation and heteronemin also blocked STAT3 signaling. Combined treatment increased p53 protein and p53 activation accumulation although heteronemin inhibited p53 expression in both cancer cell lines. The combined treatment induced antiproliferation synergistically more than a single agent. CONCLUSIONS: Both heteronemin and tetrac inhibited ERK1/2 activation and increased p53 phosphorylation. They also inhibited THBS-1 expression. Moreover, tetrac suppressed TGF-ß expression combined with heteronemin to further enhance antiproliferation and anti-metastasis in oral cancer cells.

Therapeutic applications of resveratrol and its derivatives on periodontitis.

Periodontitis is an inflammatory disease of the supporting tissues of the teeth induced by periodontopathic bacteria that results in the progressive destruction of periodontal tissues. Treatment of periodontitis is painful and time-consuming. Recently, herbal medicines have been considered for use in treating inflammation-related diseases, including periodontitis. Resveratrol and its derivative 2,3,5,4'-tetrahydroxystilbene-2-O-ß-glucoside (THSG), a polyphenol extracted from Polygonum multiflorum, have anti-inflammatory properties and other medical benefits. Here, we highlight the importance of resveratrol and its glycosylated derivative as possible complementary treatments for periodontitis and their potential for development as innovative therapeutic strategies. In addition, we present evidence and discuss the mechanisms of action of resveratrol and THSG on periodontitis, focusing on Porphyromonas gingivalis-induced inflammatory responses in human gingival fibroblasts and animal modeling of ligature-induced periodontitis. We also illuminate the signal transduction pathways and the cytokines involved.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-glucoside Isolated from Polygoni Multiflori Ameliorates the Development of Periodontitis.

Periodontitis, a chronic infection by periodontopathic bacteria, induces uncontrolled inflammation, which leads to periodontal tissue destruction. 2,3,5,4'-Tetrahydroxystilbene-2-O-beta-glucoside (THSG), a polyphenol extracted from Polygoni Multiflori, reportedly has anti-inflammatory properties. In this study, we investigated the mechanisms of THSG on the Porphyromonas gingivalis-induced inflammatory responses in human gingival fibroblasts and animal modeling of ligature-induced periodontitis. Human gingival fibroblast cells were treated with lipopolysaccharide (LPS) extracted from P. gingivalis in the presence of resveratrol or THSG to analyze the expression of TNF-α, IL-1ß, and IL-6 genes. Increased AMP-activated protein kinase (AMPK) activation and SirT1 expression were induced by THSG. Treatment of THSG decreased the expression of LPS-induced inflammatory cytokines, enhanced AMPK activation, and increased the expression of SirT1. In addition, it suppressed the activation of NF-κB when cells were stimulated with P. gingivalis LPS. The anti-inflammatory effect of THSG and P. Multiflori crude extracts was reproduced in ligature-induced periodontitis animal modeling. In conclusion, THSG inhibited the inflammatory responses of P. gingivalis-stimulated human gingival fibroblasts and ameliorated ligature-induced periodontitis in animal model.

Epigallocatechin-3-gallate attenuates Porphyromonas gingivalis lipopolysaccharide-enhanced matrix metalloproteinase-1 production through inhibition of interleukin-6 in gingival fibroblasts.

BACKGROUND: Recent studies have shown that epigallocatechin-3-gallate (EGCG), a major constituent of green tea extract, exhibits effects of anti-inflammation and antioxidation on periodontal inflammation. The present in vitro study examines the effect of EGCG on Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS)-enhanced expression of interleukin (IL)-6 and matrix metalloproteinase (MMP)-1, as well as the activation of nuclear factor-kappa B (NF-κB). Furthermore, the role of IL-6 on LPS-enhanced MMP-1 production is evaluated using human gingival fibroblasts (HGFs). METHODS: HGFs were primary cultured from human gingiva specimens. The cytotoxicities of EGCG and LPS were tested by cell viability tests. The cellular mRNA expression of IL-6 was determined by reverse-transcription polymerase chain reaction, and the protein expression of MMP-1 and IL-6 was examined by enzyme-linked immunosorbent assay. The cytosol expression and nuclear translocation of NF-κB was evaluated by immunocytochemistry followed by confocal laser scanning microscopy. RESULTS: Pg LPS significantly increased MMP-1 production in HGFs, whereas adding EGCG significantly attenuated this enhanced production of MMP-1. LPS treatment also increased the mRNA and protein expression of IL-6 and stimulated NF-κB activation in HGFs. However, the addition of EGCG significantly attenuated the IL-6 expression and NF-κB activation. Supplemental addition of IL-6 significantly enhanced cellular MMP-1 production, whereas anti-IL-6 antibody inhibited LPS-enhanced MMP-1 production. CONCLUSION: EGCG could attenuate Pg LPS-enhanced production of MMP-1 in HGFs, whereas this attenuation might be due to the inhibition of IL-6 by EGCG.

Berberine's effect on periodontal tissue degradation by matrix metalloproteinases: an in vitro and in vivo experiment.

Periodontal disease involves tissue destruction caused by interactions among bacterial antigens and inflammatory mediators including matrix metalloproteinases (MMPs). Berberine, an isoquinoline alkaloid isolated from medicinal herbs, can inhibit the degradative action of extracellular MMPs. The effect of berberine on the periodontal expression of MMPs was examined in vitro and in vivo. Gelatinolytic activity of pro-MMP-2, MMP-2, and MMP-9 in the human gingival fibroblast and/or U-937 was compared after treatment with Porphyromonas gingivalis lipopolysaccharide (P.g. LPS) in four medias containing 0, 1, 10 and 100µM of berberine each. Twelve animals were divided into three groups for the study: (A) non-ligation, (B) ligation, and (C) ligation-plus-berberine (75mg/kg berberine by gastric lavage daily); and the effect of berberine on periodontal destruction was evaluated in the ligature-induced periodontitis in rats for 8 days by micro computerized tomography (micro-CT), histology and immunohistochemistry (IHC). An enhancing effect of P.g. LPS on MMP activities was identified, with a greater effect on fibroblasts/U937 co-culture than on either culture alone. When berberine was added to the LPS-treated cultures, the activities of MMPs were significantly reduced in dose-dependent manner. In the animals, the trends of the following parameters were compared. 1. Micro-CT distances between cemento-enamel junction (CEJ) and dental alveolar bone crest: B>C>A. 2. Histometrically measured crest bone levels: B>C>A. 3. Amount of collagen deposited in tissue areas: A>C>B. 4. Attachment loss: B>C≈A. 5. Connective tissue (CT) attachment: B>either A or C. 6. Expression of cells stained positive for MMP-2 and -9 by IHC: B>C>A. In conclusion, berberine demonstrated in vitro an inhibitory effect on P.g. LPS-enhanced MMP activities of HGF and U937 macrophages, reducing in vivo gingival tissue degradation in periodontitic rats. We thus propose that berberine may slow periodontal degradation through the regulation of MMPs in periodontitis induced by bacterial plaque.