Seung-Hwa Jeong

Kochia scoparia induces apoptosis of oral cancer cells in vitro and in heterotopic tumors

ETHNOPHARMACOLOGICAL RELEVANCE Kochia scoparia grows commonly in China, Japan, and Korea and its mature fruit has been used throughout the area in traditional medicine to treat diseases including skin problems and inflammatory and allergic disease. More importantly, Kochia scoparia has been prescribed to treat the malignant tumor of head and neck region and breast mass. Although it has been proposed as an anti-cancer agent for several cancers, its exact in vivo anti-cancer properties and the molecular mechanisms underlying its effects are poorly understood. AIM OF THE STUDY To evaluate the anti-cancer activity of the methanol extract of K. scoparia, mature fruit (MEKS) on oral squamous cell carcinoma (OSCC) and to explore its mode of action. MATERIALS AND METHODS To assess proliferation inhibition and apoptosis induction by MEKS, MTT assays, cell analysis, ANNEXIN V and PI double staining, and Hoechst 33342 staining were performed. The activation of caspases and the MAP kinase p38 was evaluated using Western blot analysis. The anti-cancer properties of MEKS in vivo were elucidated in a heterotopic OSCC animal model. RESULTS After OSCC cells were treated with MEKS, the numbers of sub-G1 accumulated cells and apoptotic bodies increased, indicating that MEKS inhibited OSCC cell proliferation selectively through induction of apoptosis. Apoptosis of MEKS-treated OSCC cells was induced in a dose-dependent manner by caspase-3 and -9 activation. In addition, pretreatment with p38 inhibitor SB203580 in combination with MEKS significantly prevented MEKS-induced apoptosis in OSCC cells and also decreased cleaved capase 3, 9, and cleaved PARP activity in western blotting. MEKS treatment significantly increased the apoptosis of OSCC and inhibited tumour growth in our animal model. CONCLUSION Taken together, these results indicated that MEKS induced apoptosis of OSCC cells through caspase activation involving the p38 MAPK pathway. MEKS could be a promising anti-cancer candidate for OSCC treatment.

Antibacterial photodynamic therapy with curcumin and Curcuma xanthorrhiza extract against Streptococcus mutans

BACKGROUND Bacteria are becoming increasingly resistant to conventional antibacterial chemotherapy. This has prompted the application of antibacterial photodynamic therapy (aPDT) in bacteria-related diseases due to its excellent biocide effects. However, few studies have attempted to develop a novel photosensitizer based on natural components. The aim of the present study was to compare the aPDT effects of curcumin and Curcuma xanthorrhiza extract (CXE) against Streptococcus mutans. METHODS A planktonic suspension containing an S. mutans strain was treated in three separate groups: aPDT with curcumin, CXE, and a mixture of curcumin and CXE (ratio= 1:1) at concentrations of 0, 10, 102, 103, and 104ng/ml. Light irradiation with a center wavelength of 405nm was applied using an LED (power density of 84.5mW for 300s at an energy density of 25.3J/cm2). The phototoxicity of photosensitizers against S. mutans was investigated using a colony-forming-unit assay. Percentage logarithmic reductions [log10(CFU/ml) values] were analyzed using one-way ANOVA followed by the Tukey test (p<0.05) and Students independent t-test. RESULTS The viability of S. mutans in the presence of curcumin, CXE, and a mixture of these two components was substantially reduced during irradiation with 405nm light. The phototoxicity of the photosensitizer varied with its solubility and concentration. CONCLUSION These preliminary in vitro findings imply that combining curcumin and CXE with a 405nm LED may be a novel method of applying aPDT. This could be advantageous in preventing and treating dental caries using devices that are readily available in clinics.

Autophagic Cell Death by Poncirus trifoliata Rafin., a Traditional Oriental Medicine, in Human Oral Cancer HSC-4 Cells.

Poncirus trifoliata Rafin. has long been used as anti-inflammatory and antiallergic agent to treat gastrointestinal disorders and pulmonary diseases such as indigestion, constipation, chest fullness, chest pain, bronchitis, and sputum in Korea. P. trifoliata extract has recently been reported to possess anticancer properties; however, its mechanisms of action remain unclear. In this study, its antiproliferative effects and possible mechanisms were investigated in HSC-4 cells. The methanol extract of P. trifoliata (MEPT) significantly decreased the proliferation of HSC-4 cells (inhibitory concentration (IC)50 = 142.7 μg/mL) in a dose-dependent manner. While there were no significant changes observed upon cell cycle analysis and ANNEXIN V and 7-AAD double staining in the MEPT-treated groups, the intensity of acidic vesicular organelle (AVO) staining and microtubule-associated protein 1 light chain (LC) 3-II protein expression increased in response to MEPT treatment. Furthermore, 3-methyladenine (3-MA, autophagy inhibitor) effectively blocked the MEPT-induced cytotoxicity of HSC-4 cells and triggered the activation of p38 and extracellular signal-regulated kinases (ERK) proteins. Taken together, our results indicate that MEPT is a potent autophagy agonist in oral cancer cells with antitumor therapeutic potential that acts through the mitogen-activated protein kinase (MAPK) pathway.

Fluorescence change of Fusobacterium nucleatum due to Porphyromonas gingivalis

The aim of this study was to measure changes in the fluorescence of Fusobacterium nucleatum interacting with Porphyromonas gingivalis for excitation with blue light at 405-nm. P. gingivalis was mono- and co-cultivated in close proximity with F. nucleatum. The fluorescence of the bacterial colonies was photographed using a QLF-D (Quantitative Light-induced Fluorescence-Digital) Biluminator camera system with a 405 nm light source and a specific filter. The red, green and blue intensities of fluorescence images were analyzed using the image analysis software. A fluorescence spectrometer was used to detect porphyrin synthesized by each bacterium. F. nucleatum, which emitted green fluorescence in single cultures, showed intense red fluorescence when it was grown in close proximity with P. gingivalis. F. nucleatum co-cultivated with P. gingivalis showed the same pattern of fluorescence peaks as for protoporphyrin IX in the red part of the spectrum. We conclude that the green fluorescence of F. nucleatum can change to red fluorescence in the presence of adjacent co-cultured with P. gingivalis, indicating that the fluorescence character of each bacterium might depend on the presence of other bacteria.

The Flavonoid Jaceosidin from Artemisia princeps Induces Apoptotic Cell Death and Inhibits the Akt Pathway in Oral Cancer Cells

Jaceosidin is a single compound from the Japanese mugwort Artemisia princeps, which is used as a food and a traditional medicinal herb. A. princeps extracts and flavonoid components have been shown to have antihyperglycaemic, antioxidant, and anti-inflammatory properties. Although the anticancer properties of these extracts were recently demonstrated, the related mechanisms have not been characterised. In this study, we investigated the effects of jaceosidin in oral squamous cell carcinoma (OSCC) cells and initially showed selective suppression of proliferation (IC50 = 82.1 μM in HSC-3 cells and 97.5 μM in Ca9.22 cells) and accumulation of cells at the sub-G1 stage of the cell cycle. In addition, jaceosidin increased cleavage of caspase-9 and caspase-3 in OSCC cells, although caspase-8 was not detected. In further experiments, jaceosidin downregulated Akt phosphorylation and ectopic activation of Akt blocked the antiproliferative effects of jaceosidin. Finally, we showed that jaceosidin has no effects on HaCaT normal epithelial cell viability, indicating selective chemotherapeutic potential of jaceosidin and that tumour-specific downregulation of Akt increases apoptosis and inhibits growth in OSCC cells.

Poncirus trifoliata Rafin. induces the apoptosis of triple-negative breast cancer cells via activation of the c-Jun NH(2)-terminal kinase and extracellular signal-regulated kinase pathways

Background: Poncirus trifoliata Rafin. is a traditional medicine with known anti-inflammatory and anti-cancer properties. Traditionally, it is used to control chronic inflammation, allergy and gastrointestinal diseases such as digestive ulcers gastritis in China, Japan, and Korea. Objectives: To evaluate the apoptosis-inducing activity of a P. trifoliata methanol extract (MEPT) and elucidate the molecular mechanisms. Materials and Methods: The anti-cancer effect of MEPT and its underlying mechanisms were investigated in breast cancer cells using 3,4,5-dimethyl N-methylthiazol-2-yl-2, 5-d-phenyl tetrazolium bromide assay, cell cycle analysis, and western blotting. Results: MEPT suppressed the proliferation of MDA-MB-231 cells with inhibition dose 50% value of 119.44 μg/mL at 24 h, which have features typical of triple-negative breast cancer cells. MEPT also altered the characteristic features of the MDA-MB-231 cells and increased the proportion of cells undergoing sub-G1 arrest. In addition, MEPT increased levels of caspase 8 and 3 in MDA-MB-231 cells, whereas caspase 9 was not detected. In addition, MEPT-induced tumor necrosis factor receptor (TNFR) and TNFR type 1-associated death domain (TRADD) protein and the activations of c-Jun NH(2)-terminal kinase (JNK) and extracellular signal-regulated kinases (ERK). Conclusion: Our results indicate that MEPT has chemotherapeutic potential in triple-negative breast cancer and that at the molecular level its effects are derived from the activations of TNFR and of the mitogen-activated protein kinase pathway.