Dae-Hun Park

1'-Acetoxychavicol acetate isolated from Alpinia galanga ameliorates ovalbumin-induced asthma in mice.

The World Health Organization reports that 235 million people are currently affected by asthma. This disease is associated with an imbalance of Th1 and Th2 cells, which results in the upregulation of cytokines that promote chronic inflammation of the respiratory system. The inflammatory response causes airway obstruction and can ultimately result in death. In this study we evaluated the effect of 1′-acetoxychavicol acetate (ACA) isolated from Alpinia galanga rhizomes in a mouse model of ovalbumin (OVA)-induced asthma. To generate the mouse model, BALB/c mice were sensitized by intraperitoneal injection of OVA and then challenged with OVA inhalation for 5 days. Mice in the vehicle control group were sensitized with OVA but not challenged with OVA. Treatment groups received dexamethasone, 25 mg/kg/day ACA, or 50 mg/kg/day ACA for 5 days. Asthma-related inflammation was assessed by bronchoalveolar lavage fluid cell counts and histopathological and immunohistochemical analysis of lung tissues. Our results showed that ACA reduced the infiltration of white blood cells (especially eosinophils) and the level of IgE in the lungs of mice challenged with OVA and suppressed histopathological changes such as airway remodeling, goblet-cell hyperplasia, eosinophil infiltration, and glycoprotein secretion. In addition, ACA inhibited expression of the Th2 cytokines interleukin (IL)-4 and IL-13, and Th1 cytokines IL-12α and interferon-γ. Because asthmatic reactions are mediated by diverse immune and inflammatory pathways, ACA shows promise as an antiasthmatic drug candidate.

HPLC Analysis, Optimization of Extraction Conditions and Biological Evaluation of Corylopsis coreana Uyeki Flos

A method for the separation and quantification of three flavonoids and one isocoumarin by reverse-phase high performance liquid chromatography (HPLC) has been developed and validated. Four constituents present in a crude ethanolic extract of the flowers of Coryloposis coreana Uyeki, were analyzed. Bergenin, quercetin, quercitrin and isosalipurposide were used as calibration standards. In the present study, an excellent linearity was obtained with an r2 higher than 0.999. The chromatographic peaks showed good resolution. In combination with other validation data, including precision, specificity, and accuracy, this method demonstrated good reliability and sensitivity, and can be conveniently used for the quantification of bergenin, quercetin, quercitrin and isosalipurposide in the crude ethanolic extract of C. coreana Uyeki flos. Furthermore, the plant extracts were analyzed with HPLC to determine the four constituents and compositional differences in the extracts obtained under different extraction conditions. Several extracts of them which was dependent on the ethanol percentage of solvent were also analyzed for their antimicrobial and antioxidant activities. One hundred % ethanolic extract from C. coreana Uyeki flos showed the best antimicrobial activity against the methicillin-resistant Staphylococcus aureus (MRSA) strain. Eighty % ethanolic extract showed the best antioxidant activity and phenolic content. Taken of all, these results suggest that the flower of C. coreana Uyeki flos may be a useful source for the cure and/or prevention of septic arthritis, and the validated method was useful for the quality control of C. coreana Uyeki.

Alpha-tocopheryl succinate sensitizes human colon cancer cells to exisulind-induced apoptosis

Sulindac sulfone (also known as exisulind) and its chemical derivatives are promising anticancer agents capable of inducing apoptosis in a variety of malignant cell types with minimal toxicity to normal cells. Here, we tested the ability of alpha-tocopheryl succinate (TOS), another promising anticancer agent, to sensitize colon cancer cells to exisulind-induced apoptosis. We found that sub-apoptotic doses of TOS greatly enhanced exisulind-induced growth suppression and apoptosis in the HCT116, LoVo and SNU-C4 human colon cancer cell lines. Our results revealed that this was accounted for primarily by an augmented cleavage of poly(ADP-ribose) polymerase (PARP) and enhanced activation of caspase-8, -9 and -3. Pretreatment with z-VAD-FMK (a pan-caspase inhibitor), z-IETD-FMK (a caspase-8 inhibitor) or z-LEHD-FMK (a caspase-9 inhibitor) blocked TOS and exisulind cotreatment-induced PARP cleavage and apoptosis. Furthermore, TOS/exisulind cotreatment induced JNK phosphorylation, while pretreatment with SP600151 (a JNK inhibitor) partially blocked cotreatment-induced caspase-dependent PARP cleavage and apoptosis. Taken together, these findings indicate that TOS sensitizes human colon cancer cells to exisulind-induced apoptosis. Apoptotic synergy induced by exisulind plus TOS seems likely to be mediated through a mechanism involving activation of caspases and JNK.

Age-associated changes in pancreatic exocrine secretion of the isolated perfused rat pancreas.

Gut functions, such as gastrointestinal motility, gastric secretion and pancreatic secretion, were reduced with age. Glucose tolerance is impaired, and the release of insulin and β-cells sensitivity on glucose are reduced with age. However, a lot of controversial data have been reported as insulin concentrations after glucose ingestion are either higher or no different in elderly and young subjects. Thus, this study was aimed to investigate whether aging could affect pancreatic exocrine secretion and its action mechanisms. An isolated perfused rat pancreatic model was used to exclude the effects of external nerves or hormones. Pancreatic secretion was increased by CCK under 5.6 mM glucose background in the isolated perfused pancreas of young (3 months), 12 months and 18 months aged rats. There was no significant difference between young and aged rats. In 3 months old rats, CCK-stimulated pancreatic secretion was potentiated under 18 mM glucose background. However, the potentiation effects of endogenous insulin and CCK were not observed in 12 and 18 months old rats. Exogenous insulin also potentiated CCK-stimulated pancreatic secretion in 3 months old rats. Similarly, exogenous insulin failed to potentiate CCK-stimulated pancreatic secretion as that of 3 months old rats. Wet weight of pancreas and amylase content in pancreatic tissue were not changed with age. These results indicate that pancreatic exocrine secretion is reduced with age and endogenous insulin secretion and/or action is involved in this phenomenon.

Bacillus subtilis KCTC 11782BP-Produced Alginate Oligosaccharide Effectively Suppresses Asthma via T-Helper Cell Type 2-Related Cytokines

According to the World Health Organization in 2013, 235 million people are afflicted with asthma. Asthma is a severe pulmonary disease that can be caused by the imbalance of T-helper (Th) type 1 (Th1) and type 2 (Th2) cells, and it is potentially fatal. In this study, we evaluated the anti-asthmatic effect of alginate oligosaccharide (AO), which was prepared from seaweed and converted by Bacillus subtilis KCTC 11782BP, in the mouse model of ovalbumin (OVA)-induced asthma. BALB/c mice were divided into the vehicle control (sensitized but not challenged), asthma induction, positive control (1 mg/kg dexamethasone), 50 mg/kg/day AO-treated, 200 mg/kg/day AO-treated, and 400 mg/kg/day AO-treated groups. The numbers or levels of inflammatory cells, eosinophils, and immunoglobulin (Ig) E were measured in bronchoalveolar lavage fluid (BALF), and asthma-related morphological and cytokine changes were analyzed in lung tissues. Our results show that AO dramatically reduced inflammatory cell numbers, eosinophil count, and IgE levels in BALF, and it dose-dependently inhibited asthmatic histopathological changes in the lung. In addition, AO dose-dependently suppressed the expression of CD3+ T-cell co-receptors, CD4+ Th cells, CD8+ cytotoxic T-cell-related factors, macrophages, and MHCII class. AO dose-dependently decreased the expression levels of Th1/2 cells-regulatory transcription factors such as GATA-3 which modulates Th2 cell proliferation and T-bet which does Th1 cell proliferation. The mRNA levels of all Th1/2-related cytokines, except IL-12α, were dose-dependently suppressed by AO treatment. In particular, the mRNA levels of IL-5, IL-6, and IL-13 were significantly inhibited by AO treatment. Our findings suggest that AO has the potential to be an anti-asthmatic drug candidate, due to its modulation of Th1/Th2 cytokines, which contribute to the pathogenesis of asthma.

In Vitro and In Vivo Studies on Quercus acuta Thunb. (Fagaceae) Extract: Active Constituents, Serum Uric Acid Suppression, and Xanthine Oxidase Inhibitory Activity

Quercus acuta Thunb. (Fagaceae) (QA) is cultivated as a dietary and ornamental plant in China, Japan, South Korea, and Taiwan. It has been widely used as the main ingredient of acorn tofu, a traditional food in China and South Korea. The aim of this study was to determine in vitro and in vivo xanthine oxidase (XO) inhibitory and antihyperuricemic activities of an ethyl acetate extract of QA leaf (QALE) and identify its active phytochemicals using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC) systems. The QALE was found to possess potent in vitro antioxidant and XO inhibitory activities. In vivo study using hyperuricemic mice induced with potassium oxonate demonstrated that the QALE could inhibit hepatic XO activity at a relatively low oral dose (50 mg/kg) and significantly alleviate hyperuricemia to a similar extent as allopurinol. Several active compounds including vitamin E known to possess XO inhibitory activity were identified from the QALE. To the best of our knowledge, this is the first study that reports the active constituents and antihyperuricemic effect of QA, suggesting that it is feasible to use QALE as a food therapy or alternative medicine for alleviating hyperuricemia and gout.

6,7-di-O-acetylsinococuline (FK-3000) induces G2/M phase arrest in breast carcinomas through p38 MAPK phosphorylation and CDC25B dephosphorylation

We evaluated the cytostatic effect of 6,7-di-O-acetylsinococuline (FK-3000) isolated from Stephania delavayi Diels. against breast carcinoma cell lines MDA-MB-231 and MCF-7. FK-3000 suppressed CDC25B phosphorylation directly and indirectly via p38 MAPK phosphorylation. CDC25B dephosphorylation decreased levels of cyclin B and phospho-CDC-2, and ultimately induced cell cycle arrest at the G2/M phase. The p38 MAPK inhibitor, SB 239063 blocked FK-3000-induced p38 MAPK phosphorylation and nuclear accumulation, but did not completely rescue cell death. Conclusively FK-3000 exerts its antiproliferative effect through two pathways: i) G2/M cell cycle arrest via downregulation of cyclin B and phospho-CDC2 by p38 MAPK phosphorylation and CDC25B dephosphorylation, and ii) p38 MAPK-independent induction of apoptosis.

Quantitative Analysis, Extraction Optimization, and Biological Evaluation of Cudrania tricuspidata Leaf and Fruit Extracts

Cudrania tricuspidata Bureau (Moraceae) shows numerous pharmacological effects and has been used in traditional herbal remedies for inflammation, gastritis, tumors, and liver diseases. However, no validated analytical method for the standardization and optimization of the biological properties of C. tricuspidata preparations has been reported. We developed and validated a reverse-phase high-performance liquid chromatography (HPLC) method for the separation and quantification of active markers. Ethanolic extracts of C. tricuspidata leaves were prepared and evaluated for chemical profiles and biological activities. The 80% ethanolic extract demonstrated the greatest antioxidant activity and phenolic content, while the 100% ethanolic extract had the greatest total flavonoid content and xanthine oxidase (XO) inhibitory activity. The validated HPLC method confirmed that chlorogenic acid, rutin, and kaempferol were present in C. tricuspidata leaf extracts. We postulated that the antioxidant and anti-hyperuricemic/gout effects of C. tricuspidata extract could be attributed to these marker compounds. Our results suggested that the flavonoid-rich fraction of the leaf extract may be utilized for the treatment and prevention of hyperuricemia-related diseases, and the validated method and marker compounds could be applied for the quality control of C. tricuspidata preparations.

Erythronium japonicum attenuates histopathological lung abnormalities in a mouse model of ovalbumin-induced asthma

Asthma is a chronic lung condition that can induce mucus hypersecretion and pulmonary obstruction and may even cause death, particularly in children and older individuals. Erythronium japonicum (E. japonicum) is a traditional herb used in Korea and East Asian countries that has been found to exert free radical scavenging activity and anti-proliferative effects in human colorectal carcinoma cells. In the present study, we evaluated the anti-asthmatic effects of an extract of E. japonicum in a mouse model of ovalbumin (OVA)-induced asthma. Female BALB/c mice were sensitized with an intraperitoneal injection of OVA and aluminum hydroxide hydrate on days 1 and 8 and then received the following treatments on days 21 to 25: i) control (no treatment), ii) sterilized tap water (given orally), iii) 1 mg/kg/day dexamethasone (administered orally), iv) 60 mg/kg/day E. japonicum extract, and v) 600 mg/kg/day E. japonicum extract. On the same days, all the mice except those in the control group were challenged 1 h later with nebulized 5% OVA for 30 min. We found that treatment with E. japonicum extract suppressed the OVA-induced increase in the number of white blood cells and decreased the IgE level in the bronchoalveolar lavage fluid samples obtained from the mice. Histopathological analysis of the lung tissues revealed that E. japonicum attenuated the asthma-related morphological changes in the mouse lung tissue, including the increased secretion of mucus in the bronchioles, eosinophil infiltration around the bronchioles and vessels, and goblet cell and epithelial cell hyperplasia. Immunohistochemical analysis revealed that treatment with E. japonicum extract suppressed the OVA-induced proliferation of T helper cells (CD4+) and B cells (CD19+) in the mouse lung tissue. Furthermore, treatment with E. japonicum extract modulated the expression of both T helper 2 cell-related factors [GATA binding protein 3 (GATA-3), tumor necrosis factor-α (TNF-α), interleukin (IL)-4, IL-5, IL-6 and IL-13], as well as that of T helper 1 cell-related factors [(interferon-γ (IFN-γ), IL-12p35 and IL-12p40]. These findings suggest that E. japonicum may potentially be used as an anti-asthmatic treatment.

FK-3000 isolated from Stephania delavayi Diels. inhibits MDA-MB-231 cell proliferation by decreasing NF-κB phosphorylation and COX-2 expression

The World Health Organization (WHO) has reported that cancer is one of the most prevalent diseases and a leading cause of death worldwide. Many anticancer drug development studies have been pursued over the last few decades and several viable drugs have been discovered, such as paclitaxel, topotecan and irinotecan. Previously, our research group uncovered the cytocidal and cytostatic effects of the plant Stephania delavayi Diels. In this study, we determined the active chemical to be 6,7-di-O-acetylsinococuline (FK-3000). The FK-3000 half maximal inhibitory concentration (IC50) in MDA-MB-231 breast carcinoma cells at 48 h was 0.52 μg/ml and it induced apoptosis in a dose- and time-dependent manner. FK-3000 suppressed NF-κB nuclear translocation, decreased NF-κB phosphorylation, and decreased COX-2 protein expression. MDA-MB-231 xenografted mice were treated with FK-3000, Taxol, or their combination for 21 days. The tumor size was smallest in the co-treatment group, indicating that FK-3000 may have a synergistic effect with Taxol. FK-3000 treatment showed no adverse effects on blood cell counts, serum protein levels, or pathology. These studies demonstrate that FK-3000, isolated from S. delavayi Diels., is a promising, pathway-specific anticancer agent that exhibits low toxicity.