Hyeon-Hui Ki

Dioscin inhibits adipogenesis through the AMPK/MAPK pathway in 3T3-L1 cells and modulates fat accumulation in obese mice

Dioscin (DS) is a steroidal saponin present in a number of medicinal plants and has been shown to exert anticancer, antifungal and antiviral effects. The present study aimed to deternube the effects DS on the regulation of adipogenesis and to elucidate the underlying mechanisms. In vitro experiments were performed using differentiating 3T3-L1 cells treated with various concentrations (0-4 µM) of DS for 6 days. A cell viability assay was performed on differentiating cells following exposure to DS. Oil Red O staining and triglyceride content assay were performed to evaluate the lipid accumulation in the cells. We also carried out the following experiments: i) flow cytometry for cell cycle analysis, ii) quantitative reverse transcription polymerase chain reaction for measuring adipogenesis-related gene expression, and iii) western blot analysis to measure the expression of adipogenesis transcription factors and AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC) and mitogen-activated protein kinase (MAPK) phosphorylation. In vivo experiements were performed using mice with obesity induced by a high-fat diet (HFD) that were treated with or without DS for 7 weeks. DS suppressed lipid accumulation in the 3T3-L1 cells without affecting viability at a dose of up to 4 µM. It also delayed cell cycle progression 48 h after the initiation of adipogenesis. DS inhibited adipocyte differentiation by the downregulation of adipogenic transcription factors and attenuated the expression of adipogenesis-associated genes. In addition, it enhanced the phosphorylation of AMPK and its target molecule, ACC, during the differentiation of the cells. Moreover, the inhibition of adipogenesis by DS was mediated through the suppression of the phosphorylation of MAPKs, such as extracellular-regulated kinase 1/2 (ERK1/2) and p38, but not c-Jun-N-terminal kinase (JNK). DS significantly reduced weight gain in the mice with HFD-induced obesity; this was evident by the suppression of fat accumulation in the abdomen. the present study reveals an anti-adipogenic effect of DS in vitro and in vivo and highlights AMPK/MAPK signaling as targets for DS during adipogenesis.

Induction of IL-12 production by the activation of discoidin domain receptor 2 via NF-κB and JNK pathway

We investigated the mechanism involving discoidin domain receptor 2 (DDR2) mediated production of interleukin 12 (IL-12). When compared to control, collagen I upregulated the IL-12 luciferase activity on DDR2 expressing cells. Collagen I induced the phosphorylation of DDR2 and enhanced the phosphorylation of mitogen activated protein kinase (MAPK) kinases. In addition, NF-κB binding activity was enhanced when the cells expressing NF-κB reporter were exposed to collagen I. Moreover, when IL-12 reporter transfected cells were treated with biochemical inhibitors of c-Jun N-terminal kinase (JNK) and NF-κB, collagen-induced IL-12 promoter activity was significantly downregulated in comparison to non-treated cells. Similarly, confirmatory experiments on murine dendritic cells revealed that IL-12 promoter activity is dose dependently downregulated upon NF-κB and JNK inhibitor treatment on collagen I stimulation. In summary, DDR2 is involved in the collagen I-induced IL-12 production via NF-κB and JNK pathway.

Anti-obesity effect of Triticum aestivum sprout extract in high-fat-diet-induced obese mice.

Obesity is a common disease worldwide that often results in serious conditions including hypertension, diabetes, and hyperlipidemia. Many herbal medicines have been examined with regard to ameliorating obesity. We investigated the anti-obesity effects of 50% EtOH extract of Triticum aestivum sprout (TAEE) in high-fat-diet (HFD)-induced obese mice. TAEE administration (10, 50, or 200 mg/kg) for 6 weeks significantly decreased the body weights, serum total cholesterol (TC), and low-density lipoprotein cholesterol levels in HFD-fed mice. TAEE treatment reduced lipid accumulation in epididymal white adipose tissue (EWAT) and liver. Moreover, TC and lipid levels were decreased by TAEE treatment in liver. Serum leptin and adiponectin concentrations were reduced by TAEE treatment. TAEE-treated mice showed decreases in peroxisome proliferator-activated receptor γ (PPARγ) and fatty acid synthase expression in EWAT. Furthermore, TAEE administration elevated levels of PPARα protein in the liver of HFD-induced obese mice. These results suggest that TAEE supplementation might be beneficial for the treatment and prevention of obesity and related diseases. Graphical abstract

Triticumoside induces apoptosis via caspase-dependent mitochondrial pathway and inhibits migration through downregulation of MMP2/9 in human lung cancer cells

Non-small cell lung cancer (NSCLC) is the major cancer-related death worldwide with only 14% five-year survival rate. Triticumoside, a phenolic compound present in Triticum aestivum sprout extract, has been recognized to have antiobesity and anti-inflammatory effects. However, the effect of triticumoside on cancer cell proliferation and migration has not been studied. In order to elucidate whether triticumoside exhibits an anticancer effect, cells were incubated with different doses of triticumoside, and apoptosis was assessed by observing cell viability, cellular morphological changes, and annexin-V-fluorescein isothiocyanate/propidium iodide staining. Cell cycle analysis, western blotting, wound healing assay, and quantitative-polymerase chain reaction were also performed. Triticumoside exhibited marked cytotoxicity in the cells in dose- and time-dependent manner. Triticumoside caused morphological changes, including cellular rounding, nuclear condensation, and shrinkage. Likewise, triticumoside enhanced the sub-G1 proportion of cells. Additionally, triticumoside regulated expression of apoptosis-associated proteins, such as B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X, and procaspase-3/9. Triticumoside also inhibited migration of the cells through downregulation of matrix metalloproteinase-2/9 (MMP2/9). Collectively, these results suggest that triticumoside induces apoptosis through caspase-dependent mitochondrial pathway and suppresses migration via inhibition of MMP2/9 in NSCLC A549 cells.

Wheatgrass-Derived Polysaccharide Has Antiinflammatory, Anti-Oxidative and Anti-Apoptotic Effects on LPS-Induced Hepatic Injury in Mice

Hepatic injury occurs frequently during sepsis, and polysaccharides isolated from plants have been reported to have antiinflammatory and antioxidant effects in various models. However, the effect of wheatgrass‐derived polysaccharide (WGP) has not been previously studied. In the present study, we investigated the effect of WGP on lipopolysaccharide (LPS)‐induced hepatic injury in mice. Mice were pre‐treated with WGP (100 or 200 mg/kg daily for 2 days) and then challenged with LPS (1 mg/kg, intraperitoneal), and sacrificed after 12 h. Wheatgrass‐derived polysaccharide decreased serum aminotransferase levels and histological changes as compared with LPS‐challenged mice. Wheatgrass‐derived polysaccharide also significantly inhibited LPS‐induced pro‐inflammatory cytokine up‐regulation and improved the oxidative status of liver tissues. Furthermore, these effects were found to be mediated by the suppression of the transcriptional activity of nuclear factor‐kappa B (NF‐κB), due to inhibitions of transforming growth factor beta (TGF‐β)‐activated kinase (TAK)‐1 phosphorylation and inhibition of kappa B (IκB)‐α degradation. In addition, WGP inhibited the activations of mitogen‐activated protein kinases (MAPKs). Wheatgrass‐derived polysaccharide also attenuated hepatic cell death by modulating caspase‐3 and apoptosis associated mitochondrial proteins, such as, B‐cell lymphoma 2 (Bcl‐2) and Bcl‐2‐associated X (Bax). Taken together, WGP possesses antiinflammatory, anti‐oxidant and anti‐apoptotic activity and ameliorates LPS‐induced liver injury in mice. Copyright

Collagen I-induced dendritic cells activation is regulated by TNF-α production through down-regulation of IRF4

Previously we have shown that collagen I enhances the maturation and function of dendritic cells (DCs). Inflammatory mediators such as tumour necrosis factor (TNF)-α, interleukin (IL)-1β and lipopolysaccharide (LPS) are also known to activate DCs. Here we investigated the involvement of TNF-α on the collagen I-induced DCs activation. TNF-a neutralization inhibited collagen I-induced IL-12 secretions by DCs. Additionally, we observed suppression of collagen I-induced costimulatory molecules expression along with down-regulation of genes involved in DCs activation pathway. Furthermore, TNF-α inhibition upon collagen Istimulation up-regulated the expression of interferon regulatory transcription factor IRF4, when compared to collagen I only treated cells. Collectively, our data demonstrate that collagen I induce TNF-α production, which is crucial for the activation and function of DCs, through down-regulation of IRF4, and implicates the importance in development of anti- TNF-α therapeutics for several inflammatory diseases.

In vitro and in vivo anti-cancer activity of dichloromethane fraction of Triticum aestivum sprouts

Triticum aestivum sprouts (TA) contain significant amounts of chlorophyll, minerals, enzymes, and other functional entities. Furthermore, TA extracts have been shown to possess anti-obesity, anti-diabetic and hepatoprotective effects and are believed to help blood flow, digestion, and general detoxification of the body. In this study, the mechanism underlying the anti-cancer effects of a dichloromethane fraction of TA (TDF) was investigated in vitro and in vivo. In vitro study was done by examining cancer cells growth, morphological changes, cell cycles, expressions of death receptors and apoptosis-linked proteins in wide range of human cancer cell lines. To investigate the effect of TDF in vivo, C57BL/6 mice were injected with B16 melanoma cells and orally administered TDF. TDF markedly inhibited cancer cell growth and induced cellular morphological alterations, cell cycle arrest and apoptosis, and enhanced the expressions of death receptors (DR)-4, 5, and 6 in cell lines. In addition, TDF regulated the expressions mitochondrial apoptosis-linked proteins and induced caspase-dependent cell death. It also significantly enhanced phosphorylation of ERK1/2 and JNK, but not p38, whereas inhibited the activation of NF-κB in cancer cells. In our mouse model, TDF significantly suppressed B16 melanoma growth, to an extent similar to cisplatin (reference control) and augmented immunomodulatory cytokines. In brief, this study presents the mechanism responsible for the anti-cancer effects of TDF in vitro and in vivo.

Chrysanthemum indicum Inhibits Adipogenesis and Activates the AMPK Pathway in High-Fat-Diet-Induced Obese Mice

Chrysanthemum indicum (CI) is widely distributed in China and many parts of the tropical world, and has been reported to have antibacterial, antiviral, anti-oxidant and immunomodulatory effects, but no information is available on its effects on high fat diet (HFD)-induced obesity. This was undertaken to investigate the mechanism responsible for the effect of ethyl acetate fraction of CI (CIEA) on adipogenesis, in vitro and in vivo models of obesity. In the in vitro study, differentiating 3T3-L1 cells were treated with media to initiate differentiation (MDI) in the presence or absence of CIEA with different concentrations, and in the in vivo study, C57BL/6 mice were fed with HFD and administered CIEA daily for six weeks. Garcinia cambogia (GC) was used as the positive control, and was administered in the same manner as CIEA. Results showed CIEA reduced HFD-induced body weight gain, epididymal white adipose tissue (eWAT), and liver weight. In addition, CIEA significantly decreased serum lipid profiles, including total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterol (LDLc) and increased high density lipoprotein cholesterol (HDLc) levels. Furthermore, CIEA also reduced leptin levels and increased adiponectin levels in serum, and significantly decreased peroxisome proliferator-activated receptor [Formula: see text] (PPAR[Formula: see text]) and CCAAT/enhancer-binding protein (C/EPBs) levels, but increased PPAR[Formula: see text] level and the phosphorylation of AMP-activated protein kinase (AMPK) in eWATs and in the liver tissues of HFD fed obese mice. Taken together, these results indicate CIEA might be beneficial for preventing obesity.

Complement C1q stimulates the progression of hepatocellular tumor through the activation of discoidin domain receptor 1

C1q is known to perform several functions in addition to the role it plays in complement activation. C1q contains a collagen-like portion and DDR1 (discoidin domain receptor 1) is a well-known collagen receptor. Accordingly, we hypothesized C1q might be a novel ligand of DDR1. This study shows for the first time C1q directly induces the activation and upregulation of DDR1, and that this leads to enhanced migration and invasion of HepG2 cells. In addition, C1q was found to induce the activations of mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinase (PI3K)/Akt signaling, and to increase the expressions of matrix metalloproteinases (MMP2 and 9). Our results reveal a relationship between C1q and DDR1 and suggest C1q-induced DDR1 activation signaling may be involved in the progression of hepatocellular carcinoma.

Triticum aestivum Sprouts Extract Inhibits Azoymethane (AOM)/Dextran Sodium Sulfate (DSS)-Induced Colon Carcinogenesis in Mice

Abstract Chronic intestinal inflammation is critical risk factor of colorectal cancer. Triticum aestivum sprouts have been reported to provide a number of health benefits and used as a dietary supplement. In this study, the authors investigated the regulatory effects of T. aestivum sprouts ethanol extract (TAEE) on experimental colorectal carcinogenesis in an azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced mouse model. Oral administration of TAEE significantly attenuated crypt destruction and tumor formation in AOM/DSS-treated mice. Levels of inflammatory mediators involved in colorectal carcinogenesis, that is, tumor necrosis factor-α, interkeukin (IL)-1β, IL-6, cyclooxygenase-2, and inducible nitric oxide synthase, were lower in the colons of 200 mg/kg TAEE-treated mice than in AOM/DSS controls (p < 0.05). Immunohistochemical staining showed that levels of nuclear factor-kappa B p65 and β-catenin were attenuated by TAEE in the colon tissues of AOM/DSS-treated mice. Furthermore, levels of β-catenin-related genes (cyclin D1 and c-Myc), which are known to contribute to cell cycle regulation, were decreased in the colon tissues of TAEE-treated mice versus AOM/DSS controls (p < 0.01). These results showed TAEE inhibited colon inflammation and neoplasm formation caused by AOM/DSS treatment, suggesting that TAEE could be useful for the prevention and treatment of colitis-associated colon cancer.