In-Seung Lee

Coix seed extract attenuates the high-fat induced mouse obesity via PPARγ and C/EBPα a downregulation

The seed of the Coix lacryma-jobi L. var. ma-yuen Stapf seed (CLMS) extract has been prescribed to alleviate obesity by practitioners of traditional Korean medicine. Here, we investigated the effect of CLMS extract on PPARγ2 and c/EBPα and obesity responses in C57BL/6J obese mice fed on a high fat diet. The mouse body index, blood profile, and fat accumulation levels in the liver were measured. The protein expression levels of PPARγ2 and c/EBPα in the mice livers were also measured to determine the molecular mode-of-action of the reducing effect of CLMS extract on mouse adipogenesis. The results showed that HFD-induced mouse obesity, fat accumulation, and serum cholesterol were alleviated by the CLMS extract addition. Moreover, PPARγ2 and C/EBPα, proteins, those are related to the adipogenesis, were downregulated by the CLMS extract intake considerably. This study indicates that as a food additive, CLMS extract has a reducing effect on the high-fat diet induced fat accumulation and on body weight through the downregulation of adipogenesis.

The aglycone of ginsenoside Rg3 enables glucagon-like peptide-1 secretion in enteroendocrine cells and alleviates hyperglycemia in type 2 diabetic mice

Ginsenosides can be classified on the basis of the skeleton of their aglycones. Here, we hypothesized that the sugar moieties attached to the dammarane backbone enable binding of the ginsenosides to the sweet taste receptor, eliciting glucagon-like peptide-1 (GLP-1) secretion in the enteroendocrine L cells. Using the human enteroendocrine NCI-H716 cells, we demonstrated that 15 ginsenosides stimulate GLP-1 secretion according to the position of their sugar moieties. Through a pharmacological approach and RNA interference technique to inhibit the cellular signal cascade and using the Gαgust−/− mice, we elucidated that GLP-1 secreting effect of Rg3 mediated by the sweet taste receptor mediated the signaling pathway. Rg3, a ginsenoside metabolite that transformed the structure through a steaming process, showed the strongest GLP-1 secreting effects in NCI-H716 cells and also showed an anti-hyperglycemic effect on a type 2 diabetic mouse model through increased plasma GLP-1 and plasma insulin levels during an oral glucose tolerance test. Our study reveals a novel mechanism where the sugar moieties of ginsenosides Rg3 stimulates GLP-1 secretion in enteroendocrine L cells through a sweet taste receptor-mediated signal transduction pathway and thus has an anti-hyperglycemic effect on the type 2 diabetic mouse model.

Transcriptomic analysis of the bitter taste receptor-mediated glucagon-like peptide-1 stimulation effect of quinine

Quinine is a bitter taste receptor agonist that has been studied its anti-pyretic, anti-malarial, anti-pain, and anti-inflammatory activity. In this study, glucagon-like peptide-1 (GLP-1) stimulation effect of quinine was investigated. Bitter taste receptors are G protein-coupled receptor (GPCR), which transfer the molecular signal through its downstream cascade. The activation of bitter taste receptor, which expressed in the enteroendocrine L cells, stimulates the GLP-1 secretion and therefore can be a therapeutic target of the type-2 diabetes mellitus (T2DM). Here, we studied GLP-1 stimulation effect of quinine on the endocrine differentiated NCI-H716 cells. To investigate the molecular mode-of-action of the GLP-1 stimulation effect of quinine in the enteroendocrine L cells, transcriptomic analysis was performed. Our data suggest that quinine stimulates the GLP-1 secretion through the bitter taste receptor-signaling pathway, and thus has the possibility of therapeutic agent of T2DM.

Osteogenic differentiation of human mesenchymal stem cells promoted by the crude extracts of the mixture of Cortex mori radicis, Patrinia saniculaefolia

The present study investigated the effect of Cortex mori radicis (CMR) and Patrinia saniculaefolia (PS) on the osteogenic differentiation of the human mesenchymal stem cell. CMR and PS have been used as herbal medicine in traditional Korean medicine for a long time. Mesenchymal stem cells that can differentiate into adipocyte, chondrocyte and osteocyte recently issued as a therapeutic agent for degenerative disease. Here, mesenchymal stem cells isolated from synovial fluid of osteoarthritis patient, were cultured in specific media to differentiate into osteogenesis. Osteogenic differentiated mesenchymal stem cells were confirmed using Von Kossa and Arizarion Red S staining. And, the cells were divided into 4 groups: control group, CMR treated group, PS treated group and mixture treated group. To determine the effect of the herbal samples on the osteogenic mesenchymal stem cell, OCT4, SOX2 and NANOG mRNA expressions, known as the key maintenance factors of mesenchymal stem cell was measured using real-time Polymerase Chain Reaction (PCR). As a result, the maintenance factors, OCT4, SOX2 and NANOG, were more increased in cells treated by CMR, PS and the mixture of two herbs than control group. Therefore, we confirmed the enhancing effect of CMR, PS and their mixture on the osteogenic differentiation of mesenchymal stem cells which derived from the synovial fluid of osteoarthritis patient. This study demonstrates that the effect of the herbal samples on the osteogenic differentiation of human mesenchymal stem cell may have a possibility to be a therapeutic agent for the osteoarthritis patients.

Isolated protein of Astragalus membranaceus acts as an allergen by binding human immunoglobulin E on human sera

Allergy is nearly always triggered by protein molecules and the majority of individuals with documented immunologic reaction to foods or plants IgE reactions. However, proteins derived from herbal medicine act as an allergen is unknown. In this study, we aimed to confirm if herbal medicine, Astragalus membranaceus, at proteomic level may contain to trigger the immunoreactivity of IgE. If it does, what components of protein molecules in herbal medicine, Astragalus membranaceus, is react to a binding IgE. In order to resolve this hypothesis, we performed proteomic tools, SDS-PAGE stained coomassie blue and identified protein by LC-MS/MS. Also, we tested plasma IgE reactivity on an isolated protein of Astragalus membranaceus using western blot of human IgE and enzyme immunoassay panel, Allergy-Q test in 400 patients. Through the described performances, we could select four sera of positive candidate and identify Astragalus membranaceus IgE binding proteins. Our data suggested that herbal medicine, Astragalus membranaceus was possible to act an allergen by identify IgE binding protein with isolated protein of Astragalus membranaceus.

GLP-1 secretion is stimulated by 1,10-phenanthroline via colocalized T2R5 signal transduction in human enteroendocrine L cell

Glucagon-like peptide-1 (GLP-1) hormone is known to regulate blood glucose by an insulinotropic effect and increases proliferation as and also prevents apoptosis of pancreatic β cells. We know that GLP-1 is secreted by nutrients such as fatty acids and sweet compounds but also bitter compounds via stimulation of G-protein coupled receptors (GPCRs) in the gut. Among these, bitter compounds are multiply-contained in phytochemicals or artificial materials and perceived as ligands of various bitter taste receptors. We hypothesized that GLP-1 hormone is secreted through stimulation of a single bitter taste receptor by 1,10-phenanthroline which is known agonist of taste receptor type 2 member 5 (T2R5). To prove this hypothesis, we used the representatively well-known 1,10-phenanthroline as ligand of single receptor and evaluated the existence of T2R5 by double-labeling immunofluorescence and then 1,10-phenanthroline is able to secrete GLP-1 hormone through stimulation of T2R5 in human enteroendocrine cells. Consequently, we verify that GLP-1 hormone is colocalized with T2R5 in the human duodenum and ileum tissue and is secreted by 1,10-phenanthroline via T2R5 signal transduction in differentiated human enteroendocrine L cells.

Anti-Inflammatory Effects of Ginsenoside Rg3 via NF-κB Pathway in A549 Cells and Human Asthmatic Lung Tissue

Objective. There is limited information of the anti-inflammatory effects of Rg3 on inflamed lung cells and tissues. Therefore, we confirmed the anti-inflammatory mechanism of ginsenoside Rg3 in inflamed human airway epithelial cells (A549) and tissues whether Rg3 regulates nuclear factor kappa B (NF-κB) activity. Methods. To induce the inflammation, IL-1β (10 ng/ml) was treated to A549 cells for 4 h. The effects of Rg3 on NF-κB activity and COX-2 expression were evaluated by western blotting analysis in both IL-1β-induced inflamed A549 cell and human asthmatic airway epithelial tissues. Using multiplex cytokines assay, the secretion levels of NF-κB-mediated cytokines/chemokines were measured. Result. Rg3 showed the significant inhibition of NF-κB activity thereby reduced COX-2 expression was determined in both IL-1β-induced inflamed A549 cell and human asthmatic airway epithelial tissues. In addition, among NF-κB-mediated cytokines, the secretion levels of IL-4, TNF-α, and eotaxin were significantly decreased by Rg3 in asthma tissues. Even though there was no significant difference, IL-6, IL-9, and IL-13 secretion showed a lower tendency compared to saline-treated human asthmatic airway epithelial tissues. Conclusion. The results from this study demonstrate the potential of Rg3 as an anti-inflammatory agent through regulating NF-κB activity and reducing the secretion of NF-κB-mediated cytokines/chemokines.

Proteins derived from Prunus armeniaca kernel are possible to cause Immunoglobulin E reactivity in human sera

Allergic diseases are always caused by protein molecules and in most cases arise in individuals with documented immunologic reactions to foods, pollen, or plant IgE. However, proteins derived from herbal medicine which act as an allergen have not been widely studied. Here, we aim to confirm if the herbal medicine Prunus armeniaca kernel at the proteomic level triggers IgE immunoreactivity. If it does, we can hypothesize what components of protein molecules in the herbal medicine Prunus armeniaca kernel react with and bind to IgE. To test this hypothesis, we utilized proteomic tools and SDS-PAGE stained with Coomassie blue and identified proteins using LC-MS/MS. We also assessed the degree of plasma IgE reactivity in an isolated protein of Prunus armeniaca kernel using western blots of human IgE and an enzyme immunoassay panel, the Allergy-Q test, in 400 human sera. As a result, we found three sera which were positive candidates as Prunus armeniaca kernel IgE binding proteins. The results imply that Prunus armeniaca kernel can act as an allergen given the identification of IgE binding proteins among the isolated proteins of Prunus armeniaca kernel.

Activation of intestinal olfactory receptor stimulates glucagon-like peptide-1 secretion in enteroendocrine cells and attenuates hyperglycemia in type 2 diabetic mice

Odorants are non-nutrients. However, they exist abundantly in foods, wines, and teas, and thus can be ingested along with the other nutrients during a meal. Here, we have focused on the chemical-recognition ability of these ORs and hypothesized that the odorants ingested during a meal may play a physiological role by activating the gut-expressed ORs. Using a human-derived enteroendocrine L cell line, we discovered the geraniol- and citronellal-mediated stimulation of glucagon-like peptide-1 (GLP-1) secretion and elucidated the corresponding cellular downstream signaling pathways. The geraniol-stimulated GLP-1 secretion event in the enteroendocrine cell line was mediated by the olfactory-type G protein, the activation of adenylyl cyclase, increased intracellular cAMP levels, and extracellular calcium influx. TaqMan qPCR demonstrated that two ORs corresponding to geraniol and citronellal were expressed in the human enteroendocrine cell line and in mouse intestinal specimen. In a type 2 diabetes mellitus mouse model (db/db), oral administration of geraniol improved glucose homeostasis by increasing plasma GLP-1 and insulin levels. This insulinotropic action of geraniol was GLP-1 receptor-mediated, and also was glucose-dependent. This study demonstrates that odor compounds can be recognized by gut-expressed ORs during meal ingestion and therefore, participate in the glucose homeostasis by inducing the secretion of gut-peptides.

The therapeutic effects of Yongdamsagan-tang on autoimmune hepatitis models

Autoimmune hepatitis (AIH) is an immunity disorder that is the result of antibodies in the liver tissue of the patient that are attacked by activated immune cells due to an unknown cause. In this study, we aimed to investigate the anti-inflammatory effect of Yongdamsagan-tang (YST) extracts and confirm effects on autoimmune hepatitis models as the therapeutic agent using the YST extracted by various solvents. YST, a mixture of 11 herbal extracts, is known in traditional Korean medicine as a widely used treatment for inflammatory diseases. We proposed the AIH-condition in vitro model by the addition of recombinant IL-17A and then observed several markers linked to AIH symptoms, including an increase of IL-6 expression, lipid accumulation, and fibrosis. In AIH-condition hepatic cell model, YST reduced IL-6 expression and lipid accumulation caused by treatment of IL-17 combination in hepatocyte cells. Also, YST blocked several activated fibrosis factors including transforming growth factor-β (TGF- β1), collagen type 1 (Col-α1(I)), and α-smooth muscle actin (α-SMA) in liver stellate cells. Furthermore, pretreatment with YST protected hepatic damage and reduces histological injury by suppressing apoptosis mediator and inflammatory cytokines expression in concanavalin A (Con A)-induced autoimmune hepatitis mice model. The findings here improve our understanding of YST extracted by 80% ethanol, suggesting that YST can be used as a therapeutic treatment for AIH.