• The Journal of Korean Medicine
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• v.31 no.4
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• pp.20-37
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• 2010

Objective: This study was performed to investigate the effect of Yagwan-cheunghyeoltang (YCT) on insulin secretion in RIN-m5F cells. Methods: After treatment with various concentrations of YCT to RIN-m5F cells, cell viability, free radical-scavenging activity, SOD activity, and insulin secretion were measured. Additionally, insulin-related gene expressions were measured using real-time RT-PCR. Results: 1. YCT didn't show any influence on RIN-m5F cells viability. 2. YCT showed free radical-scavenging activity by 16% at $100{\mu}g/m{\ell}$ of concentration. 3. YCT showed enhancement of SOD activity by 60% at $100{\mu}g/m{\ell}$ of concentration. 4. YCT significantly increased insulin secretion in RIN-m5F cells in a dose-dependent manner. 5. YCT up-regulated INS-1, INS-2, IRS-1, IRS-2 and IRS-3 mRNA expressions compared to the control group. 6. YCT down-regulated INS-R, GCK, GLP-1R and GLP-2R mRNA expressions compared to the control group. Conclusion: YCT has pharmaceutical properties enhancing insulin production and controlling glucose-associated metabolism, and could be a candidate for drug development after further research.

• Biomolecules & Therapeutics
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• v.24 no.1
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• pp.49-56
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• 2016

To determine the protective effect of aloe-emodin (AE) from high glucose induced toxicity in RIN-5F (pancreatic ${\beta}$-cell) cell and restoration of its function was analyzed. RIN-5F cells have been cultured in high glucose (25 mM glucose) condition, with and without AE treatment. RIN-5F cells cultured in high glucose decreased cell viability and increased ROS levels after 48 hr compared with standard medium (5.5 mM glucose). Glucotoxicity was confirmed by significantly increased ROS production, increased pro-inflammatory (IFN-${\gamma}$, IL-$1{\beta}$,) & decreased anti-inflammatory (IL-6&IL-10) cytokine levels, increased DNA fragmentation. In addition, we found increased Bax, caspase 3, Fadd, and Fas and significantly reduced Bcl-2 expression after 48 hr. RIN-5F treated with both high glucose and AE ($20{\mu}M$) decreased ROS generation and prevent RIN-5F cell from glucotoxicity. In addition, AE treated cells cultured in high glucose were transferred to standard medium, normal responsiveness to glucose was restored within 8hr and normal basal insulin release within 24 hr was achieved when compared to high glucose.

• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.25-39
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• 2010

Background : At high glucose levels in $\beta$-cells, cell viability and insulin secretion are decreased by glucotoxicity. Sopyung-tang(SPT) had an effect on blood glucose level decrease and antioxidant enzyme activities in streptozotocin-induced diabetic rats. Objectives : This study performed a series of experiment to verify the effects of SPT extract on the cell viability, antioxidant enzyme activities, insulin secretion and insulin mRNA expression at hyperglycemic states of RIN-m5F. Methods : After treatment at various concentrations of SPT added to the RIN-m5F cells, cell viability by MTT assay, free radical-scavenging activity, SOD activity and insulin secretion were measured. Additionally, insulin-related gene expression was measured using real-time RT-PCR. Results : Compared to the control group, SPT extract showed considerable effects on RIN-m5F cell viability, DPPH radical-scavenging activity, superoxide dismutase (SOD) activity, insulin secretion and insulin-related gene expression. Conclusions : This study showed that SPT extract has an effect on $\beta$-cell cell viability, insulin secretion and insulin-related gene expression. Thus, SPT extract may be used for treatment of diabetes and its complications. Further mechanism studies of SPT seem to be necessary on the glucotoxicity and oxidative stress.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.141-149
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• 2015

"G protein-coupled receptor 40" (GPR40), a receptor for long-chain fatty acids, mediates the stimulation of glucose-induced insulin secretion. We examined the profiles of differential gene expression in GPR40-activated cells treated with linoleic acid, and finally predicted the integral pathways of the cellular mechanism of GPR40-mediated insulinotropic effects. After constructing a GPR40-overexpressing stable cell line (RIN-40) from the rat pancreatic ${\beta}$-cell line RIN-5f, we determined the gene expression profiles of RIN-5f and RIN-40. In total, 1004 genes, the expression of which was altered at least twofold, were selected in RIN-5f versus RIN-40. Moreover, the differential genetic profiles were investigated in RIN-40 cells treated with $30{\mu}M$ linoleic acid, which resulted in selection of 93 genes in RIN-40 versus RIN-40 treated with linoleic acid. Based on the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG, http://www.genome.jp/kegg/), sets of genes induced differentially by treatment with linoleic acid in RIN-40 cells were found to be related to mitogen-activated protein (MAP) kinase- and neuroactive ligand-receptor interaction pathways. A gene ontology (GO) study revealed that more than 30% of the genes were associated with signal transduction and cell proliferation. Thus, this study elucidated a gene expression pattern relevant to the signal pathways that are regulated by GPR40 activation during the acute period. Together, these findings increase our mechanistic understanding of endogenous molecules associated with GPR40 function, and provide information useful for identification of a target for the management of type 2 diabetes mellitus.

• The Journal of Internal Korean Medicine
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• v.30 no.3
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• pp.481-494
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• 2009

Background : Radix Sophora Flavescentis (SF) is used for the treatment of diabetes mellitus in Traditional Korean Medicine. However, little is known about the effects of Radix Sophora Flavescentis extract (SFE) on the hypoglycemic mechanism. Objective : We performed a series of experiments to verify the effects of SFE on the proliferation of RIN-m5F, the secretion and synthetic processes of insulin with glucose stimulation and inhibition of $\alpha$-glucosidase. Methods : Various amounts of SFE were added to the RIN-m5F cell culture to identify the effects on the cell proliferation, total amounts of insulin secretion, and related gene expression at the molecular level. Also to identify the inhibitory effect on the $\alpha$-glucosidase activities, ${\rho}NPG$ assay was done with various SFE concentrations followed by comparison with control. Results : SFE did not show considerable effects on RIN-m5F cells proliferation, insulin secretion or insulin mRNA expression, whichever phenomena did not depend on the glucose concentration. However, SFE significantly inhibited $\alpha$-glucosidase activity in a dose dependent manner compared to control. Conclusions : This study showed that SFE has potent $\alpha$-glucosidase inhibitory activity. Thus, SF may by used for the improvement of overall glycemic control. Further mechanism studies on the lipid toxicity and oxidation stress of SF seem to be necessary.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.79-100
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• 2010

Objective: Production of ROS from glucose toxicity results in injury of pancreatic $\beta$-cells in diabetes models. This study was undertaken to examine the influence of Lespedeza Cuneata extract (LCE) on cytoprotective effects on glucose toxicity, insulin secretion and gene expression in RIN-m5F cells. Methods: First, we measured LCE's antioxidant activity by DPPH free radical-scavenging activity and SOD activity. After the various concentrations of LCE were added to the RIN-m5F cells, we measured cell viability with glucose stimulation by MTT assay and glucose-stimulated insulin secretion. We analyzed gene expression with Agilent whole mouse genome 44K oligo DNA microarray and searched for related pathways in KEGG (Kyoto Encyclopedia of Genes and Genomes). Lastly we measured INS-1, INS-2, INS-R, IRS-1, IRS-2, IRS-3, GLP-1R, and GLP-2R mRNA expression by real time RT-PCR. Results: Free radical-scavenging activity, SOD activity and insulin secretion increased dependent on LCE concentration, but LCE did not show considerable cytoprotective effect on RIN-m5F cells. More than twice expressed gene was 6362 in Oligo DNA chip. In KEGG, the most related pathway was the metabolic pathway. In the insulin signaling pathway, up expressed genes were Irs1, Mapk8, Akt1, and Lipe and down expressed genes were Rhoq, Fbp2, Prkar2b, Gck, and Prkag1. In real time RT-PCR, IRS-2, and IRS-3 expression increased significantly compared to the control group on LCE $12{\mu}g/m{\ell}$ concentration and GCK expression decreased significantly compared to the control group. Conclusions: These results show that LCE encourages insulin secretion and insulin metabolism by complicated gene mechanisms. Further mechanism study and clinical study seem to be necessary about Lespedeza Cuneata.

• Korean Journal of Pharmacognosy
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• v.39 no.4
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• pp.335-340
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• 2008

Diabetes mellitus is metabolic disorder characterized by hyperglycemia caused by insufficient insulin secretion or insulin receptor insensitivity to endogenous insulin. It is well-known that hyperglycemia is one of the main causes of oxidative stress in both type 1 and 2 diabetes. Oxidative stress is related by death of pancreatic ${\beta}$ cell and dysfunction of ${\beta}$ cell. Although ${\beta}$ cell death or dysfunction is induced by many substances or molecules, increased evidences that oxidative stress plays a crucial role in ${\beta}$ cell death or dysfunction. Considering the importance of oxidative stress in the pathogenesis of diabetes mellitus, we investigated the cytoprotective effects against hydrogen peroxide-induced oxidative stress in pancreatic ${\beta}$ cell line RIN-m5F cell. 110 Plant sources were collected in Mt. Baek-du, and extracted with methanol. These extracts had been screened the protective effects against hydrogen peroxide-induced oxidative damage in RIN-m5F cells at 50 and 200 ${\mu}g$/ml. Of these, ten methanolic extracts, aerial part of Erigenron cannadensis, aerial part of Lespedeza juncea, whole plant of Alopecurus aequalis, fruit of Lycium chinense, leaf of Morus alba, rhizome of Polygonatum odoratum, root of Ampelosis japonica, whole plant of Ranunculus japonicus, aerial part of Polygonum sieboldii, rhizome of Arisaema amurense var. violaceum showed significant protective effects against hydrogen peroxide-induced oxidative damage in pancreatic ${\beta}$ cell line RIN-m5F cell.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.4
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• pp.791-795
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• 2008

In the present study, Cordyceps sinensis extract (CSE) was evaluated to determine if it could protect pancreatic ${\beta}$ cells against cytokine-induced cytotoxicity of RINm5F cells. Treatment of cells with cytokines resulted in a decrease of viability, which was caused by increase of nitric oxide (NO) production. CSE protected cytokine-mediated viability reduction in a concentration-dependent manner. Incubation with CSE also induced a significant suppression of cytokine-induced inducible nitric oxide synthase (iNOS) protein and NO production. The molecular mechanism by which CSE inhibited iNOS protein expression appeared to involve the inhibition of $NF-{\kappa}B$ activation. The cytokine-stimulated RIN cells showed increases in $NF-{\kappa}B$ binding activity compared to unstimulated cells. However, pretreatment with CSE inhibited cytokines-induced $NF-{\kappa}B$ activation in RINm5F cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.5
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• pp.499-505
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• 2014

Immunosuppressors cyclosporine A(CsA) and tacrolimus(FK506), the primary cellular target of which is calcineurin/nuclear factor of activated T cells(NFAT) signalling pathways, decrease beta-cell insulin content and mRNA expression. The posttransplantation diabetes mellitus(PTDM) is a frequent complication in immunosuppressive therapy. The present study was to examine the effect of a crude water extracts of medicinal herbs such as Sanguisorba officinalis(SOE) on the immunosuppressive activity with lymphocyte and insulin secretion in insulinoma cell lines with RIN-5mF. It was found that SOE treatment had effect of immunosuppressor on lymphocytes and also significantly increased insulin secretion in RIN-5mF compared to other agents. we might suggest a mechanism on insulin secretion by HNF4a. Taken together, the present study suggested that SOE might serve as immunosuppressive drug in PTDM.

• Natural Product Sciences
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• v.22 no.3
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• pp.175-179
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• 2016

The aim of this study was to evaluate the anti-diabetic effects of the water extract of Lespedeza cuneata (LCW) using rat insulinoma (RIN) m5F cells and streptozotocin (STZ)-induced diabetic rats. The effect of LCW on the protection of pancreatic beta cells was assessed using MTT assay, and nitric oxide production was assessed using Griess reagent. STZ-induced diabetic rats were treated with 100 and 400 mg/kg body weight of LCW for 5 weeks. In results, LCW significantly protected cytokine-induced toxicity and NO production, and increased insulin secretion in RINm5F cells. LCW significantly decreased serum blood glucose, thiobarbituric acid reactive substances (TBARS), blood urea nitrogen (BUN) and advanced glycation end products (AGEs) levels, and renal fibronectin expression in STZ-induced diabetic rats. Also, LCW effectively improved BW loss in STZ-induced diabetic rats. Thus, our results suggest that LCW has a beneficial effect on cytokine-induced pancreatic beta cell damage and biomarkers of diabetic complication in hyperglycemic rats.