• Biomolecules & Therapeutics
• /
• v.21 no.4
• /
• pp.284-289
• /
• 2013

Antidiabetic and beta cell-protection activities of purple corn anthocyanins (PCA) were examined in pancreatic beta cell culture and db/db mice. Only PCA among several plant anthocyanins and polyphenols showed insulin secretion activity in culture of HIT-T15 cells. PCA had excellent antihyperglycemic activity (in terms of blood glucose level and OGTT) and HbA1c-decreasing activity when compared with glimepiride, a sulfonylurea in db/db mice. In addition, PCA showed efficient protection activity of pancreatic beta cell from cell death in HIT-T15 cell culture and db/db mice. The result showed that PCA had antidiabetic and beta cell-protection activities in pancreatic beta cell culture and db/db mice.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.11
• /
• pp.1837-1847
• /
• 2020

Objective: To evaluate the pancreatic differentiation potential of α-1,3-galactosyltransferase knockout (GalTKO) pig-derived bone marrow-derived mesenchymal stem cells (BM-MSCs) using epigenetic modifiers with different pancreatic induction media. Methods: The BM-MSCs have been differentiated into pancreatic β-like cells by inducing the overexpression of key transcription regulatory factors or by exposure to specific soluble inducers/small molecules. In this study, we evaluated the pancreatic differentiation of GalTKO pig-derived BM-MSCs using epigenetic modifiers, 5-azacytidine (5-Aza) and valproic acid (VPA), and two types of pancreatic induction media - advanced Dulbecco's modified Eagle's medium (ADMEM)-based and N2B27-based media. GalTKO BM-MSCs were treated with pancreatic induction media and the expression of pancreas-islets-specific markers was evaluated by real-time quantitative polymerase chain reaction, Western blotting, and immunofluorescence. Morphological changes and changes in the 5'-C-phosphate-G-3' (CpG) island methylation patterns were also evaluated. Results: The expression of the pluripotent marker (POU class 5 homeobox 1 [OCT4]) was upregulated upon exposure to 5-Aza and/or VPA. GalTKO BM-MSCs showed increased expression of neurogenic differentiation 1 in the ADMEM-based (5-Aza) media, while the expression of NK6 homeobox 1 was elevated in cells induced with the N2B27-based (5-Aza) media. Moreover, the morphological transition and formation of islets-like cellular clusters were also prominent in the cells induced with the N2B27-based media with 5-Aza. The higher insulin expression revealed the augmented trans-differentiation ability of GalTKO BM-MSCs into pancreatic β-like cells in the N2B27-based media than in the ADMEM-based media. Conclusion: 5-Aza treated GalTKO BM-MSCs showed an enhanced demethylation pattern in the second CpG island of the OCT4 promoter region compared to that in the GalTKO BM-MSCs. The exposure of GalTKO pig-derived BM-MSCs to the N2B27-based microenvironment can significantly enhance their trans-differentiation ability into pancreatic β-like cells.

• 대한생식의학회:학술대회논문집
• /
• 2006.06a
• /
• pp.50-52
• /
• 2006

• Fisheries and Aquatic Sciences
• /
• v.27 no.1
• /
• pp.17-22
• /
• 2024

Diabetes Mellitus (DM) is a major health issue increasing worldwide. Currently, nearby half a billion people have diabetes. Two major types of DM that type 1 and type 2-DM have different etiologies but feature a crucial common pathological transition into dysfunction of pancreatic β-cells and consequently leading hyperglycemia and finally go into DM. Therefore, maintaining of β-cells such as preventing β-cells degeneration, and promoting β-cells regeneration and proliferation will be essential approaches in prevention and/or treatment of DM. There are many reports that various types of seaweed control metabolic diseases such as obesity, high blood pressure, and blood sugar control. However, no new drug candidates have been developed yet. Additionally, although seaweed has excellent blood sugar control effects, there is no evidence that it directly proliferates or regenerates beta cells. Therefore, we studied on the promotion of β-cell regeneration by a seaweed, Polysiponia morrowii extract (PME) which preserves β-cells and maintains its function. As a result, it was confirmed that PME directly promotes the proliferation of pancreatic islet β-cells with insulin secretion function in in vivo. Therefore, PME shows potential as a candidate for β-cell regeneration that may play a fundamental role in the treatment of diabetes.

• Journal of Food and Nutrition Research
• /
• v.10 no.1
• /
• pp.32-40
• /
• 2022

Diabetes is a chronic metabolic disease with a high prevalence worldwide. Beet (Beta vulgaris) is a plant that is widely used in many countries and has various biological activities. In this study, we aimed to evaluate the antidiabetic effect of a B. vulgaris mixture (BM). In the in vitro evaluation, we measured the inhibitory activities of α-amylase and α-glucosidase, performed the oral starch tolerance test (OATT) and oral sucrose tolerance test (OSTT) in Sprague Dawley (SD) rats, and evaluated the clinical symptoms, oral glucose tolerance test (OGTT), number of blood cells, and insulin resistance in db/db mice. BM showed an inhibitory effect against α-amylase and α-glucosidase activity and decreased the blood glucose increased in the OATT and OSTT. In the diabetes mouse model, BM alleviated the general symptoms of diabetes and OGTT results showed a decrease in the increased blood sugar level. Regarding diabetes-related tissue weight, BM decreased the reduced pancreatic weight and showed an effect on diabetes-related factors of blood. Histological analysis indicated that BM decreased insulin concentration, insulin resistance, and insulin secretion ability in serum, and increased insulin concentration in the islets of Langerhans. These results demonstrate that BM has an antidiabetic effect through the regulation of glycolytic enzymes and β cell activity in the pancreas.

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

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.3
• /
• pp.334-340
• /
• 2012

This study was carried out to investigate the effects of Opuntia ficus-indica complex (OF) on blood glucose, glucose tolerance, plasma insulin level and histopathological appearance of pancreatic islets in streptozotoxin (STZ)-induced diabetic rats. Thirty-two male Sprague-Daweley rats were divided into non-diabetic control (NC), diabetic control (DC), diabetic OF of 2% (OF-2) and diabetic OF of 5% (OF-5) and fed experimental diets for 3 weeks. Compared to the DC group fasting blood glucose levels in the OF-2 and OF-5 groups were significantly (p<0.05) reduced while fasting plasma insulin level in the OF-2 and OF-5 groups were significantly (p<0.05) increased. Glucose tolerance in the OF-2 and OF-5 groups were improved. Histopathological observation of pancreatic islets of the OF-2 and OF-5 groups showed hyperplasia which was very similar to NC. Numbers of ${\beta}$-cells in OF-2 ($47.81{\pm}0.92$) and OF-5 ($81.64{\pm}2.80$) were higher than numbers of ${\beta}$-cells in DC ($13.18{\pm}1.01$). These results imply that the intake of OF improves ${\beta}$-cell proliferation and prevents the death of ${\beta}$-cells in STZ-induced diabetic rats.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.05a
• /
• pp.1-4
• /
• 1998

Impaired insulin action in Type 2 diabetes is thought to lead to hyperglycemia, with both environmental and complex genetic factors playing key roles. Although the primary lesion in Type 2 diabetes is unknown, a number of studies suggest that metabolic defects in the liver, skeletal muscle and fat, and pancreatic ${\beta}$-cells contribute to the disease. These metabolic abnormalities are characterized by the overproduction of hepatic glucose, impaired insulin secretion, and peripheral insulin resistance. In current pharmacological treatment of Type 2 diabetes, sulfonylurea (SU) drugs have mainly been used as oral hypoglycemic drugs to stimulate endogenous insulin secretion from ${\beta}$ cells. SU drugs, however, sometimes aggravate the disease by causing fatigue of the pancreatic ${\beta}$ cells, which leads to reduced drug efficacy after long-term treatment. This class of drugs also leads to enhanced obesity arising from the stimulation of endogenous insulin secretion in obese Type 2 diabetic patients, plus an increased incidence of SU-induced hypoglycemia. Since 1980, a major challenge has been made by us to develop a potential pharmacological therapy for the treatment of insulin resistance in peripheral tissues and/or suppression of abnormal hepatic glucose production in Type 2 diabetic patients. Such a drug would be expected to have fewer side effects and retain long-term efficacy.

• Journal of Embryo Transfer
• /
• v.30 no.3
• /
• pp.249-255
• /
• 2015

Diabetes mellitus, the most common metabolic disorder, is divided into two types: type 1 and type 2. The essential treatment of type 1 diabetes, caused by immune-mediated destruction of ${\beta}-cells$, is transplantation of the pancreas; however, this treatment is limited by issues such as the lack of donors for islet transplantation and immune rejection. As an alternative approach, stem cell therapy has been used as a new tool. The present study revealed that bone marrowderived mesenchymal stromal cells (BM-MSCs) could be transdifferentiated into pancreatic cells by the insertion of a key gene for embryonic development of the pancreas, the pancreatic and duodenal homeobox factor 1 (PDX1). To avoid immune rejection associated with xenotransplantation and to develop a new cell-based treatment, BM-MSCs from ${\alpha}$-1,3-galactosyltransferase knockout (GalT KO) pigs were used as the source of the cells. Transfection of the EGFP-hPDX1 gene into GalT KO pig-derived BM-MSCs was performed by electroporation. Cells were evaluated for hPDX1 expression by immunofluorescence and RT-PCR. Transdifferentiation into pancreatic cells was confirmed by morphological transformation, immunofluorescence, and endogenous pPDX1 gene expression. At 3~4 weeks after transduction, cell morphology changed from spindle-like shape to round shape, similar to that observed in cuboidal epithelium expressing EGFP. Results of RT-PCR confirmed the expression of both exogenous hPDX1 and endogenous pPDX1. Therefore, GalT KO pig-derived BM-MSCs transdifferentiated into pancreatic cells by transfection of hPDX1. The present results are indicative of the therapeutic potential of PDX1-expressing GalT KO pig-derived BM-MSCs in ${\beta}-cell$ replacement. This potential needs to be explored further by using in vivo studies to confirm these findings.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.170-183
• /
• 2023

This study evaluated the effects of milk fermented with Pediococcus acidilactici strain BE and Pediococcus pentosaceus strain M103 on diabetes in rats (Rattus norvegicus). The bacteria were separately used as starter cultures for milk fermentation, and the products were then fed to diabetic rats for 15 days. Blood glucose levels, immunohistochemical and histological indicators, lipid profiles, and total lactic acid bacterium counts were evaluated before and after treatment. The administration of milk fermented with P. acidilactici strain BE reduced blood glucose levels from 410.27±51.60 to 304.07±9.88 mg/dL (p<0.05), similar to the effects of metformin (from 382.30±13.39 mg/dL to 253.33±40.66 mg/dL, p<0.05). Increased insulin production was observed in diabetic rats fed milk fermented with P. acidilactici strain BE concomitant with an increased number and percentage area of immunoreactive beta-cells. The structure of insulin-producing beta-cells was improved in diabetic rats fed milk fermented with P. acidilactici strain BE or metformin (insulin receptor substrate scores of 5.33±0.94 and 3.5±0.5, respectively). This suggests that the administration of milk fermented with P. acidilactici BE potentially reduces blood glucose levels and improves pancreatic beta-cell function in diabetic rats.