• Journal of Korean Medicine for Obesity Research
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• v.22 no.2
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• pp.93-101
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• 2022

Objectives: This study aimed to observe the anti-diabetic effect and underlying mechanisms of Galgunhwanggumhwangryun-tang (GHH; Gegen-Qinlian-decoction) in the C2C12 myotubes. Methods: GHH (1.0 mg/ml) or metformin (0.75 mM) or insulin (100 nM) were treated in C2C12 myotubes after 4 days differentiation. The glucose uptake was assessed by 2-[N-(7-160 nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose uptake by C2C12 cells. The expression of adenosine monophosphate-activated protein kinase (AMPK) and phosphorylation AMPK (pAMPK) were measured by western blot. We also evaluated gene expression of glucose transporter type 4 (Slc2a4, formerly known as GLUT4), glucokinase (Gk), carnitine palmitoyltransferase IA (Cpt1a), nuclear respiratory factors 1 (Nrf1), mitochondrial transcription factor A (Tfam), and peroxisome proliferator-activated receptor γ coactivator 1α (Ppargc1a) by quantitative real-time polymerase chain reaction. Results: GHH promoted glucose uptake in C2C12 myotubes. The expression of AMPK protein, which plays an essential role in glucose metabolism, was increased by treatment with GHH. GHH treatment tended to increase gene expression of Slc2a4, Gk, and Nrf1 but was not statistically significant. However, GHH significantly improved Tfam and Ppargc1a gene expression in C2C12 myotubes. Conclusions: In summary, GHH treatment promoted glucose uptake in C2C12 myotubes. We suggest that these effects are associated with increased gene expression involved in mitochondrial biosynthesis and oxidative phosphorylation, such as Tfam and Ppargc1a, and increased expression of AMPK protein.

• Biomolecules & Therapeutics
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• v.28 no.3
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• pp.240-249
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• 2020

Despite the therapeutic effect of mesenchymal stem cells (MSCs) in ischemic diseases, pathophysiological conditions, including hypoxia, limited nutrient availability, and oxidative stress restrict their potential. To address this issue, we investigated the effect of melatonin on the bioactivities of MSCs. Treatment of MSCs with melatonin increased the expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). Melatonin treatment enhanced mitochondrial oxidative phosphorylation in MSCs in a PGC-1α-dependent manner. Melatonin-mediated PGC-1α expression enhanced the proliferative potential of MSCs through regulation of cell cycle-associated protein activity. In addition, melatonin promoted the angiogenic ability of MSCs, including migration and invasion abilities and secretion of angiogenic cytokines by increasing PGC-1α expression. In a murine hindlimb ischemia model, the survival of transplanted melatonin-treated MSCs was significantly increased in the ischemic tissues, resulting in improvement of functional recovery, such as blood perfusion, limb salvage, neovascularization, and protection against necrosis and fibrosis. These findings indicate that the therapeutic effect of melatonin-treated MSCs in ischemic diseases is mediated via regulation of PGC-1α level. This study suggests that melatonin-induced PGC-1α might serve as a novel target for MSC-based therapy of ischemic diseases, and melatonin-treated MSCs could be used as an effective cell-based therapeutic option for patients with ischemic diseases.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.384-391
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• 2016

In previous studies, we confirmed that the ethanol extract of Polygonatum sibiricum (ID1216) has anti-obesity effects on high-fat diet-fed mice. To identify the obesity-related genes affected by ID1216, we studied its effects both in vivo and in vitro. In mice, single administration of ID1216 increased the expression of obesity-related genes including sirtuin1 (SIRT1), peroxisome proliferator-activated receptor ${\gamma}$ coactivator $1{\alpha}$ ($PGC1{\alpha}$) and peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) compared to that in mice administered the vehicle; their downstream genes (uncoupling proteins, acyl-CoA oxidase, adipocyte protein 2, and hormone-sensitive lipase) were also increased by ID1216. In fully differentiated 3T3-L1 adipocytes, ID1216 showed the same effects on anti-obesity genes as those in the animal model. Based on these results, we propose that ID1216 has anti-obesity effects by regulating the $SIRT1-PGC1{\alpha}-PPAR{\alpha}$ pathway and their downstream genes, thereby controlling energy and lipid metabolisms.

• Nutrition Research and Practice
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• v.8 no.6
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• pp.613-617
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• 2014

BACKGROUND/OBJECTIVES: Adipogenesis is part of the cell differentiation process in which undifferentiated fibroblasts (pre-adipocytes) become mature adipocytes with the accumulation of lipid droplets and subsequent cell morphological changes. Several transcription factors and food components have been suggested to be involved in adipogenesis. The aim of this study was to determine whether mulberry leaf ethanol extract (MLEE) affects adipogenesis in 3T3-L1 adipocytes. MATERIALS/METHODS: The 3T3-L1 adipocytes were treated with different doses of MLEE for 8 days starting 2 days post-confluence. Cell viability, fat accumulation, and adipogenesis-related factors including CCAAT-enhancer-binding protein alpha ($C/EBP{\alpha}$), peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$), $PPAR{\gamma}$ coactivator 1 alpha (PGC-$1{\alpha}$), fatty acid synthase (FAS), and adiponectin were analyzed. RESULTS: Results showed that MLEE treatments at 10, 25, 50, and $100{\mu}g/ml$ had no effect on cell morphology and viability. Without evident toxicity, all MLEE treated cells had lower fat accumulation compared with control as shown by lower absorbances of Oil Red O stain. MLEE at 50 and $100{\mu}g/ml$ significantly reduced protein levels of $PPAR{\gamma}$, PGC-$1{\alpha}$, FAS, and adiponectin in differentiated adipocytes. Furthermore, protein level of $C/EBP{\alpha}$ was significantly decreased by the treatment of $100{\mu}g/ml$ MLEE. CONCLUSION: These results demonstrate that MLEE treatment has an anti-adipogenic effect in differentiated adipocytes without toxicity, suggesting its potential as an anti-obesity therapeutic.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.499-503
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• 2015

We investigated the anti-obesity effects of ethanolic extract (ID1216) of Polygonatum sibiricum rhizome and its potential underlying mechanism in an animal model. ID1216 treatment decreased body weight gain and white adipose tissue weight in the prevention study. The mRNA levels of sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor ${\gamma}$ coactivator-$1{\alpha}$ ($PGC1{\alpha}$), and peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) significantly increased in the epididymal white adipose tissue of ID1216-administered mice. The stimulation effects of ID1216 on these gene expressions were also observed in a cell-based assay using differentiated 3T3-L1 adipocytes. In addition, similar to orlistat, ID1216 treatment improved weight gain and reduced epididymal fat in the treatment model. These results suggest that ID1216 has potential as an anti-obesity agent by modulating the expression of genes related to thermogenesis, lipid metabolism and fatty acid oxidation.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.192-202
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• 2017

In this study, factors involved in lipid and energy metabolism following treatment with ethanolic extract of the Polygonatum sibiricum rhizome (ID1216) were evaluated in high-fat diet-induced obese mice. ID1216-treated mice showed a significant reduction in weight gain compared to non-treated mice. ID1216 treatment increased the protein levels of AMP-dependent protein kinase, sirtuin1, peroxisome proliferator-activated receptor ${\gamma}$ coactivator 1-${\alpha}$ ($PGC1{\alpha}$), peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) and uncoupling proteins in the adipose tissue, liver and muscle compared to vehicle treatment. Analysis of downstream signals of the sirtuin1 $PGC1{\alpha}$-$PPAR{\alpha}$ pathway showed that ID1216 regulates the expression of ${\beta}$-oxidation related genes such as acyl-CoA oxidase, carnitine palmitoyltransferase1, acyl-CoA dehydrogenase and adipocyte protein 2. In addition, ID1216 increased the expression of adipose triglyceride lipase. These results suggest that ID1216 has anti-obesity effects by regulating the genes involved thermogenesis, ${\beta}$-oxidation and lipolysis in a diet-induced obesity model.

• Nutrition Research and Practice
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• v.16 no.1
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• pp.14-32
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• 2022

BACKGROUND/OBJECTIVES: Peroxisome proliferator-activated receptor-gamma co-activator-1α (PGC-1α) has a central role in regulating muscle differentiation and mitochondrial metabolism. PGC-1α stimulates muscle growth and muscle fiber remodeling, concomitantly regulating lactate and lipid metabolism and promoting oxidative metabolism. Gynostemma pentaphyllum (Thumb.) has been widely employed as a traditional herbal medicine and possesses antioxidant, anti-obesity, anti-inflammatory, hypolipemic, hypoglycemic, and anticancer properties. We investigated whether G. pentaphyllum extract (GPE) and its active compound, gypenoside L (GL), affect muscle differentiation and mitochondrial metabolism via activation of the PGC-1α pathway in murine C2C12 myoblast cells. MATERIALS/METHODS: C2C12 cells were treated with GPE and GL, and quantitative reverse transcription polymerase chain reaction and western blot were used to analyze the mRNA and protein expression levels. Myh1 was determined using immunocytochemistry. Mitochondrial reactive oxygen species generation was measured using the 2'7'-dichlorofluorescein diacetate assay. RESULTS: GPE and GL promoted the differentiation of myoblasts into myotubes and elevated mRNA and protein expression levels of Myh1 (type IIx). GPE and GL also significantly increased the mRNA expression levels of the PGC-1α gene (Ppargc1a), lactate metabolism-regulatory genes (Esrra and Mct1), adipocyte-browning gene fibronectin type III domain-containing 5 gene (Fndc5), glycogen synthase gene (Gys), and lipid metabolism gene carnitine palmitoyltransferase 1b gene (Cpt1b). Moreover, GPE and GL induced the phosphorylation of AMP-activated protein kinase, p38, sirtuin1, and deacetylated PGC-1α. We also observed that treatment with GPE and GL significantly stimulated the expression of genes associated with the anti-oxidative stress response, such as Ucp2, Ucp3, Nrf2, and Sod2. CONCLUSIONS: The results indicated that GPE and GL enhance exercise performance by promoting myotube differentiation and mitochondrial metabolism through the upregulation of PGC-1α in C2C12 skeletal muscle.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.347-352
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• 2017

Background: Panax ginseng (PG) has a long history of use in Asian medicine because of its multiple pharmacological activities. It has been considered that PG in a type of white ginseng may induce undesirable thermogenic effects, but not in a type of red ginseng. However, there is a lack of evidence about the correlation between ginsenoside and thermogenesis. Methods: We investigated the effects of PG with different ginsenoside compositions on body temperature, blood pressure, and thermogenesis-related factors in rats. Results: With increasing steaming time (0 h, 3 h, 6 h, and 9 h), the production of protopanaxadiol ginsenosides increased, whereas protopanaxatriol ginsenosides decreased in white ginseng. In both short- and long-term studies, administration of four ginseng extracts prepared at different steaming times did not induce significant changes in body temperature (skin, tail, and rectum) and blood pressure of rats compared to saline control. In addition, there were no significant differences in the molecular markers related to thermogenesis (p > 0.05), mRNA expressions of peroxisome proliferator-activated receptor-gamma coactivator-$1{\alpha}$ and uncoupling protein 1 in brown adipose tissue, as well as the serum levels of interleukin-6, inducible nitric oxide synthase, and nitrite among the treatment groups. Conclusion: These observations indicate that the potential undesirable effects of PG on body temperature could not be explained by the difference in ginsenoside composition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.324-330
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• 2015

In this study, the anti-diabetic activity of a cold water extract of Korean mistletoe (KME) was investigated in C57BL/6J Lep ob (ob/ob) mice. Oral administration of KME (50 or 100 mg/kg/d) significantly inhibited the level of blood glucose of ob/ob mice after 5 days from the beginning of KME treatment. And the anti-diabetic effect of KME was stabilized 10 days after oral administration, showing a substantial reduction of blood glucose levels by more than 20% as compared with control mice. The results of oral glucose tolerance test (OGTT) revealed that oral administration of KME gave rise to a remarkable improvement in overall glucose response. Oral administration of KME in ob/ob diabetic mice also significantly reduced blood total cholesterol (TCHO) and triglyceride (TG) levels compared with the diabetic control mice. Moreover, in an in vitro experiment using C2C12 myotubes, treatment of KME prominently increased glucose uptake. Interestingly, KME significantly increased the expression of peroxisome proliferator-activated receptor gamma coactivator 1-${\alpha}$ ($PGC-1{\alpha}$), a head regulator of mitochondrial biogenesis and oxidative metabolism, and $PGC-1{\alpha}$-associated genes such as glucose transporter type 4 (GLUT4), estrogen-related receptor-${\alpha}$ ($ERR-{\alpha}$), nuclear respiratory factor-1 (NRF-1), and mitochondrial transcription factor A (TmfA) in C2C12 cells. These results suggest that KME has potential as a novel therapeutic agent for diabetes, and its anti-diabetic activity may be related to the regulation of mitochondrial biogenesis.

• Preventive Nutrition and Food Science
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• v.21 no.1
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• pp.62-67
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• 2016

Green tea (Camellia sinensis) is one of the most popular beverages in the world and has been acknowledged for centuries as having significant health benefits. (-)-Epigallocatechin-3-gallate (EGCG) is the most abundant catechin in green tea, and it has been reported to have health benefit effects. Peroxisome proliferator-activated receptor ${\gamma}$ coactivator $(PGC)-1{\alpha}$ is a crucial regulator of mitochondrial biogenesis and hepatic gluconeogenesis. The objective of this study was to investigate whether EGCG from green tea can affect the ability of transcriptional regulation on $PGC-1{\alpha}$ mRNA expression in HepG2 cells and 3T3-L1 adipocytes. To study the molecular mechanism that allows EGCG to control $PGC-1{\alpha}$ expression, the promoter activity levels of $PGC-1{\alpha}$ were examined. The $PGC-1{\alpha}$ mRNA level was measured using quantitative real-time PCR. The -970/+412 bp of $PGC-1{\alpha}$ promoter was subcloned into the pGL3-Basic vector that includes luciferase as a reporter gene. EGCG was found to up-regulate the $PGC-1{\alpha}$ mRNA levels significantly with $10{\mu}mol/L$ of EGCG in HepG2 cells and differentiated 3T3-L1 adipocytes. $PGC-1{\alpha}$ promoter activity was also increased by treatment with $10{\mu}mol/L$ of EGCG in both cells. These results suggest that EGCG may induce $PGC-1{\alpha}$ gene expression, potentially through promoter activation.