Ri Ryu

Dr. Ri Ryu

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 February 2016 in Nutrients
Verified
Journal Article
Open access
PDF file
SSSu-Kyung Shin
Su-Kyung Shin
SCSu-Jung Cho
Su-Jung Cho
UJUn Ju Jung
Un Ju Jung
RRRi Ryu
Ri Ryu
MCMyung-Sook Choi
Myung-Sook Choi
Obesity, along with its related complications, is a serious health problem worldwide. Many studies reported the anti-diabetic effect of phlorizin, while little is known about its anti-obesity effect. We investigated the beneficial effects of phlorizin on obesity and its complications, including diabetes and inflammation in obese animal. Male C57BL/6J mice were divided into three groups and fed their respective experimental diets for 16 weeks: a normal diet (ND, 5% fat, w/w), high-fat diet (HFD, 20% fat, w/w), or HFD supplemented with phlorizin (PH, 0.02%, w/w). The findings revealed that the PH group had significantly decreased visceral and total white adipose tissue (WAT) weights, and adipocyte size compared to the HFD. Plasma and hepatic lipids profiles also improved in the PH group. The decreased levels of hepatic lipids in PH were associated with decreased activities of enzymes involved in hepatic lipogenesis, cholesterol synthesis and esterification. The PH also suppressed plasma pro-inflammatory adipokines levels such as leptin, adipsin, tumor necrosis factor-α, monocyte chemoattractant protein-1, interferon-γ, and interleukin-6, and prevented HFD-induced collagen accumulation in the liver and WAT. Furthermore, the PH supplementation also decreased plasma glucose, insulin, glucagon, and homeostasis model assessment of insulin resistance levels. In conclusion, phlorizin is beneficial for preventing diet-induced obesity, hepatic steatosis, inflammation, and fibrosis, as well as insulin resistance.

29 September 2020 in Nutrients
Verified
Journal Article
Open access
PDF file
JSJong Cheol Shon
Jong Cheol Shon
WKWon Cheol Kim
Won Cheol Kim
RRRi Ryu
Ri Ryu
ZWZhexue Wu
Zhexue Wu
JSJong-Su Seo
Jong-Su Seo
Kwang-Hyeon LiuKwang-Hyeon Liu
Kwang-Hyeon Liu
The Chrysanthemum morifolium Ramat (CM) is widely used as a traditional medicine and herbal tea by the Asian population for its health benefits related to obesity. However, compared to the flowers of CM, detailed mechanisms underlying the beneficial effects of its leaves on obesity and dyslipidemia have not yet been elucidated. Therefore, to investigate the lipidomic biomarkers responsible for the pharmacological effects of CM leaf extract (CLE) in plasma of mice fed a high-fat diet (HFD), the plasma of mice fed a normal diet (ND), HFD, HFD plus CLE 1.5% diet, and HFD plus luteolin 0.003% diet (LU) for 16 weeks were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with multivariate analysis. In our analysis, the ND, HFD, CLE, and LU groups were clearly differentiated by partial least-squares discriminant analysis (PLS-DA) score plots. The major metabolites contributing to this differentiation were cholesteryl esters (CEs), lysophosphatidylcholines (LPCs), phosphatidylcholines (PCs), ceramides (CERs), and sphingomyelins (SMs). The levels of plasma CEs, LPCs, PCs, SMs, and CERs were significantly increased in the HFD group compared to those in the ND group, and levels of these lipids recovered to normal after administration of CLE or LU. Furthermore, changes in hepatic mRNA expression levels involved in the Kennedy pathway and sphingolipid biosynthesis were also suppressed by treatment with CLE or LU. In conclusion, this study examined the beneficial effects of CLE and LU on obesity and dyslipidemia, which were demonstrated as reduced synthesis of lipotoxic intermediates. These results may provide valuable insights towards evaluating the therapeutic effects of CLE and LU and understanding obesity-related diseases.

30 August 2016 in Nutrients
Verified
Journal Article
Open access
PDF file
YKYe Jin Kim
Ye Jin Kim
JCJi-Young Choi
Ji-Young Choi
RRRi Ryu
Ri Ryu
JLJeonghyeon Lee
Jeonghyeon Lee
SCSu-Jung Cho
Su-Jung Cho
MCMyung-Sook Choi
Myung-Sook Choi
The Platycodon grandiflorus root, a Korean medicinal food, is well known to have beneficial effects on obesity and diabetes. In this study, we demonstrated the metabolic effects of P. grandiflorus root ethanol extract (PGE), which is rich in platycodins, on diet-induced obesity. C57BL/6J mice (four-week-old males) were fed a normal diet (16.58% of kilocalories from fat), high-fat diet (HFD, 60% of kilocalories from fat), and HFD supplemented with 5% (w/w) PGE. In the HFD-fed mice, PGE markedly suppressed the body weight gain and white fat mass to normal control level, with simultaneous increase in the expression of thermogenic genes (such as SIRT1, PPARα, PGC1α, and UCP1), that accompanied changes in fatty acid oxidation (FAO) and energy expenditure. In addition, PGE improved insulin sensitivity through activation of the PPARγ expression, which upregulates adiponectin while decreasing leptin gene expression in adipocytes. Furthermore, PGE improved hepatic steatosis by suppressing hepatic lipogenesis while increasing expression of FAO-associated genes such as PGC1α. PGE normalized body fat and body weight, which is likely associated with the increased energy expenditure and thermogenic gene expression. PGE can protect from HFD-induced insulin resistance, and hepatic steatosis by controlling lipid and glucose metabolism.

14 October 2016 in Nutrients
Verified
Journal Article
Open access
PDF file
JCJi-Young Choi
Ji-Young Choi
YKYe Jin Kim
Ye Jin Kim
RRRi Ryu
Ri Ryu
SCSu-Jung Cho
Su-Jung Cho
EKEun-Young Kwon
Eun-Young Kwon
MCMyung-Sook Choi
Myung-Sook Choi
Green tea (GT) has various health effects, including anti-obesity properties. However, the multiple molecular mechanisms of the effects have not been fully determined. The aim of this study was to elucidate the anti-obesity effects of GT via the analysis of its metabolic and transcriptional responses based on RNA-seq profiles. C57BL/6J mice were fed a normal, high-fat (60% energy as fat), or high-fat + 0.25% (w/w) GT diet for 12 weeks. The GT extract ameliorated obesity, hepatic steatosis, dyslipidemia, and insulin resistance in diet-induced obesity (DIO) mice. GT supplementation resulted in body weight gain reduction than mice fed high-fat through enhanced energy expenditure, and reduced adiposity. The transcriptome profiles of epididymal white adipose tissue (eWAT) suggested that GT augments transcriptional responses to the degradation of branched chain amino acids (BCAAs), as well as AMP-activated protein kinase (AMPK) signaling, which suggests enhanced energy homeostasis. Our findings provide some significant insights into the effects of GT for the prevention of obesity and its comorbidities. We demonstrated that the GT extract contributed to the regulation of systemic metabolic homeostasis via transcriptional responses to not only lipid and glucose metabolism, but also amino acid metabolism via BCAA degradation in the adipose tissue of DIO mice.

15 June 2019 in Nutrients
Verified
Journal Article
Open access
PDF file
RRRi Ryu
Ri Ryu
EKEun-Young Kwon
Eun-Young Kwon
JCJi-Young Choi
Ji-Young Choi
JSJong Cheol Shon
Jong Cheol Shon
Kwang-Hyeon LiuKwang-Hyeon Liu
Kwang-Hyeon Liu
MCMyung-Sook Choi
Myung-Sook Choi
This study aimed to elucidate the molecular mechanism of Chrysanthemum morifolium Ramat. against obesity and diabetes, by comparing the transcriptional changes in epididymal white adipose tissue (eWAT) with those of the bioactive compound in C. morifolium, luteolin (LU). Male C57BL/6J mice were fed a normal diet, high-fat diet (HFD), and HFD supplemented with 1.5% w/w chrysanthemum leaf ethanol extract (CLE) for 16 weeks. Supplementation with CLE and LU significantly decreased the body weight gain and eWAT weight by stimulating mRNA expressions for thermogenesis and energy expenditure in eWAT via lipid mobilization, which may be linked to the attenuation of dyslipidemia. Furthermore, CLE and LU increased uncoupling protein-1 protein expression in brown adipose tissue, leading to energy expenditure. Of note, CLE and LU supplements enhanced the balance between lipid storage and mobilization in white adipose tissue (WAT), in turn, inhibiting adipocyte inflammation and lipotoxicity of peripheral tissues. Moreover, CLE and LU attenuated hepatic steatosis by suppressing hepatic lipogenesis, thereby ameliorating insulin resistance and dyslipidemia. Our data suggest that CLE helps inhibit obesity and its comorbidities via the complex interplay between liver and WAT in diet-induced obese mice.

18 November 2016 in Nutrients
Verified
Journal Article
Open access
PDF file
RRRi Ryu
Ri Ryu
TJTae-Sook Jeong
Tae-Sook Jeong
YKYe Jin Kim
Ye Jin Kim
JCJi-Young Choi
Ji-Young Choi
SCSu-Jung Cho
Su-Jung Cho
MCMyung-Sook Choi
Myung-Sook Choi
Pterocarpans are known to have antifungal and anti-inflammatory properties. However, little is known about the changes in transcriptional profiles in response to a pterocarpan-high soybean leaf extract (PT). Therefore, this study investigated the effects of PT on blood glucose and lipid levels, as well as on the inflammation-related gene expression based on a peripheral blood mononuclear cells (PBMCs) mRNA sequencing analysis in Korean overweight and obese subjects with mild metabolic syndrome. The participants were randomly assigned to two groups and were administered either placebo (starch, 3 g/day) or PT (2 g/day) for 12 weeks. The PT intervention did not change body weight, body fat percentage and body mass index (BMI). However, PT significantly decreased the glycosylated hemoglobin (HbA1c), plasma glucose, free fatty acid, total cholesterol, and non-HDL cholesterol levels after 12 weeks. Furthermore, PT supplementation significantly lowered the homeostatic index of insulin resistance, as well as the plasma levels of inflammatory markers. Finally, the mRNA sequencing analysis revealed that PT downregulated genes related to immune responses. PT supplementation is beneficial for the improvement of metabolic syndrome by altering the fasting blood and plasma glucose, HbA1c, plasma lipid levels and inflammation-related gene expression in PBMCs.