1.γ-Oryzanol Ameliorates Endothelial Replicative Senescence via Downregulation of SGLT2 Expression to Attenuate NADPH-Driven Oxidative Stress
Saugat SHIWAKOTI ; Kushal SHARMA ; Dal-Seong GONG ; Ju-Young KO ; In-Young LEE ; Hyun-Jung KIM ; Min-Ho OAK
Biomolecules & Therapeutics 2026;34(2):401-412
Replicative senescence in endothelial cells is characterized by an irreversible cell cycle arrest and impaired endothelial function, contributing to vascular aging and cardiovascular disease. Natural compounds are being actively studied for their potential to delay cellular senescence and protect vascular health. Among them, rice bran has demonstrated several vascular benefits that are mainly attributed to gamma-oryzanol (γ-Orz), a major bioactive component in rice bran. However, its role in regulating endothelial replicative senescence and the underlying molecular mechanisms remain unclear. This study aimed to explore the protective effects of rice bran extract (RBE) and γ-Orz on replicative senescence in porcine coronary artery endothelial cells (PCAECs). Replicative senescence was modeled in PCAECs by serial passaging from P1 to P3 with varying concentrations of RBE and γ-Orz.Senescence was evaluated by measuring senescence-associated β-galactosidase (SA-β-gal) activity, cell proliferation, oxidative stress, and the expression of cell cycle regulatory proteins. RBE and γ-Orz significantly reduced SA-β-gal activity, improved proliferation, and decreased oxidative stress in P3 cells, along with downregulation of senescence-related proteins p53, p21, and p16. Additionally, γ-Orz suppressed sodium-glucose co-transporter 2 expression, reduced NADPH oxidase overexpression, and restored eNOS levels. These findings indicate that RBE and γ-Orz delay endothelial senescence by alleviating oxidative stress, highlighting their potential to reduce cardiovascular disease risk associated with endothelial senescence.
2.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.
3.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.
4.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.
5.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.
6.Cardioprotective Potential of a Marine-Derived Tetrapeptide (CAAP) from Paralichthys olivaceus with Dual Antioxidant and ACE-Inhibitory Activities
Ju-Young KO ; Ji-Hyeok LEE ; Mi-Jin CHOI ; Han-Kyu LIM ; Min-Ho OAK
Natural Product Sciences 2025;31(4):309-316
Excessive lipid peroxidation and renin–angiotensin system dysregulation are central mechanisms linking oxidative stress to hypertension. In this study, a bioactive tetrapeptide, CAAP (Cys-Ala-Ala-Pro), isolated from the muscle hydrolysate of Paralichthys olivaceus (olive flounder), was evaluated for its dual antioxidant and antihypertensive actions. In Vero cells, CAAP significantly suppressed 2,2′-azobis(2-amidinopropane)-induced lipid peroxidation, reduced malondialdehyde accumulation, and preserved cell viability. Fluorescent imaging and flow cytometric analyses revealed that CAAP mitigated nuclear fragmentation and apoptotic sub-G1 cell populations through modulation of the Bcl-xL/Bax/caspase-3 axis, indicating cell protection. Molecular docking analysis demonstrated that CAAP interacts with the S′₂ pocket of angiotensin-converting enzyme (ACE) via hydrogen bonding with Glu281, His513, Lys511, and Tyr520, supporting a strong inhibitory potential (IC50 = 39.3 µg/mL). In spontaneously hypertensive rats, oral administration of CAAP (40 mg/kg) elicited a sustained decrease in systolic blood pressure within 2–6 h post-treatment, comparable to that of captopril. Collectively, these findings highlight CAAP as a multifunctional marine peptide capable of attenuating oxidative and hypertensive injury through cell stabilization and ACE inhibition, suggesting its potential as a natural therapeutic or functional food ingredient for cardiovascular protection.
7.Isolation and Activity Evaluation of Peptides with Anti-hypertensive Activity from Commercial Enzymatic Flounder Fish Hydrolysate
Ju-Young KO ; Ji-Hyeok LEE ; Hwan-Hee SIM ; Hyun Jung KIM ; Min-Ho OAK
Natural Product Sciences 2023;29(4):337-348
The potent antioxidant and anti-hypertension activities have evidenced gastric enzymatic hydrolysates from flounder fish and their derived peptides. However, peptide composition and functional effect in various enzymatic hydrolysates differ by enzyme types, hydrolyzed times temperatures, etc. Therefore, we determined potential anti-hypertensive effect of hydrolysates produced from flounder fish using commercial enzymes such as Protamex, Flavourzyme, and Kojizyme which are common food grade proteases and characterized on its derived peptides. In this study, Protamex-mediated hydrolysate showed a more potent anti-hypertension effect than other commercial enzymes. Protamex-mediated hydrolysate was fractionated into three ranges of molecular weight (above 10 kDa (FPH-I), 5-10 kDa (FPH-II), and below 5 kDa (FPH-III)). The FPH-III exhibited the strongest anti-hypertensive effect, and it was revealed that three active peptides, valine-phenylalanine-serine-glycinetryptophan-alanine-alanine (VFSGWAA), leucine-histidine-phenylalanine (LHF) and tryptophan-proline-tryptophan (WPW) were contained. The activities were confirmed via angiotensin-converting enzyme (ACE) inhibition and molecular docking simulation. Among the three peptides, LHF and WPW have a molecular structure stability against the gastrointestinal digestion. LHF showed a significant anti-hypertension effect at 9 h after oral administration in spontaneously hypertensive rats (SHRs). Therefore, we suggest that Protamex-mediated hydrolysate would be an excellent anti-hypertensive agent due to the existence of stabilized functional peptides, including LHF and WPW.
8.Niclosamide Inhibits Aortic Valve Interstitial Cell Calcification by Interfering with the GSK-3β/β-Catenin Signaling Pathway
Radhika ADHIKARI ; Saugat SHIWAKOTI ; Eunmin KIM ; Ik Jun CHOI ; Sin-Hee PARK ; Ju-Young KO ; Kiyuk CHANG ; Min-Ho OAK
Biomolecules & Therapeutics 2023;31(5):515-525
The most common heart valve disorder is calcific aortic valve stenosis (CAVS), which is characterized by a narrowing of the aortic valve. Treatment with the drug molecule, in addition to surgical and transcatheter valve replacement, is the primary focus of researchers in this field. The purpose of this study is to determine whether niclosamide can reduce calcification in aortic valve interstitial cells (VICs). To induce calcification, cells were treated with a pro-calcifying medium (PCM). Different concentrations of niclosamide were added to the PCM-treated cells, and the level of calcification, mRNA, and protein expression of calcification markers was measured. Niclosamide inhibited aortic valve calcification as observed from reduced alizarin red s staining in niclosamide treated VICs and also decreased the mRNA and protein expressions of calcification-specific markers: runt-related transcription factor 2 and osteopontin. Niclosamide also reduced the formation of reactive oxygen species, NADPH oxidase activity and the expression of Nox2 and p22 phox . Furthermore, in calcified VICs, niclosamide inhibited the expression of β-catenin and phosphorylated glycogen synthase kinase (GSK-3β), as well as the phosphorylation of AKT and ERK. Taken together, our findings suggest that niclosamide may alleviate PCM-induced calcification, at least in part, by targeting oxidative stress mediated GSK-3β/β-catenin signaling pathway via inhibiting activation of AKT and ERK, and may be a potential treatment for CAVS.
9.Surgically Metabolic Resection of Pericardial Fat to Ameliorate Myocardial Mitochondrial Dysfunction in Acute Myocardial Infarction Obese Rats
Ki-Woon KANG ; Ju-Young KO ; Hyunghee LEE ; Seung Yong SHIN ; Wang Soo LEE ; Joonhwa HONG ; Sang-Wook KIM ; Seong-Kyu LEE ; Min-Ho OAK
Journal of Korean Medical Science 2022;37(9):e55-
Background:
Pericardial fat (PF) is highly associated with cardiovascular disease but the effectiveness of surgical resection of PF is still unknown for myocardial mitochondrial structure and function in acute myocardial infarction (AMI) with obesity. The aim of this study was to demonstrate the difference in myocardial mitochondrial structure and function between obese AMI with additionally resected PF and those without resected PF.
Methods:
Obese rats with 12-week high fat diet (45 kcal% fat, n = 21) were randomly assigned into 3 groups: obese control, obese AMI and obese AMI with additionally resected PF. One week after developing AMI and additional resection of PF, echocardiogram, myocardial mitochondrial histomorphology, oxidative phosphorylation system (OXPHOS), anti-oxidative enzyme and sarcoplasmic reticulum Ca 2+ ATPase 2 (SERCA2) in the non-infarcted area were assessed between these groups.
Results:
There was significant improvement of systolic function in AMI with PF resection compared with the AMI group in the echocardiogram. Even though the electron microscopic morphology for the mitochondria seems to be similar between the AMI with PF resection and AMI groups, there was an improved expression of PGC-1α and responsive OXPHOS including NDUFB3, NDUFB5 and SDHB are associated with the ATP levels in the AMI with PF resection compared with those in the AMI group. In addition, the expression levels of antioxidant enzymes (MnSOD) and SERCA2 were improved in the AMI with PF resection compared with those in the AMI group.
Conclusion
Surgical resection of PF might ameliorate myocardial mitochondria dysfunction in obese AMI.
10.Gemigliptin Inhibits Interleukin-1β–Induced Endothelial-Mesenchymal Transition via Canonical-Bone Morphogenetic Protein Pathway
Oak-Kee HONG ; Seong-Su LEE ; Soon Jib YOO ; Min-Kyung LEE ; Mee-Kyoung KIM ; Ki-Hyun BAEK ; Ki-Ho SONG ; Hyuk-Sang KWON
Endocrinology and Metabolism 2020;35(2):384-395
Background:
Endothelial-to-mesenchymal transition (EndMT) contributes to inflammatory conditions inducing conversion of endothelial cells (ECs) into activated fibroblasts, promoting fibrotic diseases. Pro-inflammatory cytokine is the most potent inducer of EndMT. We investigated inhibition of interleukin-1β (IL-1β)-induced EndMT by gemigliptin, a dipeptidyl peptidase-IV inhibitor.
Methods:
We exposed human umbilical vein endothelial cells (HUVECs) to 10 ng/mL IL-1β/20 μM gemigliptin and analyzed the expression of endothelial, smooth muscle, mesenchymal, and osteoblastic markers, bone morphogenetic protein (BMP), Smad, and non-Smad signaling pathway proteins.
Results:
Morphological changes showed gemigliptin blocked IL-1β-induced EndMT, upregulated EC markers, and downregulated smooth muscle and mesenchymal markers. IL-1β activation of HUVECs is initiated by the BMP/Smad and non-smad BMP signaling pathways. Gemigliptin inhibited IL-1β induction of BMP2 and 7, activin receptor type IA, BMP receptor type IA, and BMP receptor type II. Reversal of IL-1β-mediated inhibition of BMP-induced Smad1/5/8, Smad2, and Smad3 phosphorylation by gemigliptin suggests involvement of the Smad pathway in gemigliptin action. In the non-Smad BMP pathway, gemigliptin treatment significantly increased the deactivation of extracellular regulated protein kinase (ERK), p38, and JNK by IL-1β. Gemigliptin treatment suppressed BMP-2-induced expression of key osteoblastic markers including osterix, runt-related transcription factor 2, and hepcidin during IL-1β-induced EndMT.
Conclusion
We demonstrated a novel protective mechanism of gemigliptin against fibrosis by suppressing IL-1β-induced EndMT.

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